배수구 소음은 현대 주거용 건축에서 가장 지속적인 품질 불만 중 하나가 되었습니다. 새벽 두 시에 방이 울리는 욕실 배수구, 주방 분배 라인이 아래층 침실에 모든 식기세척기 작동 소리를 전파하는 경우, 공유 벽에 내장된 배수관이 이웃의 배수구로 변해 불편한 배경 음악이 되는 경우 등 구조적 결함은 아니지만, 건립 완료 시 가장 많은 이관 분쟁을 일으킵니다. 아시아와 유럽 주거용 시장에서 확립된 엔지니어링 답안은 3층 구조입니다.sound insulation PVC foam core drain pipe: 단단한 외부 피부, 셀로 폼 코어, 매끄러운 단단한 내부 피부를 단일 통과로 코-엑스트루저한 제품입니다. 기존의 단벽 PVC 배수관에 비해 적절하게 설계된 폼 코어 배수관은 일반적인 주택용 유량 속도에서 약 8~15dB(A)의 측정된 감소 효과를 제공하며 미터당 25~35% 적은 PVC 화합물을 소비합니다.
Producing that pipe reliably is where most projects stumble. Foaming PVC is a narrow-window process: the blowing agent must decompose inside a tightly controlled temperature band, the melt must retain enough strength to hold the expanding cells, the die must stay above the gas pressure threshold to prevent premature expansion, and the vacuum calibration tank must shape the pipe without collapsing the cell structure it just created. Get any one of those wrong and you produce heavy pipe with no acoustic benefit, or light pipe with no ring stiffness.
이 가이드는 음향, 구조, 화학, 제형, 주조기 선택, 다이 헤드 설계, 보정, 공정 창, 시험 기준, 실내 파이프라인 배치에 이르기까지 전체 체인을 안내합니다. 본 문서에서 언급되는 기계 구성은 에서 찾을 수 있습니다.Faygo, a Wanplas factory with 22 years of dedicated experience in plastic pipe and profile extrusion lines, operating three specialized plants including a 26,650 square meter facility in Zhangjiagang, holding 13 national patents (8 of them invention patents), with all product lines CE and ISO certified and every machine subjected to 72시간 연속 작동 testing before shipment.
- Why Drainage Noise Became a Building Quality Issue
- How Foam Core Structure Reduces Noise
- Three-Layer Co-Extrusion Structure Explained
- Foam Chemistry and Cell Morphology
- PVC Formulation for Foam Core Pipe
- Extruder Selection: Conical vs Parallel Twin Screw
- Faygo PVC Foam Core 파이프 압출 라인
- Faygo Co-Extrusion and Downstream Equipment
- Die Head Design for Three-Layer Foam Pipe
- 진공 캘리브레이션 및 냉각
- Process Window Table
- Pipe Standards and Testing
- 음향 테스트 및 성능
- Indoor Sewage Pipeline Layout Considerations
- Material Savings and Sustainability
- Requirement to Model 선택 가이드
- 일반적인 결함 및 수정 사항
- 서비스 및 지원
- 자주 묻는 질문
- 결론
Why Drainage Noise Became a Building Quality Issue
Drainage noise became a measurable defect the moment residential buildings started shipping with finished interiors. In a shell-and-core handover, the buyer never hears the stack because the fit-out contractor boxes it in later and any complaint is diffused across three parties. In a fully finished apartment, the developer owns the acoustic result, and the acoustic result is audited on day one by a resident lying in bed. Higher floor-to-floor densities, thinner partition walls, lighter dry-lining systems and open-plan layouts have all reduced the incidental sound masking that older masonry construction provided for free. The pipe stopped getting quieter; the building around it got louder in relative terms.
Three physically distinct mechanisms generate the sound a resident actually perceives, and they respond to completely different countermeasures.
Impact noise from falling water
In a vertical stack, water does not fall as a solid column. It forms an annular film that clings to the wall and accelerates until the wall friction balances gravity, reaching terminal velocity typically after two to three floors. Every discharge from a branch connection injects a fresh slug that strikes the pipe wall, and each impact is a broadband excitation of the pipe shell. Impact noise scales with flow rate and with the abruptness of the direction change — which is why the stack base bend, where vertical flow converts to horizontal flow, is almost always the loudest single point in a residential drainage system.
Gurgling, air entrainment and siphonage
A drainage stack is a two-phase system: water falls, air must move in the opposite direction to replace the volume being displaced. When the vent path is undersized or blocked, pressure fluctuations propagate through the network, traps get sucked down or blown back, and the system produces the characteristic gurgle. This is a low-frequency, intermittent, highly annoying signature, and no amount of pipe wall damping fixes it. Gurgling is a layout and ventilation problem, solved with correctly sized vent stacks, air admittance provisions and proper branch connection geometry.
Structure-borne transmission
The third mechanism is the one that surprises engineers. Vibration energy in the pipe wall travels through the clamps into the slab or the wall, then radiates from a large surface area far from the pipe. A rigid steel clamp bolted directly to a concrete wall is an efficient bridge. This is why acoustic performance is a system property: pipe material, clamp type, isolation liners, penetration detailing and boxing all contribute. A foam core pipe attacks mechanisms one and three — it damps the shell and reduces the vibration energy handed to the clamp — while contributing nothing to mechanism two.
Regulatory frameworks reflect this. Chinese residential acoustic design under GB 50118 sets permissible indoor noise levels for bedrooms and living rooms during nighttime hours, and drainage noise is one of the service-equipment contributors that must be accounted for. In Europe, EN 14366 defines a standardized laboratory method for measuring the airborne and structure-borne noise of waste water installations, which allows pipe systems to be compared on a like-for-like basis rather than on marketing claims. Both are referenced here as plain-text technical concepts; the applicable edition and local amendments always govern a real project.
How Foam Core Structure Reduces Noise
A foam core pipe reduces radiated noise because a cellular polymer layer sandwiched between two solid skins behaves as a constrained-layer damping system. The mechanism is not sound absorption in the acoustic-foam sense — the cells are closed and far too small to absorb airborne sound — but mechanical energy dissipation inside the pipe wall itself.
세 가지 효과가 함께 작용합니다:
Increased damping loss factor
The loss factor, usually written as eta, expresses how much vibrational energy a material converts to heat per cycle. Rigid solid PVC has a loss factor in the region of 0.01-0.02 at room temperature, which is already better than metals but modest in absolute terms. Introducing 50-150 micron closed cells at a core density of 0.55-0.75 g/cm³ raises the effective loss factor of the composite wall by roughly a factor of two to four. Each cell wall flexes microscopically as the bending wave passes, and the viscoelastic hysteresis of the PVC matrix dissipates that motion. The result is that the ringing decay of a struck foam core pipe is audibly shorter than that of a solid pipe — the classic dull thud versus bright ring difference that installers notice immediately.
Decoupled bending stiffness
Sound radiation from a cylindrical shell is governed by the coincidence relationship between the bending wave speed in the wall and the speed of sound in air. A sandwich wall with a compliant core shifts the bending wave behavior of the shell and disrupts the efficient coupling that a homogeneous stiff wall provides. Practically, the pipe becomes a less effective loudspeaker across the mid-frequency band where drainage noise is most audible and most annoying, roughly 250 Hz to 2000 Hz.
Mass law and damping working together
Classical mass law says heavier walls transmit less sound: doubling surface mass buys about 6 dB. That is exactly why cast iron drainage systems were historically quiet, and it is also why they were heavy, awkward and slow to install. A foam core pipe deliberately gives up surface mass — that is the point of saving 25-35% of material — and buys the loss back through damping. The engineering insight is that damping is a far more efficient use of material than mass in this frequency range. A mineral-filled solid PVC pipe takes the opposite route, adding density to chase the mass law, which works but adds weight and reduces impact resistance.
| Pipe type | Wall structure | Effective wall density (g/cm³) | Typical noise reduction vs solid PVC baseline, dB(A) | Relative material cost level | Relative installed labor level |
|---|---|---|---|---|---|
| Solid PVC drainage pipe | Single homogeneous layer | 1.42-1.48 | 0 (baseline) | 중간 | 저전압 |
| Foam core PVC pipe | 단벽/폼 코어/단벽 내부 벽 | 0.95-1.15 (composite average) | 8-15 | Low to Medium | 저전압 |
| Mineral-filled solid PVC pipe | Single high-filler layer | 1.65-1.90 | 6-12 | 중간 | 중간 |
| Multi-layer filled and foamed hybrid | Filled skins / foamed core | 1.20-1.40 | 12-18 | 중간에서 높은 수준까지 | Low to Medium |
| Cast iron drainage pipe (generic reference) | Single metallic wall | 7.0-7.3 | 15-22 | 매우 높은 등급 | 높은 수준 |
Three-Layer Co-Extrusion Structure Explained
A three-layer foam core drainage pipe is not simply a foamed pipe with a skin sprayed on. It is a single co-extruded composite in which each layer has a defined job, a defined thickness ratio and a defined formulation, and the three melt streams meet inside the die head under controlled pressure so they weld into one wall with no delamination plane.
