KEY TAKEAWAYS
A high-end PET sheet extrusion line like the SWT-75S-1000 converts PET pellets and crushed material into 0.2–2.0 mm finished sheet at 350–500 kg/h, using a 75 mm parallel twin-screw extruder with vacuum degassing — eliminating pre-drying. Full Schneider Electric PLC control, 132 kW permanent magnet synchronous motor, and mirror-polished calender rolls (Ra ≤0.025 μm) deliver food-contact-grade sheet for thermoforming. CE and ISO 9001 certified, exported to 80+ countries, with 12-month warranty and lifetime maintenance.
A PET sheet extrusion machine is an industrial production line that melts polyethylene terephthalate (PET) resin and forms it into flat, continuous plastic sheets used for thermoformed food packaging, medical device trays, and industrial blister packs. A complete line integrates material feeding, twin-screw extrusion, vacuum degassing, melt filtration, die forming, precision calendering, and automated winding into one controlled process.
What to Look for in a Production-Grade PET Sheet Line
Not all PET sheet extrusion machines are built equal. When you are buying for a factory — not a lab — four factors separate a line that makes money from one that causes downtime.
Twin-Screw Extruder vs. Single-Screw
A parallel co-rotating twin-screw extruder delivers three advantages over single-screw designs. First, twin screws achieve better melt mixing and more uniform temperature distribution — critical for PET, which degrades above 290°C. Second, the intermeshing screw profile self-wipes, reducing material residence time and preventing carbonized spots in the sheet. Third, twin-screw extruders handle higher percentages of recycled crushed material without output fluctuation. The SWT-75S-1000 uses a SW75/40 parallel twin-screw extruder with a 40:1 L/D ratio, 75 mm screw diameter, and wear-resistant 38CrMoAlA screws hardened to HV 900–1000.
Vacuum Degassing: Eliminate the Pre-Drying Step
Traditional PET extrusion requires 4–6 hours of dehumidifying drying at 160–180°C before the resin enters the extruder. A special vacuum degassing system removes moisture directly from the melt through multi-stage vacuum ports on the barrel — 7.5 kW rotary-vane pump plus 3 kW roots pump in series. This eliminates the separate crystallizer and dryer equipment entirely, cutting line length by several meters and reducing energy consumption by an estimated 15–25% per kilogram of finished sheet. Critically, it enables consistent sheet clarity from 100% recycled PET bottle flake — a capability that standard vented single-screw lines cannot match.
Automation: Schneider Electric Full-Line PLC Control
Manual temperature adjustments and speed settings create variability sheet-to-sheet and shift-to-shift. Full-line PLC control with a 15-inch touchscreen (Chinese/English selectable) centralizes every parameter — barrel zone temperatures, screw RPM, melt pump pressure, roll gaps, roll temperatures, haul-off speed, and winding tension. One-touch start with recipe data storage means operators switch between product specifications without recalibration. Remote network monitoring lets technical support diagnose issues without waiting for an on-site visit — valuable when the line runs in a different country.
Precision Calendering: Where Sheet Quality Is Won or Lost
The calendering stack determines final sheet thickness, surface finish, and flatness. An L-type 3-roll configuration with mirror-polished rolls (Ra ≤0.025 μm, chrome-plated to hardness ≥HRC 55–62, plating thickness ≥0.08 mm) produces optical-grade PET sheet. Three independent 4.4 kW Schneider Electric servo motors drive each roll, with hydraulic open/close and manual worm-gear fine adjustment for gap control. Special internal spiral flow channels ensure uniform roll surface temperature during continuous production. Sheet that leaves a subpar calender with thickness variation or surface marks becomes thermoforming scrap.
Real Production Specifications
The following specifications are based on an actual high-end PET single-layer sheet extrusion line configuration. All figures are production-verified.
