CA2530017A1 - Blow molded pallet with wave-like supports - Google Patents
Blow molded pallet with wave-like supports Download PDFInfo
- Publication number
- CA2530017A1 CA2530017A1 CA002530017A CA2530017A CA2530017A1 CA 2530017 A1 CA2530017 A1 CA 2530017A1 CA 002530017 A CA002530017 A CA 002530017A CA 2530017 A CA2530017 A CA 2530017A CA 2530017 A1 CA2530017 A1 CA 2530017A1
- Authority
- CA
- Canada
- Prior art keywords
- pallet
- portions
- distant
- channels
- protrusions
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 229920003023 plastic Polymers 0.000 claims description 24
- 239000004033 plastic Substances 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 14
- 238000000071 blow moulding Methods 0.000 claims description 8
- 238000000465 moulding Methods 0.000 claims description 7
- 238000007493 shaping process Methods 0.000 claims 1
- 239000000463 material Substances 0.000 description 32
- -1 however Substances 0.000 description 13
- 239000004698 Polyethylene Substances 0.000 description 12
- 229920000573 polyethylene Polymers 0.000 description 12
- QLZJUIZVJLSNDD-UHFFFAOYSA-N 2-(2-methylidenebutanoyloxy)ethyl 2-methylidenebutanoate Chemical compound CCC(=C)C(=O)OCCOC(=O)C(=C)CC QLZJUIZVJLSNDD-UHFFFAOYSA-N 0.000 description 8
- 229920006244 ethylene-ethyl acrylate Polymers 0.000 description 8
- 239000005042 ethylene-ethyl acrylate Substances 0.000 description 8
- 239000000203 mixture Substances 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- 230000003014 reinforcing effect Effects 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000007789 gas Substances 0.000 description 4
- 229920001903 high density polyethylene Polymers 0.000 description 4
- 239000004700 high-density polyethylene Substances 0.000 description 4
- BFMKFCLXZSUVPI-UHFFFAOYSA-N ethyl but-3-enoate Chemical compound CCOC(=O)CC=C BFMKFCLXZSUVPI-UHFFFAOYSA-N 0.000 description 3
- 229920001684 low density polyethylene Polymers 0.000 description 3
- 239000004702 low-density polyethylene Substances 0.000 description 3
- 229940099514 low-density polyethylene Drugs 0.000 description 3
- 239000000155 melt Substances 0.000 description 3
- 244000043261 Hevea brasiliensis Species 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000000295 complement effect Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 238000001746 injection moulding Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- VLKZOEOYAKHREP-UHFFFAOYSA-N methyl pentane Natural products CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229920003052 natural elastomer Polymers 0.000 description 2
- 229920001194 natural rubber Polymers 0.000 description 2
- 239000002023 wood Substances 0.000 description 2
- 241000285023 Formosa Species 0.000 description 1
- 241000238631 Hexapoda Species 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- DSSYKIVIOFKYAU-UHFFFAOYSA-N camphor Chemical compound C1CC2(C)C(=O)CC1C2(C)C DSSYKIVIOFKYAU-UHFFFAOYSA-N 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000032798 delamination Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000003000 extruded plastic Substances 0.000 description 1
- 239000011152 fibreglass Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000008570 general process Effects 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000002991 molded plastic Substances 0.000 description 1
- 238000010137 moulding (plastic) Methods 0.000 description 1
- 230000008707 rearrangement Effects 0.000 description 1
- 239000002990 reinforced plastic Substances 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000007788 roughening Methods 0.000 description 1
- 239000005060 rubber Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000012815 thermoplastic material Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D19/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
- B65D19/0004—Rigid pallets without side walls
- B65D19/0006—Rigid pallets without side walls the load supporting surface being made of a single element
- B65D19/0008—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface
- B65D19/001—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface the base surface being made of a single element
- B65D19/0014—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface the base surface being made of a single element forming discontinuous or non-planar contact surfaces
- B65D19/0016—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface the base surface being made of a single element forming discontinuous or non-planar contact surfaces and each contact surface having a stringer-like shape
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D19/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
- B65D19/0004—Rigid pallets without side walls
- B65D19/0006—Rigid pallets without side walls the load supporting surface being made of a single element
- B65D19/0008—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface
- B65D19/001—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface the base surface being made of a single element
- B65D19/0014—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface the base surface being made of a single element forming discontinuous or non-planar contact surfaces
- B65D19/0018—Rigid pallets without side walls the load supporting surface being made of a single element forming a continuous plane contact surface the base surface being made of a single element forming discontinuous or non-planar contact surfaces and each contact surface having a discrete foot-like shape
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
- B65D2519/00004—Details relating to pallets
- B65D2519/00009—Materials
- B65D2519/00014—Materials for the load supporting surface
- B65D2519/00034—Plastic
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
- B65D2519/00004—Details relating to pallets
- B65D2519/00009—Materials
- B65D2519/00049—Materials for the base surface
- B65D2519/00069—Plastic
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
- B65D2519/00004—Details relating to pallets
- B65D2519/00258—Overall construction
- B65D2519/00263—Overall construction of the pallet
- B65D2519/00273—Overall construction of the pallet made of more than one piece
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
- B65D2519/00004—Details relating to pallets
- B65D2519/00258—Overall construction
- B65D2519/00283—Overall construction of the load supporting surface
- B65D2519/00288—Overall construction of the load supporting surface made of one piece
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
- B65D2519/00004—Details relating to pallets
- B65D2519/00258—Overall construction
- B65D2519/00313—Overall construction of the base surface
- B65D2519/00318—Overall construction of the base surface made of one piece
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
- B65D2519/00004—Details relating to pallets
- B65D2519/00258—Overall construction
- B65D2519/00313—Overall construction of the base surface
- B65D2519/00328—Overall construction of the base surface shape of the contact surface of the base
- B65D2519/00333—Overall construction of the base surface shape of the contact surface of the base contact surface having a stringer-like shape
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
- B65D2519/00004—Details relating to pallets
- B65D2519/00258—Overall construction
- B65D2519/00313—Overall construction of the base surface
- B65D2519/00328—Overall construction of the base surface shape of the contact surface of the base
- B65D2519/00338—Overall construction of the base surface shape of the contact surface of the base contact surface having a discrete foot-like shape
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
- B65D2519/00004—Details relating to pallets
- B65D2519/00547—Connections
- B65D2519/00552—Structures connecting the constitutive elements of the pallet to each other, i.e. load supporting surface, base surface and/or separate spacer
- B65D2519/00557—Structures connecting the constitutive elements of the pallet to each other, i.e. load supporting surface, base surface and/or separate spacer without separate auxiliary elements
- B65D2519/00562—Structures connecting the constitutive elements of the pallet to each other, i.e. load supporting surface, base surface and/or separate spacer without separate auxiliary elements chemical connection, e.g. glued, welded, sealed
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D2519/00—Pallets or like platforms, with or without side walls, for supporting loads to be lifted or lowered
- B65D2519/00004—Details relating to pallets
- B65D2519/00547—Connections
- B65D2519/00552—Structures connecting the constitutive elements of the pallet to each other, i.e. load supporting surface, base surface and/or separate spacer
- B65D2519/00557—Structures connecting the constitutive elements of the pallet to each other, i.e. load supporting surface, base surface and/or separate spacer without separate auxiliary elements
- B65D2519/00567—Structures connecting the constitutive elements of the pallet to each other, i.e. load supporting surface, base surface and/or separate spacer without separate auxiliary elements mechanical connection, e.g. snap-fitted
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Pallets (AREA)
Abstract
A pallet system has a pallet body that includes a first portion with an outer surface and an inner surface that has at least a portion distant from the outer surface and a corrugating form. The pallet body also includes a second portion with an outer surface and an inner surface that has at least a portion distant from the outer surface and a corrugating form. The inner surface of the first portion is connected to the inner surface of the second portion between each respective corrugating form. Channels and protrusions may be used to add strength and support to the body. The portions are connected at tack points.
