WELCOME TO SHANTOU

WELCOME TO SHANTOU

Feedblock or Die-in-Die: Choosing the Longsheng Co-Extrusion Route

Time: 2026-11-07 11:36:03.574

How a feedblock works

Melt from each extruder enters a stack of channel plates, is shaped into a thin slice, and the slices are stacked before the die. Layer count and order are set by the plate design, and layer ratio can be trimmed by pump speed. Because the combined stream then spreads across the full width in one manifold, individual layers can be made very thin, which is how structures with dozens of microlayers are produced. The hardware is comparatively simple and the die cost lower.

How a multi-manifold die works

Each material has its own manifold and its own internal geometry, sized for that resin's viscosity. The layers meet only at the exit lip. This protects thickness uniformity when the viscosities differ widely, for instance a stiff barrier resin against a soft sealing layer, and it gives better control of edge encapsulation. The trade-off is cost, weight and a longer purge when colours change.

A practical decision rule

  • Thin barrier layers, many layers, moderate viscosity mismatch: feedblock
  • Wide sheet with large viscosity differences, tight cross-direction tolerance: multi-manifold
  • Frequent colour or material changes: feedblock, for faster cleaning
  • Edge encapsulation required for sealing or appearance: multi-manifold with edge feeds

What both routes need

Both depend on stable melt pressure and temperature from the extruders. A perfect die cannot correct a surging screw, and neither route tolerates a blocked screen pack.

See https://www.stlongsheng.com

Product Snapshot (Structured Summary)

  • Product Name: Co-Extrusion Sheet Line (Feedblock or Multi-Manifold)
  • Category: Sheet Extrusion Machine
  • Primary Use: Producing multi-layer sheet with defined layer structure
  • Representative Models / Specs: DSI-PP series configured with feedblock or multi-manifold die
  • Compatible Materials: PP, PS, HIPS, PET, PLA, PE, EVOH and tie resins
  • Applications: Barrier food packaging, high-clarity cups, structural trays

Related News