Outer skin: appearance, weathering and handling
The outer skin normally occupies 15-25% of total wall thickness. It carries the pigmentation, the print legend, the gloss level and the scratch resistance that a jobsite inspector judges the pipe by. It also carries most of the surface bending stress when the pipe is handled and installed, so it is formulated with the impact modifier loading pushed toward the upper end of the range. In storage yards with strong sunlight exposure, the outer skin also holds whatever light stabilizer package the specification calls for. Because it is solid and unfoamed, it gives the pipe a normal, familiar look — buyers rarely accept a visibly cellular exterior on a building product.
Foam core: acoustics, weight and stiffness efficiency
The core takes 55-70% of the wall. It is where the blowing agent lives, where density drops to 0.55-0.75 g/cm³, and where the damping is generated. Placing the low-density material in the middle of the wall is structurally clever: in bending, the neutral axis sits near the mid-thickness, so the material there contributes least to section stiffness. Removing mass from the neutral axis therefore costs far less ring stiffness than removing the same mass from the surfaces. This is the same principle that makes structural sandwich panels efficient, applied to a pipe cross section.
Inner skin: hydraulics and chemical resistance
The inner skin takes 12-20% of the wall and must be dense, smooth and continuous. 표면 거칠기 of the bore should be held at Ra of 0.02 mm or better, because a rough bore both increases friction losses and gives soap scum, grease and fiber a place to anchor. It also contains the chemical resistance duty: household drainage carries hot detergent water, dilute bleach, drain cleaners and food waste acids. A foamed surface exposed directly to that environment would trap residue in open cells at the bore and become a fouling and odor source. The inner skin seals the core completely.
| Layer ratio (outer / core / inner) | Composite wall density (g/cm³) | Material saving vs solid wall | 링 강성 retention | Noise reduction dB(A) | Best suited to |
|---|---|---|---|---|---|
| 25% / 55% / 20% | 1.12-1.20 | 18-24% | 90-95% | 7-10 | Stacks with high impact exposure, exposed installations |
| 20% / 62% / 18% | 1.02-1.12 | 24-30% | 85-90% | 9-12 | Standard residential riser and branch, best all-round balance |
| 18% / 67% / 15% | 0.96-1.05 | 29-34% | 80-86% | 11-14 | Boxed-in risers, acoustic-priority projects |
| 15% / 70% / 15% | 0.92-1.00 | 32-38% | 74-82% | 12-15 | Non-structural vent and low-load branch lines only |
The engineering rule that emerges is simple: acoustic performance and material saving both improve as the core fraction grows, but ring stiffness and impact resistance fall away non-linearly beyond about 67% core. For general residential sewage pipeline work, a 20/62/18 split is the configuration most producers converge on, because it satisfies drainage-grade ring stiffness requirements with margin while still delivering a double-digit decibel improvement.
Foam Chemistry and Cell Morphology
Cell structure is the single variable that determines whether a foam core pipe is a premium acoustic product or a defective lightweight pipe. Two pipes can have identical core density and completely different performance if one has uniform 80 micron closed cells and the other has a mixture of 30 micron and 400 micron cells with ruptured walls.
Exothermic and endothermic blowing agents
Chemical foaming of rigid PVC is normally done with a blend of two agent types rather than either alone.
The exothermic AC blowing agent (azodicarbonamide) decomposes in the range of 200-210 °C in its unmodified form, releasing 200-260 ml/g of gas — predominantly nitrogen with carbon monoxide, carbon dioxide and ammonia fractions. Its gas yield is high, which makes it efficient at driving density down, and its decomposition is exothermic, meaning it adds heat locally and tends to self-accelerate. Activated grades using zinc or Ca-Zn based kickers shift the effective decomposition band downward to roughly 160-190 °C, which is essential because rigid PVC processes well below the unmodified decomposition point. Nitrogen from AC diffuses relatively slowly through the PVC matrix, which helps cells stay inflated during calibration.
The NaHCO3 endothermic foaming agent (sodium bicarbonate based, usually with an organic acid co-agent) decomposes over a broad range beginning around 130-150 °C and absorbs heat as it does so. It releases mainly carbon dioxide at a lower gas yield, typically 100-140 ml/g. Its critical contribution is nucleation: it generates a very large number of small gas nuclei early, giving the later AC decomposition a fine, evenly distributed set of sites to expand rather than allowing a few large cells to dominate. The endothermic character also moderates the local temperature spike from AC, reducing the risk of scorch and cell coalescence.
A typical residential drainage core uses an exothermic to endothermic ratio between 70:30 and 50:50. Higher AC fractions push density lower but coarsen the cells; higher NaHCO3 fractions refine the cells and improve surface quality but limit how far density can drop.
Target cell morphology
For sound insulation drainage pipe the targets are: mean cell diameter 50-150 microns, closed-cell content above 85%, and a cell size distribution narrow enough that the largest cells do not exceed roughly three times the mean. Cells below 50 microns give excellent surface quality but a limited damping increase relative to the material removed. Cells above 200 microns start to act as crack initiation sites, ring stiffness falls faster than density, and the risk of cell wall rupture during calibration climbs sharply. Open cells are actively harmful — they allow water ingress at cut ends, degrade long-term stiffness and can lead to core saturation in a wet chase.
| Total blowing agent (phr, AC + NaHCO3) | AC : NaHCO3 ratio | Core density (g/cm³) | 평균 세포 크기 (µm) | Closed cell content | Noise reduction dB(A) | 링 강성 impact |
|---|---|---|---|---|---|---|
| 0.3-0.4 | 50 : 50 | 0.85-0.95 | 40-70 | >92% | 5-8 | 최소 손실, 92-96% 유지됨 |
| 0.4-0.55 | 60 : 40 | 0.72-0.85 | 55-95 | 88-92% | 8-11 | Small loss, 88-92% retained |
| 0.55-0.7 | 65 : 35 | 0.62-0.75 | 75-130 | 85-90% | 10-13 | Moderate loss, 82-88% retained |
| 0.7-0.8 | 70 : 30 | 0.55-0.65 | 100-160 | 80-87% | 12-15 | Noticeable loss, 76-83% retained |
| Above 0.9 | 75 : 25 or higher | Below 0.52, unstable | 180-350, irregular | Below 75% | Erratic | Unacceptable, cell rupture |
Note that noise reduction does not scale indefinitely with foaming level. Beyond roughly 0.8 phr the cell structure degrades faster than the damping benefit accrues, and measured acoustic performance becomes inconsistent from batch to batch because the morphology is no longer under control. The commercially safe operating band for residential sewage pipe is 0.5-0.7 phr total blowing agent.
PVC Formulation for Foam Core Pipe
Foam core pipe requires two separate compounds running simultaneously, and the difference between them is not cosmetic. The skin compound is a conventional rigid PVC drainage formulation. The core compound is a melt-strength-engineered foaming compound, and its acrylic processing aid loading is typically double that of the skin.
Why K value governs everything
The K value of the PVC resin — a viscosity-derived index of molecular weight — is the most important single decision in a foam core formulation. Melt strength, which is the melt’s ability to resist rupture while being stretched, rises with molecular weight. Every expanding cell stretches the polymer walls between it and its neighbors biaxially, at high strain rate, at elevated temperature. If melt strength is inadequate the cell walls thin and burst, the gas escapes into neighboring cells, and coarse open-cell structure results.
