Multi-layer laminated preform and method of its manufacture

Abstract

A blank ( 2 ) is molded for the manufacture of a multi-layer preform ( 1 ). The blank possesses protrusions ( 5 ). After the protrusions ( 5 ) have been brought to a plasticized state under the action of heat, those surfaces that contain protrusions ( 5 ) are covered by a layer of plasticized material. The blank ( 2 ) becomes connected to the layer ( 6 ) in the area of the protrusions ( 5 ). After cooling of the preform created from the blank ( 2 ) and the layer ( 6 ), the blank ( 2 ) will be connected with the layer ( 6 ) by means of microweld positions ( 7 ) in the area of the said protrusions ( 5 ). With that, delamination of the preform ( 1 ) during further processing or use-will be effectively prevented.

What is claimed is:  
     
         1 . A method of manufacturing a multi-layer laminated preform made of a plastic comprising the steps of: 
 (a) providing a blank having at least one area of protrusion on its surface;    (b) heating-said surface of the blank so as to melt or plasticize the protrusions;    (c) applying a plasticized or liquid layer of a plastic onto the surface of the blank and forming spot or zone shaped welding positions at least between the protrusion and the adjacent surface of the layer to produce a preform; and    (d) cooling the preform and solidifying the weld positions.    
     
     
         2 . A method according to    claim 1   , wherein the blank in step: 
 (a) is molded as a hollow body and is provided with protrusion on its outer surface.    
     
     
         3 . A method according to    claim 2   , wherein the blank is molded in an injection molding tool which has a surface structure that molds the protrusions.  
     
     
         4 . A method according to    claim 1   , wherein the blank in step: 
 (a) is molded as a hollow body and is provided with protrusion on its inner surface.    
     
     
         5 . A method according to    claim 2   , wherein the blank is molded in an injection molding tool which has a surface structure that molds the protrusions.  
     
     
         6 . A method according to    claim 1   , wherein the blank in step: 
 (a) is molded as a hollow body and is provided with protrusion on its inner and on its outer surface.    
     
     
         7 . A method according to    claim 2   , wherein the blank is molded in an injection molding tool which has a surface structure that molds the protrusions.  
     
     
         8 . A method according to    claim 1   , wherein the protrusions of the blank are melted or plasticized by means of infra-red radiation.  
     
     
         9 . A method according to    claim 1   , wherein the protrusions of the blank are melted or plasticized by a gas flame.  
     
     
         10 . A method according to    claim 1   , wherein the protrusions of the blank are melted or plasticized by means of induction heating, corona discharge or high-frequency energy.  
     
     
         11 . A method according to    claim 1   , wherein the plasticized or liquid layer of a plastic that is applied onto the surface of the blank in step (c) is hot and wherein the heating of step (b) is done at the same time by applying additional heat energy so the protrusions are melted or plasticized.  
     
     
         12 . A method according to    claim 1   , wherein the protrusions on the blank in step (a) are created by mechanically treating the surface of the blank.  
     
     
         13 . A method according to    claim 12   , wherein the protrusions on the blank are ground by means of an abrasive tool.  
     
     
         14 . A method according to    claim 12   , wherein the protrusions on the blank are stamped.  
     
     
         15 . A method according to    claim 10   , wherein the protrusions on the blank are created by means of incisions.  
     
     
         16 . A method according to    claim 1   , wherein the protrusions on the blank are approximately vertical in relation to the surface of the blank and have an approximate circular cross section.  
     
     
         17 . A method according to    claim 1   , wherein the protrusions on the blank possess a scale-like structure.  
     
     
         18 . A preform made from a blank having one or more covering layers comprising: 
 (a) a blank provided with protrusion on at least one side; and    (b) at least one cover layer 
 (1) engaging the side of the blank with the protrusions, and  
 (2) forming a connecting zone by a plurality of microweld positions.  
   
     
     
         19 . A preform according to    claim 18   , wherein the microweld positions are located-in the area of the protrusions of the blank and the surface of the cover layer has complementary depressions for engaging the protrusions on the blank.  
     
     
         20 . A preform according to    claim 19   , wherein the blank has an inner surface and an outer surface, the protrusions are on its outer surf ace and the cover layer engages the outer surface.  
     
     
         21 . A preform according to    claim 19   , wherein the blank has an inner surface and an outer surface, the protrusions are on its inner surface and the cover layer engages the inner surface.  
     
     
         22 . A preform according to    claim 19   , wherein the blank has an inner surface and an outer surface, the protrusions are on its inner and outer surfaces and cover layers engage the inner and the outer surfaces.  
     
