Analysis of the causes of brittleness and white fog in PC material injection molded parts

A few years ago, we rarely saw the problem of the brittleness of PC injection molded parts. That is because the PC brand used at that time is relatively small, usually only the Japanese PC7025A and 1250Y. Nowadays, more and more manufacturers of PC materials are produced, and the brands and brands are naturally more and more.
Then the problem will follow. Because the processing technology of various grades of PC materials is different, and the strictness of the process requirements is different, it is inevitable that the injection molding process of PC7025A and 1250Y will be used to produce other grades of PC materials. It can be seen that PC injection molded parts sometimes cannot withstand the brittleness of impact. After research, we found that due to the different heat resistance and physical properties of various grades of PC materials, the temperature of the melt, even the temperature of the baking and the drying time will have a significant impact on the impact resistance of the molded parts.
Usually, in the production of PC7025A and 1250Y, the temperature of the melt is generally adjustable to 290 to 310 degrees. When some grades of PC material are produced, the temperature is used to inject the molded part, and the molded part becomes very brittle. Therefore, for this PC material, the injection temperature should not exceed 290 degrees, and some may be even lower to solve the brittle problem. Therefore, as long as the fluidity of the melt is sufficiently filled, it is preferable to produce it at a lower temperature to prevent the molded part from becoming brittle and causing unstable strength.
Followed by the effect of the temperature of the baking. Both PC7025A and 1250Y can be baked to 110 to 120 degrees for more than 4 hours. However, some grades of PC material can not exceed 100 degrees, otherwise the injection molded parts will become very brittle, and it will also white fog, affecting the appearance and transparency.
The most difficult thing to notice is the drying time. Usually, when injecting PC7025A and 1250Y materials, fill the 50kg drying hopper, as long as it is baked to produce no steam, it will not cause any problem after slowly producing for six or seven hours. However, some PC materials are baked in the drying hopper for more than 4 hours. The injection molded parts not only produce obvious white fog, but also become very brittle, and the longer the time, the more brittle, the more white fog, the more the beer parts become . At this time, if a bucket of material is enough to produce for 6 hours, then only half of the bucket material can be added. If the water injection of the injection molded part is caused, the problem will not happen again if a little more is added and the feed is added a little bit. Sometimes, there are occasional white mists in beer. This should be a bit of a surprise. It is stuck in the drying hopper for a long time. Then, from time to time, a few pieces of material flow out into the barrel and are shot into the mold.
This is an important cause of the brittleness of the PC material in production and the white fog. Therefore, in order to produce various types of PC injection molded parts, it is necessary to pay attention to the characteristics and requirements of the injection molding process of various grades of materials. Of course, due to the different performance of various brands, the strength and impact resistance will be different, and the resistance of some brands is really poor.
Therefore, in the future production, if the PC injection molded parts suddenly have problems of brittleness and insufficient transparency, we can give priority to the melting temperature and the temperature and time of the baking, so that people can take a lot of detours.

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