A Guide To Plastic Fabrication Processes

by | Aug 23, 2021 | Plastic Fabrication, Thermoforming, Vacuum Forming

A Guide To Plastic Fabrication Processes

Many kinds of plastic manufacturing processes have developed over recent years. The objective of these methods is to cover several applications, plastic types, and part geometrics.

 

Because of this, it’s imperative that every person involved in product development gets familiar with the different options available. Below, we outline the most common plastic forming techniques in manufacturing.

 

The Most Common Plastic Forming Techniques

 

Injection Molding

 

This method is one of the most ubiquitous plastic processing techniques. It involves the melting of plastic pellets, which could either be thermostatic or thermosetting polymers.

 

The next part involves the injection of the melted plastic into a mold cavity at pressure once they are pliable enough. Injection into the mold cavity fills and solidifies the plastic to make the final product.

 

This method is standard in any plastic fabrication company. It may involve a steel or aluminum mold.

 

Vacuum Casting

A cost-effective alternative to the previous technique is vacuum casting. It is a form of what’s known as a ‘copying’ technique for custom plastic fabrication.

 

Vacuum casting involves the production of a small series of functional plastic parts or prototypes. Therefore, a master model with a high-quality surface finish is needed for an efficient vacuum casting process. Then, the next step involves the encapsulation of the master model into a silicone mold.

 

Curing of the silicone mold occurs at high temperatures, ensuring strength and durability. After curing, the mold is cut open, revealing a hollow space with the same dimensions as the master model.

 

The cut mold is then filled with the designated resin material in a vacuum chamber. Many manufacturers often mix the resin with coloring pigment or metallic powder. Therefore, you can be sure of achieving aesthetic or certain functional characteristics. The resin’s final curing occurs in the oven at high temperatures, after which there’s the removal of the silicone mold.

 

Blow Molding

Here’s another popular method involved in plastic fabrication. It involves the inflation of heated plastic tubes to create hollow plastic parts. The raw material in blow molding are thermoplastic pellets, which could include any of the following:
  • Low-Density Polyethylene (LDPE)
  • High-Density Polyethylene (HDPE)
  • Polypropylene (PP)
  • Polyethylene Terephthalate (PET)
  • Polyvinyl Chloride (PVC)
  • Co-polyester
  • Polystyrene

 

Thermoforming

 

This is a unique process that involves the heating of thermoplastic to a pliable temperature. The heated thermoplastic can then be formed into a specific shape in the mold. After then, it will be trimmed to create the final product.

 

Thermoforming can use different mold types and processes to get the finished parts. It could involve the bending of plastic sheets on strip heaters. Also, molding of complex plastics occurs via the vacuum forming method.

 

Thermoformed parts usually have lower tooling costs. This is because the instrument do not need to operate at very high temperatures and pressures. Thermoforming is an efficient and versatile process. It helps to create plastic parts including disposable cups, medicinal equipment, and more.