Process for manufacturing a film cup mold
The main products of the film cup refer to the film fabric with a thickness less than 1.2mm (nylon, polyester cloth, etc.). The product has a concave and convex arc surface, which is used to improve the flexural energy of the product. The shape of a typical product is shown in Figure l-21. (a) is shown.
The film cup is also called rubber diaphragm and pump membrane. The article is in a conventional manner. Firstly, according to the product pattern or the actual sample, the design and measurement of the rubber mold diagram, due to the high thickness, uniformity and precision requirements of the product, the general tolerance is in the range of 0. 03~0. 05mm, for the mold cavity with concave and convex surface, According to the conventional machining by ordinary lathe, it is difficult to achieve the desired accuracy requirements. The general qualification rate is low, especially for multi-cavity film products, the qualification rate is lower. Most of the conditional factories are processed by computer-controlled CNC lathes to ensure high-demand products. , but the processing costs are high.
In order to overcome the above problems, the following improved process can be employed: from the ordinary, typical upper and lower mold cavity mold structure, the lower mold cavity shown in Fig. 21(c) is used instead, and the upper mold is replaced by the non-cavity flat mold. The surface is required to be brushed (sandblasted or hand-sanded with sandpaper), and the adhesive is applied. After drying, the first mold solid rubber is pressed together with the lower mold. After the mold is opened, the solid rubber is firmly bonded to the upper mold plate. On the surface, the solid rubber surface of the mold requires light, no bubbles, no impurities and other defects. The hardness of the mold is required to be within 75 ± 5 of the Shore, and it is required to be made of heat-resistant and elastic rubber. At the beginning of the second mold, the preformed semi-finished or semi-vulcanized film film can be placed in the lower mold cavity and vulcanized to obtain the desired film product.
If the mold with the cavity of the lower mold is used, the machining accuracy is greatly reduced. The rubber clearance of the lower mold cavity is not required to maintain the high precision requirement of ±0. 02mm.