What is cast sheet extrusion?

Cast sheet extrusion is a process where a molten polymer is pushed through a flat die to form a continuous sheet, then cooled and sized—typically using chill rolls—to reach a stable thickness and surface finish.

Where is cast sheet used?

• Thermoforming sheet for trays, lids, clamshells, and inserts
• Flat sheet for protective layers, liners, and technical applications
• Mono- or multilayer structures where barrier, stiffness, or toughness is required

What is PHA?

PHA (Polyhydroxyalkanoates) is a bio-based polymer produced through fermentation. It’s positioned as an alternative to conventional plastics and is valued for end-of-life options such as biodegradation and compostability, depending on grade and conditions.

How does PHA behave in cast sheet extrusion?

• Thermal control: stable melt temperature helps thickness consistency and surface quality
• Crystallization & cooling: chill-roll settings impact flatness, stability, and convertibility
• Moisture sensitivity: storage and pre-drying reduce defects and help retain properties
• Shear management: gentle melt conveying supports stable processing and uniform sheet

Practical considerations

• Drying strategy: keep moisture low and consistent batch-to-batch
• Die & melt uniformity: stable temperature profile supports gauge control
• Chill-roll tuning: balance cooling, flatness, crystallization, and windability
• Formulation options: blends/additives can widen the processing window

Explore other processing routes