Method of reducing internal stresses and improving the mechanical properties of injection molded thermoplastic resins
AssigneeSunds AB
InventorsJosef Kubat, Jan K. Djurner
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Abstract
A method of reducing internal stresses in and improving the mechanical properties of injection molded articles made of thermoplastic resins is disclosed wherein under in other respects normal injection molding conditions thermoplastic resins are injection molded at high injection and holding pressures within the range 250-800 MPa.
Claims8
In a method of injection molding a thermoplastic resin under conditions of melt temperature, mold temperature, injection time, holding time, and cooling time appropriate for said thermoplastic resin, the improvement comprising carrying out the injection molding at injection and holding pressures from 250-800 MPa, whereby the molded thermoplastic resin has reduced internal stresses and an essentially reduced tendency to mold shrinkage, warping, crazing and cracking, post-shrinkage and time-dependent deformation.
Dependencies are inferred from the claim text.