Model design and its importance in injection molding

mold design

Mold design is applied in the process of injection molding. Injection molding is the process through which manufacturers make intricate designs of water bottles’ toys and other products from plastic or glass. Mold design for injection molding can be traced from as early as 1872 when the first injection molding machine was invented and used in the manufacture of hair combs out of plastic. The designs for molding machines became more complicated after the second world war when a more complex mechanism was established and used in the manufacture of plastic water bottles. It may sound basic, but mold design in injection modeling is a complex process. To understand more on the topic, read more!

The functioning of an injection molding machine

A regular injection molding machine has four central units.

  • The feed hopper

This unit is where plastic or glass is fed to the machine. At this step, the plastic is either in granular or plastic form. In case the molding process involves other raw materials like silicone rubber, they are fed into the hopper in molten form. 

  • The heater barrels

In this unit of the injection molding machine, the raw materials like plastic are heated. The aim if to transform them into liquid form. Raw materials like silicone rubber, however, do not need to be passed through this chamber.

  • The ram

From the heater barrels, the molten raw material is passed through the ram, which forces the liquid into the tightly clamped mold. The pressure is required in this process. For more viscous liquids, more pressure may be necessary when forcing the molten into the crevices or corners.

mold design
  • The mold

The mold is usually made out of metal. The metal in the molds works to conduct the heat away from the plastic hence forcing the plastic to cool. Once the plastic is cooled, the press is cycled to enable the plastic to get removed from the molding. This is the last step of the injection molding process. 

Importance of mold design in injection molding

  • The mold design determines the quality of the final outcome and the final product in the process of injection molding
  • Mold design helps manufacturers and engineers predict future issues in the injection molding process and how to resolve them
  • Mold design helps to reduce the costs incurred in injection molding
  • Mold design helps to make the injection molding process more comfortable and allows it to flow easily
  • It will enable engineers to determine and make adjustments to the final products and their designs.

Types of machines used in injection molding

  • Hydraulic injection molding machine- the cheapest of the devices
  • Electric injection molding machine- less cost-efficient of the devices and the most energy-efficient from the rest.
  • Hybrid injection molding machines- this is the most diverse and fastest of the molding machines.

Bottom Line

When determining the best mold design for plastic injection, you ought to consider the cost of the process, the type of molding machine, the design of the product, the type of gate, and also the mold release element. Different product designs may call for various machines and different processes. 


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