25 kinds of phenomenon in injection molding process

A key link in the process of injection molding is required for all kinds of plastic in the shape of a product or blank. There are more than 30 injection molding method. The choice of it mainly depends on the type of plastic, the initial shape and shape and size of the product. Today, injection molding factory to introduce you to 25 kinds of phenomena in the process of injection molding:
1. Insufficient injection: in plastic processing, plastic parts of incomplete appearance is caused by a lack of cavity filling.
2。 Flash: in the process of plastic processing and forming, the overflow of the gap between the surface of clamping and residue on the plastic parts of excess materials.
3。 Weld mark: linear marks on the surface of the plastic parts, is in the process of injection or extrusion, several streams in the desert of shunt rendezvous. Melt in the interface can't completely fusion, the fusion together to produce fusion, affect the appearance of the plastic parts quality and mechanical properties.
4。 Wave flow mark: inside the mold cavity melt flow is undeserved, cause the uneven surface of the ring and spiral or defects such as irregular wave.
5。 There is crack surface turbidity: refers to the plastic parts surface crack and damage. Applying below plastic mechanical properties due to the long-term or repeated stress caused by the phenomenon of crack of external or internal, plastic parts called stress cracking; Plastic parts under a certain temperature due to the constant load and suddenly completely fracture phenomenon called stress fracture. Some thermoplastic parts under high temperature caused by excessive exposure of crack and fracture is called thermal stress crack.
6。 Fracturing: refers to the resin layer by covering on the surface, you can see the outside of a layer or layers of laminate reinforced material visible cracks.
7。 Wrinkle: laminate surface cracking and the obvious defect separation.
8。 Fold: in the process of plastic processing, plastic parts of layer or one multilayer folds or wrinkles on the appearance of the defect.
9。 Obvious crackle on cracking white: plastic known as crack, similar to micro cracks crack frost shape is called. Cracks and bleaching micro cracks are no crack. When the plastic parts exposed to a certain chemical environment or stress condition, environment stress cracking happens.
10。 Silver: plastic parts along the material flow to the surface of the needle silvery white frost shape the appearance of fine lines.
11。 Stripes: plastic parts surface or internal linear stripe defect.
12. Spots: due to poor dispersing pigments or mix and other reasons, lead to plastic parts surface mica flake shading defects.
13。 Orange: the plastic parts surface similar to the appearance of the orange peel defect.
14。 Bubble hole stripe: a bubble with its inherent structure different dip hole layer.
15。 Black: in the process of plastic processing molding, melt overheating decomposition under high temperature and high pressure, lead to plastic parts surface carbide black spots.
16。 White dots or points of light: transparent or translucent plastic film, sheet, or in the plastic parts have inadequate plasticizing particles, visible light transmission when white spots, known as the 'fish eye'. If the material is not transparent or colored spots known as white dots or window.
17。 Pitting: plastic parts regular or irregular small holes on the surface, usually the depth and width are the same.
18岁。 Fill a point: plastic parts when filling material such as wood powder or asbestos is present in the produced obvious spots.
19。 Dark spots: in dark spots in laminated structures based on fabric.
20。 Burning or spots: plastics processing process, under the condition of high temperature and high pressure molding, melt due to overheating decomposition, carbide carbide after coke mixed in the melt, the spot defects in the plastic parts surface and internal.
21。 Bubble: in the process of plastic processing and molding, if you have a lot of residual gas in the melt, or not completely discharge the air in the cavity, after molding plastic parts inside will form small volume or a series of blowhole defects.
22。 Vacuum bubble or dark bubble: plastic parts in plastic processing in the process of cooling solidification, sometimes outside the surface has been cooling solidification, but inside is still in a state of hot melt. Cooling contraction, once the center of the plastic internal can produce vacuum hole, generally called vacuum bubble or dark bubble, also known as the shrinkage cavity.
23。 Pinhole: plastic or film on a hole the size of pinhole defects.
24。 Bubble collapse: foam plastic manufacturing process, due to the bubble pore structure damage defects of local density increases.
25。 Sag and contract: in the cooling process of plastics processing, surface cooling curing first, internal or wall thickness part cooling solidification, the volume contraction inconsistent shrinkage rate, both inside and outside the plastic parts surface inward stretch forming sag, shallow hole or pit.