Description
BLOW MOLDED PALLET WITH WAVE-LIKE SUPPORTS
BACKGROUND OF THE INVENTION
1. Field of the Invention The present invention relates in general to the held of plastics. More particularly, the present invention relates to a pallet system and a pallet apparatus and a method of pallet manufacturing. Specifically, one preferred embodiment of the present invention relates to blow molding a first pallet section or portion with a wave-like support and then inserting it into another mold to j oin it to a second blow molded pallet section or portion with a wave-like support.
BACKGROUND OF THE INVENTION
1. Field of the Invention The present invention relates in general to the held of plastics. More particularly, the present invention relates to a pallet system and a pallet apparatus and a method of pallet manufacturing. Specifically, one preferred embodiment of the present invention relates to blow molding a first pallet section or portion with a wave-like support and then inserting it into another mold to j oin it to a second blow molded pallet section or portion with a wave-like support.
2. Discussion of the Related Art Pallets are used for transporting and storing various types of cargo throughout the world. Therefore, it is important for a pallet to be lightweight, compact and strong.
Traditionally pallets were made of wood, however, plastic pallets are now being used with increased frequency as they are lightweight, generally stronger, do not absorb moisture, and they can be cleaned and disinfected which is important in particular for the food industry.
One disadvantage of plastic pallets is that they tend to break up with continued use over time.
Therefore, for these and other various reasons it is important that plastic pallets be reinforced by a variety of means. . _ . . _ . .
The below-referenced U.S. patents disclose embodiments that were at least in part satisfactory for the purposes for which they were intended. The disclosure of all the below-referenced prior United States patents, in their entireties, are hereby expressly incorporated by reference into the present application for purposes including, but not limited to, indicating the background of the present invention and illustrating the state of the art.
U.S. Patent No. 5,417,167 discloses a plastic shipping pallet of the type usually manufactured from wood which is made of hollow plastic stringers and deck boards. The stringers and deck boards are made of plastic materials that may be either virgin plastic, recycled plastics or mixes. The stringers and deck boards are hollow but have closed ends to prevent entry of dirt, fluids, insects and vermin. The stringers and declc boards may be made in a blow molding process or using continuous extrusion and molding processes similar to that used in the manufacture of cornigated pipe. Various connection configurations for affixing the deck boards to the stringers are described including fixation by screws as well as interlocking connections between the plastic parts themselves and the use of separate interlocking components that engage the deck board and stringers.
U.S. patent No. 5,845,588 discloses a pallet fabricated of a thermoplastic material which is produced by joining together individually fabricated structural components, each of which is individually thermoformed from an extruded plastic parison of a multiplayer structure. The structural components include a deck in the form of a continuous sheet with longiW dinal and transverse sides, one or more upper runner components fastened by their top side to the bottom of the deck, each of which includes a cross member with downward-facing posts, and one or more lower runner components, each of which includes a cross member with upward-facing posts and which is fastened by the tops of its posts to the bottoms of matching posts on the corresponding upper runner components.
U.S. patent No. 5,868,080 discloses a reinforced plastic pallet construction and assembly method are presented wherein multiple reinforcing bars are employed. At least some of the reinforcing bars have an exposed surface at a topside surface, underneath surface or underside surface of the pallet. In addition to functioning as a reinforcing member, the exposed surfaces of the reinforcing bars comprise an anti-skid surface for maintaining positioning of payload on the pallet or facilitating transport of the pallet, e.g., via a forklift or automated transport system.
Various techniques for retaining the reinforcing bars within channels form in the plastic pallet body are described. The reinforcing bars preferably comprise composite strucW
ral members of fiberglass-reinforced plastic fabricated from a pultrusion process.
U.S. Patent No. 6,209,464 discloses a pallet that includes a rectangular support deck having a substantially planar upper supporting surface including a plurality of channels formed therein and extending across the pallet. The deck includes support members extending fiom an underside of the deck that nest in recesses formed in the upper surface of the deck. An alignment portion is formed at a center point along the first edge of the deck and a second alignment portion is formed at a center point of an opposed edge of the deck. The alignment portion includes angled sides for receiving a tapered member of a complement device.
SUMMARY AND OBJECTS OF THE INVENTION
It is one object of the present invention to provide a pallet system that is relatively inexpensive to manufacture, recyclable, and environmentally friendly.
It is another object, to provide a pallet design that is structurally strong, yet relatively lightweight, and generally easy to manufacture.
In accordance with one aspect of the invention, the inventive pallet stem has a first portion and a second portion having interiors that fit together to provide strength and stability to a preferably blow molded pallet body.
Traditionally pallets were made of wood, however, plastic pallets are now being used with increased frequency as they are lightweight, generally stronger, do not absorb moisture, and they can be cleaned and disinfected which is important in particular for the food industry.
One disadvantage of plastic pallets is that they tend to break up with continued use over time.
Therefore, for these and other various reasons it is important that plastic pallets be reinforced by a variety of means. . _ . . _ . .
The below-referenced U.S. patents disclose embodiments that were at least in part satisfactory for the purposes for which they were intended. The disclosure of all the below-referenced prior United States patents, in their entireties, are hereby expressly incorporated by reference into the present application for purposes including, but not limited to, indicating the background of the present invention and illustrating the state of the art.
U.S. Patent No. 5,417,167 discloses a plastic shipping pallet of the type usually manufactured from wood which is made of hollow plastic stringers and deck boards. The stringers and deck boards are made of plastic materials that may be either virgin plastic, recycled plastics or mixes. The stringers and deck boards are hollow but have closed ends to prevent entry of dirt, fluids, insects and vermin. The stringers and declc boards may be made in a blow molding process or using continuous extrusion and molding processes similar to that used in the manufacture of cornigated pipe. Various connection configurations for affixing the deck boards to the stringers are described including fixation by screws as well as interlocking connections between the plastic parts themselves and the use of separate interlocking components that engage the deck board and stringers.
U.S. patent No. 5,845,588 discloses a pallet fabricated of a thermoplastic material which is produced by joining together individually fabricated structural components, each of which is individually thermoformed from an extruded plastic parison of a multiplayer structure. The structural components include a deck in the form of a continuous sheet with longiW dinal and transverse sides, one or more upper runner components fastened by their top side to the bottom of the deck, each of which includes a cross member with downward-facing posts, and one or more lower runner components, each of which includes a cross member with upward-facing posts and which is fastened by the tops of its posts to the bottoms of matching posts on the corresponding upper runner components.
U.S. patent No. 5,868,080 discloses a reinforced plastic pallet construction and assembly method are presented wherein multiple reinforcing bars are employed. At least some of the reinforcing bars have an exposed surface at a topside surface, underneath surface or underside surface of the pallet. In addition to functioning as a reinforcing member, the exposed surfaces of the reinforcing bars comprise an anti-skid surface for maintaining positioning of payload on the pallet or facilitating transport of the pallet, e.g., via a forklift or automated transport system.
