Low-Density Polyethylene

LDPE is highly branched polyethylene. The branching prevents tight chain packing, which lowers crystallinity and produces a softer, more flexible, lower-melting material than HDPE.

It is the standard squeeze resin. If a product has to be dispensed by hand pressure and the bottle has to spring back, LDPE or an LDPE blend is the specification.

• Squeezability and recovery: Compresses under hand pressure and returns to shape without permanent deformation.
• Low-temperature impact: Excellent. Stays ductile well below freezing.
• Clarity: Better than HDPE but still translucent. Not a clarity resin.
• Chemical resistance: Good, a step below HDPE.
• Stiffness: Low. Not suitable where the container must resist stacking load.

Squeeze bottles for lotions, sauces, and gels. Dropper bottles. Malibu tubes and tottles. Flexible film and bags. Dispensing closures where a soft seal is needed.

Process: Extrusion blow molding and injection molding.

Shrinkage: 1.5-3.5%, the highest of the resins we run regularly. High shrinkage means neck finish dimensional control depends on tight process discipline. Cooling time and mold temperature drift will move thread dimensions.

Watch for: Warpage on thin flat sections. Because LDPE is soft, parts can distort during ejection if cooling is cut short to reduce cycle time.