     
         23 . A preform according to    claim 18   , wherein the connecting zone is formed by protrusions and the protrusions extend approximately vertically to said connecting zone and have an approximate circular cross section.  
     
     
         24 . A preform according to    claim 18   , wherein the connecting zone is formed by protrusions possessing a scalelike structure.  
     
     
         25 . A preform according to    claim 18   , wherein the protrusions have a height of about 0.25 to 1.5 mm and more preferably 0.75 mm, and a circular cross-sectional area of about 0.5 to about 44 mm 2  and more preferably 5-7 mm 2 .  
     
     
         26 . A method of making a closeable container comprising the steps of: 
 (a) providing a blank having at least one area of protrusions on its surface;    (b) heating the surface of the blank so as to melt or plasticize the protrusions;    (c) applying a plasticized or liquid layer of a plastic material onto the surface of the blank and forming spot or zone shaped welding positions at least between the protrusions and the adjacent surface of the layer to form a preform;    (d) cooling the preform and solidifying the weld positions; and    (e) molding the container from the preform.    
     
     
         27 . A method of making a container according to    claim 26   , wherein the preform is provided at its open end with a mouth and a finish portion.  
     
     
         28 . A method of making a container according to    claim 26   , wherein the finish of the preform is molded by injection molding of the preform.  
     
     
         29 . A method of making a container according to    claim 26   , wherein the finish of the preform is formed in a separate step subsequent to injection casting of the preform.  
     
     
         30 . A method of making a container according to    claim 26   , wherein the finish of the preform is applied to an area of the blank that is not covered by the layer.  
     
     
         31 . A method of making a container according to    claim 26   , wherein the container is molded from the preform by means of blow molding.  
     
     
         32 . A method of making a container according to    claim 26   , wherein the container is molded from the preform by means of a stretch blow molding method.  
     
     
         33 . A method of making a container according to    claim 26   , wherein the container is molded by injection blow molding prior to cooling from the preform.  
     
     
         34 . A container having a mouth area, a cylindrical body connected to the mouth area, and a base connected to the body, said container comprising at least two layers wherein the adjacent surfaces of two layers engage with one another and form a connecting zone, said connecting zone being formed by a plurality of microweld positions.  
     
     
         35 . A container according to    claim 34   , wherein the microweld positions are located in the area of the protrusions of one layer and the protrusions engage complementary depressions on the surface of the other layer.  
     
     
         36 . A container according to    claim 35   , wherein the connecting zone is formed of protrusions and the protrusions extend approximately vertically in relation to the connecting zone and have approximately a circular cross section.  
     
     
         37 . A container according to    claim 36   , wherein the connecting zone is formed of protrusions having a scalelike structure.  
     
     
         38 . A container according to    claim 34   , wherein the container is provided with a thread in its mouth area.  
     
     
         39 . A container according to    claim 34   , wherein the density of the welding positions is 3 per cm 2  to 80 per cm 2 .  
     
     
         40 . A container according to    claim 39   , wherein the density of the welding positions is about 8 per cm 2 .  
     
     
         41 . A container according to    claim 39   , wherein the total surface area of the welding position is about 5% to about 50% of the total surface area.  
     
     
         42 . Method of manufacturing a multi-laminated preform made of plastic, comprising the steps of 
 (a) providing a blank    (b) heating at least one surface of said blank by applying heat in a pattern, so as to melt or plasticize the surface in a regular pattern of limited surface zones or spots    (c) applying a plasticized or liquid layer of a plastic onto the surface of the blank and forming spot or zone shaped welding positions at least between the protrusions and the adjacent surface of the layer to produce a preform; and    (d) cooling the preform and solidifying the weld positions.    
     
     
         43 . Method according to    claim 41   , wherein the heat pattern is generated by a IR radiation source radiating through a mask.  
     
     
         44 . A method of making a closeable container comprising the steps of: 
 (a) providing a blank    (b) heating at least one surface of said blank by applying heat in a pattern, so as to melt or plasticize the surface in a regular pattern of limited surface zones or spots    (c) applying a plasticized or liquid layer of a plastic material onto the surface of the blank and forming spot or zone shaped welding positions at least between the protrusions and the adjacent surface of the layer to form a preform;    (d) cooling the preform and solidifying the weld positions; and    (e) molding the container from the preform.    
     
     
         45 . Method according to    claim 44   , wherein the heat pattern is generated by a IR radiation source radiating through a mask.  
     
     
         46 . A preform made from a blank, having one or more covering layers, wherein the adjacent surfaces of two layers are bonded with one another in a connecting zone, said connecting zone being formed by a plurality of microweld positions.