Molds standard parts

The China Die and Mold Industry Association was founded in 1984. It is the sole nationwide organization for the dies and moulds trade in China. Under the Council of Directors, there are nine special committees Technical Committee, Operation and Management Committee, Consulting and Education/Training Committee, Die and Mold Standard Part and Component Committee, Committee of Information of Die Mold, Committee of Automobile Body Die Mold, Committee of Materials of Die Mold, Wire Drawing Die Committee, Rubber Mold Committee. 

CFR, Metal Molding and Casting Industry Point Source Category Effluent Limitations Guidelines, Pretreatment Standards and New Source Performance Standards, Part 464, Code of Federal Register,... 

Figures 9-6 and 9-7 show the type of data that are available to the product designer for use to set tolerances on injection or compression molded parts. The standard part shown has dimensions in all of the typical directions encountered in molded parts. The graphs show the expected variation in dimension as a function of the part size and within the tolerance level of coarse, standard, and fine. These are...

Standards help the manufacturer design and implement the mold in the most simple and economic way. With a diversified range of standard parts (Figures 2.30 and 2.31), i.e. standardized components for plastics processing, simple and fast implementation of mold making is possible. 

The most important standards for tool and mold design are listed and explained below. A complete description of the most common standard parts with all its facets would go beyond the scope at this section. 

To achieve further improvements in the course of the manufacture of the mold, additional work to the available steel plates is offered by many standard parts manufacturers. The plates are machined (to customer specifications) on modern machining centers (Figure 2.32). 

Costly deep-hole drillings as well as the complex milling operations should also be considered. All processing steps up to the mold contour can be obtained from the standard parts manufacturer. Through this extended workbench of the mold maker, optimum quality and precision can be achieved. 

Molders Division of The Society of Plastics Industry (SPI) has developed cosmetic specifications of injection-molded parts. The purpose of this standard is to provide quantitative definitions and recommended methods of inspection and measurement of the cosmetic quality attributes in the absence of customer provided specifications. The specification addresses the cosmetic quality of molded plastic parts and related post-molding activities. Figure 16-12h shows one of the cosmetic specifications. 

PCTFE plastic is available in products that conform to ASTM 1430-89 Type 1 (Grades 1 and 2) and is suitable for processing into parts that meet MIL-P 46036 (Federal Specification LP-385C was canceled 1988). Standards for fabricated forms are available for compression molded heavy sections (AMS-3645 Class C), thin-walled tubing, rod, sheet, and molded shapes (AMS-3650). PCTFE plastics have been approved for use in contact with food by the FDA (55). 

The basic resin for EPS is in the form of beads that ate expanded to a desired density before molding. Densities for packaging parts are typically 20—40 kg/m. Once expanded, the beads are fused in a steam-heated mold to form a specific shape. Most parts are molded of standard-white resins, although several pastel colors are available. 

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