Various techniques for retaining the reinforcing bars within channels form in the plastic pallet body are described. The reinforcing bars preferably comprise composite strucW
ral members of fiberglass-reinforced plastic fabricated from a pultrusion process.
U.S. Patent No. 6,209,464 discloses a pallet that includes a rectangular support deck having a substantially planar upper supporting surface including a plurality of channels formed therein and extending across the pallet. The deck includes support members extending fiom an underside of the deck that nest in recesses formed in the upper surface of the deck. An alignment portion is formed at a center point along the first edge of the deck and a second alignment portion is formed at a center point of an opposed edge of the deck. The alignment portion includes angled sides for receiving a tapered member of a complement device.
SUMMARY AND OBJECTS OF THE INVENTION
It is one object of the present invention to provide a pallet system that is relatively inexpensive to manufacture, recyclable, and environmentally friendly.
It is another object, to provide a pallet design that is structurally strong, yet relatively lightweight, and generally easy to manufacture.
In accordance with one aspect of the invention, the inventive pallet stem has a first portion and a second portion having interiors that fit together to provide strength and stability to a preferably blow molded pallet body.
These and other aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration an not of limitation. Many changes and modifications may be made within the scope of the present invention without 'departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
A clear conception of the advantages and features constituting the present invention, and of the construction and operation of typical mechanisms provided with the present invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the drawings accompanying and forming a part of this specification, wherein like reference numerals designate the same elements in the several views, and in which:
Fig. 1 shows a top perspective view of one embodiment of the pallet of the present invention;
Fig. 1A shows a cross-sectional view along line A-A in Fig. 1;
Fig. 1B shows a cross-sectional view along line B-B of Fig. l;
Fig. 1C shows a cross-sectional view along line C-C of Fig. 1;
Fig. 1D shows a cross-sectional view along line D-D of Fig.l;
Fig: 1E shows a cross-sectional view along line E-E of Fig. 1;
Fig. 2 shows a bottom-perspective view of the pallet of Fig. 1;
Fig. 3 shows an exploded top-perspective view of the pallet of Fig. l;
Fig. 4 shows an exploded bottom-perspective view of the pallet of Fig. 1;
Fig. 5 shows an exploded front view of the pallet of Fig. l;
Fig. 6 shows mold form halves used to form the pallet of Fig. 1;
Fig. 7 is a top-perspective view of another embodiment of the present invention;
Fig. 8 is a bottom-perspective view of the pallet of Fig. 7;
Fig. 9 is a front view of the pallet of Fig. 7;
Fig. 10 s a side view of the pallet of Fig. 7;
Fig. 11 is an exploded top-perspective view of the pallet of Fig. 7;
Fig. 12 is an exploded bottom perspective view of the pallet of Fig. 7;
Fig. 13 is an exploded top-perspective view of yet still another embodiment of the pallet of the present invention;
Fig. 14 is an exploded bottom-perspective view of the pallet of Fig. 13;
BRIEF DESCRIPTION OF THE DRAWINGS
A clear conception of the advantages and features constituting the present invention, and of the construction and operation of typical mechanisms provided with the present invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the drawings accompanying and forming a part of this specification, wherein like reference numerals designate the same elements in the several views, and in which:
Fig. 1 shows a top perspective view of one embodiment of the pallet of the present invention;
Fig. 1A shows a cross-sectional view along line A-A in Fig. 1;
Fig. 1B shows a cross-sectional view along line B-B of Fig. l;
Fig. 1C shows a cross-sectional view along line C-C of Fig. 1;
Fig. 1D shows a cross-sectional view along line D-D of Fig.l;
Fig: 1E shows a cross-sectional view along line E-E of Fig. 1;
Fig. 2 shows a bottom-perspective view of the pallet of Fig. 1;
Fig. 3 shows an exploded top-perspective view of the pallet of Fig. l;
Fig. 4 shows an exploded bottom-perspective view of the pallet of Fig. 1;
Fig. 5 shows an exploded front view of the pallet of Fig. l;
Fig. 6 shows mold form halves used to form the pallet of Fig. 1;
Fig. 7 is a top-perspective view of another embodiment of the present invention;
Fig. 8 is a bottom-perspective view of the pallet of Fig. 7;
Fig. 9 is a front view of the pallet of Fig. 7;
Fig. 10 s a side view of the pallet of Fig. 7;
Fig. 11 is an exploded top-perspective view of the pallet of Fig. 7;
Fig. 12 is an exploded bottom perspective view of the pallet of Fig. 7;
Fig. 13 is an exploded top-perspective view of yet still another embodiment of the pallet of the present invention;
Fig. 14 is an exploded bottom-perspective view of the pallet of Fig. 13;
Fig. 15 is an exploded front view of the pallet of Fig. 13;
Fig. 16 is a side view of the pallet of Fig. 13; and Fig. 17 is an exploded top-perspective view of yet still another embodiment of the pallet of the present invention;
Fig. 18 is an exploded bottom-perspective view of the pallet of Fig. 17;
Fig. 19 s sectional schematic with a magnified view of the pallet of Fig.l7;
Fig.20 is a side view of another embodiment of the present invention; and Fig. 21 is a schematic illustrating the method of the present invention.
In describing the preferred embodiment of the invention, which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity.
However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. For example, the word "connected" or teens similar thereto are often used. They are not limited to direct connection but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.
DETAILED DESCRIPTION
The present invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments described in detail in the following description, 1. Resume As shown in the embodiment of Fig. I, the present invention comprises a pallet system that has a body including a first portion and a second portion. The first portion is preferably the op portion and the second portion is preferably the bottom portion. The first portion has a generally planar outer surface and an inner surface at least a portion of which is distant the outer surface. The inner surface of the first portion is non-planar. In one preferred embodiment adjacent one set of outer edges, the imier surface has a pair of generally U-shaped feet that extend from one edge of the pallet to an opposing edge. Preferably, at the bottom of each foot is a rib that extends the length of the foot. Inside each foot and parallel to it is a chamiel. Between the channels and parallel to them is a middle support having generally the same width as each channel. The middle support extends away from the outer surface a distance less than the distance that the feet extend away from the outer surface.
The channels and middle support has a succession of curves having spaced apart ridges that define grooves.
The second portion has an outer surface and an inner surface at least a portion of which is distant the outer surface. The inner surfaces of the first and second portions each have complementary undulating forms. The inner surfaces of the first and second portions each include a succession of curves.
Fig. 16 is a side view of the pallet of Fig. 13; and Fig. 17 is an exploded top-perspective view of yet still another embodiment of the pallet of the present invention;
Fig. 18 is an exploded bottom-perspective view of the pallet of Fig. 17;
Fig. 19 s sectional schematic with a magnified view of the pallet of Fig.l7;
Fig.20 is a side view of another embodiment of the present invention; and Fig. 21 is a schematic illustrating the method of the present invention.
In describing the preferred embodiment of the invention, which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity.
However, it is not intended that the invention be limited to the specific terms so selected and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. For example, the word "connected" or teens similar thereto are often used. They are not limited to direct connection but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art.