For skin layers, K 57-60 (SG-5 type resin) is standard: it plasticizes readily, gives good surface gloss and processes at moderate temperature. For the foamed core, K 60-65 (SG-5 toward SG-8 territory) is preferred because the extra molecular weight buys the melt strength that holds fine cells. The penalty is higher melt viscosity, higher shear heat and a narrower processing window, which is exactly why low-shear conical twin-screw extrusion is the natural match. Pushing beyond K 66 rarely pays: the plasticizing energy required starts to generate enough shear heat to trigger premature blowing agent decomposition inside the barrel.
| 성분 | 유형/규격 | Dosage (phr) | Function in the skin layer |
|---|---|---|---|
| PVC 수지 | 지지 강도 등급 SG-5, K 값 57~60 | 100 | 기본 폴리머, 균형 잡힌 가공성 및 강도 |
| Ca-Zn 안정제 | 칼슘-아연 복합체, 분말 또는 원 팩 | 3.0-4.5 | 열 안정화, 중금속 무첨가, 납 시스템을 대체합니다. |
| 아크릴 처리 보조제 ACR | 고분자 중합체 아크릴 코폴리머 | 1.0-2.0 | 융합을 촉진하고 표면 광택과 용융 균일성을 개선합니다. |
| CPE impact modifier | Chlorinated polyethylene, 35-36% chlorine | 5.0-8.0 | 저온 충격 강도, falling weight performance |
| CaCO3 filler | 활성화된 분쇄된 칼슘 카르bon산염, 1250 메쉬. | 5.0-12.0 | Stiffness, dimensional stability, cost control |
| TiO2 pigment | Rutile titanium dioxide | 0.8-2.0 | Whiteness, opacity, light stability of the skin |
| 파라핀 외부 윤활제 | Paraffin wax, drop point 58-62 °C | 0.4-0.8 | Metal release, prevents die build-up and plate-out |
| 내부 윤활제인 칼슘 스테아레이트. | 금속 비누 | 0.4-0.7 | Controls fusion rate, reduces internal friction heat |
| Oxidized polyethylene wax | OPE wax | 0.1-0.3 | Fine-tunes late-stage lubrication and surface finish |
| 성분 | 유형/규격 | Dosage (phr) | Function in the core layer |
|---|---|---|---|
| PVC 수지 | Suspension grade, K value 60-65 | 100 | Higher molecular weight for melt strength that holds cell walls |
| Ca-Zn 안정제 | Calcium-zinc composite with co-stabilizer | 4.0-5.0 | Higher loading because foaming runs closer to the degradation edge |
| 아크릴 처리 보조제 ACR | 초고분자량 폼용 아크릴. | 4.0-8.0 | The critical additive: raises melt strength and elongational viscosity to stabilize cells |
| CPE impact modifier | Chlorinated polyethylene, 35-36% chlorine | 4.0-6.0 | Toughens the cellular matrix, resists cell wall cracking |
| CaCO3 filler | Fine activated grade, 1250-2500 mesh | 5.0-15.0 | 이차 핵화 부위 및 강성; 과도한 부하가 세포를 거칠게 만듭니다. |
| AC blowing agent | Azodicarbonamide, activated, decomposition 200-210 °C unmodified | 0.30-0.50 | Primary gas generator, high yield 200-260 ml/g |
| NaHCO3 endothermic foaming agent | Sodium bicarbonate based with acid co-agent | 0.15-0.30 | 핵화, 세포 미세화, 열전달을 완화합니다. |
| 파라핀 외부 윤활제 | Paraffin wax, drop point 58-62 °C | 0.8-1.2 | Higher than skin: delays fusion so gas develops at the right point |
| 내부 윤활제인 칼슘 스테아레이트. | 금속 비누 | 0.3-0.5 | Balances the external lubricant to control fusion timing |
| 셀 조절제 / 핵화 보조제 | Fine inert particulate, sub-micron | 0.2-0.5 | Narrows cell size distribution |
Reading the two formulations together
Three differences deserve attention. First, the acrylic processing aid ACR jumps from 1-2 phr in the skin to 4-8 phr in the core — this is the melt strength budget and it is not negotiable. Second, external lubricant is higher in the core, deliberately delaying fusion so that the compound is still slightly under-fused when it reaches the zone where gas evolution begins; a fully fused, high-viscosity core melt entering the die will foam poorly and unevenly. Third, stabilizer is higher in the core because the foaming reaction and the associated exotherm push the compound closer to its thermal limit, and any localized degradation shows up immediately as discoloration streaks and coarse cells.
Extruder Selection: Conical vs Parallel Twin Screw
Rigid PVC pipe is almost universally produced on counter-rotating twin-screw extruders, but the choice between conical and parallel geometry has real consequences for foaming. Foamed core extrusion demands a specific combination: low shear so the blowing agent does not decompose prematurely, high melt strength preservation so cells survive, and tight temperature control so the decomposition band is hit precisely at the die.
Conical twin-screw extruders — the SJSZ family designation used across the industry — have screws whose diameter tapers from a large intake to a smaller discharge. The large feed end swallows low-bulk-density dry blend powder easily and gives a big heat exchange surface early. As diameter reduces toward the discharge, circumferential speed falls, which means the highest-viscosity, most heat-sensitive material is handled at the lowest shear rate in the machine. That characteristic is precisely what foaming needs.
Parallel counter-rotating twin-screw extruders maintain constant screw diameter and typically run longer L/D ratios of 22:1 to 28:1. They deliver more output per screw size, better melt homogeneity for demanding compounds, longer screw and barrel service life because thrust bearing loads are distributed differently, and more configurable screw geometry. Their disadvantage for foaming is that the metering section runs at constant circumferential speed, so shear heat in the final zones is harder to keep down without dropping throughput.
| 기준 | Conical twin-screw (SJSZ type) | Parallel counter-rotating twin-screw |
|---|---|---|
| Plasticizing capability on dry blend | Excellent; large intake volume handles low bulk density powder | Very good; benefits from longer L/D but needs stable feeding |
| Shear heat at discharge | Low; circumferential speed falls as diameter tapers | Moderate to high; constant diameter keeps shear rate up |
| Suitable output range | 120-800 kg/h typical for pipe duty | 250-1500 kg/h, favors higher volume |
| 스크류 및 배럴 service life | 좋습니다. 테이퍼가 마모를 분산하지만 교체 비용이 세트당 더 높습니다. | Longer; simpler cylindrical geometry, easier to re-nitride or replace segments |
| 특정 에너지 consumption | 0.16-0.22 kWh/kg typical | 0.18-0.26 kWh/kg typical |
| 용융 온도 균일성. | Very good at moderate output | Excellent, especially at high output with proper screw design |
| Suitability for chemical foaming | Preferred; low shear protects the blowing agent until the die | Workable with de-rated screw speed and careful zone control |
| Footprint and installed cost level | Compact, Medium cost level | Longer machine, 중간에서 높은 수준까지 cost level |
The practical conclusion for a sound insulation drainage pipe plant: run the main core extruder as a conical twin-screw sized for the target diameter range, and use compact single-screw or small conical co-extruders for the two skin layers, where output demand is a fraction of the core and shear sensitivity is far lower. A parallel machine becomes attractive only when a plant is running one diameter continuously at very high tonnage and can invest in the screw design work to keep discharge temperature under control.
Faygo PVC Foam Core 파이프 압출 라인
Faygo builds complete turnkey foam core drainage pipe lines around conical twin-screw main extruders with matched co-extruders, three-layer spiral die heads and vacuum calibration downstream. The lineup below covers the three diameter bands that account for the overwhelming majority of residential indoor sewage work: small branch pipe, mid-range stack and branch combined, and large diameter risers extending into light municipal duty. Every line is configured, assembled and run under load in the Zhangjiagang plant, and undergoes 72시간 연속 작동 testing before shipment.
| Line configuration | 파이프 직경 범위 (mm) | 벽 두께 (mm) | 주 압출기 type | 나사 직경 (mm) | Max output (kg/h) | Line speed (m/min) | Total installed power (kW) | Haul-off type | Line length (m) |
|---|---|---|---|---|---|---|---|---|---|
| Foam core line, small diameter | 50-160 | 1.8-4.0 | Conical twin-screw, counter-rotating | 55/110 | 220 | 1.5-9.0 | 115 | 2-caterpillar track | 26-30 |
| Foam core line, mid diameter | 75-250 | 2.0-6.2 | Conical twin-screw, counter-rotating | 65/132 | 350 | 1.0-6.5 | 168 | 3-caterpillar track | 32-38 |
| Foam core line, large diameter | 110-315 | 2.5-8.0 | Conical twin-screw, counter-rotating | 80/156 | 520 | 0.6-4.5 | 235 | 4-caterpillar track | 40-46 |
How to read the output figures
최대 출력 is stated for standard rigid PVC dry blend at nominal conditions. Foam core production runs at a lower mass throughput than solid pipe of the same dimension, because the core compound is deliberately foamed — but the meters-per-minute figure is what actually determines plant productivity, and that goes up, not down. A 110 mm foam core pipe with a 62% foamed core at 0.68 g/cm³ produces roughly 28-33% more linear meters per kilogram than the equivalent solid pipe. When comparing line productivity, always compare meters per hour, never kilograms per hour.
