Light irradiation molding apparatus and light irradiation molding method

Abstract

A light irradiation molding apparatus includes a pair of rubber die units, which are formed of a rubber material having a property of transmitting light therethrough and form a cavity between facing sides which face each other, and a light irradiation device, which applies light to a particulate or solid thermoplastic resin arranged in the cavity through surfaces of a pair of the rubber die units. In the light irradiation molding apparatus a pair of the rubber die units are made to come close to each other while the thermoplastic resin arranged in the cavity is molten by the light applied from the light irradiation device, and a molded article of the thermoplastic resin is formed in the cavity having a reduced volume.

1 . A light irradiation molding apparatus comprising:
 a pair of rubber die units which are formed of a rubber material having a property of transmitting light therethrough and form a cavity between facing sides which face each other, and   a light irradiation means for applying light to a particulate or solid thermoplastic resin arranged in the cavity through surfaces of a pair of the rubber die units,   wherein a pair of the rubber die units are made to come close to each other to reduce a volume of the cavity while the thermoplastic resin arranged in the cavity is molten by applying the light emitted from the light irradiation means, whereby a molded article of the thermoplastic resin is formed in the cavity having a reduced volume.   
     
     
         2 . The light irradiation molding apparatus according to  claim 1 , comprising:
 a vacuum means for vacuating the cavity,   wherein a pressure in the cavity is made lower than a pressure outside a pair of the rubber die units by the vacuum means to generate a suction force on a pair of the rubber die units, whereby a pair of the rubber die units are made to come close to each other when the thermoplastic resin is molten.   
     
     
         3 . The light irradiation molding apparatus according to  claim 1 ,
 wherein a pair of the rubber die units are set in an initial position by engaging an engaging protrusion formed in one of the rubber die units with a depression to be engaged formed in the other rubber die unit before a pair of the rubber die units are made to come close to each other, and   a parting plane formed between a pair of the rubber die units is entirely closed by the engaging protrusion and the depression to be engaged.   
     
     
         4 . The light irradiation molding apparatus according to  claim 1 ,
 wherein a pair of the rubber die units are set in an initial position by arranging a cavity-forming protrusion formed in one of the rubber die units in a cavity-forming depression formed in the other rubber die unit before a pair of the rubber die units are made to come close to each other, and   a parting plane formed between a pair of the rubber die units is entirely closed by a resin tape which is pasted to an entire circumference of the parting plane.   
     
     
         5 . The light irradiation molding apparatus according to  claim 1 ,
 wherein one of a pair of the rubber die units comprises a cavity-forming protrusion which forms a reverse face of the molded article, an annular engagement depression which is formed on an entire circumference of a fringe area of the cavity-forming protrusion, and an annular outer circumference protrusion which is projected from an entire circumference of a fringe area of the annular engagement depression;   the other rubber die unit comprises a cavity-forming depression which has the cavity-forming protrusion arranged therein to form a designed face of the molded article, and an annular inner circumference protrusion which is projected from an entire circumference of a fringe area of the cavity-forming depression and is engaged with an inner circumferential surface of an annular outer circumference protrusion so as to be arranged in the annular engagement depression;   the cavity is continuously formed between an apical surface of the cavity-forming protrusion and a bottom face of the cavity-forming depression, between an outer circumferential surface of the cavity-forming protrusion and an inner circumferential surface of the annular inner circumference protrusion, and between a bottom face of the annular engagement depression and an apical surface of the annular inner circumference protrusion, in an initial position before a pair of the rubber die units are made to come close to each other;   a suction port which opens in an apical surface of the cavity-forming protrusion, and suction gates which open in a bottom face of the annular engagement depression, are formed in one of a pair of the rubber die units; and   the suction port and the suction gates are communicated with a vacuum suction pathway for vacuating by means of the vacuum means.   
     
     
         6 . The light irradiation molding apparatus according to  claim 5 ,
 wherein the suction port further serves as an input port for throwing the particulate thermoplastic resin into the cavity.   
     
     
         7 . The light irradiation molding apparatus according to  claim 5 ,
 wherein a pair of the rubber die units are made to come close to each other until a bottom face of the annular engagement depression in one of the rubber die units comes into contact with an apical surface of the annular inner circumference protrusion in the other rubber die unit, and the thermoplastic resin is supplied from a surplus space formed between the bottom face of the annular engagement depression and the apical surface of the annular inner circumference protrusion to a stand-up wall space formed between the outer circumferential surface of the cavity-forming protrusion and the inner circumferential surface of the annular inner circumference protrusion so as to form the molded article.   
     
     
         8 . The light irradiation molding apparatus according to  claim 5 ,
 wherein the suction gate has a smaller fluid passage cross-sectional area than that of the suction port, and is formed in an open state at a position facing the bottom face of the cavity-forming depression and a position facing the annular inner circumference protrusion on the bottom face of the annular engagement depression.   
     