DETAILED DESCRIPTION
The present invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments described in detail in the following description, 1. Resume As shown in the embodiment of Fig. I, the present invention comprises a pallet system that has a body including a first portion and a second portion. The first portion is preferably the op portion and the second portion is preferably the bottom portion. The first portion has a generally planar outer surface and an inner surface at least a portion of which is distant the outer surface. The inner surface of the first portion is non-planar. In one preferred embodiment adjacent one set of outer edges, the imier surface has a pair of generally U-shaped feet that extend from one edge of the pallet to an opposing edge. Preferably, at the bottom of each foot is a rib that extends the length of the foot. Inside each foot and parallel to it is a chamiel. Between the channels and parallel to them is a middle support having generally the same width as each channel. The middle support extends away from the outer surface a distance less than the distance that the feet extend away from the outer surface.
The channels and middle support has a succession of curves having spaced apart ridges that define grooves.
The second portion has an outer surface and an inner surface at least a portion of which is distant the outer surface. The inner surfaces of the first and second portions each have complementary undulating forms. The inner surfaces of the first and second portions each include a succession of curves.
5 The outer surface of the second portion includes at least a pair of channels that extend from one edge to an opposing edge. The pair of channels is dimensioned a configured to receive tines of a forklift. On each outer side of the tine-accepting channels is a leg with at least one foot at extends parallel to the channels from one edge to an opposing edge and that rests on a surface.
In a preferred erribodiment, the feet run the longitudinal length of the pallet. In between the pair 1'0 of channels is a support that extends parallel to the channels and preferably spans the longitudinal length of the pallet.
The inner surfaces of the ftrst and second portions each includes a succession of curves having rises and falls that run perpendicular to the series of ridges and grooves on the outer surface of the second portion.
The inner surface of the first portion is molded to the inner surface of the second portion.
The outer surface of the second portion comprises a series of ridges and grooves.
The outer surface of the ftrst portion is generally planar such that, e.g., boxes can be stacked upon it.
The inner surface of the first portion is connected to the inner surface of the second portion. The inner surface of the ftrst portion and the inner surface of the second portion comprise complementarily shaped surfaces.
2. Presently Preferred Embodiments With reference now to the drawing ftgures in which like reference numerals designate like parts throughout the disclosure, Fig. 1 sliows a pallet system 5 of the present invention.
As best shown in Figs. lA-Fig. 4, the pallet system 5 consists of a pallet body 10 having a ftrst or upper portion 12 with a first outer surface 14 and a first inner surface 16 (see Fig. 4). The pallet body also has a second or bottom portion 20 having a second outer surface 22 and a second inner surface 24 (see, e.g., Figs. 2 and 3). A ftrst distant portion 18 is also contained in the first portion 12 and a second distant portion 26 is contained in the second portion 20 (see Fig. 1A).
The ftrst portion 12 preferably has a first set of protnisions 30 which connect to the second portion 20. In one preferred embodiment, protnisions 30 interdigitate between a second set of protrusions 32 1 ocated on the second portion 20 (see Fig. 3).
As best shown in Fig. 4, a first leg 38 and a second leg 39 may also be provided on the pallet body 10. In other embodiments, these legs acW ally may be made up of one or more feet (40, 41, 42,43, 44, and 45) as shown in Figs. 7 through 12. As shown in yet another embodiment (Figs. 13-15), the legs 38, 39 are preferably formed from an extension 51 on the first portion 12 that is received by a channel 46 on the second portion 20 as best shown in Fig. 15.
In one embodiment, one significant feature is that a plurality of con-ugations 56a, 58a from the first portion 12 preferably interconnect with a plurality of corrugations 56b, 58b from the second portion 20. The cornxgations may be made up of a combination of humps 56 and valleys 58 in combination with ridges 52 and grooves 48 (see, e.g., Figs. 4, 12 and 14). The ridges, humps, valleys and grooves may have various shapes and sizes. When the corrugations are mated together, the upper corrugations 56a, 58a may have extending members 76 in the middle between the tine holes which fit into cavities 78 in the tine holes on the lower corrugations 56b, 58b (see Fig. 14).
The corrugations may run along the X direction and/or the y direction.
Preferably, the Y
direction is 48-inches and the X direction is 40-inches.
As shown in Fig. 15, one preferred embodiment also has apertures 80 which receive ribs or locking members 82. Escape holes 84 may also be formed in the first portion 12 and the second portion 20 by mold form pins (not shown) to allow the injected gases that are inserted in the blow molding process to properly escape. When the extending W embers 76 and the cavity 78 come together while the blow molded plastic portions are still hot, they may form an attachment or tack- off point 90 (see Figs. l, 7, 9).
As shown in Fig. 13, the embodiment may have inserts 94 that are formed from a more rubberized plastic (e.g., EVA). This material also has greater friction to prevent loads from slipping off an otherwise slick polyethylene top surface. Alternatively, a coating 96 may be applied as shown in Fig. 11 where it is shown applied to one half of the first outer surface 14.
In one embodiment, best shown in Fig. 16, the body 10 of the pallet system is "bowed" at an angle a from the horizontal plane. Angle a is preferably 6° or less.
2. Manufacture The presently preferred embodiments are preferably manufactured in several ways.
Fig. 17 shows a general process flow diagram illustrating the method used to construct the pallet of the present invention. The process begins preferably with the first forming of the bottom portion in a conventional blow molding form having two halves. The cycle times and molding characteristics are adjusted to the materials being molded. When inserts are required they may be molded in a separate injection molding process. The bottom portion is formed to mate with the mold form used to blow mold the top portion. Additional chemical bond or bon-promoting agents may be used or some roughening of the surface may also be used to enhance bonding. A gap or air port may be provided between these pieces so that air can be released during the bonding of the two portions together. Such a gap normally occurs around the midline or pinch-off area where the mold halves meet.
Fig. 6 depicts one pair of symmetrical extrusion mold forms that are used to form a pallet portion. Water-cooling channels within the mold form (not shown), parison pinch-offs (not shown) and air/gas access ports or needles (not shown) are provided in conventional fashion within the mold form to effect proper molding. It may be necessary to provide grooves, clamps, or other retaining mechanisms within the mold to provide retention of the lower piece into the mold foim for the upper piece.
First, various types of plastic (e.g., virgin and recycled) are added to a hopper. The hopper feeds an extruder where the plastic is heated. A parison of molten plastic (e.g., a polyethylene material) is next extruded and vertically suspended between mold halves.
Typically, the material is heated to a molten state and the temperature is in the range from 350°F
to 450°F. One the material is introduced into the mold form, the parison is pinched off as the mold closes. After the mold closes about the parison, an air or gas is injected via one or more injection needles into the parison. The air is directed such that the material is blown onto the contoured wall surfaces of the mold forms.
The pallet portions may be made out of a variety of materials such as linear low Polyethylene (LLPE), high-density polyethylene (HDPE), and/or may include some natural rubber. For example, a mixture of 20% to 30% polyethylene and a natural rubber product called Duraprene may be used. This allows for a flexible yet strong pallet which can properly carry o three thousand pounds. One preferred material will the meet the following ASTM stand D297, D412, Die G, D624, Die C, F36, D2240, F147, D471,as well as ASTM #1, #3, and Fuel A and Fuel C. Duraprene can be obtained through a company called Lamatelc (see htt ://www.lamatek.com .
Next, the bottom portion is placed into a mold form to make an upper portion.
