Yes, you got it right! You know that plastics are everywhere and in fact, they have become environmentalists’ main concern because of rather invulnerability against decomposition. Yes, you are aware that this material composes most products on earth or that a piece of that thing you’re holding onto right now is made of it. But do you originally know where if it came from? Are you all aware that its creative procedure could be as quite complicated as its storage/ dispensing concerns? Blame it all to injection molding and know how a plain, ordinary plastic could be molded into its unique shapes today!
Injection molding is the method used to massively manufacture plastics! Through the years, this comprehensive process plays an influential role to the plastic manufacturing industry and the other sectors which need the product. Throughout the decade, the ‘art’ has revolutionalized, making it easier, producing higher quality and catering into the public’s more customised design.
Currently, steps to injection molding involve melting the plastic and injecting it into a predesigned mold. Unlike metals, small plastic pieces, called resins, need to be injected with force. Thus, larger machines are needed, to progress them though the six major phases to produce anything from your smartphone’s parts to your plastic toys.
First, clamping necessitates high pressure to initiate the injection and cooling process. Pelletized resins are then fed into the machine, plus some proper colorants. These pieces enter the injection barrel, where they are placed under melting point heat and then, transported into the mold by a screw or ramming device. The latter is called the injection phase.
After the molten plastic pieces are injected, they are contained inside the mold- a process called dwelling. Hydraulic or mechanical force is applied to ensure that all cavities within the mold are filled in.
Once filled up, the cooling phase starts allowing the plastic parts to solidify. Cooled enough? The step to opening it up usually involves separating the two halves of the mold. Then comes the final step- ejection! From the injection mold tool, rods, a plate or air blast aid in the transfer. The completed part may have random bits called runners which are trimmed off and recycled. These six processes, from the time closing the mould to ejecting it, make up one cycle. Each one could range from ten to 100 seconds, depending on the needed cooling time. And, sometimes, it requires more than one cycle to get a good quality finished product!
Yes, you got it right! Plastics have history too! Now, do you think injection moulding is not as complicated as you first thought it is?