Injection Molding Process

Injection Molding Process 

The injection machine takes plastic granules--raw material, heats them until molten, and the

iects molten plastic material into the mold. The barrel in injector contains a screw or auger. The

heater bands around the outside raise the temperature to melt the plastic to the desired level.The

plastic injection molding process usually produces large numbers of workpieces of high quality at

Injector basically is a machine for raising plastic temperature to a point where it will flow

under pressure, for allowing the plastic to cavity and solidify in the mold, which the machine keeps

closed, and for opening the mold to eject the solid plastic workpiece

The plastic injection molding process is as follow

• The moving and stationary(fixed) platens of the injection molding machine holds the

  lold together under pressure

• The molten plastic that has been melted from pellet or granule form in the barrel is she

  into the mold under high pressure

• When the molten plastic has been injected into the mold, the pressure is applied to ensure

  all cavities are filled. The plastic workpieces are then allowed to solidify in the mold

• Open mold and eject workpiece

Plastic material in the form of granules is melted until soft enough to be injected under

pressure to fill a mold. The result is that the shape is exactly copied. Once the plastic molding has

cooled sufficiently to harden the mold opens releasing the workpiece. The whole injection molding

illustrates an injection molding cycle time. A molded workpiece takes 60 s to mold

process then repeats

From this is shown the different time in seconds of the machine operations. It should be noted that

the actual injection of the material into the mold is only 5 s, while the plastic part cooling time in the mold is 47s.After the gate sections in the mold have frozen to prevent backflow, the screw begins to rotate and moves backward for the next cycle.