Retaining pins or clamps may hold the bottom portion in the mold form. Parison is again extruded between the mold form halves and the above process begins again. The blown polyethylene material thereby retains the bottom portion against the mold walls. During this insert molding process, other already formed pieces (such as rings to add surface friction) may also be inserted into the blow mold form (having two halves) where they are retained during the blow molding process and integrally bonded into one of the newly formed blow-molded surfaces. Relative temperatures of the inserted pieces and/or bottom portion and the material are such that the hot material coats and melts the inner surface of the pieces and/or the portion to coalesce and form integral bond with one another. Depending on the materials, the mold forms may also preheat and soften the pieces and/or portions. For the pieces, an EEA
material may be used while polyethylene may be used for the portions.
The EEA material used has a melt temperature typically in the range of 250°F to 300°F
and the preferred polyethylene material typically has a melt temperature in the range of 375° to 450°F. Other relative temperature ranges could be used, provided the materials will flow melt bond to one another. It is important that the dwell time of each mold is properly set to prevent the formation of air pockets at the bonding surface that can prevent proper lamination.
Further increasing the cooling time may be necessary to prevent any sinking or shrinking of the bonding surface. Again, which could produce unwanted delamination.
Alternatively, reducing the dwell time helps to release air which becomes trapped at the bonding surface during molding. Typical cycle times of lx to 2x at air gas pressures of 80 psi to 150 psi and dwell times of 1y to 1.5y, where y and x are comparable values for non-composite pieces of identical design.
While the pallet body 10 is preferably formed from two blow mold portions, it is possible the portions may be formed by injection molding, theimo-forming, or another plastic molding process.
The depths of any grooves or projections (e.g., Fig. 15 references 80, 82) that are used to enhance bonding can be adjusted to take into account shrinking and/or melting that occurs at the bonding of the surface. The projections may comprise annular or lateral ribs or studs or combinations thereof. Dovetail projections or studs with heads may also be used. Some projections may serve to retain a tread piece while others create an air channel and melt away.
As shown in Figs. 13-16, the upper portion 12 may be made of a first plastic mixture and the bottom portion 20 may be made of a second plastic mixture. Such mixtures may give the give the upper and bottom portions different relative anti-slippage or weight-bearing properties.
For example, the upper portion material (e.g., EEA and real rubber) may be stiffer while the bottom portion material may have greater impact strength.
The pre-formed insert pieces 94 are preferably constructed from a 1 ow density, relatively soft polyethylene material of the polyoleEn family. The material particularly comprises an ethylene-ethyl acrylate (EEA). This material doesn't readily bond to polyethylene using traditional adhesion methods, such as RF sealing, ultrasonic bonding or spin welding. EEA, however, is commercially available in a number of compositions that accommodate a variety of operating temperahmes or melt ranges below that of the materials used to blow mold the pallet 5.
Two 18% EEA compositions having respective 20 and 6 melt ranges have been shown to be desirable. The lower temperature (i.e. 20 melt) material is softer and reeadily assures proper bonding, but is less scuff resistant. Alternative pre-formed insert materials may comprise ethyl-vinyl acetate (EVA), low- density polyethylene (LDPE) or linear, low-density polyethylene (LLDPE). Variations of the foregoing materials may also be blended, as necessary, to provide desirable mechanical properties for particular application.
An EEA pre-formed insert material is presently preferred for the pallet 5 because it is relatively durable and readily bonds under flow melt conditions to the polyethylene upper portion. The EA material is also less dense than many materials, in particular, the polyethylene materials used to typically mold the pallet. The pre-formed insert 94 thus exhibits a softer texture than the pallet top portion 12, which produces improved traction between the pallet and the load: Depending upon the application, it may however be desirable to use a harder pre-formed insert material, similar to that of the pallet top portion 12.
In the embodiments shown in Figs. 17-20, pallet 99 has a body 100. The runners attached to the body 100 that are preferably designed with a slight radius 102, 103 on the outside edges 104, 105 to add strength and durability and to prevent the pallet 99 from getting hung up on expansion joints in a warehouse floor or a conveyor and also to prevent breakage of fragile comers or edges. In this embodiment, all of the pallet body's edges (e.g.,125) have radiused corners (see e.g, 106, 108, 110, 112, 114, and 116).
This palllet 99 may also have three components 118, 120, and 122 (a top, middle and bottom section respectively as shown in Figs 17 -19) or two components (e.g., a top and bottom section as shown in Fig. 20) depending on the application. For example, the three-portion pallet would be used for more heavy-duty applications while the two-portion pallet may be used for medium-duty applications. The same molds may be used make the top sections and bottom sections of the three portion and two portion pallets. However, as can be seen, a middle section mold is only likely to be used by the three-portion heavy-duty pallet.
When the portions are insert molded, the portion weld points or tack or kiss-offs 126 are preferably found at both the peaks 130 and the valleys 132 of the inner aces 140, 141, 142, 143 where the portions 118, 120, and 122 meet as shown in Fig. 18. This feature gives added structural strength and stability to the pallet 99. Fig. 19 illustrates this embodiment of the blow-molded pallet 99 has a 0.5 inch lip 150 around the center edge 160. The lip 150 allows for easier handling by pallet transfer equipment and provides an anchor point for plastic shrink-wrap and/or tie down straps.
In the preferred embodiment shown in Figs. 17-19, the rumlers are preferably about 4.75 inches high and about 6.5 inches wide. The peaks extend to a height about 0.75 inches from the inner surface and are about 1 inch wide. The pallet from top surface to bottom surface is approximately 5.75 inches high. The length of the pallet may be 40 inches and the width may be 48 inches.
The runners or legs 101 are preferably formulated from a puncture resistant HDPE plastic 5 resin. These HDPE plastics may be acquired from FORMOSA PLASTICS CORPORATION
USA (see www.fpcusa.com) and may, for example, include hexane copolymers, homopolymers, extra high molecular weight copolymers having densities between about 0.945 -0.955 g/cc and melt indexes about 0.30 -10.0 (HLMI) min. Alternatively, puncture resistant properties may be added by blending in plastics with these characteristics into the typical polyethylene material.
In a preferred erribodiment, the feet run the longitudinal length of the pallet. In between the pair 1'0 of channels is a support that extends parallel to the channels and preferably spans the longitudinal length of the pallet.
The inner surfaces of the ftrst and second portions each includes a succession of curves having rises and falls that run perpendicular to the series of ridges and grooves on the outer surface of the second portion.
The inner surface of the first portion is molded to the inner surface of the second portion.
The outer surface of the second portion comprises a series of ridges and grooves.
The outer surface of the ftrst portion is generally planar such that, e.g., boxes can be stacked upon it.
The inner surface of the first portion is connected to the inner surface of the second portion. The inner surface of the ftrst portion and the inner surface of the second portion comprise complementarily shaped surfaces.
2. Presently Preferred Embodiments With reference now to the drawing ftgures in which like reference numerals designate like parts throughout the disclosure, Fig. 1 sliows a pallet system 5 of the present invention.
As best shown in Figs. lA-Fig. 4, the pallet system 5 consists of a pallet body 10 having a ftrst or upper portion 12 with a first outer surface 14 and a first inner surface 16 (see Fig. 4). The pallet body also has a second or bottom portion 20 having a second outer surface 22 and a second inner surface 24 (see, e.g., Figs. 2 and 3). A ftrst distant portion 18 is also contained in the first portion 12 and a second distant portion 26 is contained in the second portion 20 (see Fig. 1A).