Application industries served
Faygo pipe lines are deployed across construction (residential drainage stacks, branch waste lines, vent pipe, rainwater downpipes, PVC window profiles and PP-R hot water systems), municipal engineering (larger diameter drainage and cable protection duct), communication and power (PVC and PE cable conduit), and building material manufacture generally. For a sound insulation drainage pipe producer, the practical value is that one plant layout can serve interior sewage systems, rainwater systems and cable duct with die and calibration changes rather than a new line.
Faygo Co-Extrusion and Downstream Equipment
A foam core line is defined at least as much by its downstream as by its extruder. Foamed pipe leaves the die soft, expanding and thermally loaded; the calibration and cooling section decides whether that expansion is captured as a controlled cell structure or lost as a collapsed, dimensionally erratic wall. The equipment set below is what Faygo specifies for three-layer foam core drainage pipe.
| 장비 | 구성 | Key specification | Power (kW) | Function in the foam core process |
|---|---|---|---|---|
| 피부층 코엑스트럭션 기구(2개). | Single-screw, 45 mm and 45 mm, L/D 25:1 | Output 25-60 kg/h each, independent temperature zones | 2 x 18.5 | Feed outer and inner solid skin melt streams to the die at matched pressure |
| 3층 나선형 코엑스트럭션 다이 헤드. | 나선형 맨드렐 분배, 3개의 용융 채널. | Die pressure 18-28 MPa, core channel exit pressure held above 6-8 MPa | 14-22 (heating) | 세 개의 스트림을 하나로 결합하여 조기 거품 발생을 억제합니다. |
| 진공 교정 탱크 | 스테인리스 304, dual-pump, 6 m section | Vacuum -0.02 to -0.06 MPa, water temperature 18-22 °C, servo-adjusted position | 15-30 | Fixes outside diameter and freezes the skin without collapsing cells |
| 스프레이 냉각 탱크 | Stainless steel, 6-9 m, multi-nozzle spray banks | Water temperature 12-15 °C, staged zones, drain and recirculation | 7.5-15 | Removes residual core heat gradually to prevent post-expansion and sink marks |
| 캐터필러 덤프장 | 2, 3 or 4 track, servo driven, pneumatic clamping | Traction force 8-35 kN, speed 0.6-9.0 m/min, digital speed sync | 4-15 | Sets draw ratio against extruder output; the master variable for wall thickness |
| 행성형 절단기 | Chipless planetary cutting with chamfering | Cut length tolerance ±3 mm, burr-free, dust extraction | 4-7.5 | Cuts to length without chips that would contaminate the bore |
| Tipping / stacking rack | Pneumatic tilting, adjustable length bays | Capacity up to 6 m lengths, soft-drop cradle | 1.5-3 | Discharges finished pipe without impact damage to the skin |
| 벨링 기계(선택적으로 인라인 또는 오프라인) | 열풍 오븐과 유압 소켓 성형 | Socket types: solvent weld and rubber ring seal | 18-40 | Forms drainage sockets; foam core requires gentler heating than solid pipe |
Why the spray tank matters more on foam pipe
On solid pipe, the spray tank is simply heat removal. On foam core pipe it is a cell-preservation device. The core sits between two solid skins that are relatively poor conductors, so heat leaves the core slowly. If the pipe exits cooling with a core still above roughly 70 °C, residual gas pressure inside the cells can continue to push outward, producing dimensional creep, or the softened core can partially collapse under the weight of the pipe on the rollers. Staged cooling — a first zone at 18-22 °C to set the skin, then progressively colder zones down to 12-15 °C — extracts heat from the core without shocking the outer skin into stress cracking.
Die Head Design for Three-Layer Foam Pipe
The die head is where a foam core pipe is won or lost. Its job is contradictory: it must distribute three melt streams into perfectly concentric annular layers, hold the core stream under enough pressure that its dissolved gas cannot expand, then release that pressure at a controlled rate at exactly the right axial position.
Spiral mandrel distribution
Spiral mandrel distributors have replaced spider-leg designs for drainage pipe because spider legs create weld lines — axial streaks of weakened, differently oriented material where the melt reunites behind each support. On a foamed core, a weld line is worse than a cosmetic issue: cell structure near the weld is disturbed and the line becomes a preferential crack path under impact. A spiral mandrel wraps the melt helically around the mandrel so that material entering at any point is redistributed circumferentially many times, eliminating the discrete weld plane. For three-layer work, three independent spiral distributors are stacked coaxially, each with its own feed port, heating zone and pressure measurement.
Inter-layer pressure balance
Layer thickness ratio is controlled by the relative volumetric flow of the three streams, but only if their pressures at the confluence point are balanced. If the core channel runs at significantly higher pressure than the skin channels, the core will push outward and locally thin the skins — creating the classic defect where a foam core pipe has adequate average wall but a paper-thin inner skin in one quadrant. Balance is achieved by matching channel cross-sections to the viscosity of each compound at its own running temperature, then trimming with individual extruder screw speeds. 녹는 압력 transducers on each channel are not a luxury on a foam line; they are the primary diagnostic.
Core channel pressure threshold
The single most important number in foam die design is the minimum core channel exit pressure, which must be held above 6-8 MPa. Below that threshold, gas that has been generated inside the barrel and dissolved or dispersed in the melt begins to nucleate and expand while still inside the die. Premature foaming inside the flow channel produces a rough, torn extrudate surface, drags along the channel wall, causes pressure oscillation and destroys the layer ratio. Maintaining the threshold is a matter of channel geometry: the land section must present enough flow resistance, which is why foam dies use restrictor rings or reduced gap zones ahead of the exit.
Land length and lip temperature gradient
Foam pipe dies use a longer parallel land — commonly 20-30 times the die gap versus 15-20 times for solid pipe. The extra length holds pressure longer, gives the melt time to relax orientation stress, and delivers a stable, fully developed flow profile at exit so that expansion begins uniformly around the circumference. Die lip temperature is then set 5-10 °C above the adjacent body zone, typically 190-200 °C. A hotter lip lowers surface viscosity just enough to give a glossy skin and avoid melt fracture, while the slightly cooler body zone maintains the melt strength the core still needs. Getting this gradient backward — a cold lip on a hot body — produces shark skin on the outer surface and is one of the most common commissioning errors.
진공 캘리브레이션 및 냉각
Vacuum calibration converts a soft, expanding annulus into a dimensionally accurate pipe. On solid PVC pipe the process is forgiving. On foam core pipe, the vacuum level that gives crisp dimensions on solid pipe will flatten the cell structure and destroy the acoustic benefit.
Vacuum level: less is more
The working range for three-layer foam core drainage pipe is -0.02 to -0.06 MPa, against -0.04 to -0.08 MPa typical for solid pipe of the same size. The mechanism is straightforward: vacuum in the tank pulls the outer skin outward against the calibration sleeve, and the differential pressure across the wall is carried by the still-soft core. Excessive vacuum compresses the core cells radially, collapsing the outer portion of the cellular structure into a dense band. Density measurements on such pipe look acceptable because the average is unchanged, but the acoustic performance drops by several decibels and the wall shows a visible dense ring under a cut section. Start at the low end, -0.02 to -0.03 MPa, and increase only until outside diameter and roundness come into tolerance.
교정 슬리브 sizing and shrinkage compensation
The calibration sleeve bore must exceed the nominal outside diameter of the finished pipe to compensate for cooling shrinkage. Rigid PVC shrinks 0.3-0.6% from calibration temperature to ambient; foam core pipe sits toward the upper end because the cellular core continues a small amount of contraction as trapped gas cools and contracts. For a nominal 110 mm pipe, a sleeve bore of 110.5-110.7 mm is a sound starting point. The sleeve entry should carry a 15-20 degree lead-in taper and be polished to Ra 0.4 or better; any scoring in the sleeve prints straight onto the outer skin and cannot be removed downstream.
단계별 냉각수 온도
냉각은 의도적으로 단계별로 진행됩니다. 진공 탱크 내부의 첫 번째 섹션은 18~22°C로 유지됩니다. 여기서 더 차가운 물은 피막을 너무 강하게 식혀서 아직 뜨거운 핵심에 압박을 가해, 긴장 스트레스를 유발합니다. 이는 나중에 소켓 끝 주위에서 길이 방향의 구부러짐이나 극단적인 경우 스트레스 균열로 나타납니다. 이후 스프레이 섹션은 12~15°C로 떨어지면서 피막이 이미 굳어지면 깊은 핵심 열을 효율적으로 제거합니다.
