Apparatus for extruding plastic storage bags
OwnerEdward C. Brunoinventor
Life of this patent
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Abstract
An apparatus and method is provided for fabricating storage bags that have complementary sealing ribs out of stock material which may be a tubular extruded stock. When produced according to this apparatus and method, the storage bags have open mouths, that is, the sealing ribs are not engaged. The apparatus includes a separator bar to separate and disengage the sealing ribs prior to transversely joining the tube to form the side edges of the bag. Guide plates and a platen maintain alignment of the separated sealing ribs when the side edges are formed. The formed bags are then sequentially cut from the tube.
Claims10
Apparatus adapted to fabricate storage bags wherein each bag has front and back panels joined to one another along a common bottom edge and along a pair of common side edges so that said bag has an interior, said front and back panels having a respective top edge defining a mouth opening into the interior and having a pair of complementary sealing ribs extending between said side edges so that one sealing rib is on thee front panel proximate the top edge thereof and another of the sealing ribs is on the back panel proximate the top edge thereof, said sealing ribs oriented to engage one another to close said mouth and separable to open said mouth, said apparatus comprising:
- an extruder at an upstream location operative to longitudinally extrude a continuous tube of material having a tube interior and wherein said tube has a pair of complementary sealing ribs formed integrally therewith longitudinally along the tube interior, said sealing ribs oriented parallel to one another so that said tube has first and second arcuate tube portions therebetween;
- means for flattening said tube along first and second longitudinal tube edges whereby said sealing ribs are engaged and whereby continuous front and back panel strips are defined;
- slit means for cutting said tube of plastic longitudinally between said sealing ribs along said first arcuate tube portion to form a longitudinal slit;
- separator means located downstream of said slit means for disengaging said sealing ribs;
- guide means extending through the slit in said tube for receiving and guiding said sealing ribs whereby said sealing ribs are maintained in a facing pre-engagement position with respect to one another;
- drive means downstream of said guide means for advancing said tube, said sealing ribs correspondingly advancing through said guide means, said drive means including drive rollers having formed therein channels sized and positioned to accommodate said sealing ribs without re-engagment of said sealing ribs;
- and
- edge forming means for sealing and cutting said tube transversely thereacross so that side edges are formed for adjacent storage bags and so that storage bags are cut from said tube with each said storage bag having its respective pair of sealing ribs engaged at the side edges of the respective storage bag and with the pair of sealing edges disengaged from one another between the side edges thereof whereby the mouth of the respective storage bag is open.
Dependencies are inferred from the claim text.