Mobil Oil Corporation

Tenneco Packaging Inc.

Pactiv Corporation

Tenneco Plastics Company

Edward M Bullard

Daniel J DiBiasi

Edward W Forman

Kirk E Belmont

David E McIntyre

Gregory M Smith

Fox J Herrington

William P Belias

William F Briggs

David V Dobreski

George N Eichbauer

Stephen K Guerrera

A Michael Nahmias

Richard E Leone

Thomas A White

Robert T Maddock

Frank J Feeney

Carl R Letendre

Ivy Wolpin

Paul E Viscontini

W Mark Dutt

An apparatus and method for heating and cooling a polymer structure employs a tube structure. The tube structure includes a conductive tube and a conductive strip. The tube is composed of a first conductive material having a first electrical resistivity, and the strip is composed of a second conductive material having a second electrical resistivity less than the first resistivity. The strip is connected to only a portion of an outer surface of the tube and extends along a length of the tube. In the method, an impulse of electric current is passed through the tube structure until the strip is heated to a predetermined sealing temperature. The strip and the polymer structure are brought into contact with each other for a dwell time sufficient to generate a heat seal in the polymer structure. A cooling medium is passed through the tube to cool the strip to a predetermined release temperature that facilitates release of the strip from the polymer structure.

Apparatus for high-speed heating and cooling of a polymer

A polymeric multilayer film is disclosed that has improved optical qualities while having structural qualities that are not significantly compromised. The film is composed of outer film layers of a low polydispersity polymer which are placed around at least one inner film layer of a high molecular weight high density polyethylene (HDPE) polymer. The outer film layer polymer has a polydispersity of from about 1 to about 4. In a preferred embodiment this low polydispersity polymer is formed in the presence of a metallocene catalyst. The inner film layer high molecular weight HDPE polymer has a melt index of less than 0.1 and a density of at least about 0.940 g/cm.sup.3. Any of the layers of the film may be constructed of polymer blends.

Clear high molecular weight film

A multilayer, thermoplastic stretch wrap film containing at least four polymeric film layers and comprised of a first outer cling layer, a second outer cling layer, at least one inner polymeric layer and at least one core layer. The first and second layers have a cling force to s each other of at least about 140 grams/inch. The stretch wrap film has at least one inner polymeric layer, located between the first and second layers. The inner polymeric layer comprises a low polydispersity polymer. The low polydispersity polymer has a polydispersity of from about 1 to about 4, a melt index (I.sub.2) of from about 0.5 to about 10 g/10 min., and a melt flow ratio (I.sub.20 /I.sub.2) of from about 12 to about 22. The core layer, also located between the outer cling layers, comprises either a random copolymer of propylene and ethylene, a heterophasic copolymer of propylene with domains of ethylene interspersed, a polypropylene homopolymer, or blends thereof. The random ethylene-propylene copolymer has a melt flow ratio of from about 2 to about 15 and an ethylene content in the range of from about 2 to about 6 wt. % of the propylene copolymer. The heterophasic copolymer has a melt flow ratio of about 10 to about 18 and an ethylene content in the range of from about 12 to 30 wt. % of the heterophasic propylene. The polypropylene homopolymer has a melt flow ratio of from about 2 to about 15. The multilayer stretch wrap film has a maximum stretch of at least 340% and a machine direction stress force @ 200% elongation of between about 1400 and about 1900 psi. It is contemplated that additional layers may be added to the present invention.

Multilayered Metallocene stretch wrap films

There is provided a thermoplastic film bag having at least two integral members that facilitate opening the bag. The bag is manufactured from a flattened tube of thermoplastic material which may be distinctively severed along independent phase shifted sinusoidal oscillating paths down the center of the collapsed tube. The bag may have two opposed tie members which are offset from the vertical center axis of the bag and from each other. The tie members may be grasped and pulled apart to facilitate the easy opening of the bag. The tie members may then be tied together to form a strong member by which the bag may be picked up and carried. In alternate embodiments the shape of the integral tie members can be modified to create a bag having only the easy open feature with no tie members. A method for making the bag is also described.

Method of making easy open thermoplastic bag

A trash container for the storage and ready removal of filled disposable garbage bags and receptacles or the like from a side of the container. The trash container is of an essentially frusto-conical configuration narrowing towards an upper end and incorporating an opening or top aperture for the inserton of filled garbage bags or similar refuse, and in which at least one of the upwardly converging container sidewalls includes a wall portion which is pivotably openable so as to enable the discharge of the trash container contents through a side thereof in its lower region.

Side discharge trash container

A thermoplastic bag having a flexible top has a stiff strip around the mouth of the bag which when rolled outward bends to hold open the bag.

Hold-open bag top

A plastic bag, such as a trash bag or the like, of linear low density polyethylene or a blend of low density polyethylene and low density polyethylene has a closure portion along its open end. The closure portion is of a plastic having dead fold properties, such as oriented high density polyethylene or polystyrene. The bag can be closed by twisting the closure portion. The dead fold property of the closure portion will maintain the twisted condition of the closure portion to maintain the bag closed.