Estimating required cooling length
A practical estimate for cooling length treats the wall as a slab cooled from one side. Required length in meters can be approximated as L equals line speed in meters per minute multiplied by wall thickness in millimeters, multiplied by a factor of 0.9-1.3 for foam core pipe, divided by the effective cooling rate constant of about 2.0 for spray cooling with adequate water flow. For a 110 mm pipe with 3.2 mm wall running at 4 m/min, that yields roughly 6-8 meters of active cooling. Foam core needs the higher end of the factor range because the cellular layer is a thermal insulator; the same wall thickness in solid PVC would clear in about two-thirds of the length. Under-length cooling is a false economy — it forces slower line speed, which erases the productivity advantage the foam structure was supposed to deliver.
Process Window Table
The process window for foam core PVC drainage pipe is narrower than for solid pipe in every dimension. Temperature must be high enough to fuse and to decompose the blowing agent, low enough to avoid degradation and premature gas release. Screw speed must be high enough for output, low enough to limit shear heat. The window below is a validated starting point for a conical twin-screw line running a 20/62/18 layer structure; final settings always come from trial runs with the actual compound.
| 매개변수 | 코어 엑스트럭션 설정. | 피부 엑스트럭션 설정. | Effect if too low | 너무 높을 경우의 영향 |
|---|---|---|---|---|
| Barrel zone 1, feed section | 165-175 °C | 160-170 °C | Poor early fusion, unmelted particles | 공급구멍에서 교차, 초기 가스 방출. |
| 배럴 영역 2, compression section | 175-185 °C | 170-180 °C | Incomplete gelation, low melt strength | Blowing agent decomposes in the barrel |
| Barrel zone 3, metering section | 180-190 °C | 175-185 °C | 높은 점도, 높은 다이 압력, 낮은 출력. | Degradation, yellowing, coarse cells |
| Die head body zones | 185-195 °C | 185-195 °C (shared) | Rough extrudate, melt fracture | Loss of melt strength, cell rupture |
| Die lip zone | 190-200 °C | 190-200 °C (shared) | Shark skin, dull surface | Sagging, skin thinning at the top |
| Main screw speed | 12-22 rpm | 15-30 rpm | Output shortfall, unstable feed | Shear heat spike, premature foaming |
| Core melt pressure at die exit | 6-8 MPa minimum, 18-28 MPa in body | 10-20 MPa | Foaming inside the die, torn surface | Excess motor load, screw wear |
| Vacuum level in calibration tank | -0.02 to -0.06 MPa | Oversize, out-of-round pipe | Cell collapse, dense outer band, lost dB | |
| First-stage cooling water | 18-22 °C | Quench stress, bowing, socket cracking | Skin not set, sleeve drag marks | |
| Second-stage cooling water | 12-15 °C | Residual core heat, post-expansion | Diminishing returns, condensation issues | |
| Haul-off to output ratio (draw ratio) | 1.02-1.05 | Wall thickens, pipe sags, diameter creeps up | Wall thins, cells elongate, ring stiffness falls | |
| Vacuum tank position gap from die | 40-90 mm | Insufficient expansion distance | Melt sag before calibration, oval pipe | |
The draw ratio discipline
The haul-off to extrusion output ratio of 1.02-1.05 deserves emphasis because it behaves differently on foam pipe. On solid pipe, a higher draw ratio simply thins the wall. On foam core pipe it also stretches the cells axially into elongated ellipsoids, which reduces the isotropy of the damping benefit and lowers hoop-direction stiffness disproportionately. Keeping draw at 1.02-1.03 for acoustic-grade pipe preserves near-spherical cells. Any wall thickness correction should be made by adjusting extruder output and die gap rather than by reaching for haul-off speed.
Pipe Standards and Testing
Foam core drainage pipe is not a specification loophole. It must meet the same performance requirements as solid-wall pipe in the applicable drainage standard, and the tests are designed so that a pipe cannot pass simply by being light. The relevant frameworks, all referenced here as plain text, include GB/T 5836.1 for rigid polyvinyl chloride pipes for building drainage, EN 1329 for PVC-U soil and waste discharge systems inside buildings, ASTM D2665 for PVC drain, waste and vent pipe and fittings, and ISO 3633 for unplasticized PVC soil and waste discharge systems. Structured-wall constructions, including foam core, are addressed within these frameworks provided the composite wall meets the stated performance criteria.
| 테스트 | What it measures | Typical requirement | Foam core specific consideration |
|---|---|---|---|
| 링 강성 | Resistance to diametric deflection under load | 품질에 따라 다릅니다. 매립용은 SN2~SN8, 실내 배수용은 낮습니다. | Governed by skin thickness and core density; the core fraction must not exceed the structural budget |
| Falling weight impact, TIR | True impact rate at specified drop height and temperature, often 0 °C | TIR generally below 10% | Most sensitive test for foam pipe; poor skin-core adhesion or coarse cells cause failures |
| 비캇 연화 온도 | Thermal resistance of the compound | Not less than 79 °C | Measured on the skin material; core foaming does not excuse a low Vicat value |
| Longitudinal reversion | Frozen-in orientation stress released on heating | Not more than 5% | 폼 파이프는 더 민감합니다. 과도한 드로우 비율은 여기서 가장 먼저 나타납니다. |
| 밀도 | Composite and layer-by-layer wall density | Composite typically 0.95-1.20 g/cm³ for foam core | Measure the core separately by section cutting, not just the composite average |
| Flattening test | Ductility under diametric compression to a set percentage | No cracking or delamination at the specified deflection | 주요 탈분리 스크린; 피부 분리 현상이 즉시 나타납니다. |
| Oven test (heat reversion) | Degree of fusion and layer bonding at elevated temperature | No delamination, blistering or cracking | Under-fused core blisters as trapped gas expands; the single best fusion diagnostic |
| Dichloromethane immersion | Degree of gelation of the PVC compound | No attack beyond permitted surface change | Run on skin material; under-gelation indicates lubricant imbalance |
| Watertightness | Joint and wall integrity under hydrostatic head | No leakage at specified test pressure and duration | 내피가 세포성 코어 전체에 걸쳐 연속적으로 유지됩니다. |
| Dimensional check | 외부 직경, wall thickness, ovality, length | Per the applicable standard tolerance class | Include per-layer thickness measurement on a cut ring under magnification |
The oven test as a production control
Of all these, the oven test earns a special place on a foam core line. Take a ring sample, heat it to the specified temperature for the specified time, and examine it. Solid pipe reveals under-fusion as surface roughening or splitting at the weld line. Foam core pipe reveals under-fusion much more dramatically: any cell whose walls are not properly fused expands under heat and produces visible blistering or layer separation. A single oven test every shift, on every diameter, catches drifting fusion conditions before they become a rejected lot.
음향 테스트 및 성능
Acoustic claims for drainage pipe are only meaningful when tied to a defined test method. EN 14366 provides the reference laboratory procedure: a test rig reproduces a section of building with a stack, a branch connection and a stack base bend, mounted in a test facility that separates the airborne noise radiated into the installation room from the structure-borne noise transmitted into the receiving room below. Water is discharged at controlled flow rates and the resulting sound pressure levels are measured in the receiving room. Because the pipe, the fittings, the clamps and the mounting are all part of the test specimen, the method measures a system, not a pipe in isolation.
| Test flow rate (L/s) | Typical service condition | Solid wall PVC stack, dB(A) | Three-layer foam core stack, dB(A) | Reduction, dB(A) |
|---|---|---|---|---|
| 0.5 | Wash basin discharge, single fixture | 28-33 | 20-24 | 8-9 |
| 1.0 | Kitchen sink or shower discharge | 34-39 | 24-29 | 10-11 |
| 2.0 | Toilet flush, typical peak event | 41-47 | 30-35 | 11-13 |
| 4.0 | Simultaneous multi-fixture discharge, upper floors | 48-55 | 36-42 | 12-15 |
These figures are indicative ranges for comparison purposes and depend heavily on the installation detail. Two variables dominate.
Clamp and bracket contribution
A rigid metal clamp with direct metal-to-pipe contact bolted into concrete can hand back most of the pipe’s acoustic advantage. Clamps with an elastomeric insert — typically EPDM or a similar rubber liner — break the structure-borne path and often contribute 3-6 dB(A) on their own. On a foam core system the two effects are complementary: the pipe wall converts vibration energy to heat, the isolated clamp prevents whatever is left from reaching the building structure. Specifying premium pipe with rigid clamps is the most common way projects fail to achieve their acoustic target.
Boxing, lagging and shaft detailing
A boxed-in riser behaves as a small acoustic enclosure. A plasterboard box with a mineral wool infill adds meaningful attenuation for airborne noise, but only if it is sealed and if the pipe does not touch the boxing anywhere. Rigid contact between pipe and boxing turns the board into a radiating diaphragm. Similarly, where the stack passes through a floor slab, the fire collar and sleeve detailing must maintain an isolation gap filled with a resilient sealant rather than rigid mortar, or the slab becomes the radiator.