Line Overview
| Specification | SWT-75S-1000 Value |
|---|---|
| Extruder Type | SW75/40 Parallel Co-rotating Twin-Screw |
| Output Capacity | 350–500 kg/h |
| Sheet Width | ≤800 mm |
| Sheet Thickness Range | 0.2–2.0 mm |
| Raw Material | PET pellets + regular crushed material |
| Installed Power | ≈250 kW (actual consumption ~70%) |
| Floor Space | ≈30m × 6m × 5m |
| Power Supply | 380V / 3-Phase / 50 Hz |
Extruder Core Specifications
| Parameter | Value |
|---|---|
| Screw Diameter | 75 mm |
| L/D Ratio | 40:1 |
| Main Drive Motor | 132 kW PMSM |
| Barrel Heating | ≈60 kW |
| Screw Material | 38CrMoAlA, nitrided |
| Screw Hardness | HV 900–1000 |
| Barrel Hardness | HV 950–1050 |
| Shaft Torque Rating | ≤11 N·m/cm³ |
| Vacuum Vent Ports | 3 |
| Barrel Cooling | Deionized water, centrifugal pump + heat exchanger |
Key Component Brands
| Component | Brand | Origin |
|---|---|---|
| PLC / Servo Motors / Drives / Contactors / Relays | Schneider Electric | France |
| Variable Frequency Drives | Inovance Technology | China |
| Switching Power Supply | Mean Well | Taiwan |
| Solid-State Relays | Yangming | Taiwan |
| Main Drive Motor | Yinmengda | German design |
| Die Head | Jingcheng Era | China |
| Safety Interlock Switches | — | Italy |
| Pressure Sensors | — | Italy |
| Length Counter | — | Korea |
Calender and Winding Specifications
| Parameter | Value |
|---|---|
| Roll Configuration | L-type 3-Roll (#1 Ø350, #2 Ø500, #3 Ø500 × 1000 mm) |
| Roll Surface Finish | Ra ≤0.025 μm mirror polish |
| Chrome Plating | ≥0.08 mm, hardness HRC 55–62 |
| Roll Drive | 3 × 4.4 kW Schneider servo motors |
| Winder | 3-station turntable, max roll Ø800 mm |
| Winding Drive | 3 × 2 kW Schneider servo motors |
| Edge Trimmer | 2 sets, rotary disc cutter, both sides |
| Cooling Water Requirement | ≤20°C, ≥40 m³/h, ≥0.4 MPa |
After-Sales Support
The machine ships with a spare parts kit (die tools, contactors, relays, cutter blades, heating rods). Upon equipment arrival, 1–2 technical engineers are dispatched for installation and commissioning. The full machine warranty is 12 months from successful commissioning, with lifetime maintenance service. During the warranty period, free on-site service is provided as needed. After warranty, labor and spare parts are charged at preferential rates.
How a PET Sheet Extrusion Line Works
The process follows seven sequential stages, each with measurable quality checkpoints.
Stage 1 — Material Feeding: PET pellets and crushed material enter through a two-point vacuum loading system with 7.5 kW blower. Two volumetric feeders (1.5 kW each, twin-screw, SUS stainless steel) meter material into the extruder. Two masterbatch feeders (0.37 kW each, spiral screw, microcomputer-controlled) add colorants or additives, synchronized with the main extruder speed.
Stage 2 — Melting and Plasticizing: The parallel twin screws compress, shear, and melt the material across heated barrel zones. The 132 kW permanent magnet synchronous motor drives the screws through a high-torque gearbox rated at 10 N·m/cm³. Wear-resistant 38CrMoAlA barrel segments with cast copper/aluminum heating bands and stainless steel guards maintain precise temperature control.
Stage 3 — Vacuum Degassing: At three vent ports along the barrel, the multi-stage vacuum system (7.5 kW rotary-vane + 3 kW roots pump) extracts moisture vapor and volatile compounds from the melt. Stainless steel pipes and valves with a pre-filter cartridge protect the pump system.
Stage 4 — Filtration and Metering: The molten PET passes through a 145B hydraulic cylindrical screen changer with two filter positions. A 90E melt metering pump (7.5 kW) then delivers constant-pressure, pulsation-free melt flow to the die, with an Italian pressure sensor monitoring inlet pressure.
Stage 5 — Sheet Forming: The melt enters a Jingcheng Era coat-hanger die with an effective width of 650–950 mm (150 mm single-side dam adjustability). Die lip flow surfaces are polished to Ra 0.03–0.04 μm and chrome-plated to 0.025–0.05 mm thickness for consistent sheet profile.
Stage 6 — Calendering and Cooling: The molten sheet passes through the L-type 3-roll polishing stack. Three independent water supply pumps with temperature control groups (ambient to 100°C) regulate each roll. The gap between rolls — adjusted via hydraulic open/close with manual worm-gear fine adjustment — determines final sheet thickness.
Stage 7 — Edge Trimming, Coating, and Winding: A cooling frame with dual-side rotary disc edge trimmers straightens both edges while a torque-controlled scrap-edge winder collects trim. An oil coating unit applies silicone oil to both sheet surfaces via roll coating, followed by two stainless steel oven units with digital temperature control. The 3-station turntable winder (Korean length counter, 3 × 2 kW Schneider servo motors) produces finished rolls up to 800 mm diameter.
Applications and Target Markets
PET sheet from this line configuration serves three primary markets:
Food Packaging: Thermoformed trays, clamshell containers, cups, and lids for fresh produce, baked goods, and ready meals. The sheet is produced under ISO 9001 quality management and is CE compliant for EU market access. With vacuum degassing, food-grade sheet is achievable from 100% recycled PET.
Medical and Pharmaceutical: Sterile barrier trays for surgical instruments and medical devices. The mirror-polished calender surface (Ra ≤0.025 μm) and full Schneider Electric automation provide the consistency and traceability that medical packaging buyers require.