The ftrst portion 12 preferably has a first set of protnisions 30 which connect to the second portion 20. In one preferred embodiment, protnisions 30 interdigitate between a second set of protrusions 32 1 ocated on the second portion 20 (see Fig. 3).
As best shown in Fig. 4, a first leg 38 and a second leg 39 may also be provided on the pallet body 10. In other embodiments, these legs acW ally may be made up of one or more feet (40, 41, 42,43, 44, and 45) as shown in Figs. 7 through 12. As shown in yet another embodiment (Figs. 13-15), the legs 38, 39 are preferably formed from an extension 51 on the first portion 12 that is received by a channel 46 on the second portion 20 as best shown in Fig. 15.
In one embodiment, one significant feature is that a plurality of con-ugations 56a, 58a from the first portion 12 preferably interconnect with a plurality of corrugations 56b, 58b from the second portion 20. The cornxgations may be made up of a combination of humps 56 and valleys 58 in combination with ridges 52 and grooves 48 (see, e.g., Figs. 4, 12 and 14). The ridges, humps, valleys and grooves may have various shapes and sizes. When the corrugations are mated together, the upper corrugations 56a, 58a may have extending members 76 in the middle between the tine holes which fit into cavities 78 in the tine holes on the lower corrugations 56b, 58b (see Fig. 14).
The corrugations may run along the X direction and/or the y direction.
Preferably, the Y
direction is 48-inches and the X direction is 40-inches.
As shown in Fig. 15, one preferred embodiment also has apertures 80 which receive ribs or locking members 82. Escape holes 84 may also be formed in the first portion 12 and the second portion 20 by mold form pins (not shown) to allow the injected gases that are inserted in the blow molding process to properly escape. When the extending W embers 76 and the cavity 78 come together while the blow molded plastic portions are still hot, they may form an attachment or tack- off point 90 (see Figs. l, 7, 9).
As shown in Fig. 13, the embodiment may have inserts 94 that are formed from a more rubberized plastic (e.g., EVA). This material also has greater friction to prevent loads from slipping off an otherwise slick polyethylene top surface. Alternatively, a coating 96 may be applied as shown in Fig. 11 where it is shown applied to one half of the first outer surface 14.
In one embodiment, best shown in Fig. 16, the body 10 of the pallet system is "bowed" at an angle a from the horizontal plane. Angle a is preferably 6° or less.
2. Manufacture The presently preferred embodiments are preferably manufactured in several ways.
Fig. 17 shows a general process flow diagram illustrating the method used to construct the pallet of the present invention. The process begins preferably with the first forming of the bottom portion in a conventional blow molding form having two halves. The cycle times and molding characteristics are adjusted to the materials being molded. When inserts are required they may be molded in a separate injection molding process. The bottom portion is formed to mate with the mold form used to blow mold the top portion. Additional chemical bond or bon-promoting agents may be used or some roughening of the surface may also be used to enhance bonding. A gap or air port may be provided between these pieces so that air can be released during the bonding of the two portions together. Such a gap normally occurs around the midline or pinch-off area where the mold halves meet.
Fig. 6 depicts one pair of symmetrical extrusion mold forms that are used to form a pallet portion. Water-cooling channels within the mold form (not shown), parison pinch-offs (not shown) and air/gas access ports or needles (not shown) are provided in conventional fashion within the mold form to effect proper molding. It may be necessary to provide grooves, clamps, or other retaining mechanisms within the mold to provide retention of the lower piece into the mold foim for the upper piece.
First, various types of plastic (e.g., virgin and recycled) are added to a hopper. The hopper feeds an extruder where the plastic is heated. A parison of molten plastic (e.g., a polyethylene material) is next extruded and vertically suspended between mold halves.
Typically, the material is heated to a molten state and the temperature is in the range from 350°F
to 450°F. One the material is introduced into the mold form, the parison is pinched off as the mold closes. After the mold closes about the parison, an air or gas is injected via one or more injection needles into the parison. The air is directed such that the material is blown onto the contoured wall surfaces of the mold forms.
The pallet portions may be made out of a variety of materials such as linear low Polyethylene (LLPE), high-density polyethylene (HDPE), and/or may include some natural rubber. For example, a mixture of 20% to 30% polyethylene and a natural rubber product called Duraprene may be used. This allows for a flexible yet strong pallet which can properly carry o three thousand pounds. One preferred material will the meet the following ASTM stand D297, D412, Die G, D624, Die C, F36, D2240, F147, D471,as well as ASTM #1, #3, and Fuel A and Fuel C. Duraprene can be obtained through a company called Lamatelc (see htt ://www.lamatek.com .
Next, the bottom portion is placed into a mold form to make an upper portion.
Retaining pins or clamps may hold the bottom portion in the mold form. Parison is again extruded between the mold form halves and the above process begins again. The blown polyethylene material thereby retains the bottom portion against the mold walls. During this insert molding process, other already formed pieces (such as rings to add surface friction) may also be inserted into the blow mold form (having two halves) where they are retained during the blow molding process and integrally bonded into one of the newly formed blow-molded surfaces. Relative temperatures of the inserted pieces and/or bottom portion and the material are such that the hot material coats and melts the inner surface of the pieces and/or the portion to coalesce and form integral bond with one another. Depending on the materials, the mold forms may also preheat and soften the pieces and/or portions. For the pieces, an EEA
material may be used while polyethylene may be used for the portions.
The EEA material used has a melt temperature typically in the range of 250°F to 300°F
and the preferred polyethylene material typically has a melt temperature in the range of 375° to 450°F. Other relative temperature ranges could be used, provided the materials will flow melt bond to one another. It is important that the dwell time of each mold is properly set to prevent the formation of air pockets at the bonding surface that can prevent proper lamination.
Further increasing the cooling time may be necessary to prevent any sinking or shrinking of the bonding surface. Again, which could produce unwanted delamination.
Alternatively, reducing the dwell time helps to release air which becomes trapped at the bonding surface during molding. Typical cycle times of lx to 2x at air gas pressures of 80 psi to 150 psi and dwell times of 1y to 1.5y, where y and x are comparable values for non-composite pieces of identical design.
While the pallet body 10 is preferably formed from two blow mold portions, it is possible the portions may be formed by injection molding, theimo-forming, or another plastic molding process.
The depths of any grooves or projections (e.g., Fig. 15 references 80, 82) that are used to enhance bonding can be adjusted to take into account shrinking and/or melting that occurs at the bonding of the surface. The projections may comprise annular or lateral ribs or studs or combinations thereof. Dovetail projections or studs with heads may also be used. Some projections may serve to retain a tread piece while others create an air channel and melt away.
As shown in Figs. 13-16, the upper portion 12 may be made of a first plastic mixture and the bottom portion 20 may be made of a second plastic mixture. Such mixtures may give the give the upper and bottom portions different relative anti-slippage or weight-bearing properties.
For example, the upper portion material (e.g., EEA and real rubber) may be stiffer while the bottom portion material may have greater impact strength.
The pre-formed insert pieces 94 are preferably constructed from a 1 ow density, relatively soft polyethylene material of the polyoleEn family. The material particularly comprises an ethylene-ethyl acrylate (EEA). This material doesn't readily bond to polyethylene using traditional adhesion methods, such as RF sealing, ultrasonic bonding or spin welding. EEA, however, is commercially available in a number of compositions that accommodate a variety of operating temperahmes or melt ranges below that of the materials used to blow mold the pallet 5.