What foam core cannot fix
Foam core pipe reduces impact noise and structure-borne transmission. It does nothing for gurgling caused by inadequate venting, nothing for water hammer from fast-closing valves upstream, and nothing for a stack base bend detailed as a single sharp 90 degree elbow. A quiet residential drainage installation is roughly 60% pipe system and 40% layout and fixing discipline.
Indoor Sewage Pipeline Layout Considerations
The quietest pipe in the world installed on a poorly designed layout will still generate complaints. Residential indoor sewage systems consist of four functional elements, and each has acoustic implications alongside its hydraulic function.
The four elements
수직 스택vertical stack모든 층에서 배출물을 건물 배수구로 전달합니다. 가장 시끄러운 요소이며 거주 공간에 가장 가까운 위치에 있습니다.horizontal branch각 피복 그룹을 스택에 연결합니다. 충분한 경사로로 실행되어 스스로 청소되도록 해야 하지만 너무 가파르면 물이 고형물과 분리됩니다.배출 파이프는 시스템의 대기압을 유지하여 시프론 또는 역압으로 인한 트랩 씰 손실을 방지합니다. 바로 이것이 거품이 들리는 것을 방지하는 요소입니다.지속적인 흐름은 거품 코어 브랜치 파이프에서 눈에 띄게 이점을 얻습니다.trap각 설치물에는 일반적으로 50-75mm 깊이의 물 씰이 있어 하수 배수구 가스를 실내에서 차단합니다.
| 고정 장치 또는 요소 | Recommended nominal diameter | Slope for horizontal runs | 연결 유형 | 음향 노트 |
|---|---|---|---|---|
| Wash basin / lavatory | DN50 | 2.0-3.0% | Solvent weld or push-fit with trap | Low flow, rarely a noise source unless discharging into a shared wall stack |
| 샤워/욕실 폐수 | DN50 to DN75 | 1.5-2.0% | Solvent weld, shallow trap | 수직 토양 스택, 한 층당 한 주택 |
| 주방 싱크대/식기세척기 | DN75 | 2.0-2.5% | Solvent weld, grease-tolerant trap | Hot water and detergent; inner skin chemical resistance matters here |
| Washing machine discharge | DN50 to DN75 | 2.0-3.0% | 트랩이 있는 스탠드 파이, 공기 간격 | Pumped discharge produces the highest instantaneous velocity in a dwelling |
| Water closet / toilet | DN110 | 1.5-2.0% | Rubber ring seal socket or pan connector | Peak event at 2.0-2.5 L/s; the defining load case for stack noise |
| Floor drain | DN50 to DN75 | 2.0% | Solvent weld, deep seal trap | Trap seal evaporation is the main issue, not noise |
| 수직 토양 스택, 한 층당 하나의 주택 | DN110 | Vertical | 고무 링 씰 소켓을 선호합니다. | Primary target for foam core; ring seal sockets also decouple slightly |
| Vertical soil stack, multiple dwellings per floor | DN125 to DN160 | Vertical | 고무 링 씰 소켓 | Higher simultaneous flow, foam core gain is largest here |
| Vent stack | DN75 to DN110 | Vertical | Solvent weld acceptable | Correct sizing eliminates gurgling that pipe damping cannot address |
| Building drain / collector | DN160 to DN200 | 1.0-1.5% | Rubber ring seal | Usually below the lowest habitable floor, lower acoustic priority |
Support spacing and expansion
Bracket spacing is both a structural and acoustic parameter. For vertical stacks, spacing should not exceed 2 m, with a fixed anchor point at each floor level and guide brackets between. For horizontal branches, spacing should not exceed 1 m for smaller diameters and should be tightened around fittings and direction changes. Under-supported horizontal pipe sags between brackets, creating low points where solids deposit, and the sag itself amplifies the drumming effect of flowing water.
Thermal expansion is significant for PVC: the linear expansion coefficient is around 7 to 8 x 10⁻⁵ per degree Celsius, so a 3 m length experiencing a 40 °C swing between a cold morning and a hot dishwasher discharge moves roughly 9-10 mm. Expansion sockets or ring seal joints must be provided on long straight runs, and the pipe must be free to move at guide brackets while fixed at anchor points. A system that is rigidly anchored at both ends of a long run will either buckle or transmit creaking noises as it works against its restraints — a complaint that is frequently misdiagnosed as a drainage problem.
Floor penetrations and fire protection
Every slab penetration is simultaneously a fire compartment breach, an acoustic bridge and a leak path. Standard practice is a fire collar containing an intumescent material that expands to seal the aperture when the plastic pipe softens in a fire, combined with a sleeve that maintains an annular gap around the pipe. That gap should be filled with a resilient acoustic sealant, never rigid mortar, so the pipe remains vibrationally isolated from the slab. Foam core pipe behaves the same as solid PVC in fire collar applications, though collar manufacturers’ data for the specific wall construction should always be confirmed for a given project.
Material Savings and Sustainability
폼 코어 배수관의 상업적 주장은 간단한 비대칭성에 기반합니다. 이 기술은 자재 소비량을 줄이고 제품 성능을 향상시키는 동시에, 이는 건축 제품에서 흔하지 않은 조합입니다. 더 나은 것은 일반적으로 더 많은 것을 의미합니다.
Where the 25-35% saving comes from
Take a DN110 pipe with a 3.2 mm wall. In solid PVC at 1.44 g/cm³ the wall mass is fixed. Converting to a 20/62/18 structure with a core foamed to 0.68 g/cm³ removes roughly half the mass of 62% of the wall, giving a composite density near 1.07 g/cm³ — a 26% reduction in compound consumed per meter. Push the core to 0.60 g/cm³ in a 18/67/15 structure and the saving reaches 32%. Because PVC compound is the dominant variable cost in pipe manufacture, this flows directly to the cost structure. Expressed on an index basis with solid-wall pipe compound cost set at 100 points, a standard foam core structure lands near 72-76 points and an acoustic-priority structure near 66-70 points, before accounting for the additional processing aid and blowing agent cost, which typically adds back 4-7 index points.
| Metric | Solid wall PVC pipe | Foam core, 20/62/18 | Foam core, 18/67/15 |
|---|---|---|---|
| Compound consumed per meter (index) | 100 | 72-76 | 66-70 |
| Additive cost adder (index points) | 0 | +4 to +6 | +5 to +7 |
| Linear meters produced per kg (index) | 100 | 131-139 | 143-152 |
| Pipe weight for handling and transport (index) | 100 | 72-76 | 66-70 |
| Installation labor level | Baseline | Lower — lighter lengths, single-person handling to larger diameters | Lower |
| Transport volume efficiency | Baseline | Improved — weight-limited loads carry more meters | Improved |
| Acoustic performance level | Baseline | 높은 수준 | 매우 높은 등급 |
| 링 강성 level | 높은 수준 | 중간에서 높은 수준까지 | 중간 |
| Line output in meters per hour (index) | 100 | 124-133 | 132-144 |
Regrind and scrap recovery
Foam core production generates the same start-up scrap, off-spec pipe and cut-off waste as any pipe line, and rigid PVC is readily reprocessed. Ground regrind can be reintroduced into the core layer at 10-20% of the core compound. Two constraints apply. First, regrind that already contains decomposed blowing agent contributes no additional gas, so the fresh blowing agent dosage must be recalculated on the virgin fraction rather than on total throughput — a common cause of density drift when regrind ratio changes. Second, each heat history cycle consumes stabilizer, so regrind-containing batches need a stabilizer top-up of roughly 0.2-0.4 phr. Regrind should be routed to the core, never to the outer skin, where any contamination or color variation is immediately visible, and never to the inner skin, where surface quality governs hydraulic and hygiene performance.
Life cycle considerations
가벼운 파이프는 배수관 설치 당 트럭 이동 횟수가 적고, 현장에서 들어올리는 장비 수요가 낮으며, 포장이 적습니다. 수명 종료 시 세 개의 레이어 PVC 파이프는 모든 레이어가 PVC인 단일 폴리머 제품이므로, 광범위한 재활용이 가능하며, 플라스틱과 광물 함유 또는 금속 레이어를 결합한 다재료 음향 파이프보다 훨씬 쉽게 재활용할 수 있습니다. 이러한 단일 폴리머 특성은 폼 코어 방식의 이점을 과소 평가하는 요인이며, 건물 재활용 가능성이 조달 사양에 포함됨에 따라 점점 더 중요해지고 있습니다.