Closable plastic bag

A multiple layer hand-grip reinforcement for thermoplastic draw tape handles for thermoplastic bags and method of making the same is disclosed. The hand-grip reinforcement is produced by slitting a thermoplastic tape longitudinally with an undulating pattern to divide the tape into a pair of draw tapes each having alternating wide and narrow sections. The wide section has a dimension at least twice as great as the intervening narrow section. The wide section is folded over along a longitudinal crease line to provide a multiple layer tape section intermediate two single layer tape sections. The folded tapes are inserted into each hem of a draw tape bag with the multiple layer tape section aligned with a central cut out opening intermediate the ends of the hem and the ends of each draw tape are secured to the ends of the respective hems so that when the multiple layer tape section is gripped and pulled through the cut out opening in the hems to draw closed the open top of the bag the multiple layer hand-grip reinforcement minimizes the discomfort caused by roping at the hand area while the bag is under load.

Multiple layer hand-grip reinforcement for thermoplastic draw tape

A thermoplastic draw tape bag having a tacky surface on the inside lip of the mouth of the bag and extending around the inner periphery of the lip on the open mouth of the bag, the surface comprising a material having the characteristic of sticking to itself and being adapted to seal the open mouth and hold the bag closed after the draw tape is pulled tight. In one form of the invention, the tacky surface comprises a coating of glycerol mono-oleate. The surface may also comprise a layer of polyvinylidene chloride or a layer of polyisobutylene.

Thermoplastic draw tape bag with tacky closure surface

A hand-grip for thermoplastic draw tape handles for thermoplastic bags and method of making the same is disclosed. The hand-grip is produced by perforating each hem of the thermoplastic bag at a center section thereof with a substantially U-shaped perforation extending from the mouth of the bag to a location below the bottom of the hem whereby the center section of each hem is separable from the bag along the U-shaped perforation to provide a hand-grip surrounding each draw tape when the bag is lifted by the draw tapes.

Hand-grip for thermoplastic draw tape handles for thermoplastic bags

A padded reinforced handle for thermoplastic draw tape bags and method of making the same is disclosed. The padded hand-grip reinforcement for the draw tape handle is produced by folding a thermoplastic draw tape longitudinally into a V-shaped cross-section and inserting a predetermined quantity of padding material into the V-shaped cross section of the tape to provide a padded tape area at predetermined spaced intervals corresponding to the width of the draw tape bag. The padded tape section has a length adequate to provide a padded hand-grip reinforcement. The padded tapes are inserted into the hems of the draw tape bag with the padded tape section aligned with a central cut out opening intermediate the ends of the hems. The ends of the draw tape at the unpadded tape sections are secured to the ends of the respective hems so that when the padded tape section is gripped and pulled through the cut out openings in the hems to draw closed the open top of the bag, the padded hand-grip reinforcement minimizes the discomfort caused by roping at the hand area while the bag is under load. In a preferred form of the invention the padding material comprises a curable foam which is cured by ultraviolet light.

Reinforced handle for thermoplastic draw tape bags

Draw tape bags for carrying trash have a draw tape with ribs extending across the width of the tape, each rib having a thickness greater than the thickness of the tape. The ribs prevent roping of the draw tape handle when a loaded bag is lifted. Roping is prevented because the packing of the ribs is not uniform, thereby creating free space between the ribs. Triangular and cylindrical elements are embedded in the tape to form the ribs.

Ribbed draw tape for thermoplastic bag

A process for preparing a poly(p-methylstyrene) polymer foam including extruding a poly(p-methylstyrene) foam structure from a melt at a temperature which will yield an open cell percentage less than that formed in general purpose polystyrene foamed under the same general conditions. It also includes performing the extrusion from a melt at a rate which will yield a foam structure at least comparable to that of general purpose polystyrene foam, wherein the extrusion rate is greater than the extrusion rate for said polystyrene foam.

Process for preparing a poly(p-methylstyrene) foam

This present invention relates to novel coextruded thermoplastic film and the employment of such multi-layer film as stretch-wrap material for packaging of goods, including relatively large palletized loads of material. More specifically, such coextruded stretch-wrap films comprise three-layer laminations having a relatively thin skin layer and a relatively thicker core layer. Suitable skin layers include highly-branched low-densty polyethylene, and suitable core layers include linear low-density polyethylene co-polymers, such as ethylene co-polymerized with a minor amount of at least one C.sub.4 to C.sub.10 alpha-olefin, such as octene-1 and 4-methyl-pentene-1, and butene-1.

Coextruded thermoplastic stretch-wrap

This present invention relates to novel coextruded thermoplastic film and the employment of such multi-layer film as stretch-wrap material for packaging of goods, including relatively large palletized loads of material. More specifically, such coextruded stretch-wrap films comprise three-layer laminations having a relatively thin skin layer and a relatively thicker core layer. Suitable skin layers include highly-branched low-density polyethylene, and suitable core layers include linear low-density polyethylene co-polymers, such as ethylene co-polymerized with a minor amount of at least one C.sub.4 to C.sub.10 alpha-olefin, such as octene-1 and 4-methyl-pentene-1, and butene-1.

Growing community of inventors

Rochester, NY, United States of America

Edward M Bullard