Method for manufacturing laminate-molded products and apparatus therefor

A method for manufacturing a laminate-molded product, comprising the steps of:

• positioning a sheet of skin material between a first mold and a second mold, one of said first mold and said second mold having a mold cavity,
• holding the thus positioned sheet of skin material under tension,
• moving said second mold toward said first mold and inserting a portion of the thus held sheet of skin material into said mold cavity,
• varying the tension on the thus held sheet of skin material as said portion of the thus held sheet of skin material is inserted into said mold cavity,
• injecting melted resin into said mold cavity and into contact with said portion of the thus held sheet of skin material, and
• solidifying the thus injected melted resin so as to form a molded article which is a laminate of said portion of said sheet of skin material and the thus solidified resin;
• wherein said step of varying the tension comprises changing said tension in consonance with a speed at which said portion of the thus held sheet of skin material is inserted into said mold cavity;
• wherein said step of moving said second mold toward said first mold comprises moving said second mold toward said first mold at a high speed from a first predetermined position to a second predetermined position and then at a lower speed from said second predetermined position to a third predetermined position, such that at said third predetermined position said second mold is positioned near said thus held sheet of skin material;
• wherein said second mold is held at said third predetermined position while said step of injecting melted resin is initiated and an initial quantity of said melted resin is injected into said mold cavity.

A method for manufacturing a laminate-molded product, comprising the steps of:

• positioning a sheet of skin material between a first mold and a second mold, one of said first mold and said second mold having a mold cavity,
• holding the thus positioned sheet of skin material under tension,
• moving said second mold toward said first mold and inserting a portion of the thus held sheet of skin material into said mold cavity,
• varying the tension on the thus held sheet of skin material as said portion of the thus held sheet of skin material is inserted into said mold cavity.
• injecting melted resin into said mold cavity and into contact with said portion of the thus held sheet of skin material, and
• solidifying the thus injected melted resin so as to form a molded article which is a laminate of said portion of said sheet of skin material and the thus solidified resin;
• wherein said step of moving said second mold toward said first mold comprises moving said second mold from a first predetermined position to a second predetermined position;
• wherein said second mold is held at said second predetermined position while said step of injecting a melted resin is initiated and an initial quantity of said melted resin is injected into said mold cavity;
• and
• wherein, after said initial quantity of said melted resin has been injected into said mold cavity, said step of moving said second mold toward said first mold further comprises moving said second mold from said second predetermined position to a mold closed position as said portion of the thus held sheet of skin material is inserted into said mold cavity and said step of injecting said melted resin into said mold cavity is completed.

Apparatus for manufacturing a laminate-molded product, comprising:

• a mold clamping device;
• a first mold and a second mold that are attached to said clamping device, one of said first and second molds having a mold cavity;
• a skin material holding unit for applying tension to a sheet of skin material positioned between said first mold and said second mold;
• a detector for detecting when said first and second molds are clamped by said mold clamping device and for providing a signal representative thereof;
• means for moving said second mold toward said first mold, after said first and second molds are clamped by said mold clamping device, so as to insert a portion of said sheet of skin material into said mold cavity;
• an injection device for injecting melted resin into said mold cavity and into contact with said portion of the thus tensioned sheet of skin material;
• and
• a skin material holding controller for receiving said signal from said detector and, upon receipt of said signal from said detector, outputting to said skin material holding unit a command to change a tension that is applied to said sheet of skin material as said portion of said sheet of skin material is inserted into said mold cavity.

A method for manufacturing a laminate-molded product, comprising the steps of:

• positioning a sheet of skin material between a first mold and a second mold, one of said first mold and said second mold having a mold cavity,
• providing in a cylinder of an injection device a mixture of a melted core resin and a foaming agent at a first temperature in a non-foamed state, said foaming agent having a thermal decomposition temperature, said first temperature being lower than said thermal decomposition temperature of said foaming agent,
• clamping said first mold and said second mold with at least a portion of the thus positioned sheet of skin material being exposed to said mold cavity,
• passing a first portion of said mixture from said cylinder through a heating element in which said first portion of said mixture is heated to a second temperature which is higher than said first temperature and lower than said thermal decomposition temperature of said foaming agent,
• injecting said first portion of said mixture, having said second temperature and being in a non-foaming state, into said mold cavity and into contact with said portion of said sheet of skin material,
• solidifying the resin of the thus injected first portion of said mixture so as to form a first non-foamed skin layer which is bonded to said sheet of skin material,
• passing a second portion of said mixture from said cylinder through said heating element in which said second portion is heated to a third temperature which is higher than said thermal decomposition temperature of said foaming agent,
• injecting said second portion, having said third temperature and being in a foaming state, into said mold cavity and into contact with said first portion of said mixture,
• solidifying the resin of the thus injected second portion so as to form a foamed core which is bonded to said non-foamed skin layer,
• passing a third portion of said mixture from said cylinder through said heating element in which said third portion is heated to a fourth temperature which is higher than said first temperature and lower than said thermal decomposition temperature of said foaming agent,
• injecting said third portion, having said fourth temperature and being in a non-foaming state, into said mold cavity and into contact with said foamed core, and
• solidifying the resin of the thus injected third portion so as to form a second non-foamed skin layer which is bonded to said foamed core in order to form a molded article which is a laminate of said portion of said sheet of skin material and the thus solidified resin of said first, second, and third portions.

A method for manufacturing a laminate-molded product, comprising the steps, in any suitable order, of:

• positioning a sheet of skin material between a first mold and a second mold, one of said first mold and said second mold having a mold cavity,
• clamping said first mold and said second mold with at least a portion of the thus positioned sheet of skin material being exposed to said mold cavity,
• providing a mixture of a core resin and a foaming agent, said core resin having a melting temperature, said foaming agent having a thermal decomposition temperature which is higher than said melting temperature,
• heating a first portion of said mixture to a first temperature which is higher than said melting temperature of said core resin and lower than said thermal decomposition temperature of said foaming agent,
• injecting said first portion, having said first temperature and being in a non-foaming state, into said mold cavity and into contact with said portion of said sheet of skin material,
• solidifying the resin of the thus injected first portion so as to form a first non-foamed skin layer which is bonded to said sheet of skin material,
• heating a second portion of said mixture to a second temperature which is higher than said thermal decomposition temperature of said foaming agent,
• injecting said second portion, having said second temperature and being in a foaming state, into said mold cavity and into contact with said first portion,
• solidifying the resin of the thus injected second portion so as to form a foamed core which is bonded to said non-foamed skin layer,
• heating a third portion of said mixture to a third temperature which is higher than said melting temperature of said core resin and lower than said thermal decomposition temperature of said foaming agent,
• injecting said third portion, having said third temperature and being in a non-foaming state, into said mold cavity and into contact with said foamed core, and
• solidifying the resin of the thus injected third portion so as to form a second non-foamed skin layer which is bonded to said foamed core in order to form a molded article which is a laminate of said portion of said sheet of skin material and the thus solidified resin of said first, second, and third portions.