Method of injection molding

Abstract

An injection molded article with which a sheet material is integrated is manufactured without causing damage to the sheet material. A molten resin injected into a mold cavity, passes smoothly a peripheral edge of the mold cavity, and flows into a groove portion without accumulating in the vicinity of the peripheral edge. When cooling the molten resin, the temperature of the molten resin in the groove decreases more quickly than the temperature of the molten resin in the mold cavity, because the volume of the groove portion is small. The viscosity of the molten resin is increased rapidly, preventing further molten resin from flowing into the groove portion. The sheet material in the vicinity of the peripheral edge is covered and protected against exposure to heat and/or pressure of the molten resin.

1 - 9 . (canceled) 
     
     
         10 . A method of injection molding wherein a molten resin injected into a mold cavity and a sheet material supplied in mold sections are integrated in said mold sections, and said molten resin integrated with said sheet material is molded by said mold sections, the method comprising:
 disposing said sheet material in said mold sections to expand from the interior of said mold cavity to the exterior of said mold cavity continuously;   fixing said sheet material to said mold sections;   injecting said molten resin into said mold cavity to mold an injection molded body made from the molten resin filled in said mold cavity and mold a protrusion made from the molten resin flowing out of the peripheral edge of said mold cavity, wherein said injection molded body is in contact with said sheet material in the interior of said mold cavity, said protrusion is in contact with said sheet material in the exterior of said mold cavity, and said protrusion has a predetermined thickness;   cooling said mold sections and increasing a resin viscosity of said protrusion more rapidly than a resin viscosity of said injection molded body in said mold sections due to the difference of the volume capacities between said protrusion and said injection molded body; and   applying a predetermined pressure to said molted resin injected into said mold cavity when the resin viscosity of said protrusion has increased to a predetermined value, and integrate said injection molded body and said protrusion with said sheet material in said mold sections.   
     
     
         11 . The method of injection molding as set forth in  claim 10 , including forming said resinous protrusion from the molten resin that has flowed into a groove or recess portion from said mold cavity, wherein said groove or recess portion is outside the peripheral edge of said mold cavity and extends along a surface of said sheet material in said mold sections. 
     
     
         12 . The method of injection molding as set forth in  claim 11 , wherein said molten resin moves smoothly in the vicinity of the peripheral edge of said mold cavity and flows into said groove or recess portion from said mold cavity. 
     
     
         13 . The method of injection molding as set forth in  claim 11 , wherein the fluidity of the resinous material of said protrusion is diminished by cooling said mold sections, and the diminished fluidity of the resinous material of said protrusion prevents a further volume of the molten resin from flowing into said groove or recess portion from the mold cavity. 
     
     
         14 . The method of injection molding as set forth in  claim 10 , wherein said sheet material is a decorative sheet made of an olefin-based thermoplastic elastomer. 
     
     
         15 . The method of injection molding as set forth in  claim 10 , wherein the fluidity of the resinous material in the vicinity of the peripheral edge of said mold cavity is diminished by cooling said mold sections, and the sheet material lying in the vicinity of the peripheral edge of said cavity mold comes to be covered by the resinous material of diminished fluidity or increased viscosity so that said sheet-like material is protected against exposure to heat and/or pressure in the vicinity of the peripheral edge of said cavity mold. 
     
     
         16 . The method of injection molding as set forth in  claim 11 , wherein said mold cavity is defined between a cavity surface of said cavity mold and a cavity surface of said core mold, and said core mold reciprocates relative to said cavity mold to define said cavity mold when closed against said cavity mold. 
     
     
         17 . The method of injection molding as set forth in  claim 16 , including supplying said sheet material to the parting surface of said cavity mold when said cavity mold and said core mold are separated, and then fixing said sheet material to the parting surface of said cavity mold by one or more clampers so said sheet material extends across the parting surface and the cavity surface of said cavity mold. 
     
     
         18 . The method of injection molding as set forth in  claim 17 , including fixing said sheet material to the parting surface of said cavity mold to seal the cavity surface of said cavity mold from the atmosphere, and then pre-shaping said sheet material by the cavity surface of said cavity mold by vacuum molding. 
     
     
         19 . The method of injection molding as set forth in  claim 17 , comprising:
 closing said core mold against said cavity mold and disposing said sheet material within said mold cavity, and, simultaneously, defining said groove or recess portion between the parting surface of said core mold and said sheet material extending outside said mold cavity, wherein said groove or recess portion has an opening in the peripheral edge of said mold cavity;   injecting a molten resin into said mold cavity defined between the cavity surface of said core mold and said sheet material disposed within said mold cavity and forming an injection molded body, wherein said injection molded body is in contact with said sheet material in said mold cavity, and filling said groove or recess portion with said molten resin to form a resinous protrusion having a predetermined thickness, wherein said resinous protrusion is in contact with said sheet material outside said mold cavity;   cooling said core mold and said cavity mold and increasing a resin viscosity of said protrusion more rapidly than a resin viscosity of said injection molded body in said mold sections due to the difference of the volume capacities between said protrusion and said injection molded body; and   applying a predetermined pressure to said molted resin injected into said mold cavity when the resin viscosity of said protrusion has increased to a predetermined value, and integrate said injection molded body and said protrusion with said sheet material in said mold sections.   
     
