Sheet Extrusion Guide for Cups, Lids & Trays | PP, PET & BOPS
70% of a thermoformed product's quality is determined before it even reaches the mold. It is determined by the Sheet.
If your sheet has "flow marks," your trays will look dirty. If your sheet is brittle, your cups will crack.
You cannot buy a "Universal Extruder." The machine that makes cheap water cups is engineeringly different from the one that makes premium crystal-clear bakery trays. As a complete line manufacturer, here is how we match the Plastic Sheet Extrusion Machine to your specific end-product.
1. For Disposable Water & Yogurt Cups (PP/PS)
The Goal: Lowest possible material cost.
The Challenge: Virgin Polypropylene (PP) is expensive. If you use 100% virgin material, you cannot compete on price.
The Solution: A/B/A Co-Extrusion Line.
We configure the extruder with Two Screws feeding One Die.
Layer "A" (Outer/Inner): Thin layers of 100% Virgin material for whiteness and hygiene.
Layer "B" (Middle): Thick layer of recycled crushed cup waste (Regrind).
This sandwich structure allows you to reuse your own scrap without sacrificing the cup's appearance. This is the standard feeder for any high-volume Plastic Cup Making Machine.
2. For Coffee Lids & Fruit Punnets (PET)
The Goal: Glass-like clarity and rigidity.
The Challenge: PET absorbs moisture. If you use a standard single-screw extruder, the sheet will turn hazy and brittle (IV drop).
The Solution: Twin-Screw PET Extrusion (No-Drying).
We recommend a High-Torque Twin Screw Extruder with a specialized vacuum venting system. This mechanically removes moisture inside the barrel, eliminating the need for a separate crystallization dryer (saving 40% energy).
This ensures the sheet retains high viscosity, which is crucial for the precision punching required by high-speed Plastic Lid Making Machines.
3. For Bakery & Pharma Trays (BOPS/HIPS)
The Goal: Superior gloss and snap-shut rigidity.
The Challenge: Standard plastics can look dull. Premium sushi boxes or cake trays require "Sparkle."
The Solution: Specialized BOPS Lines.
For these niche applications, the calendar rollers are key. We use Mirror-Polished Chrome Rollers with oil heating to ensure perfect surface finish.
This high-end sheet is designed specifically for our High Transparency Tray Maker, creating packaging that makes food look more expensive.
Conclusion: Start with the Product
Don't ask "How much is an extruder?" Ask "What extruder do I need for a 5-gram Yogurt Cup?"
We are one of the few manufacturers who build Both the Extruder and the Thermoformer. We know exactly how the sheet behaves in the mold.
Not sure which line fits? Send us a photo of your final product. We will recommend the exact Screw Configuration (Single vs. Twin) and Layer Structure (Mono vs. Multi) for you.
