亚洲va中文字幕欧美不卡-亚洲va在线va天堂成人-亚洲va在线va天堂va手机-亚洲va在线va天堂va888www-久一视频在线-久污tv

Welcome to Shenzhen Zhongyuan Plastic Co., Ltd!

News



Tel:(0755)27151698
Fax:(0755)27150611
Mailbox:szzyzcl@163.com / szzy@szzy99.com
Add:Building A1 and A2, No.1 Industrial Zone, yuliu property company, Gongming town, Bao'an District, Shenzhen
Industry information

當(dāng)前位置:

首頁 News Industry information

Solution to surface crack of plastic shell of power supply

Release time:2023-05-06

Plastic shell of power supplyDuring injection molding, cracks formed by surface cracking are called cracks. We solve this problem through fault analysis and troubleshooting.


1. Residual stress is too high

In terms of mold design and manufacturing, the direct gate with small pressure loss and high injection pressure can be used, and the forward gate can be changed into multiple needle point gates or side gates to reduce the gate diameter. When designing the side gate, the convex gate that can remove the broken part after forming can be used.

From the perspective of process operation, reducing the injection pressure is a relatively simple method to reduce the residual stress, because the injection pressure is in direct proportion to the residual stress. The temperature of the barrel and the mold should be appropriately increased, the temperature of the melt and the mold should be reduced, and the cooling time and speed of the parison in the mold should be controlled, so that the oriented molecules have a longer recovery time.


2. Residual stress concentration caused by external force

Generally, this kind of fault always occurs around the ejector rod. In case of such failure, the ejector shall be carefully checked and calibrated, and the ejector rod shall be set at the position with large demoulding resistance such as boss and stiffener. If the number of ejector pins cannot be expanded due to the limitation of pushing area, the method of small area and multiple ejector pins can be adopted. If the mold cavity demoulding slope is not enough, the surface of the plastic shell of the power supply will also be scratched to form wrinkles.

圖片3-1.png


3. There are differences in thermal expansion coefficients between raw materials and metal inserts

Metal inserts should be preheated, especially when cracks appear on the surface of the plastic shell of the power supply at the initial stage of startup, most of which are caused by the low temperature of the inserts.

In addition, in the selection of insert materials, try to use materials with linear expansion coefficient close to resin characteristics. When selecting raw materials for molding, high molecular weight resins should be used as much as possible. If low molecular weight molding raw materials must be used, the thickness of plastic around the insert should be designed to be thicker.


4. Improper or impure selection of raw materials

Practice shows that low viscosity loose resin is not easy to crack. Therefore, in the production process, appropriate molding raw materials should be selected according to the specific situation. During operation, pay special attention not to mix polyethylene, polypropylene and other resins together, which is easy to produce cracks. During the molding process, the release agent is also a foreign matter for the molten material. If the amount is improper, it will also cause cracks, so the amount should be reduced as much as possible.


5. The structural design of the plastic shell of the power supply is poor

The sharp corners and cracks in the structure of the plastic shell of the power supply are easy to produce stress concentration, resulting in cracks and cracks on the surface of the plastic shell of the power supply. Therefore, the outer and inner corners of the plastic shell shape structure of the power supply should be made into an arc with the largest radius as far as possible. The experiment shows that the best transition arc radius is that the ratio of arc radius to wall thickness at the corner is 1:1.7.


6. The cracks on the mold are reflected on the surface of the plastic shell of the power supply

In the process of injection molding, due to the repeated action of injection pressure on the mold, fatigue cracks will occur at the edges with acute angles in the cavity, especially near the cooling hole.

When the cracks on the surface of the mold cavity are reflected on the surface of the plastic housing of the power supply, the cracks on the surface of the plastic housing of the power supply always appear continuously in the same shape and position. When such cracks appear, immediately check whether the cavity surface corresponding to the cracks has the same cracks. If the crack is caused by reflection, the mold should be repaired by machining.

Copyright: Shenzhen Zhongyuan Plastic Co., Ltd. | mold processing customized manufacturer. If you want to know the processing price of the factory, how much is it, and which is good, please contact us Yue ICP Bei No. 17060480
主站蜘蛛池模板: 午夜精品久久久久久 | 在线亚洲精品国产成人二区 | 五月综合色| 四虎免费在线观看视频 | 日日夜干 | 亚洲伊人久久精品 | 日本在线视频网站www色下载 | 亚洲天堂一区二区 | 伊人影视传媒有限公司 | 亚洲成av人片在线观看天堂无码 | 热の综合热の国产热の潮小说 | 亚州三级| 五月天激情在线 | 手机看片国产福利 | 在线不卡一区二区三区日韩 | 欧美性猛交xxxx乱大交 | 日韩在线国产精品 | 青青草视频黄色 | 日夜啪啪 | 最新中文字幕一区二区乱码 | 亚洲热播 | 午夜毛片在线观看 | 日日摸夜夜添夜夜添特色大片 | 人人澡天天澡夜夜澡 | 欧美中文字幕一区 | 日日夜夜操天天干 | 一二三四日本高清免费看 | 三级黄色免费 | 五月天堂婷婷 | 夜夜揉揉日日人人视频 | 天天综合天天看夜夜添狠狠玩 | 色综合手机在线 | 亚洲欧美另类精品久久久 | 亚洲欧洲精品久久 | 视频在线亚洲 | 亚洲影院在线播放 | 在线国产91 | 日韩在线第三页 | 五月婷婷 六月丁香 | 色爱区综合激情五月综合激情 | 日韩三级视频在线 |