What is Plastic Injectiong Moudling Process? Injection moulding is a manufacturing process for producing parts by injecting molten material into a mould or mold. Injection moulding can be performed with a host of materials mainly including metals (for which the process is called die-casting), glasses, elastomers, confections, and most commonly thermoplastic and thermosetting polymers. Material for the part is fed into a heated barrel, mixed (using a helical screw), and injected into a mould cavity, where it cools and hardens to the configuration of the cavity, After a product is designed, usually by an industrial designer or an engineer, moulds are made by a mould-maker (or toolmaker) from metal, usually either steel or aluminium, and precision-machined to form the features of the desired part. Injection moulding is widely used for manufacturing a variety of parts, from the smallest components to entire body panels of cars. Advances in 3D printing technology, using photopolymers that do not melt during the injection moulding of some lower-temperature thermoplastics, can be used for some simple injection moulds. Some Thermoset material can be injection: Material Mold Temperature(°C) Melt Temperature(°C) Melt Pressure(MPa) PE 60-70 170-200 60-100 PP 80-90 160-220 70-100 PC 60-110 230-285 80-130 POM 90-120 160-190 80-130 ABS 50-80 170-200 60-100 PMMA 40-60 160-180 80-130 Surface Finish Options Draft angle requirements will vary by requested finish. Industry standard Mold-Tech finishes are also available.             FINISH   DESCRIPTION PM-F0  non-cosmetic, finish to Protolabs' discretion PM-F1 low-cosmetic, most toolmarks removed PM-F2   non-cosmetic, EDM permissible SPI-C1 600 grit stone, 10-12 Ra PM-T1 SPI-C1 + light bead blast PM-T2 SPI-C1 + medium bead blast SPI-B1 600 grit paper, 2-3 Ra SPI-A2 grade #2 diamond buff, 1-2 Ra  What's main  defect of injection molding? The complexity of the injection molding process, and the interdependence of the many variables involved, means that any molding defect may have several different causes, of which more than one may be present at any given time Problem Possible Causes Picture Sink Marks Melt temperature too high Insufficient material injected Insufficient dwell time Premature gate freezing Sharp variations in wall thickness Wrong gate location Part ejected too hot Cavity pressure too low Voids Volatiles from overheated material Condensation on granules Premature freezing of flow path to thick section Flow marks Melt temperature too low Weld lines Incorrect gate location mold temperature too low Burn marks Incorrect filling pattern Warping Melt temperature too low Incorrect part design Overpacking near gate Sharp variations in wall thickness Flow length too great Unbalanced multiple gates Part ejected too hot Inadequate or badly located ejectors Temperature variations between the mold halves Some Case From Xiamen wiesel Technology co.,Ltd