Mold parting line venting system

Well-designed molds are vented, as entrapped air in the mold prevents good contact between the parison and the mold cavity surface. When air entrapment occurs, the surface of the blown part is rough and pitted in appearance. A rough surface on a shampoo bottle, for example, is undesirable because it can interfere with the quality of decoloration and can detract from the overall appearance. Molds are easily vented by means of their parting line, with core vents and with small holes. A typical mold parting line venting system is shown in Fig. 13.23. 

Figure 13.23 Typical mold parting line venting system.

Note that depending on the resin system used in VARTM, the mold temperature may need to be elevated during the curing q cle of the VARTM process. For a large or complex composite part (with inserts, hybrid fabric systems, co-cured parts, etc.), multiple injection lines and vents could be used to improve the resin infusion. The flow distribution medium layer could also be placed in different patterns to create versatile resin infusion paths that can promote the resin infusion quality of a large or complex composite part. 

The battery jacket can be made of various components metal, paper, plastic, polymer films, plain or asphalt-lined cardboard, or foil in combination or alone. The jacket provides strength, protection, leakage prevention, electrical isolation, decoration, and a site for the manufacturer s label. In many manufacturers designs, the jacket is an integral part of the sealing system. It locks some seals in place, provides a vent path for the escape of gases, or acts as a supporting member to allow seals to flex under internal gas pressures. In the inside-out construction, the jacket was the container in which a carb on-wax collector was impact-molded (Fig. 8.4). 

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