Definition
Applying a molten polymer layer onto a substrate (paper/film) to add sealability, moisture barrier, or stiffness.
Applications
- Paper wraps
- Lidding and cartons
- Hybrid paper/plastic structures
Benefits
- Adds moisture resistance
- Creates heat-seal surfaces
- Improves stiffness and tear behavior
Industry Examples
- Medical: coated paper for clean, sealable overwraps (application-dependent).
- Industrial: coated kraft for fertilizer or feed packaging where moisture exposure is expected.
- Electronics: adds moisture-resistant polyethylene layers to paper-based protective wraps for electronic subassemblies.
FAQ
Q: Is extrusion coating the same as lamination?
A: It adds a layer; lamination bonds multiple webs together.
Q: What polymers are used?
A: Commonly LDPE/LLDPE, sometimes PP or specialty resins.