国产精品乱码久久久久久软件_高潮又爽又无遮挡又免费_极品熟妇大蝴蝶20p_免费毛片全部不收费的_国产精品爽爽久久久久久蜜臀

Plastic shellProcessing refers to the processing of plastic molding and plastic blank making tools. It consists of an upper mold and a lower mold. Its basic characteristics are as follows:

1、 High machining accuracy requirements

Plastic shell is generally composed of female mold, male mold and mold base, and some can be multi piece split modules. Therefore, the combination of upper and lower dies, the combination of inserts and cavities, and the combination of modules all need high machining accuracy. The dimensional accuracy of precision plastic shells often reaches the micron level.

2、 The plastic shell has excellent material and high hardness

The main material of the plastic shell is mainly made of high-quality alloy steel, especially the long-life plastic shell, which is usually made of LELAI steel such as Crl2 and CrWMn. This kind of steel has strict requirements from blank forging, processing to heat treatment. Therefore, the preparation of processing technology can not be ignored. Heat treatment deformation is also a serious problem that needs to be taken seriously in processing.

3、 Copy processing

In the production of the shell, sometimes there are neither drawings nor data, and the copying process must be carried out according to the actual object. This requires high simulation accuracy and no deformation.

4、 Complex shapes and surfaces

For some products, such as car covers, aircraft parts, toys and household appliances, their formed surfaces are composed of various curved surfaces. Therefore, the cavity surface of the plastic shell is very complex. Some surfaces must be treated mathematically.

5、 Repeated production

The service life of the shell is long. When the service life of a pair of shells exceeds its service life, a new plastic shell must be replaced, so the production of the shell is often repeated.

6、 Small batch

The production of plastic shell is not mass production. In many cases, only one pair is produced.

7、 Multi process

Plastic shell manufacturers always use milling, boring, drilling, reaming, tapping and other processes.