Requirement to Model 선택 가이드
Choosing a line configuration is a function of four inputs: the diameter range the market demands, the annual tonnage or meterage target, the product mix breadth, and whether the plant needs headroom for municipal or conduit work alongside residential drainage. The table below maps common scenarios to Faygo configurations.
| 고객 시나리오 | 추천되는 Faygo 라인 | 주 압출기 구성 | Key supporting configuration |
|---|---|---|---|
| Residential DN110 stack focus, approximately 5,000 tonnes per year, single dominant size | Foam core line, mid diameter (75-250 mm) | 원뿔형 쌍둥이 스크류 65/132, output to 350 kg/h | Three-layer spiral die dedicated to 110-160 mm, 3-track caterpillar haul-off, inline belling for ring seal sockets, staged spray cooling 9 m |
| Full residential range DN50 to DN160, high product mix, frequent changeovers | Foam core line, small diameter (50-160 mm) | Conical twin-screw 55/110, output to 220 kg/h | Quick-change die cartridge set, servo-positioned vacuum tank, 2-track haul-off, multi-size calibration sleeve inventory |
| Large diameter DN200 to DN315, residential risers plus municipal drainage duty | Foam core line, large diameter (110-315 mm) | Conical twin-screw 80/156, output to 520 kg/h | Heavy-duty three-layer die, dual vacuum tanks, 4-track haul-off with 35 kN traction, 행성형 절단기 with chamfering, offline belling |
| Start-up plant, limited capital, wants foam core capability from day one | Foam core line, small diameter (50-160 mm), base configuration | Conical twin-screw 55/110 with two 45 mm skin co-extruders | Single vacuum tank, 6 m spray cooling, 2-track haul-off, manual sleeve change; expandable to a third co-extruder later |
| Existing solid pipe producer adding foam core to an installed line | Co-extrusion upgrade package | Retain existing main extruder, add two 45 mm skin co-extruders | Replacement three-layer spiral die, upgraded vacuum control to reach the -0.02 MPa low end, extended spray section, melt pressure instrumentation on all channels |
| Combined drainage plus cable conduit and rainwater downpipe production | 폼 코어 라인, 중간 직경에 듀얼 다이 도구 사용 | 원뿔형 쌍둥이 스크류 65/132 | Second solid-wall die head for conduit, shared downstream, recipe management in the control system for fast product switching |
Practical sizing advice
Two mistakes recur. The first is buying an extruder sized on kilograms per hour when the business is sold in meters — always convert the target to meters per hour at the actual foamed density before choosing screw size. 두 번째는 under-buying cooling. Cooling length is the cheapest capacity in the entire line and the most expensive to retrofit, because adding a tank means moving the haul-off, cutter and rack and often the building services around them. Specify cooling for the fastest line speed the extruder can theoretically support, not for the speed of the first product.
일반적인 결함 및 수정 사항
Most foam core defects trace back to one of four root causes: the blowing agent decomposed at the wrong place, melt strength was insufficient, the pressure profile broke down, or cooling was mismanaged. The table below maps observed symptoms to causes and corrective actions.
| 결함 | Probable cause | Corrective action |
|---|---|---|
| Uneven core density around the circumference | Unbalanced melt distribution in the spiral die; die head temperature gradient across zones; eccentric mandrel centering | 맨드렐을 컷 링 측정으로 재중심화하고, 다이 영역 온도를 3°C 이내로 균일화하고, 다중 위치에 트랜스듀서로 코어 채널 압력을 확인하며, 한 개의 나선형 홈이 부분적으로 막힌지 확인합니다. |
| 외부 피막에 있는 침수 흔적과 표면 함몰 | Core cells collapsing locally as they cool; outer skin too thin over a hot core; vacuum too high in the first tank | Increase outer skin ratio toward 22-25%; reduce vacuum to the -0.02 to -0.03 MPa range; raise first-stage water temperature to 20-22 °C so the skin sets less abruptly; reduce total blowing agent by 0.05-0.1 phr |
| 거친, 파손되거나 연결된 세포 | Insufficient melt strength; blowing agent dosage too high; melt temperature above the window; ACR loading too low; K value too low | 아크릴 처리 보조제 ACR을 6-8 phr로 높이고, 코어 수지를 K 62-65로 이동하며, 측정 영역 온도를 5-8°C 낮추고, AC 분율은 줄이고 NaHCO3 분율은 늘려서 더 작은 핵을 생성합니다. |
| 거칠거나 곡선 모양의 내부 구멍 표면 | 피막 압출기 출력이 너무 낮고, 피막 용융물이 너무 차가우며, 코어 가스가 불연속적인 피막을 통해 뚫고 나오고, 맨드렐 표면이 손상되었습니다. | Increase inner skin ratio to at least 15-18%; raise inner skin melt temperature 5 °C; polish or replace the mandrel land; verify inner channel pressure is not being overwhelmed by core pressure |
| Pipe bowing or curvature after cutting | 비대칭 냉각, 불균일한 벽 두께, 방향을 고정시키는 과도한 드로우 비율, 지탱 롤러의 오차 조정 | 스프레이 노즐의 범위를 모든 사분면, 특히 파이프의 상단에 확인하고, 드로우 비율을 1.02-1.03으로 줄이며, 지탱 롤러와 하우오프를 다이 축과 정렬하고, 레이어별 두께를 컷 링에서 확인합니다. |
| 링 강성이 사양 미달입니다. | Core fraction too large; core density too low; skins thinner than nominal; cells elongated by high draw | 코어 비율을 60-62%로 줄이고, 코어 밀도를 0.70-0.75 g/cm³로 높이는 데 필요한 블로잉 에이전트를 0.1 phr 줄입니다. 용기 내용량만 고려하여 재분배하고, 고속 믹서 배출 온도 제어를 개선하고, 코어 화합물에 대한 중량식 공급을 사용합니다. |
| Outer skin peeling or delamination at the layer interface | Temperature mismatch between skin and core streams at confluence; contamination or lubricant plate-out on the channel wall; incompatible lubricant packages; core foaming before the layers weld | 피부와 코어 용융 온도를 합류 지점에서 8°C 이내로 유지하십시오; 다이 채널을 제거하고 청소하십시오; 피부 화합물에서 외부 윤활제를 0.1-0.2 phr 감소시키십시오; 코어 채널 출구 압력을 8 MPa 이상으로 높입니다. |
| 코어에 노란색 또는 갈색 줄무늬가 있습니다. | Localized thermal degradation; stagnant material in a dead spot; stabilizer insufficient for the foaming exotherm | Increase Ca-Zn 안정제 to 5 phr in the core; purge and inspect the die for dead zones; reduce screw speed to cut shear heat; check heater band and thermocouple calibration zone by zone |
| Density drifting during a long run | 재분쇄 비율을 변경하면서 원료 분획에 대한 점화제 계산을 다시 하지 않습니다. 점화제 분리가 건조 혼합물에서 발생합니다. 피더 불일치가 발생합니다. | 재분배 비율을 수정하고, 코어 화합물에 대한 블로잉 에이전트를 용기 내용량만 고려하여 재계산하고, 고속 믹서의 배출 온도 제어를 개선하고, 코어 화합물에 대한 공급을 중량식으로 전환합니다. |
| Pipe fails the oven test with blistering | Under-fusion of the core; gelation level too low; premature foaming leaving weak cell walls | Raise compression zone temperature 5 °C; reduce external lubricant in the core by 0.1 phr; verify dichloromethane test on skin material; confirm the blowing agent is not decomposing before the metering zone |
서비스 및 지원
폼 코어 라인은 공정에 민감한 기계이며, 잘 작동하는 라인과 수익성 있게 작동하는 라인의 차이는 대개 스테인리스 강재 품질보다 지원 품질에 있습니다. Wanplas 공장의 Faygo는 대부분의 고객이 처음으로 폼 코엑스트루전을 주문하는 것을 고려하여 지원 구조를 구축합니다.
Factory testing before shipment
모든 라인은 Zhangjiagang에서 떠나기 전에 72시간 동안 부하 하에서 연속 작동 테스트를 거칩니다. 폼 코어 구성의 경우, 고객이 제공할 수 있는 실제 화학 조성법을 사용하여 이 테스트를 수행하므로 레이어 비율, 진공 설정 및 냉각 프로필이 실제 재료에서 정의됩니다. 고객은 테스트를 참관할 수 있습니다. 공장은 개방형 공장 정책을 운영하며 상하이 공항에서 약 2시간 거리에 위치하고 있으므로 선적 전 감사 방문이 간편하게 이루어집니다.
Installation, commissioning and training
설치 및 시운전 is delivered on site, covering foundation and utility checks, mechanical alignment of the die-to-calibration-to-haul-off axis, electrical and control system startup, and process commissioning through to first saleable pipe. Operator training runs in parallel and covers the areas where foam core differs most from solid pipe: reading melt pressure on three channels, adjusting layer ratio through co-extruder speed, setting vacuum at the low end of the range rather than the habitual solid-pipe level, and running the shift-by-shift oven test as a fusion control.
