Method and apparatus for manufacturing synthetic resin tubular film having occludent means in the inside surface thereof

Abstract

.Iadd.A method and apparatus for manufacturing a tube to be used for forming plastic reclosable bags including means for extruding a continuous annular tube of plastic with circumferentially spaced axially extending interlocking rib and groove profiles on the surface from a die shaped to form the tube and profiles, means for delivering tube separating air through the die into the tube interior, means for delivering a flow of outside cooling air around the outer surface of the tube to cool the tube at a rate to maintain the profiles on the surface of the tube and drawing means positioned for receicing the tube and drawing it from the die and flattening it. .Iaddend.

Having thus set forth the nature of the invention, what is claimed is: 
     
       1. A method of manufacturing a tube to be used for forming synthetic resin bags provided with occludent means comprising, (a) a step wherein is molded continuously by passing through a mold plastic forming a tubular bag body and integrally therewith in the inside of said bag body in pairs male and female ribs for occludent use, next,   (b) a step wherein air is delivered into said tubular body and said body is kept under uniform pressure,   (c) tension is imparted to the tubular film between said mold and delivery rolls provided as clasping means of said tubular body,   (d) cold air is delivered from a zone surrounding said tubular body during its travel to cool the film directly from the outside, and further   (e) a step wherein the male and female ribs are occluded while said tubular bag body is being pressed flat.   
     
     
       2. The method of forming a continuous plastic tube with circumferentially spaced axially extending complementary interlocking profiles formed integrally therewith by extruding the tube through a die having an annular opening and profiles projecting therefrom comprising, (a) delivering a main flow stream of plastic to the annular opening in the die forming a tube with shaped interlocking profiles of a critical shape on the surface of the tube,   (b) delivering separate flow streams of plastic to the profiles with the separate flow streams joining the main flow stream at the profiles of the die,   (c) and cooling the plastc at a controlled rate to cool the tubing and the profiles.   
     
     
       3. The method of making a unitary container material which comprises, (a) extruding a one piece continuous closed tube having continuous axially extending .Iadd.male and female interlocking .Iaddend.closure elements integral therewith formed at circumferentially spaced locations on the tube surface and shaped for releasably interlocking with each other with said elements each projecting from one surface only of the tube,   (b) .Iadd.directing a small amount of air into the tube to maintain the tube in its tubular shape, .Iaddend.   .[.b.]. .Iadd.(c) directing a flow of outer cooling air annularly around the outer surface of the tube at a location where the tube has reached its final size and diameter after being extruded and after being filled with the air directed into the tube and .Iaddend.cooling the extruded tube at a rate so that said elements remain on the surface on which they appear and do not project on the opposite surface .Iadd.and so that the closure elements are cooled retaining their shape and size.Iaddend.,   .[.(c).]. .Iadd.(d) .Iaddend.and separating the tube longitudinally between said elements.   
     
     
       4. The method of making a unitary container material which comprises, (a) extruding a one piece continuous closed tube of a heated plastic,   (b) simultaneously extruding continuously axially extending .Iadd.male and female .Iaddend.interlocking elements shaped for cooperative pressure interengagement and for forcible separation with one having a shaped projection and the other a shaped groove, said elements spaced apart from each other in both circumferential directions and being further apart in one direction than the other, each element projecting from its one surface only of the tube and being integral with the tube material and extending therealong,   (c) .Iadd.directing a small amount of air into the tube to maintain the tube in its tubular shape, .Iaddend.   .[.(c).]. .Iadd.(d) .Iaddend.and .Iadd.directing a flow of outer cooling air annularly around the outer surface of the tube at a location where the tube has reached its final size and diameter after being extruded and after being filled with the air directed into the tube and .Iaddend.cooling the extruded plastic at a rate so that each of the elements remains on its one surface only and does not project from the other surface .Iadd.and so that the closure elements are cooled retaining their shape and size. .Iaddend.   
     
     
       5. The method of making a unitary container material which comprises, (a) extruding a one piece continuous closed tube of a heated plastic .Iadd.from an extruder head, .Iaddend.   (b) simultaneously extruding a continuous axially extending .Iadd.male .Iaddend.fastener element shaped for cooperative pressure interengagement and for forcible separation with another .Iadd.female .Iaddend.interlocking element with the element being integral with the tube and projecting from one surface only and extending therealong,   (c) and .Iadd.directing a flow of outer cooling air annularly around the outer surface of the tube at a location spaced axially from the extruder head .Iaddend.cooling the plastic after it is extruded at a rate so that the element remains on its one surface only and does not project from the other surface .Iadd.and so that the closure elements are cooled retaining their shape and size. .Iaddend.   
     
     
       6. The method of making a container material for use in forming a plurality of bags which comprises, (a) extruding a continuous closed annular heated plastic tube .Iadd.from an extruder head, .Iaddend.   (b) simultaneously extruding a plurality of pairs of continuous axially extending .Iadd.male and female .Iaddend.interlocking elements integral with the tube and extending uniformly axially therealong with each of the interlocking elements projecting from one surface only of the tube, .[.and.].   .Iadd.(c) cooling the tube at a rate so that the elements remain on the surface of the tube on which they were initially formed, .Iaddend.   .[.(c).]. .Iadd.(d) directing a flow of outer cooling air annularly around the outer surface of the tube at a location spaced axially from the extruder head .Iaddend.cooling the plastic after it is extruded at a rate so that the elements .[.remains.]. .Iadd.remain .Iaddend.on .[.its.]. one surface only and .[.does.]. .Iadd.do .Iaddend.not project from the outer surface .Iadd.and so that the closure elements are cooled retaining their shape and size, .Iaddend.   .[.(d).]. .Iadd.(e) and drawing the tube axially after it has been extruded..Iaddend.   
     
