Things You Need To Know About Plastic Injections

In plastic mold injection large number of high quality plastic parts is produced with great accuracy and very quickly. The plastic granule is melted until soft enough to be injected under pressure to fill a mold. The result is that the shape is exactly copied and once the plastic molding cools sufficiently to harden the mold opens releasing the part, the whole injection molding process, and then repeats.

The characteristics of the process

The plastic mold injection uses a screw type plunger to force molten plastic material into a mold cavity. This solidifies into a shape which conforms to the contour of the mold. It is most commonly used to process both thermoplastic and thermosetting polymers. Thermoplastics are prevalent due to features which make them highly suitable for injection molding, such as the ease with which they may be recycled, their versatility, allowing them to be used in a wide variety of applications and their ability to soften and flow upon heating. Thermoplastics also have an element of safety over thermostats. If a thermosetting polymer is not ejected from the injection barrel in time, chemical cross linking may occur, causing the screw and checks valves to seize and potentially damaging the injection molding machine.

In custom injection molding, the granular plastic is fed by a forced ram from a hopper into a heated barrel. As the granules are slowly moved forward by a screw type plunger, the plastic is forced into a heated chamber, where it is melted. As the plunger advances, the melted plastic is forced through a nozzle that rests against the mold, allowing it to enter the mold cavity through a gate and runner system. As the mold remains cold the plastic solidifies almost as soon as the mold is filled.

Injection molding cycle

The stage of events during the Injection mold of a plastic part is called the Injection Molding Cycle. The cycle begins when the mold closes, followed by the injection of the polymer into the mold cavity. Once the cavity is filled, a pressure is maintained to compensate for material shrinkage. In the next step, the screw turns, feeding the next shot to the front screw. This causes the screw to retract as the next shot is prepared. Once the part is sufficiently cool, the mold opens and the part is ejected. The whole Cycle of custom injection molding is stated by definite names as Clamping, Injection, Cooling and Ejection.

Raw materials for plastic molding

When it is about trends in the injection molding industry, plastic raw material technology plays a crucial role. Improved part quality at shorter lead times and lower unit costs are the most important current trends. Most polymers, sometimes referred to as resins, may be used, including all thermoplastics, some thermostats, and some elastomers.

• Polypropylene
• Polycarbonate
• Polyamides
• Polymer additives

Torch Mold is one of the most preferred plastic injection molding companies in China that manufactures a range of top-quality injection mould products for medical, technical and defence industries. Call on: +86 -755-21520959