Plastic Injection Molding Works

Use of plastic injection mold

Plastic injection molding is the most common and widely used method for mass manufacturing of plastic products worldwide due to its convenience and ease of use. Plastic products made by this method include plastic chairs and tables, covers for electronic products and disposable spoons and knives, as well as other tableware products, for commercial consumption.

History of Injection Molding

Injection molding was originally created to solve a problem that many pool players face. The 19th century billiard balls were originally made of ivory, obtained from ivory taken from elephants. Celluloid was one of the first plastics used to manufacture billiard balls.

Procedure Explained

The scientific procedure used for the manufacture of plastic products by injection molding application is quite simple. Your plastic is melted and taken into a giant syringe. It is then put into a forming mold of a suitable shape according to the product being made and cooled for a sufficient period of time until it reaches the desired shape. However, the actual practical process of injection molding is not that simple and can be broadly divided into 3 subdivisions – injection units, mold parts and finally clamps.

The plastic pellet is gradually poured into the injection unit through the tunnel which is gradually melted and is in a fully liquid state by the time it reaches the front of the barrel. After reaching the forming mould, it is cooled to solidify into the desired fixed shape. The mold then returns to its previous original position in the machine.

All injection molded objects start with plastic pellets, which are a few millimeters in diameter. They can be mixed with a limited amount of pigment, called “dye” or with up to 15% recycled material – then the mixture is fed into an injection molding machine. Early molding units use a pusher to press from above. However, the exterior is either too hot or too cold and the smelting process is not going well. The solution to this is reciprocating threads – often considered the most important contribution no less than a revolution in the plastic product manufacturing industry.

The screw induces the shear stress required to melt the plastic – with residual heat coming from the traditional heating band surrounding the machine. When molten plastic is injected into the mold, it releases air from vents placed on the sides. The plastic, which has the consistency of honey, is thick enough not to slip through these holes, which are only a few microns wide.

Engraving witness marks on plastic products is also an important part of marketing because you need to be able to see and find multiple witness marks and dividing lines to authenticate and verify the authenticity of the product. It is made using removable inserts and proves very useful for tracking defects.