How does extrusion differ from injection moulding

Unlike extrusion, injection molding forms three-dimensional shapes. Joseph Brahman patented the first hydraulic press in However, the process was more fully developed in after Thomas Burr developed the first hydraulic powered press for producing shapes. It was not until that the process was expanded to include brass and copper alloys for the non-continuous extrusion of finished parts.

In terms of plastic extrusion, this technology was pioneered by Thomas Hancock in and Edwin Chafee in for the processing of rubber. The first thermoplastic extrusion is credited to Paul and Ashley Troester much later, in This is a method by which molten plastic or varying alternative materials are pushed continuously, driven by feed screws through a two-dimensional die opening.

Able to create detailed features and complex geometry. Enhances the strength to the part after it has been molded. Ability to use multiple plastic types simultaneously. Extrusion Molding This technique extrudes, or forces out, materials through a die to create shapes using constant cross sections like window sections, drinking straws, pipes, and seals. The Process The machine motor, extrusion machine, turns a screw that feeds plastic through a heater.

Advantages Some of the advantages of the extrusion process are: Shaping hard and brittle materials. Favorable for the creation of atypical cross-sections. Guarantees a smooth finish on the end product. Alterations to the product after it has been removed from the extruder. One benefit of the extrusion process is that the dies create very smooth finishes that are ideal for pipes, straws, and other commonly-extruded products.

Conclusion The question of plastic extrusion vs. These methods have their own purposes and advantages, and both are valuable to plastic manufacturers. Each method has a unique place in plastic manufacturing. Fill in the form below and we will send a free quote! Skip to content Polymeric dye. Plastic pellets. For end-product differences and advantages. While the final shape required for a part often dictates the process used, both extrusion and injection molding have their advantages.

Injection molding typically has a higher, initial design cost due to the complexity of the mold structure.

Its cyclical production, however, typically creates a finished piece that often does not require further assembly or secondary processing. The extruder can create complex cross-sections such as multi-lumen tubing used in medical devices or food processing. Recycling and Pelletizing Machine. These are general differences and similarities between extruder and mold injection machine.