     
         9 . The light irradiation molding apparatus according to  claim 2 ,
 wherein one of a pair of the rubber die units comprises a cavity-forming protrusion which forms a reverse face of the molded article, an annular engagement depression which is formed on an entire circumference of a fringe area of the cavity-forming protrusion, and an annular outer circumference protrusion which is projected from an entire circumference of a fringe area of the annular engagement depression;   the other rubber die unit comprises a cavity-forming depression which has the cavity-forming protrusion arranged therein to form a designed face of the molded article, and an annular inner circumference protrusion which is projected from an entire circumference of a fringe area of the cavity-forming depression and is engaged with an inner circumferential surface of an annular outer circumference protrusion so as to be arranged in the annular engagement depression;   the cavity is continuously formed between an apical surface of the cavity-forming protrusion and a bottom face of the cavity-forming depression, between an outer circumferential surface of the cavity-forming protrusion and an inner circumferential surface of the annular inner circumference protrusion, and between a bottom face of the annular engagement depression and an apical surface of the annular inner circumference protrusion, in an initial position before a pair of the rubber die units are made to come close to each other;   a suction port which opens in an apical surface of the cavity-forming protrusion, and suction gates which open in a bottom face of the annular engagement depression, are formed in one of a pair of the rubber die units;   the suction port and the suction gates are communicated with a vacuum suction pathway for vacuating by means of the vacuum means;   the light irradiation means applies light on the outside surface of the other of the rubber die units, and   the light irradiation means prevent the suction gate from closing by melting and filling the particulate thermoplastic resin arranged in the cavity on the cavity-forming depression side first so that the vacuum suction by the vacuum means is continued until the thermoplastic resin is filled in the whole cavity.   
     
     
         10 . The light irradiation molding apparatus according to  claim 1 ,
 wherein the light irradiation means apply the light, moving partially, sequentially and relatively from one side of the outside surface in the other of a pair of the rubber die units to the other side, and   the thermoplastic resin is sequentially filled in the cavity from one side thereof to the other side.   
     
     
         11 . A light irradiation molding method comprising:
 using a pair of rubber die units which are formed of a rubber material having a property of transmitting light therethrough and form a cavity between facing sides which face each other, and a light irradiation means for applying light to a particulate or solid thermoplastic resin arranged in the cavity through surfaces of a pair of the rubber die units;   making a pair of the rubber die units to come close to each other to reduce a volume of the cavity, while the thermoplastic resin arranged in the cavity is molten by applying light emitted from the light irradiation means; and   forming a molded article of the thermoplastic resin in the cavity having a reduced volume.   
     
     
         12 . The light irradiation molding method according to  claim 11 ,
 wherein a vacuum means for vacuating the cavity is used; and   a pressure inside the cavity is made lower than a pressure outside a pair of the rubber die units by the vacuum means to generate a suction force on a pair of the rubber die units, whereby a pair of the rubber die units are made to come close to each other when the thermoplastic resin is molten.   
     
     
         13 . The light irradiation molding method according to  claim 12 ,
 wherein the light emitted from the light irradiation means is applied to the outside surface of the other of a pair of the rubber die units, and the suction gates is prevented from closing by melting and filling the particulate thermoplastic resin arranged in the cavity from the cavity-forming depression side first so that the vacuum suction by the vacuum means is continued until the thermoplastic resin is filled in the whole cavity.   
     
     
         14 . The light irradiation molding method according to  claim 12 ,
 wherein the light emitted from the light irradiation means is applied, moving partially and sequentially from one side of the outside surface of the other of the rubber die units to the other side, and   the thermoplastic resin is sequentially filled in the cavity from one side thereof to the other side.   
     
     
         15 . The light irradiation molding apparatus according to  claim 2 ,
 wherein a pair of the rubber die units are set in an initial position by engaging an engaging protrusion formed in one of the rubber die units with a depression to be engaged formed in the other rubber die unit before a pair of the rubber die units are made to come close to each other, and   that a parting plane formed between a pair of the rubber die units is entirely closed by the engaging protrusion and the depression to be engaged.   
     
     
         16 . The light irradiation molding apparatus according to  claim 2 ,
 wherein a pair of the rubber die units are set in an initial position by arranging a cavity-forming protrusion formed in one of the rubber die units in a cavity-forming depression formed in the other rubber die unit before a pair of the rubber die units are made to come close to each other, and   a parting plane formed between a pair of the rubber die units is entirely closed by a resin tape which is pasted to an entire circumference of the parting plane.   
     
     
         17 . The light irradiation molding apparatus according to  claim 2 ,
 wherein one of a pair of the rubber die units comprises a cavity-forming protrusion which forms a reverse face of the molded article, an annular engagement depression which is formed on an entire circumference of a fringe area of the cavity-forming protrusion, and an annular outer circumference protrusion which is projected from an entire circumference of a fringe area of the annular engagement depression;   the other rubber die unit comprises a cavity-forming depression which has the cavity-forming protrusion arranged therein to form a designed face of the molded article, and an annular inner circumference protrusion which is projected from an entire circumference of a fringe area of the cavity-forming depression and is engaged with an inner circumferential surface of an annular outer circumference protrusion so as to be arranged in the annular engagement depression;   the cavity is continuously formed between an apical surface of the cavity-forming protrusion and a bottom face of the cavity-forming depression, between an outer circumferential surface of the cavity-forming protrusion and an inner circumferential surface of the annular inner circumference protrusion, and between a bottom face of the annular engagement depression and an apical surface of the annular inner circumference protrusion, in an initial position before a pair of the rubber die units are made to come close to each other;   a suction port which opens in an apical surface of the cavity-forming protrusion, and suction gates which open in a bottom face of the annular engagement depression, are formed in one of a pair of the rubber die units; and   the suction port and the suction gates are communicated with a vacuum suction pathway for vacuating by means of the vacuum means.