Material handling system for plastic film molding apparatus

Claim 2

In combination, storage means for holding plastic and including means for feeding stored plastic to extruder means, extruder means in direct communication with the storage means, said extruder means receiving stored plastic from the storage means and extruding it into a thin, continuous film, thermoformer means in direct communication with the extruder means, said thermoformer means receiving from the extruder means said film and forming therein an article or articles of manufacture, trimming means in direct communication with the thermoformer means, said trimming means receiving the film from the thermoformer means and trimming said film to cut away the article or articles of manufActure and leave thereafter a skeletal film, grinding means in direct communication with the trimming means, said grinding means receiving skeletal film from the trimming means and grinds it into small pieces of plastic, means for moving ground plastic from the grinding means to the storage means, and bypass means which permit the thin, continuous film of plastic coming from the extruder means to be transported directly to the grinding means, bypassing the thermoformer means and trimming means.

Claim 3

In combination, storage means for holding plastic and including means for feeding stored plastic to extruder means, extruder means in direct communication with the storage means, said extruder means receiving stored plastic from the storage means and extruding it into a thin, continuous film, thermoformer means in direct communication with the extruder means, said thermoformer means receiving from the extruder means said film and forming therein an article or articles of manufacture, trimming means in direct communication with the thermoformer means, said trimming means receiving the film from the thermoformer means and trimming said film to cut away the article or articles of manufacture and leave thereafter a skeletal film, grinding means in direct communication with the trimming means, said grinding means receiving the skeletal film from the trimming means and grinding it into small pieces of plastic, means for moving ground plastic from the grinding means to the storage means, and bypass means which permit the film including the article or articles of manufacture coming from the thermoformer means to be transported directly to the grinding means, bypassing the trimming means.

Claim 4

In combination, storage means for holding plastic and including means for feeding stored plastic to extruder means, extruder means in direct communication with the storage means, said extruder means receiving stored plastic from the storage means and extruding it into a thin, continuous film, thermoformer means in direct communication with the extruder means, said thermoformer means receiving from the extruder means said film and forming therein an article or articles of manufacture, trimming means in direct communication with the thermoformer means, said trimming means receiving the film from the thermoformer means and trimming said film to cut away the article or articles of manufacture and leave thereafter a skeletal film, grinding means in direct communication with the trimming means, said grinding means receiving the skeletal film from the trimming means and grinding it into small pieces of plastic, means for moving ground plastic from the grinding means to the storage means, and bypass means which permit the film including the article or articles of manufacture coming from the thermoformer means to be transported directly to the grinding means, bypassing the trimming means.

Claim 5

Apparatus comprising, extruder means which extrude plastic into a thin, continuous film, thermoformer means which receive said film from extruder means and form therein an article or articles of manufacture, trimming means which receive the film from the thermoformer means and trim said film to cut away the article or articles of manufacture and leave thereafter a skeletal film, and grinding means which receive the skeletal film from the trimmer means and grind it into small pieces of plastic, said apparatus characterized by being operable in either a direct feed mode or a bypass feed mode, wherein in the direct feed mode the film moves directly, sequentially and continuously from the extruder means, through the thermoformer means and trimming means to the grinding means, and in the bypass mode the film moves along two alternate paths where along the first path the film bypasses the thermoformer means and the trimming means and along the second path the film bypasses the trimming means.

Claim 6

Apparatus comprising, extruder means which extrude plastic into a thin, continuous film, thermoformer means which receive said film from extruder means and form therein an article or articles of manufacture, trimming means which receive the film from the thermoformer means and trim said film to cut away the article or articles of manufacture and leave thereafter a skeletal film, and grinding means which receive the skeletal film from the trimmer means and grind it into small pieces of plastic, said apparatus characterized by being operable in either a direct feed mode or a bypass feed mode, wherein in the direct feed mode the film moves directly, sequentially and continuously from the extruder means, through the thermoformer means and trimming means to the grinding means, and in the bypass mode the film moves along two alternate paths where along the first path the film bypasses the thermoformer means and the trimming means and along the second path the film bypasses the trimming means.

Claim 7

The apparatus of claim 3 additionally including means for mixing plastics of different bulk densities with virgin plastic and/or color concentrate, comprising first storage means which hold the plastics of different bulk densities, weighing means in communication with the first storage means for receiving and weighing said plastics of different bulk densities, said weighing means including signal generating means which generate a control signal proportional to the weight of the plastic weighed by the weighing means, first moving means for moving the weighed plastics of different bulk densities to a mixing point where they are mixed with the virgin plastic and/or color concentrate, second storage means which hold the virgin plastic and/or color concentrate, and second moving means in communication with the second storage means for receiving the virgin plastic and/or color concentrate and moving it to the mixing point, said second moving means including drive means responsive to the control signal from the signal generating means to vary the rate at which said virgin plastic and/or color concentrate is moving in accordance with the weight of the plastics of different bulk densities.

Claim 8

The apparatus of claim 3 additionally including means for mixing plastics of different bulk densities with virgin plastic and/or color concentrate, comprising first storage means which hold the plastics of different bulk densities, second storage means which hold the virgin plastic and/or color concentrate, first moving means in communication with the first storage means for receiving the plastics of different bulk densities and moving said plastics to a mixing point, second moving means in communication with the second storage means for receiving the virgin plastic and/or color concentrate and moving said virgin plastic and/or color concentrate to said mixing point, weighing means at the mixing point for receiving and weighing the mixture of plastics, said weighing means including signal generating means which generate a control signal proportional to the weight of the mixture of plastics, and drive means for the second moving means which are responsive to said control signal from the signal generating means to vary the rate at which said virgin plastic and/or color concentrate is moved to said mixing point in accordance with the weight of the mixture of said plastics.

Claim 9

The apparatus of claim 3 additionally including means for cutting plastic film or the like, comprising cutter means for severing the plastic film into short lengths, conveyor means for moving the plastic film to the cutter means, means for moving plastic along a predetermined path to said conveyor means, signal generating means including sensor means along said path which provide a control signal corresponding to the rate of speed of the plastic film as it moves to said conveyor means, drive means for the conveyor means including a variable speed motor responsive to the control signal to vary the rate at which said conveyor means moves the plastic film to the cutter means in response to said control signal, and grinding means which receive the severed lengths of plastic and grind them into small pieces of plastic.

Claim 10

The apparatus of claim 3 wherein the grinding means comprises cutter means including a movable blade for severing the plastic into short lengths, conveyor means for moving the plastic film to the cutter means, means for moving plastic along a predetermined path to said conveyor means, signal generating means including sensor means along said path which provide a control signal whenever the plastic film deviates substantially from said path, common drive means for the blade and the conveyor means including a variable speed motor responsive to the control signal to vary the movement of the blade and the rate at which the plastic film is conveyed to the cutter means in response to said control signal, and means which receive the severed lengths of plastic and grind them into small pieces of plastic.