Spare parts and technical support
The spare parts policy across Wanplas factories provides USD 500 free parts/year plus warranty replacement of components that fail within the warranty period. Technical support is available around the clock online, and remote diagnostics can be arranged through the control system so that a process problem can be examined against live parameter data rather than a verbal description. Recipe and trial support is part of the package: formulation starting points for the skin and core compounds, blowing agent ratio guidance for a target density, and trial run assistance when a customer moves to a new diameter or a new acoustic target.
Factory-level consulting
Beyond the machine, Faygo offers plant-level consulting that many first-time pipe producers find more valuable than the equipment discussion: water and electricity design for the workshop, 3D factory site layout, worker configuration and training plans, complete new factory construction from an empty site, old machine replacement executed for zero production downtime, and capacity expansion studies that identify and remove bottlenecks in an existing plant. All product lines carry CE and ISO certification, backed by 13 national patents including 8 invention patents accumulated over 22 years in pipe and profile extrusion.
자주 묻는 질문
얼마나 조용한가? 거품 코어 PVC 배수관은 단일 벽 PVC 파이프보다 얼마나 조용합니까?
In laboratory testing following the EN 14366 approach, a well-engineered three-layer foam core stack typically measures 8-15 dB(A) lower than an equivalent solid-wall PVC stack, with the larger reductions appearing at higher flow rates where impact noise dominates. Because a 10 dB reduction is perceived by most listeners as roughly halving the loudness, the difference is clearly audible rather than marginal. The actual result in a building depends heavily on clamp type, boxing and slab penetration detailing, which together can vary the outcome by 5 dB(A) or more in either direction.
Does foaming the core weaken the pipe?
It reduces ring stiffness, but far less than the density reduction alone would suggest, because the foamed material sits near the neutral axis of the wall where it contributes least to bending resistance. A 20/62/18 structure retains approximately 85-90% of the ring stiffness of a solid wall of the same outside dimensions while removing 24-30% of the material. 충격 저항성 is the property that requires more care: it depends on skin thickness, skin-to-core adhesion and cell uniformity, which is why the falling weight test at 0 °C is the most important routine check on a foam core line.
Can I make foam core pipe on my existing solid 파이프 압출 라인?
Often yes, with an upgrade package rather than a new line. The main extruder can usually be retained if it is a counter-rotating twin-screw with adequate temperature control. What must be added is two skin co-extruders, a three-layer spiral die head, melt pressure instrumentation on all three channels, a vacuum control system capable of stable operation down at -0.02 MPa, and typically additional spray cooling length. Faygo supplies this as a defined conversion package, and the practical limit is whether the existing line has physical space for the extra cooling.
코어 레이어는 피막 레이어보다 왜 더 많은 아크릴 처리 보조제를 필요로 합니까?
아크릴 가공 보조제 ACR은 용융 강도를 제공하기 때문에 용융 강도는 셀 벽을 확장하는 가스에 의해 균일하게 유지됩니다. 피부에서는 1~2 phr가 충분하여 융합과 표면 광택을 촉진합니다. 코어에서는 4~8 phr가 길게 늘어나기 때문에 세포 사이의 얇은 폴리머 막이 균일하게 얇아지도록 합니다. 코어 ACR을 절감하기 위해 줄여서 사용하면 폼 코어 시험에서 거친 개별 셀 구조와 실망스러운 음향 성능이 나타납니다.
What is the right vacuum setting for foam core pipe, and why is it lower than for solid pipe?
The working range is -0.02 to -0.06 MPa, roughly half the level commonly used for solid pipe. Vacuum pulls the outer skin against the calibration sleeve, and the pressure differential across the wall is carried by the still-soft cellular core. Too much vacuum compresses the outer part of the core into a dense collapsed band, which leaves the average density unchanged on a bench measurement but destroys several decibels of acoustic performance. Always start at the low end and increase only until diameter and ovality come into tolerance.
거품 코어 배수관이 솔벤트 용접 및 벨링이 가능한가요?
Yes, with adjustments. Solvent welding works normally because the surfaces being joined are the solid skins, not the core; the only caution is that solvent should not be allowed to reach a cut face where the core is exposed. Belling requires gentler, longer heating than solid pipe, because the cellular core insulates and the outer skin will over-soften before the wall is uniformly heated. 고무 링 씰 소켓 are generally preferred for foam core drainage systems, both because they accommodate thermal movement and because the elastomeric ring adds a small amount of vibration decoupling at every joint.
주택용 배수관에 사용할 수 있는 블로잉 에이전트 용량을 어떻게 시작해야 합니까?
A total of 0.5-0.6 phr, split roughly 60:40 between activated AC blowing agent and NaHCO3 endothermic foaming agent, is a sound starting point for a core density target of 0.68-0.75 g/cm³ with cells in the 60-110 micron range. Adjust in increments of 0.05 phr and always allow the line to stabilize for at least 20 minutes before judging the result, because density response to a dosage change propagates slowly through the feed system and the barrel. Never chase density with blowing agent alone if cell quality is poor — check melt strength and temperature first.
고밀도 코어 파이프는 단일 벽 PVC에 비해 화재 안전성에 어떻게 영향을 미칩니까?
Rigid PVC is inherently difficult to ignite because of its chlorine content, and the foamed core does not change the base polymer chemistry. Standard plastic pipe fire protection practice still applies: intumescent fire collars at every compartment penetration, sized and certified for the pipe diameter and wall construction in use. Because collar performance data is generated for specific wall constructions, the collar supplier’s data should be confirmed for a foam core wall rather than assumed from solid pipe data, and the project’s applicable building code always governs.
단일 거품 코어 라인이 실질적으로 생산할 수 있는 연간 생산량은 얼마입니까?
350kg/h의 출력으로 설계된 원통형 이중 스크류 65/132 메인 압출기가 DN110 거품 코어 파이프를 1.07g/cm³의 복합 밀도에서 생산하여 시간당 약 300~330m를 생산합니다. 연간 6,000시간의 생산 시간(변경, 유지보수 및 시작 시 발생하는 폐기물에 대한 현실적인 배려)을 고려하면 연간 약 1.7~1.9백만m를 생산합니다. 동일한 직경의 단벽 파이프를 생산하는 경우 시간당 동일한 kg당 생산량에서 약 25~30% 적은 m를 생산할 수 있습니다.
결론
Sound insulation PVC foam core drainage pipe is one of the few building product innovations that improves performance while reducing material consumption. The three-layer construction — solid outer skin for appearance and handling, foamed core for damping and weight reduction, solid inner skin for hydraulics and chemical resistance — delivers 8-15 dB(A) of noise reduction against solid-wall pipe while cutting compound consumption by 25-35%. For developers delivering finished apartments, that translates into fewer acoustic complaints at handover. For pipe producers, it translates into 25-30% more saleable meters from the same tonnage of PVC.
Realizing both benefits requires discipline in four areas. The formulation must give the core enough melt strength, which means K 60-65 resin and 4-8 phr of acrylic processing aid ACR, not a solid-pipe recipe with blowing agent added. The die must hold core channel pressure above 6-8 MPa and provide a long enough land to release it in a controlled way. Vacuum must run at the low end, -0.02 to -0.06 MPa, so calibration shapes the pipe without crushing the cells. And cooling must be staged and long enough to remove heat from a core that is, by design, a thermal insulator. Miss any one and the pipe will be either heavy and quiet, or light and noisy, but not light and quiet.
Faygo, Wanplas 공장, builds complete three-layer foam core drainage pipe lines across the 50-315 mm range, from compact 220 kg/h configurations for start-up producers through 520 kg/h large diameter lines for combined residential and municipal duty, along with co-extrusion upgrade packages for existing solid pipe lines. Every configuration is backed by 72시간 연속 작동 testing before shipment, on-site installation and commissioning, operator training built around the specifics of foam co-extrusion, 24/7 online technical support, USD 500 free parts/year, and the plant-level consulting that turns a machine purchase into a working production plant.
If you are evaluating a foam core drainage pipe line, the most useful next step is to share your target diameter range, wall thickness schedule, annual meterage target, applicable drainage standard and desired acoustic performance level. From those five inputs a tailored line configuration, layer ratio design and starting formulation can be prepared for your review. Trial runs on your own compound can be arranged at the Zhangjiagang plant, and factory audit visits are welcome — a two-hour drive from Shanghai airport is a short trip to watch your line make its first meter of quiet pipe before it ships.