Two 18% EEA compositions having respective 20 and 6 melt ranges have been shown to be desirable. The lower temperature (i.e. 20 melt) material is softer and reeadily assures proper bonding, but is less scuff resistant. Alternative pre-formed insert materials may comprise ethyl-vinyl acetate (EVA), low- density polyethylene (LDPE) or linear, low-density polyethylene (LLDPE). Variations of the foregoing materials may also be blended, as necessary, to provide desirable mechanical properties for particular application.
An EEA pre-formed insert material is presently preferred for the pallet 5 because it is relatively durable and readily bonds under flow melt conditions to the polyethylene upper portion. The EA material is also less dense than many materials, in particular, the polyethylene materials used to typically mold the pallet. The pre-formed insert 94 thus exhibits a softer texture than the pallet top portion 12, which produces improved traction between the pallet and the load: Depending upon the application, it may however be desirable to use a harder pre-formed insert material, similar to that of the pallet top portion 12.
In the embodiments shown in Figs. 17-20, pallet 99 has a body 100. The runners attached to the body 100 that are preferably designed with a slight radius 102, 103 on the outside edges 104, 105 to add strength and durability and to prevent the pallet 99 from getting hung up on expansion joints in a warehouse floor or a conveyor and also to prevent breakage of fragile comers or edges. In this embodiment, all of the pallet body's edges (e.g.,125) have radiused corners (see e.g, 106, 108, 110, 112, 114, and 116).
This palllet 99 may also have three components 118, 120, and 122 (a top, middle and bottom section respectively as shown in Figs 17 -19) or two components (e.g., a top and bottom section as shown in Fig. 20) depending on the application. For example, the three-portion pallet would be used for more heavy-duty applications while the two-portion pallet may be used for medium-duty applications. The same molds may be used make the top sections and bottom sections of the three portion and two portion pallets. However, as can be seen, a middle section mold is only likely to be used by the three-portion heavy-duty pallet.
When the portions are insert molded, the portion weld points or tack or kiss-offs 126 are preferably found at both the peaks 130 and the valleys 132 of the inner aces 140, 141, 142, 143 where the portions 118, 120, and 122 meet as shown in Fig. 18. This feature gives added structural strength and stability to the pallet 99. Fig. 19 illustrates this embodiment of the blow-molded pallet 99 has a 0.5 inch lip 150 around the center edge 160. The lip 150 allows for easier handling by pallet transfer equipment and provides an anchor point for plastic shrink-wrap and/or tie down straps.
In the preferred embodiment shown in Figs. 17-19, the rumlers are preferably about 4.75 inches high and about 6.5 inches wide. The peaks extend to a height about 0.75 inches from the inner surface and are about 1 inch wide. The pallet from top surface to bottom surface is approximately 5.75 inches high. The length of the pallet may be 40 inches and the width may be 48 inches.
The runners or legs 101 are preferably formulated from a puncture resistant HDPE plastic 5 resin. These HDPE plastics may be acquired from FORMOSA PLASTICS CORPORATION
USA (see www.fpcusa.com) and may, for example, include hexane copolymers, homopolymers, extra high molecular weight copolymers having densities between about 0.945 -0.955 g/cc and melt indexes about 0.30 -10.0 (HLMI) min. Alternatively, puncture resistant properties may be added by blending in plastics with these characteristics into the typical polyethylene material.
10 Puncture resistance of the plastic is desirable in some applications because some pallets are frequently moved by forklifts bearing sharp tines or forks.
Of course, one of ordinary skilled may see other possible changes to the pallet designs for example with the corrugations running in the 40-inch direction. In the some of the above described embodiments, the corrugations in the bottom portion the pallet stop at the inside face of the runners, with the top surface (of the bottom portion) dropping into the runners. However, another design change (see, e.g., Figs. 17-19) involves rumiing the con-ugations to the outside of the runners, except at each end of the runner where the top surface will continue to drop into the runner. This change will help to stiffen the runners (rotationally), but still provide an extra layer at the ends of the runners that see impact from forks.
Adding additional structural rigidity may be accomplished by adding aluminum or steel inserts, running the length of the runners, in, for example, the four-way pallet design.
The individual components described herein need not necessarily be formed in the disclosed shapes or assembled in the disclosed configuration, but could be provided in virtually any shape, and assembled in virtually any conftguration. Furthermore, all the disclosed features of each disclosed embodiment can be combined with, or substituted for, the disclosed features of every other disclosed embodiment except where such features are mutually exclusive. Finally, it is intended that the appended claims cover all such additions modiftcations and rearrangements.
Expedient embodiments of the present invention are differentiated by the appended claims.
What is claimed is:
Of course, one of ordinary skilled may see other possible changes to the pallet designs for example with the corrugations running in the 40-inch direction. In the some of the above described embodiments, the corrugations in the bottom portion the pallet stop at the inside face of the runners, with the top surface (of the bottom portion) dropping into the runners. However, another design change (see, e.g., Figs. 17-19) involves rumiing the con-ugations to the outside of the runners, except at each end of the runner where the top surface will continue to drop into the runner. This change will help to stiffen the runners (rotationally), but still provide an extra layer at the ends of the runners that see impact from forks.
Adding additional structural rigidity may be accomplished by adding aluminum or steel inserts, running the length of the runners, in, for example, the four-way pallet design.
The individual components described herein need not necessarily be formed in the disclosed shapes or assembled in the disclosed configuration, but could be provided in virtually any shape, and assembled in virtually any conftguration. Furthermore, all the disclosed features of each disclosed embodiment can be combined with, or substituted for, the disclosed features of every other disclosed embodiment except where such features are mutually exclusive. Finally, it is intended that the appended claims cover all such additions modiftcations and rearrangements.
Expedient embodiments of the present invention are differentiated by the appended claims.
What is claimed is:
Claims (23)
1. A pallet comprising:
a) a first portion having an outer surface and an inner surface at least a portion of which is distant the outer surface; and b) a second portion having an outer surface and an inner surface at least a portion of which is distant the outer surface, wherein the inner surface of the first portion interdigitates with the inner surface of the second portion.
a) a first portion having an outer surface and an inner surface at least a portion of which is distant the outer surface; and b) a second portion having an outer surface and an inner surface at least a portion of which is distant the outer surface, wherein the inner surface of the first portion interdigitates with the inner surface of the second portion.
2. The pallet of claim 1 wherein the inner surface of the first portion and the inner surface of the second portion comprise complementarily shaped surfaces.
3. The pallet of claim 1 wherein the inner surfaces of the first and second portions each have an undulating form.
4. The pallet of claim 1 wherein inner surfaces of the first and second portions each comprise a succession of curved protrusions.
5. The pallet of claim 1 wherein the outer surface of the second portion comprises at least two segments that are closer to the first portion than the remainder of the second portion.
6. The pallet of claim 1 wherein the outer surface of the second portion comprises at least two feet.
7. The pallet of claim 1 wherein the outer surface of the second portion comprises a series of ridges and grooves.
8. The pallet of claim 7 wherein the inner surfaces of the first and second portions each comprise a succession of curves having rises and falls that run perpendicular to the series of ridges and grooves on the outer surface of the second portion and further comprising tine accepting channels in the second portion.