     
       7. Apparatus for forming a stream of plastic into an annular continuous tube with circumferentially spaced axially extending interlocking means formed integrally with the tube comprising, (a) a die having an annular opening to form a tube with shaped complementary .Iadd.male and female .Iaddend.interlocking profiles opening radially therefrom, each of said profiles projecting on its own one radial surface only of the tube,   (b) means for delivering tube separating air into the tube interior,   (c) means for delivering a flow of outside cooling air around the outer surface of the tube .Iadd.at a location spaced axially from the die, .Iaddend.said air delivery means having a size and operating to cool the tube at a rate to maintain said profile on its own one radial side only of the tube .Iadd.and so that the closure elements are cooled retaining their shape and size, .Iaddend.   (d) and drawing means positioned for receiving the tube and flattening and drawing it from the die.   
     
     
       8. Apparatus for forming a stream of plastic into an annular continuous tube with circumferentially spaced axially extending interlocking means formed integrally with the tube comprising, (a) a die having an annular opening with shaped complementary interlocking profiles opening radially therefrom,   (b) means defining an annular plastic flow channel leading to said annular die opening,   (c) means delivering plastic to said flow channel,   (d) a separate plastic flow passage carrying a separate stream of plastic to at least one of said profiles,   (e) means for delivering a flow of outside cooling air annularly around the outer surface of the tube,   (f) and drawing means positioned for receiving the tube and flattening it.   
     
     
       9. Apparatus for forming a stream of plastic into an annular continuous tube with circumferentially spaced axially extending interlocking means formed integrally with the tube comprising, (a) a die having an annular opening with shaped complementary interlocking profiles opening radially therefrom,   (b) means defining an annular plastic flow channel leading to said annular die opening for carrying a main flow of plastic,   (c) means delivering plastic to said flow channel,   (d) separate plastic flow passages carrying separate streams of plastic from the main stream to the profiles,   (e) means for delivering a flow of tube separating air into the tube interior,   (f) means for delivering a flow of outside cooling air to the outer surface of the tube,   (g) and drawing means positioned for receiving the tube and flattening it drawing it from the die.   
     
     
       10. Apparatus for forming a stream of plastic into an annular continuous tube with circumferentially spaced axially extending interlocking means formed integrally with the tube comprising, (a) a die having an annular opening with shaped complementary interlocking profiles opening radially therefrom,   (b) means defining an annular plastic flow channel leading to said annular die opening for carrying a main flow of plastic,   (c) means delivering plastic to said flow channel,   (d) separate plastic flow passages carrying separate streams of plastic from the main flow to the profiles,   (e) means for controlling plastic flow rate through said passages,   (f) means for delivering tube separating air into the tube interior,   (g) means for delivering a flow of outside cooling air around the outer surface of the tube,   (h) and means positioned for receiving the tube and flattening it.   
     
     
       11. Apparatus for forming a stream of plastic into an annular continuous tube with circumferentially spaced axially extending interlocking means formed integrally with the tube comprising, (a) a die having an annular opening with shaped complementary interlocking profiles opening radially therefrom for extruding the tube,   (b) means defining an annular plastic flow channel leading to said annular die opening for carrying a main flow of plastic,   (c) means delivering plastic to said flow channel,   (d) separate plastic flow passages carrying separate streams of plastic from the main flow to the profiles,   (e) flow regulating projections adjustably movable into the passages individually controlling the plastic flow rate through said passages relative to the main stream,   (f) means for delivering a tube inflating flow of air into the tube interior,   (g) means for delivering a flow of outside cooling air around the outer surface of the tube,   (h) and drawing means positioned for receiving and flattening the tube from the die.   
     
     
       12. Apparatus for forming a stream of plastic into an annular continuous tube with circumferentially spaced axially extending interlocking means formed integrally with the tube comprising, (a) a die having an annular opening with shaped complementary interlocking profiles opening radially therefrom,   (b) means for delivering tube separating air into the tube interior after it has been extruded from the die,   (c) means for delivering a flow of outside cooling air around the surface of the tube,   (d) a pair of pinch rolls positioned above the die for receiving the tube and flattening it,   (e) means positioned after the pinch rolls for forcing the interlocking means together,   (f) and a floating guiding member within the tube below said forcing means aligning the profiles of the tube so that they are pressed together to interlock between said forcing means.   
     
     
       13. Apparatus for forming a stream of plastic into an annular continuous tube with circumferentially spaced axially extending interlocking means formed integrally with the tube comprising, (a) a die having an annular opening with shaped complementary interlocking profiles opening radially therefrom,   (b) means defining a plastic flow channel leading to said annular die opening for carrying a main flow of plastic,   (c) separate plastic flow passages carrying separate streams of plastic to the profiles,   (d) flow regulating means for the passages controlling the plastic flow rate through the passages relative to said channel,   (e) means for delivering a tube separating flow of air into the tube interior extruded from the die,   (f) means for delivering a flow of outside cooling air around the outer surface of the tube,   (g) and drawing means positioned for receiving and flattening the tube from the die.