Klarm is one of the most professional injection mold makers of a wide range of industries in China. Precision injection molding has a number of advantages over other methods. In particular, plastic precision injection molding involves several methods to make components in an efficient manner.
The quality of plastic injection mold parts is as good as the molding process is. Klarm is helping customers with products should be competent enough to fight the common molding problems so that in the end have high gloss parts that fetch the kind of results expected with the products.
The injection molding process is used for the production of all kinds of items including garden tools, electronic and even kitchen utensils and others. The components can be made from glass, polymers, metals and plastics among others.
The defects can result from the mold, raw materials used by the injection molding process. Fortunately, there are so many ways of dealing and preventing the injection molding defects and using these approaches manufacturer will be able to make highest quality injection molds. Here are some of the things that can be done to avoid defects and get high quality molds and parts in the end.
They are common on narrow sections of components and may be viewed as minor or major defects depending on the product and expected use. To avoid the defective appearance, the manufacturer should increase nozzle diameter, injection speed of the injection pressure. The cylinder temperature increase can also help in preventing this defect for a high quality part in the end.
The most common are dull concentric rings that can appear around sprue like a halo. Usually this happens when there is poor flow of material and high viscosity. Contrary to what many might think, this is not a packaging defect, but rather a defect that occurs at the very beginning of filling cycle.
To minimize the possibilities, the injection speed profile should be tailored so there is a flow-front velocity that is uniform throughout the filling phase. It may also be helpful to raise screw back pressure and barrel temperature to reduce dull surfaces that result from low melt temperatures. For dull surfaces generated by design related issues, reducing radius between part and gate can be the remedy.
This is common with plastic molds and they appear like dark red or black discolorations. It may be considered a minor defect that arises from excessive melt temperature, overheating when there is trapped air and excessive injection speed.
Corrective actions for this kind of defect on parts include lowering the temperature, shortening cycle time and slowing the injection speed. The manufacturer should also ensure that there is adequate gate sizes and gas vents to resolve the issue of trapped air that leads to this defect.
Gloss difference on textured surfaces tend to be more conspicuous and part may have irregular gloss appearance even though the surface texture is uniform. This is a problem that comes with poor replication of mold surface in some part areas. It can be fixed by raising melt or mold temperature or even the holding pressure. When holding pressure time is extended, chances of accurate mold surface replication are increased.