e mould.Р5.2、Ejection techniquesРWhen a molding cools,it contracts by an amount depending on the material being processed.For a molding which has no internal form,for example,a solid rectangular block,the molding will shrink away from the cavity walls,thereby permitting a simple ejection technique to be adopted.However,when the molding has internal form,the molding,as it cools,will shrink onto the core and some positive type of ejection is necessary.РThe designer has several ejection techniques from which to choose,but in general,the choice will be restricted depending upon the shape of the molding.The basic ejection techniques are as follows:(ⅰ)pin ejection(ⅱ)sleeve ejection(ⅲ)stripper plate ejection and(Ⅳ)air ejection.РFigure 2-1aРFigure 2-1bРFigure 3-1РFigure 3-2РFigure 4-1aРFigure 4-1b
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