     
         20 . A method of injection molding for manufacturing an injection molded article with which a surface material is integrated, comprising:
 disposing a sheet material in said mold sections to expand from the interior of said mold cavity to the exterior of said mold cavity continuously;   fixing said sheet material to said mold sections;   injecting said molten resin into said mold cavity to mold an injection molded body made from the molten resin filled in said mold cavity and mold a protrusion made from the molten resin flowing out of the peripheral edge of said mold cavity, wherein said injection molded body is in contact with said sheet material in the interior of said mold cavity, said protrusion is in contact with said sheet-like material in the exterior of said mold cavity, and said protrusion has a predetermined thickness;   cooling said mold sections and increasing a resin viscosity of said protrusion more rapidly than a resin viscosity of said injection molded body in said mold sections due to the difference of the volume capacities between said protrusion and said injection molded body;   applying a predetermined pressure to said molted resin injected into said mold cavity when the resin viscosity of said protrusion has increased to a predetermined value, and integrate said injection molded body and said protrusion with said sheet material in said mold sections; and   taking said injection molded body out of said mold sections, wherein said injection molded body has been integrated with said sheet material and molded into a predetermined shape, and cutting out said protrusion together with the sheet material extending outside said mold cavity from said injection molded body.   
     
     
         21 . The method of injection molding as set forth in  claim 20 , wherein said resinous protrusion is formed from the molten resin that has flowed into a groove or recess portion from said mold cavity, and said groove or recess portion is located outside the peripheral edge of said mold cavity and extends along a surface of said material in said mold sections. 
     
     
         22 . The method of injection molding as set forth in  claim 21 , wherein said molten resin moves smoothly in the vicinity of the peripheral edge of said mold cavity and flows into said groove or recess portion from said mold cavity. 
     
     
         23 . The method of injection molding as set forth in  claim 21 , wherein the fluidity of the resinous material of said protrusion is diminished by cooling said mold sections, and the diminished fluidity of the resinous material of said protrusion prevents a further volume of the molten resin from flowing into said groove or recess portion from the mold cavity. 
     
     
         24 . The method of injection molding as set forth in  claim 20 , wherein said sheet material is a decorative sheet made of an olefin-based thermoplastic elastomer. 
     
     
         25 . The method of injection molding as set forth in  claim 20 , wherein the fluidity of the resinous material in the vicinity of the peripheral edge of said mold cavity is diminished by cooling said mold sections, and the sheet material lying in the vicinity of the peripheral edge of said cavity mold comes to be covered by the resinous material of diminished fluidity or increased viscosity so that said sheet material is protected against exposure to heat and/or pressure in the vicinity of the peripheral edge of said cavity mold. 
     
     
         26 . The method of injection molding as set forth in  claim 21 , wherein said mold cavity is defined between a cavity surface of said cavity mold and a cavity surface of said core mold, and said core mold reciprocates relative to said cavity mold to define said cavity mold when closed against said cavity mold. 
     
     
         27 . The method of injection molding as set forth in  claim 26 , including supplying said sheet material to the parting surface of said cavity mold when said cavity mold and said core mold are separated, and then fixing said sheet material to the parting surface of said cavity mold by one or more clampers so the sheet material extends across the parting surface and the cavity surface of said cavity mold. 
     
     
         28 . The method of injection molding as set forth in  claim 27 , including fixing said sheet material to the parting surface of said cavity mold to seal the cavity surface of said cavity mold from the atmosphere, and then pre-shaping said sheet material by the cavity surface of said cavity mold by vacuum molding. 
     
