Injection molding is a widely used technique for manufacturing plastic products including bottle caps, chairs, toys, enclosures, automotive parts, syringes, and battery casings among others. The process helps in producing complicated shapes from thermosetting and thermoplastic materials quickly.
Low labor cost, minimal material wastage, and minimal finishing requirements are some amongst the many advantages of the plastic injection molding technique.Are you curious to know how plastic products are produced using the injection molding method? Read on to understand the steps involved in the process.
The Five Steps Described :
Plastic injection molding service providers follow the below mentioned steps to create intricate shapes from thermosetting and thermoplastic materials.
- Clamping – An injection molding machine encompasses three parts, the mold, the clamp, and an injection unit. During the injection process, the mold experiences extreme pressure. The clamping unit is supplied to hold molds securely under extreme pressure. Prior to the injection, ensure that the two halves of the mold are firmly clutched by the clamping unit.
- Injection – At first, the plastic material – in the form of pellets – are fed into a hopper on top of the injection unit. The pellets are then conveyed to the machine’s heating cylinder, where they are melted at high pressure (typically 10,000 – 30,000 psi). This molten plastic is then injected into the mold through a motorized screw. This screw is responsible for regulating the speed and pressure of the injection process. Once the molds are completely filled with molten plastics, the motorized screw remains stationary for some time. This ‘holding time’ helps set the molten plastics in the mold. After some time, the mold is again filled with molten substances to compensate for the gaps created due to contraction.
- Cooling – Following the injection process, the molten plastic is allowed to cool within the mold until it has achieved a solid form. The cooling time varies according to the type of thermosetting and thermoplastic material used.
- Open the Clamping Unit – Once the sufficient cooling time has elapsed, open the camping unit that secured the two halves of the mold in place.
- Ejection – An ejection system is supplied to the rear half of the mold that helps eject the solid plastic product from the mold. The ejection mechanism is designed to expel the plastic part out of the mold. To ease the ejection process, a mold-releasing agent is sprayed on the mold surface.
Following the aforementioned processes is mandatory to produce parts with great accuracy, without any material wastage. The technique helps produce a wide variety of plastic products, which vary in their size and complexity.
