Galvanized Inserts and Molds

Vacuum systems are often used in the so-called RTM process. The mold load is therefore extremely low and galvanized molds can be manufactured in a lightweight design, i.e., the galvanized molds with wall thicknesses from 3 to 5 mm are fixed to the tubular steel frame using inserts such as the molds for the aerospace industry. The pipe system for the temperature control is inserted and covered by a 10 to 15 mm thick cast resin laminate layer. This mold manufacturing method is very inexpensive. It was successfully used for the production of car body parts. 

At low ambient temperatures, dry cells and other galvanic cells lose their faculty to give their nominal current output. Pyrotechnic heat sources can be employed to remedy this deficiency. Experimentally, one such system consists of cheap, easily molded, relatively cool burning pellets, inserted into metal tubes, which are immersed in the electrolyte. The pellets consist of fine iron powder and sulfur in the proportion 70/30 (theory 64/36 calc. 250 cal/g). They are easily ignited and while expanding in a semiliquid state, glow at bright red heat... 

Generally speaking, the wear behavior of nickel, depending on the composition and hardness, almost reaches the wear behavior of hard chrome. Usually galvanized mold inserts for injection molding are used with a nickel hardness of 44 to 48 HRC. For other applications, such as in the aviation industry or in the slush technology, sulfamate nickel is used with a hardness of about 25 HRC. 

FIGURE 4.53 Galvanized mold with a subsequently inserted slider brakethrough and injection channel... 

The previous discussions refer mainly to the use of galvanized mold inserts in injection molds. Figure 4.54 shows an application example. The extensive field of rotational molding and the so-called slush technology is discussed in detail in... 

FIGURE 4.54 Injection molding galvanized mold inserts for impeller and spreading disc... 

C and to be vacuum-tight at the same time. In addition to molds made from steel or aluminum, galvanic molds made from sulfamate nickel with integrated steel inserts, via which a mounting on a mobile tubular frame is done, have proved to be very effective (Figures 4.58 and 4.59). 

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