Why is dual-layer co-extrusion used in PE sheet extrusion equipment?
The primary purpose of dual-layer co-extrusion equipment is to enable PE sheets to achieve functional, cost-effective, and performance advantages unattainable with single-layer extrusion. The core technology combines two PE materials with different properties to meet more complex application requirements.
1. The Core Purpose of PE PP Double-layer Co-extrusion Board Machine: Achieving "Functional Stratification" to Meet Multiple Needs
Single-layer extruded PE sheets offer a single performance. Dual-layer co-extrusion, by combining two PE materials (or PE with other compatible materials), allows the sheet's "surface layer" and "core layer" to perform distinct functions. Typical application scenarios include:
Cost Control: The core layer uses recycled PE or low-grade PE, while the surface layer uses high-purity, high-gloss virgin PE. This ensures the sheet's surface aesthetics and weather resistance while significantly reducing raw material costs.
Performance Enhancement: The surface layer uses a specialized, abrasion-resistant and UV-resistant PE material, while the core layer uses standard PE. This allows the sheet surface to withstand outdoor exposure and frequent friction while controlling overall costs.
Functional stacking: For example, adding an antimicrobial agent to the surface layer for medical/food applications while maintaining basic toughness in the core layer; or using high-density polyethylene (HDPE) for the surface layer to enhance hardness while using low-density polyethylene (LDPE) for the core layer to retain impact resistance.
2.PE PP Double-layer Co-extrusion Board Machine Improves Production Efficiency: Reduces Subsequent Processing and Reduces Costs
To achieve "surface functionalities" on single-layer sheets, secondary processes such as coating and printing are often required. However, double-layer co-extrusion allows for a single-step lamination process, directly producing sheets with multi-layer properties. Specific advantages include:
Eliminating coating and lamination processes shortens production cycles and reduces equipment and labor costs.
It avoids the "interlayer delamination" problem that can occur during secondary processing, improving the overall structural stability of the sheet.
3. PE PP Double-layer Co-extrusion Board Machine Achieves Material Compatibility: Expanding the Applications of PE Sheets
PE materials themselves come in different varieties (such as HDPE, LDPE, and LLDPE) and are compatible with other polyolefin materials (such as PP). Double-layer co-extrusion can combine the advantages of these materials and break through the performance limitations of single-layer PE.