9. The pallet of claim 1 wherein the outer surface of the first portion is generally planar.
10. The pallet of claim 1 wherein:
a) the inner surface of the first porti is molded to the inner surface the second portion;
b) the pallet is formed from puncture-resistant plastics; and c) tack of points are located along peaks and valleys of the portions.
a) the inner surface of the first porti is molded to the inner surface the second portion;
b) the pallet is formed from puncture-resistant plastics; and c) tack of points are located along peaks and valleys of the portions.
11. A pallet comprising a pallet body including:
a) a first portion having an outer surface and an inner surface having at least a portion of which that is distant the outer surface and having a corrugating form;
b) a second portion having an outer surface and an inner surface having at least a portion of which that is distant the outer surface and having a corrugating form; and
a) a first portion having an outer surface and an inner surface having at least a portion of which that is distant the outer surface and having a corrugating form;
b) a second portion having an outer surface and an inner surface having at least a portion of which that is distant the outer surface and having a corrugating form; and
12 c) wherein the inner surface of the first portion is connected to the inner surface of the second portion between each respective corrugating form.
12. The pallet of claim 11 wherein the inner surface of the first portion is molded to the inner surface of the second portion.
12. The pallet of claim 11 wherein the inner surface of the first portion is molded to the inner surface of the second portion.
13. A method of forming a pallet comprising the steps of:
a) blow molding a first portion having an outer surface and an inner surface at least a portion of which is distant the outer surface; and b) blow molding a second portion having an outer surface and inner surface at least a portion of which is distant the outer surface around the first portion.
a) blow molding a first portion having an outer surface and an inner surface at least a portion of which is distant the outer surface; and b) blow molding a second portion having an outer surface and inner surface at least a portion of which is distant the outer surface around the first portion.
14. The method of claim 13 wherein one of the first portion and the second portion is inserted into a mold shaping the other one of the first portion and the second portion prior to the blow molding of the other one of the first portion and the second portion.
15. A blow-molded pallet comprising:
a) a bottom portion having a first bottom surface and a first top surface wherein said top surface has a first set of channels and protrusions;
b) an upper portion having a second top surface and a second bottom surface having a second set of channels and protrusions; and c) wherein the second set of channels and protrusions of the upper portion interlock with the first set of protrusions and channels respectively of the bottom portion.
a) a bottom portion having a first bottom surface and a first top surface wherein said top surface has a first set of channels and protrusions;
b) an upper portion having a second top surface and a second bottom surface having a second set of channels and protrusions; and c) wherein the second set of channels and protrusions of the upper portion interlock with the first set of protrusions and channels respectively of the bottom portion.
16. The pallet of claim 15, wherein the upper portion and the bottom portion are fused by applying heat to one of the portions and pressing the two portions together.
17. The pallet of claim 15, wherein at least one portion contains cavities and wherein the other portion contains an extending member which is inserted into the cavity during molding to lock one portion to another portion.
18. The pallet of claim 15, wherein one portion contains a locking member, and wherein the other portion contains a receiving member so that the locking member and receiving member communicate to lock one portion to the other portion.
19. The pallet of claim 15, wherein one portion has at least one tack of point that allows the upper portion to become attached to the bottom portion.
20. The pallet of claim 15, wherein the upper portion includes at least one leg, and wherein the bottom portion includes one foot having a hollow portion for receiving a foot of the upper portion.
21. The pallet of claim 15, further comprising an upper portion first en and an upper portion second end included with the upper portion; and a bottom portion first end and a bottom portion second end included with the bottom portion, wherein at least the upper first end mates with the bottom first end.
22. The pallet of claim 15, wherein the upper portion and the bottom portion are fused during molding.
23. The pallet of claim 15, further comprising:
a) a lip extending from the pallet;
b) radiused corners on edges of the pallet; and c) a third blow molded portion.
a) a lip extending from the pallet;
b) radiused corners on edges of the pallet; and c) a third blow molded portion.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/601,138 | 2003-06-20 | ||
US10/601,138 US20040255828A1 (en) | 2003-06-20 | 2003-06-20 | Blow molded pallet with wave-like supports |
PCT/US2004/004567 WO2004074118A2 (en) | 2003-02-17 | 2004-02-17 | Blow molded pallet with pre-formed inserts |
USPCT/US04/004567 | 2004-02-17 | ||
PCT/US2004/019824 WO2004113179A2 (en) | 2003-06-20 | 2004-06-21 | Blow molded pallet with wave-like supports |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2530017A1 true CA2530017A1 (en) | 2004-12-29 |
Family
ID=33544773
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002530017A Abandoned CA2530017A1 (en) | 2003-06-20 | 2004-06-21 | Blow molded pallet with wave-like supports |
Country Status (2)
Country | Link |
---|---|
CA (1) | CA2530017A1 (en) |
WO (1) | WO2004113179A2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NZ542334A (en) * | 2005-11-07 | 2008-08-29 | Pallenz Plastics Ltd | Method of construction |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3720176A (en) * | 1970-08-13 | 1973-03-13 | Moraine Box Co | Molded pallet |
US5401347A (en) * | 1992-12-18 | 1995-03-28 | Shuert; Lyle H. | Method of making a panel structure and pallet utilizing same |
US5470641A (en) * | 1992-12-18 | 1995-11-28 | Shuert; Lyle H. | Panel structure |
DE29717902U1 (en) * | 1997-10-08 | 1998-02-19 | Hsieh, Chuan-Jen, Taoyuan | Pressed pallet |
US6112672A (en) * | 1999-05-28 | 2000-09-05 | Burnham Service Company, Inc. | Selectively arrangeable pallet |
US6718888B2 (en) * | 2000-04-11 | 2004-04-13 | Nextreme, Llc | Thermoformed platform |
-
2004
- 2004-06-21 CA CA002530017A patent/CA2530017A1/en not_active Abandoned
- 2004-06-21 WO PCT/US2004/019824 patent/WO2004113179A2/en active Application Filing
Also Published As
Publication number | Publication date |
---|---|
WO2004113179A3 (en) | 2006-02-09 |
WO2004113179A2 (en) | 2004-12-29 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6962115B2 (en) | Blow molded pallet with pre-formed inserts | |
US20040255828A1 (en) | Blow molded pallet with wave-like supports | |
US8141500B2 (en) | Plastic pallet with sleeved reinforcing rods and associated method for making the same | |
US6976437B2 (en) | Blow molded pallet with inserts | |
RU2152894C2 (en) | Thermoplastic pallet | |
US8215244B2 (en) | Plastic pallet | |
US5527585A (en) | Molded structure | |
US5046434A (en) | Plastic reinforced thermoformed pallet | |
US6807911B2 (en) | Pallet with stress resistant structure | |
US7086340B2 (en) | Pallet assembly | |
US6386118B1 (en) | Pallet with stress resistant structure | |
NZ299185A (en) | Thermoformed pallet comprises plastics structure formed from twin-sheet thermoplastics sheeting and having a load supporting deck and feet | |
CA2577658A1 (en) | Pallet | |
US20170088309A1 (en) | Pallet and method of making a pallet | |
CA2530017A1 (en) | Blow molded pallet with wave-like supports | |
US5922269A (en) | Plastic pallet | |
AU707915B2 (en) | Lightweight plastic pallet | |
MXPA01000202A (en) | Pallet assembly | |
JPS5881135A (en) | Manufacture of synthetic resin pallet |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
FZDE | Discontinued |