Something on the Injection Molding

When high volumes of the same object are needed, the mold came into being in to optimize the labor distribution and work flow. Before the invention, the repeated procedures cause the exhaustion of labor, time and funding. It is easy to drive companies/factories out of the advancing process. Fortunately, with the competitive advantages like high production rates, repeatable high tolerances, the ability to use a wide range of materials, low labor cost, minimal scrap losses, and little need to finish parts after molding, the mold industry grows up to benefit many aspects indeed.

When a product is designed, usually by an industrial designer or an engineer, the according molds would followed be made by a mold maker from metal, steel or aluminum and precision-machined to form the features of the desired part if it is necessary. It is widely used for manufacturing a variety of parts, from the smallest component to entire body panel of cars. Actually, from the proper manufacturing materials to the manufactured products, it tends to be a long but regulated process.

Referring to the material which is suited for injection molding, there were approximately 18000 different types available in 1995 and the number was increasing at an average rate of 750 per year. For example, most polymers including all thermoplastics may be used, such as epoxy, nylon and polystyrene. The properties for the suited material are considered in terms of strength and function required for the final part, together with different parameters for molding.

On the injection molding machine, it generally consists of a material hopper, an injection ram or screw-type plunger, and a heating unit. It is rated by tonnage. The force calculated from the tonnage would keep the mold closed during the injection process. The pressure required to fill the mold is determined by the material used and size of the part.

In fact, the cost to manufacture a mold is expensive. Thus, only products need to be mass produced would molds are employed. Some typical molds are constructed from hardened steel, pre-hardened steel, aluminum, and/or beryllium-copper alloy. For the steel molds in general, it costs much higher to construct. But the lifespan is longer enough that it would offset the higher initial cost over a higher number of parts made before wearing out. Since with the expensive equipment investment, potentially high running costs, molds are definitely favorable for the mass production indeed.


Post time: 04-05-2017