     
         29 . The method of injection molding as set forth in  claim 27 :
 closing said core mold against said cavity mold and disposing said sheet material within said mold cavity, and, simultaneously, defining said groove or recess portion between the parting surface of said core mold and said sheet material extending outside said mold cavity, wherein said groove or recess portion has an opening in the peripheral edge of said mold cavity;   injecting a molten resin into said mold cavity defined between the cavity surface of said core mold and said sheet material disposed within said mold cavity and forming an injection molded body, wherein said injection molded body is in contact with said sheet material in said mold cavity, and filling said groove or recess portion with said molten resin to form a resinous protrusion having a predetermined thickness, wherein said resinous protrusion is in contact with said sheet material outside said mold cavity;   cooling said core mold and said cavity mold and increasing a resin viscosity of said protrusion more rapidly than a resin viscosity of said injection molded body in said mold sections due to the difference of the volume capacities between said protrusion and said injection molded body; and   applying a predetermined pressure to said molted resin injected into said mold cavity when the resin viscosity of said protrusion has increased to a predetermined value, and integrate said injection molded body and said protrusion with said sheet-like material in said mold sections; and   taking said injection molded body out of said mold sections, wherein said injection molded body has been integrated with said sheet material and molded into a predetermined shape, and cutting out said protrusion together with the sheet material extending outside said mold cavity from said injection molded body.   
     
     
         30 . The method of injection molding as set forth in  claim 29 , wherein said injection molded article is an interior component for vehicles. 
     
     
         31 . The method of injection molding as set forth in  claim 14 , wherein the fluidity of the resinous material in the vicinity of the peripheral edge of said mold cavity is diminished by cooling said mold sections, and the sheet-like material lying in the vicinity of the peripheral edge of said cavity mold comes to be covered by the resinous material of diminished fluidity or increased viscosity so that said sheet material is protected against exposure to heat and/or pressure in the vicinity of the peripheral edge of said cavity mold. 
     
     
         32 . The method of injection molding as set forth in  claim 18 , comprising:
 closing said core mold against said cavity mold and disposing said sheet material within said mold cavity, and, simultaneously, defining said groove or recess portion between the parting surface of said core mold and said sheet material extending outside said mold cavity, wherein said groove or recess portion has an opening in the peripheral edge of said mold cavity;   injecting a molten resin into said mold cavity defined between the cavity surface of said core mold and said sheet material disposed within said mold cavity and forming an injection molded body, wherein said injection molded body is in contact with said sheet material in said mold cavity, and filling said groove or recess portion with said molten resin to form a resinous protrusion having a predetermined thickness, wherein said resinous protrusion is in contact with said sheet material outside said mold cavity;   cooling said core mold and said cavity mold and increasing a resin viscosity of said protrusion more rapidly than a resin viscosity of said injection molded body in said mold sections due to the difference of the volume capacities between said protrusion and said injection molded body; and   applying a predetermined pressure to said molted resin injected into said mold cavity when the resin viscosity of said protrusion has increased to a predetermined value, and integrate said injection molded body and said protrusion with said sheet material in said mold sections.   
     
     
         33 . The method of injection molding as set forth in  claim 23 , wherein the fluidity of the resinous material in the vicinity of the peripheral edge of said mold cavity is diminished by cooling said mold sections, and the sheet material lying in the vicinity of the peripheral edge of said cavity mold comes to be covered by the resinous material of diminished fluidity or increased viscosity so that said sheet material is protected against exposure to heat and/or pressure in the vicinity of the peripheral edge of said cavity mold. 
     
     
         34 . The method of injection molding as set forth in  claim 24 , wherein the fluidity of the resinous material in the vicinity of the peripheral edge of said mold cavity is diminished by cooling said mold sections, and the sheet material lying in the vicinity of the peripheral edge of said cavity mold comes to be covered by the resinous material of diminished fluidity or increased viscosity so that said sheet material is protected against exposure to heat and/or pressure in the vicinity of the peripheral edge of said cavity mold. 
     
     
         35 . The method of injection molding as set forth in  claim 28 ,
 closing said core mold against said cavity mold and disposing said sheet material within said mold cavity, and, simultaneously, defining said groove or recess portion between the parting surface of said core mold and said sheet-like material extending outside said mold cavity, wherein said groove or recess portion has an opening in the peripheral edge of said mold cavity;   injecting a molten resin into said mold cavity defined between the cavity surface of said core mold and said sheet material disposed within said mold cavity and forming an injection molded body, wherein said injection molded body is in close contact with said sheet-like material in said mold cavity, and filling said groove or recess portion with said molten resin to form a resinous protrusion having a predetermined thickness, wherein said resinous protrusion is in contact with said sheet material outside said mold cavity;   cooling said core mold and said cavity mold and increasing a resin viscosity of said protrusion more rapidly than a resin viscosity of said injection molded body in said mold sections due to the difference of the volume capacities between said protrusion and said injection molded body; and   applying a predetermined pressure to said molted resin injected into said mold cavity when the resin viscosity of said protrusion has increased to a predetermined value, and integrate said injection molded body and said protrusion with said sheet material in said mold sections; and   taking said injection molded body out of said mold sections, wherein said injection molded body has been integrated with said sheet material and molded into a predetermined shape, and cutting out said protrusion together with the sheet material extending outside said mold cavity from said injection molded body.