Device and method for decorating plastic parts

Abstract

There is described an apparatus for performing the in-mold decoration method with an injection tool ( 1 ). The injection tool ( 1 ) has a first tool portion ( 11 ) having a first mold recess ( 13 ) and a second tool portion ( 12 ) having a second mold recess ( 15 ) corresponding to the first mold recess. The second tool portion ( 12 ) has at least one injection passage ( 12 e ), wherein a portion of an endless decorative film ( 16 ) can be arranged between the first tool portion ( 11 ) and the second tool portion ( 12 ). The mold recess ( 13 ) of the first tool portion ( 11 ) has a raised edge region ( 14 ) extending in a closed configuration around the mold recess ( 13 ) and having an end face ( 14 s ) which is flattened or rounded or pointed in cross-section. The second tool portion ( 12 ) has a corresponding end face ( 12 s ) parallel to the end face ( 14 s ) of the raised edge region ( 14 ). When the injection tool ( 1 ) is closed there is a spacing (s) between the end face ( 14 s ) of the raised edge region ( 14 ) of the first tool portion ( 11 ) and the corresponding end face ( 12 s ) of the second tool portion ( 12 ) at least over a subregion, wherein the spacing is sealed by the decorative film ( 16 ). A method for same is further described.

1 . An apparatus for performing an in-mold decoration method comprising an injection tool, wherein the injection tool has a first tool portion having a first mold recess and a second tool portion and the second tool portion or the first tool portion has at least one injection passage, wherein a portion of a decorative film can be arranged between the first tool portion and the second tool portion, and
 wherein the mold recess of the first tool portion has a raised edge region extending in a closed configuration around the mold recess and having an end face which is flattened or rounded or pointed in cross-section,   the second tool portion has an end face corresponding to the end face of the raised edge region, and   when the injection tool is closed, there is a spacing forming a gap between the end face of the raised edge region of the first tool portion and the corresponding end face of the second tool portion at least over a subregion, wherein the spacing is sealed by the decorative film.   
     
     
         2 . Apparatus as set forth in  claim 1  wherein the first tool portion is in the form of a movable mold insert. 
     
     
         3 . Apparatus as set forth in  claim 1 , wherein the second tool portion has the injection passage and is in the form of a fixed mold insert. 
     
     
         4 . Apparatus as set forth in  claim 1 , wherein, when the injection tool is closed, the spacing of the end face of the raised edge region and the corresponding end face of the second tool portion is less than 50% of the thickness of the provided decorative film. 
     
     
         5 . Apparatus as set forth in  claim 1 , wherein the spacing is in the range of between 20 μm and 50 μm. 
     
     
         6 . Apparatus as set forth in  claim 1 , wherein the apparatus has a supply roll which is associated with the injection tool and from which the decorative film in the form of a strip-shaped endless film can be unwound. 
     
     
         7 . Apparatus as set forth in  claim 6 , wherein, arranged downstream of the injection tool is a winding-on roll, onto which the residual decorative film can be wound. 
     
     
         8 . Apparatus as set forth in  claim 7 , wherein the apparatus has a film transport device which is associated with the injection tool and which cooperates or cooperate with the decorative film and/or the winding-on roll. 
     
     
         9 . Apparatus as set forth in  claim 8 , wherein the film transport device and/or the winding-on roll is in the form of a device cooperating with optical markings and/or mechanical markings. 
     
     
         10 . Apparatus as set forth in  claim 1 , wherein the injection tool has a plurality of mold inserts in the first tool portion and in the second tool portion. 
     
     
         11 . Apparatus as set forth in  claim 10 , wherein respectively corresponding mold inserts in the second tool portion are associated with the plurality of mold inserts in the first tool portion. 
     
     
         12 . Apparatus as set forth in  claim 10 , wherein the plurality of mold inserts are arranged in each tool portion in a matrix. 
     
     
         13 . Apparatus as set forth in  claim 10 , wherein one or more of the plurality of mold inserts is or are of such a configuration that one or more test pieces can be produced therein. 
     
     
         14 . An in-mold decoration method using an apparatus, wherein the apparatus has an injection tool including a first tool portion having a first mold recess and a second tool portion wherein the first or the second tool portion has an injection passage, wherein
 the following steps are cyclically performed:   a) providing a portion of the decorative film on the first tool portion or the second tool portion in such a way that, when the injection tool is closed, the decorative film lies on an end face of the raised edge region which delimits the first mold recess and which extends around the mold recess,   b) closing the injection tool to such an extent that in the region of the end face of the raised edge region between the first tool portion and the second tool portion there is a gap between the end face of the raised edge region of the first tool portion and the corresponding end face of the second tool portion at least over a subregion and the gap is sealed off by the interposed decorative film which is pinched in the region of the gap,   c) injecting a plastic melt through the injection passage into the injection tool, wherein the plastic melt is injected behind the decorative film in the region surrounded by the raised edge region without plastic melt passing through the sealed gap so that a decorated plastic part is produced,   d) opening the injection tool by moving the first and second tool portions relatively away from each other and removing the decorated plastic part from the injection tool, and   e) removing the residual portion of the decorative film and preparing a further portion of the decorative film.   
     
     
         15 . A method as set forth in  claim 14 , wherein, in step b), the decorative film is firstly partially severed by pinching and/or cutting upon cooperation of the raised edge region of the mold recess of the first tool portion with the corresponding end face of the second tool portion. 
     
     
         16 . A method as set forth in  claim 14 , wherein, upon pinching and/or severing of the decorative film in step b), the decorative film is compressed to less than 50% of its thickness. 
     
     
         17 . A method as set forth in  claim 14 , wherein the raised edge region of the first tool portion is at least region-wise in the form of a stamping edge. 
     
     
         18 . A method as set forth in  claim 14 , wherein, in step a), the decorative film is so arranged that its decoration is remote from the plastic melt which is injected in step c). 
     
     
         19 . A method as set forth in  claim 14 , wherein a lamination film is used as the decorative film. 
     
     
         20 . A method as set forth in  claim 19 , wherein a knitted fabric of natural fibers and/or synthetic fibers and/or paper is used as the lamination film. 
     
     
         21 . A method as set forth in  claim 19 , wherein the lamination film has a stretchability in the range of between 12% and 20%. 
     
     
         22 . A method as set forth in  claim 14 , wherein the lamination film is of a thickness in the range of between 20 μm and 500 μm. 
     
     
         23 . A method as set forth in  claim 14 , wherein an at least partially and/or region-wise transparent or translucent plastic melt is used.