System and apparatus for injection molding articles with reduced crystallization

Abstract

An injection molding system for the formation of molded articles with reduced crystallinity comprising a laser cutoff subsystem for the removal of an elongated vestige or sprue from the molded article.

What is claimed is:  
     
         1 . An injection molding machine for the production of a molded article exhibiting reduced crystallinity properties comprising: 
 an injection unit for the communication of a molten material to at least one mold cavity;    said mold cavity forming said molded article with a sprue thereon;    a transport subsystem for the communication of said molded article from said mold cavity to a laser cutting station;    said laser cutting station comprising at least one laser aimed at a predetermined position of said sprue, wherein said laser severs said sprue from said molded article.    
     
     
         2 . The injection molding machine of  claim 1  further comprising a rotary turret, said rotary turret comprising a plurality of mold halves whereby each mold halve is successively positioned for the receipt of said molten material from said injection unit for the formation of said molded articles.  
     
     
         3 . The injection molding machine of  claim 1  further comprising a robot for the movement of said molded articles from said transport subsystem to a serpentine track where each molded article is passed by said laser station in a single file line.  
     
     
         4 . The injection molding machine of  claim 3 , further comprising a conveyor attached to an end of said serpentine track for the communication of said molded articles to a rotary table, said rotary table moving said molded article past said laser station at a predetermined rotational speed.  
     
     
         5 . The injection molding machine of  claim 4 , wherein said predetermined rotational speed is variable.  
     
     
         6 . The injection molding machine of  claim 4 , wherein said rotary table further comprises; 
 an array of holders for the removable receipt of said molded articles;    a plate to hold said molded articles in said holders;    a shield with a plurality of holes for insertion of said sprue before said molded article is moved past said laser cutting station;    a motive force for passing each of said molded articles passed said laser cutting station at a predetermined rate.    
     
     
         7 . The injection molding machine of  claim 1 , wherein said transport subsystem further comprises: 
 a shuttle table, said shuttle table comprising a plurality of holes for the receipt of said molded articles from said mold cavities;    a track running from under said injection molding machine to a predetermined position away from said injection molding machine;    said shuttle table running in a back and forth motion on said track to align with said mold cavities at a first distal end of said track, and align with a robot at a second distal end of said track;    said robot in communication with said shuttle table for the removal of said molded articles from said shuttle table to a conveyor;    said conveyor moving said molded articles passed said laser cutting station.    
     
     
         8 . The injection molding machine of  claim 7 , wherein each of said plurality of holes includes 
 a spacer for reduction of surface blemishes on said molded articles that may occur during the insertion of said molded articles in said plurality of holes.    
     
     
         9 . The injection molding machine of  claim 7 , wherein said robot further comprises: 
 a frame for the suspension of a trackway over said second distal end of said track;    a pickup table suspended from said frame riding back and forth on said trackway selectably aligning with said shuttle table and said conveyor;    a plurality of fingers extending from said pickup table, selectably inserted into said plurality molded articles, each finger expandable by the communication of a fluid to said fingers for gripping each said molded article.    
     
     
         10 . The injection molding machine of  claim 9 , wherein each of said plurality of fingers comprises an elastic bladder in communication with an air supply.  
     
     
         11 . The injection molding machine of  claim 1 , wherein said molded article is a PET preform.  
     
     
         12 . The injection molding machine of  claim 1 , wherein said laser cutting station further comprises at least one splitter for the formation of at least two laser beams aimed to be in communication with said sprue of each said molded article.  
     
     
         13 . The injection molding machine of  claim 1 , wherein said laser comprises a CO 2  laser.  
     
     
         14 . The injection molding machine of  claim 1 , wherein said laser has a power output of at least 500 watts.  
     
     
         15 . The injection molding machine of  claim 1 , wherein said laser has a predetermined power output required to achieve a predetermined cut quality.  
     
     
         16 . The injection molding machine of  claim 1 , wherein said laser emits a beam having a predetermined diameter.  
     
     
         17 . The injection molding machine of  claim 16 , wherein said predetermined diameter is between 0.05-0.25 mm.  
     
     
         18 . The injection molding machine of  claim 1 , wherein said laser cutting station further comprises: 
 two lasers each emitting a beam of at least 500 watts of power;    two splitters in the path of each said beam, each said splitter creating two beams for a total of four beams, wherein each said splitter communicates a first of said beams to a first location coincident with said sprue as it travels along said conveyor and further communicates a second of said beams to a mirror;    said mirror communicating said second beam to a second location coincident with said sprue as it travels further along said conveyor.    
     
     
         19 . The injection molding machine of  claim 1 , wherein said sprue is elongated.  
     
     
         20 . The injection molding machine of  claim 1 , further comprising a flowing fluid in communication with said molded articles to reduce the deposition of vaporized plastic created by said laser on said molded article.  
     
     
         21 . The injection molding system of  claim 1 , further comprising an electrical charge applied to said molded articles to repel the deposition of vaporized plastic created by said laser on said molded article.