Different Types Of Injection Molding Processes


The injection molding process is a type of procedure used in forming any plastic resin into functional objects. This intricate process involves the use of tools such as molding machines and channels. Hot or cold channels may be used in the injection molding procedure.

The quality of the product depends on the proper utilization of the tools. Plastic, metal, and rubber are among the types of material used for injection molding. To know how the different processes of injection molding work, here is a brief overview about them.

Plastic Injection Molding Process

This procedure uses polymer resin pellets and thermoplastic pellets. These types of material can withstand multiple melting processes.

  • The first step in the melting phase is the placing of the pellets in the injection machine. The pellets pass through the hopper located at the back portion of the barrel.
  • When the pellets are placed in the machine, the auger pushes the pellets toward the barrel. The intense heat produced in the barrel melts the pellets.
  • The molten material accumulates behind the injection nozzle.
  • When the heat limit has been reached, there is a halt in the force that the plastic causes to the auger.
  • The mold may already be injected with the molten plastic upon completion of the desired heat limit.

Rubber Injection Molding Process

There are many types of molding processes, and rubber injection molding is the most intricate of all the procedures.

  • Rubber is turned into liquid form or gum stock through a heating process. When the material has achieved the ideal form, it is placed inside the injection machine.
  • The tool uses a nozzle placed in the mold. The liquefied rubber is injected into the mold with the use of the machine.
  • The amounts of rubber placed on the mold should be ideal in filling the cavities in molding a particular component.

Metal Injection Molding

This method is ideal for producing powder-fine metal parts by applying the injection procedure.

  • The initial step in the process includes placing the base material or metal into the machine.
  • The material is mixed with plastic, which is used as a binding material.
  • Then, combination of plastic and metal is turned into granules through a grinding procedure. When the contents are very small, they can fit in the injection machine.
  • The machine heats the materials until they turn into liquid. The liquefied materials, or the green part, have the ideal quality that allows them to be filled into a mold. These materials are heated, so that the binding materials will adhere to the metal.

Metal injection produces excellent quality materials because of the huge percentage of density that comes from metal. This process is used in making surgical tools, automobile designs, and several other products that require durable materials.

The injection molding technique provides efficiency in making several molded components. Different materials are used in this method such as rubber, metal and plastic. Many people prefer to use this molding procedure because they can produce molds with different cavities. The most essential thing for people to remember is to observe safety guidelines before they apply this technique, so that they can avoid injury and accidents.