Industrial and Consumer: Anti-static electronics trays, stationery products (folders, file boxes), and retail display packaging. The line handles masterbatch additives for anti-static, colored, or UV-stabilized sheet without process disruption.
How to Evaluate a PET Sheet Extrusion Machine: 5 Decision Factors
1. Output-to-Investment Ratio: Calculate your annual production target in metric tons, divide by 350–500 kg/h operating rate, and multiply by your selling price per ton. A line running 6,000 hours/year produces 2,100–3,000 metric tons. Match the extruder size to your realistic demand — oversizing wastes capital and energy.
2. rPET Processing Capability: If recycled content matters to your customers or your margin targets, prioritize vacuum degassing extruder designs. A line that processes only virgin PET locks you out of the growing rPET packaging market and exposes you to virgin resin price volatility.
3. Component Brands, Not Just Assembly: A PET sheet line is only as reliable as its weakest component. French Schneider Electric PLC/servo/drive/contactor package, Italian pressure sensors and safety switches, and a German-design main motor represent the standard that keeps a line running at 92%+ uptime. Ask for a complete component brand list — not just the extruder brand.
4. Calender Quality Determines Sheet Quality: Inspect the mirror polish specification (Ra value), chrome plating thickness and hardness, and roll drive system. Sub-Ra 0.03 μm finish with ≥0.08 mm chrome plating on HRC 55+ substrate is the threshold for optical-grade PET sheet.
5. After-Sales Support Reach: For imported equipment, confirm: Does the manufacturer maintain a service network in your region? What is the spare parts inventory policy? Is remote diagnostic capability included? An SWT-75S-1000 includes remote network monitoring as standard — enabling technical support to diagnose problems without travel delays.
FAQ
What is the difference between twin-screw and single-screw PET sheet extrusion?
A twin-screw extruder provides better melt mixing, more uniform temperature distribution, and superior degassing. For PET, which is heat-sensitive and hygroscopic, these advantages directly improve sheet clarity, reduce gels and black spots, and enable higher recycled content percentages. A single-screw extruder is simpler and lower-cost but compromises quality when processing PET — especially with crushed or recycled material.
Can this machine process 100% recycled PET?
Yes. The vacuum degassing system extracts moisture from the melt, removing the primary barrier to quality rPET sheet production. The twin-screw design with wear-resistant 38CrMoAlA screws (HV 900–1000) handles the slightly abrasive nature of recycled material. For food-contact applications, a multi-layer co-extrusion configuration places virgin PET on food-contact surfaces with rPET in the core — though this particular SWT-75S-1000 is a single-layer configuration.
What is the typical installation and commissioning timeline?
From equipment arrival, installation requires 2–4 weeks, depending on whether the customer has completed foundation work, utility connections (380V/3-phase power, cooling water ≤20°C / ≥40 m³/h, compressed air 0.5–0.8 MPa), and raw material preparation. The manufacturer dispatches 1–2 technical engineers for commissioning, which typically takes 7–14 days. Plan for 1–2 additional weeks of trial production before reaching stable commercial output.
How much does a line of this specification cost?
A PET sheet extrusion line at this configuration level — 75 mm parallel twin-screw with full Schneider Electric automation, vacuum degassing, mirror-polish calender, and 3-station winder — ranges from approximately USD 150,000 to 400,000 depending on exact configuration, optional features (co-extrusion, wider die), and delivery location. Request a detailed quotation specifying your material, thickness range, output target, and required certifications.
What maintenance does the line require?
Daily: clean screen changer filter elements. Weekly: inspect roll surface condition and bearing lubrication. Monthly: check gearbox oil level. Annually: replace barrel heater bands and thermocouples. The extruder screw and barrel should be inspected for wear every 12–18 months under continuous operation. The spare parts kit includes contactors, relays, cutter blades, and heating rods for immediate replacement. A well-maintained line achieves over 92% uptime across 6,000–7,200 operating hours per year.
Professional Summary
A PET sheet extrusion machine is a capital investment that determines your product quality, production cost, and market access. The technology has advanced significantly — today’s high-end lines combine parallel twin-screw extrusion, vacuum degassing, full PLC automation, and mirror-polish calendering into one integrated process.
The SWT-75S-1000 configuration described here represents a production-grade specification: 350–500 kg/h output across 0.2–2.0 mm thickness, Schneider Electric control architecture, Italian precision sensors, German-design motor, and CE / ISO 9001 certification for EU market access. It processes both virgin PET pellets and regular crushed material, with vacuum degassing that eliminates the separate pre-drying stage.
When evaluating a line, focus on the five factors that determine long-term profitability: output-to-investment ratio, rPET capability, component brand quality, calender specifications, and after-sales support reach. Request production samples using your own raw material before committing — a sample test on the manufacturer’s demonstration line is the most reliable predictor of production performance.
For a quotation or technical consultation on the SWT-75S-1000 PET sheet extrusion line, contact Frank Lee at [email protected] or visit tz-machinery.com.