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US 5,308,420 AGranted
EVA insole manufacturing process
OwnerKuo-Nan Yanginventor
Life of this patent
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Abstract
An EVA insole manufacturing process includes a step of making a molding by injecting molding an EVA resin and foaming agent mixture without through crushing or cutting procedure, and a step of heating the molding thus obtained in a mold so that it forms into a predetermined shape. Two or more moldings which respectively contain a different concentration of foaming agent or a different pigment color may be molded together so as to produce an insole which has different hardness and color at different parts thereof.
Claims1
An EVA insole manufacturing process comprising:
- (i) forming a first molding and a second molding respectively by the steps of:
- (a) mixing an ethylene vinyl acetate resin with a foaming agent according to predetermined proportions, thereby forming first and second mixtures, the concentration of the foaming agent being different in each mixture;
- (b) injection molding the resulting mixtures into the first molding and the second molding, so that the first molding has an opening for receiving the second molding;
- (ii) placing the second molding within the opening of the first molding and heat foaming both the first and second moldings together in a mold to form an integral molding;
- and
- (iii) form setting the integral molding into an insole.
3 more elements
Dependencies are inferred from the claim text.