HDPE Injection Molding Processing Guide

author: Universe plastic

2024-05-13

HDPE (High Density Polyethylene) is a commonly used plastic material known for its high crystallinity and strength. It performs particularly well in the injection molding process, as its resistance to chemicals and heat makes it ideal for use in a variety of industrial applications. The density of HDPE generally ranges from 0.91 to 0.965 g/cm³, which determines its physical and chemical properties, including tensile strength, high temperature distortion temperature, viscosity and chemical stability.

HDPE injection molding processing conditions

When performing HDPE injection molding, the following key process parameters need to be considered

Melting temperature:

Typically between 220 and 260°C, for materials with larger molecular weights the recommended melting temperature range is between 200 and 250°C.

Mold temperature:

Generally set between 50 and 95°C. For plastic parts with a wall thickness below 6mm, a higher mold temperature should be used, while for plastic parts with a wall thickness above 6mm, a lower mold temperature should be used.

Injection pressure:

recommended between 700 and 1050 bar.

Injection speed:

High-speed injection is recommended.

Runner and gate:

The runner diameter should be between 4 and 7.5mm, the runner length should be as short as possible, and the gate length should not exceed 0.75mm.

HDPE injection molding application areas

HDPE injection molding is widely used in many fields, including but not limited to refrigerator containers, storage containers, household kitchenware, sealing covers, etc. Due to its lightweight, high-strength properties, HDPE is also very popular in manufacturing products such as plastic boxes.

Precautions for HDPE injection molding processing

When using HDPE for injection molding, you need to pay attention to its susceptibility to environmental stress cracking. To mitigate this phenomenon, less fluid materials can be used to reduce internal stresses.

In addition, HDPE easily dissolves in hydrocarbon solvents at temperatures above 60°C, although its resistance to dissolution is better than that of LDPE (low-density polyethylene).

Summarize

HDPE injection molding is a complex process that requires a variety of factors to be considered to ensure the quality and performance of the final product. In actual operation, process parameters also need to be adjusted according to specific application requirements.

Injection molding machine controller types and uses

Injection molding machine type: micro injection molding machine