US20070000415A1 - Thermoplastic article having portions with different fire resistances - Google Patents
Thermoplastic article having portions with different fire resistances Download PDFInfo
- Publication number
- US20070000415A1 US20070000415A1 US11/358,867 US35886706A US2007000415A1 US 20070000415 A1 US20070000415 A1 US 20070000415A1 US 35886706 A US35886706 A US 35886706A US 2007000415 A1 US2007000415 A1 US 2007000415A1
- Authority
- US
- United States
- Prior art keywords
- pallet
- deck
- thermoplastic article
- accordance
- fire retardant
- 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
- 229920001169 thermoplastic Polymers 0.000 title claims abstract description 23
- 239000004416 thermosoftening plastic Substances 0.000 title claims abstract description 23
- 239000003063 flame retardant Substances 0.000 claims abstract description 37
- 239000000203 mixture Substances 0.000 claims abstract description 10
- 239000004033 plastic Substances 0.000 claims description 15
- 229920003023 plastic Polymers 0.000 claims description 15
- 238000000576 coating method Methods 0.000 claims description 4
- 230000003014 reinforcing effect Effects 0.000 claims 1
- 239000010410 layer Substances 0.000 description 11
- 239000000463 material Substances 0.000 description 10
- 238000000034 method Methods 0.000 description 4
- -1 polyethylene Polymers 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000009970 fire resistant effect Effects 0.000 description 3
- 229920001903 high density polyethylene Polymers 0.000 description 3
- 239000004700 high-density polyethylene Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000004743 Polypropylene Substances 0.000 description 2
- ADCOVFLJGNWWNZ-UHFFFAOYSA-N antimony trioxide Chemical compound O=[Sb]O[Sb]=O ADCOVFLJGNWWNZ-UHFFFAOYSA-N 0.000 description 2
- 238000009863 impact test Methods 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000001746 injection moulding Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- RREGISFBPQOLTM-UHFFFAOYSA-N alumane;trihydrate Chemical compound O.O.O.[AlH3] RREGISFBPQOLTM-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 1
- 229910052794 bromium Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000003292 diminished effect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000012815 thermoplastic material Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Images
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
- B65D19/002—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 more than one element
- B65D19/0024—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 more than one element forming discontinuous or non-planar contact surfaces
- B65D19/0026—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 more than one 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
- B65D19/002—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 more than one element
- B65D19/0024—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 more than one element forming discontinuous or non-planar contact surfaces
- B65D19/0028—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 more than one 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
- B65D2519/00009—Materials
- B65D2519/00119—Materials for the construction of the reinforcements
- B65D2519/00129—Metal
-
- 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
- B65D2519/00328—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
- B65D2519/00258—Overall construction
- B65D2519/00398—Overall construction reinforcements
- B65D2519/00432—Non-integral, e.g. inserts
- B65D2519/00442—Non-integral, e.g. inserts on the base surface
-
- 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
- B65D2519/00736—Details
- B65D2519/0086—Protection against environmental hazards, e.g. humidity, bacteria, fire
Definitions
- thermoplastic articles that benefit from fire-resisting properties.
- One method of imparting fire-resisting properties to a plastic is inclusion within the plastic of a fire-retardant component.
- inclusion of such fire retardants even in minimally effective amounts, often carries adverse side effects. More specifically, such fire retardants can decrease mechanical properties and moldability, increase weight and cost, and be environmentally undesirable.
- Fire resistant coatings may also be used, however such coatings are subject to wear and degradation. Once the coating layer is penetrated, particularly with objects having large relative mass, there is little effect.
- Plastic pallets are an example of plastic articles, which might incorporate fire-retardant components therein.
- An important criterion for all pallet uses is that the pallet has adequate fire resisting properties. Indeed, all pallets must pass tests that determine how fast and with what heat evolution pallets burn in a simulated warehouse fire. These same pallets must also pass durability and impact tests.
- Plastic pallets have not gained wide acceptance due in large measure to the failure to satisfactorily meet fire resistance criteria, while additionally meeting the structural and durability standards of Grocery Manufacturers of America (GMA). Pallets should have fire resistance sufficient to not exceed the heat release set by Underwriters Lab Standard 3435. In a test under the standard, pallets are subjected to a fire in a test facility, to simulate a warehouse fire. Any fire resisting pallet also must be strong enough to carry specified loads, must not be too heavy, and must be durable in resisting damage during use, as measured by certain tests and field use.
- One partial solution is to construct the deck of a pallet can from metal, while constructing the rest of the pallet as plastic. That has the effect of reducing the amount of plastic in the pallet and the favorably improving the burn test characteristics, and reducing the gross amount of fire retardant in the pallet.
- thermoplastic article that is satisfactorily fire resistant, and that is also satisfactorily impact resistant or durable.
- thermoplastic article comprising plastic parts that having differing fire resistances.
- rate of heat evolution is concerned compared to the total heat evolution, those portions of a plastic pallet having a higher surface area or those portions of the pallet that are more exposed have higher heat resistances relative to those portions having lower surface areas or those portions that are less exposed.
- a pallet's thermoplastic material has different fire retardant content (composition) is tailored according to the portion of the pallet that the material forms.
- thinner and higher surface area to volume ratio sections have higher fire retardant content than do other sections.
- the edges of the top deck of the pallet, or like areas of some other article that are prone to impact damage have lower fraction of retardant than those portions not prone to impact damage.
- the deck of a pallet has higher fire retardant content than the columns upon which the deck is mounted.
- part of, or all of, the periphery of the deck has less retardant or no retardant, compared to the interior of the deck which has fire retardant.
- a pallet's differing components include a fire resistant coating or layer on portions having a higher surface area or on portions that are more exposed.
- the deck is formed of two or more layers of material that are joined together, wherein the deck comprises a top layer having less fire retardant than a bottom layer.
- FIG. 1 is a cross sectional view of an exemplary pallet
- FIG. 2 is a cross sectional view of an exemplary pallet column
- FIG. 3 is a cross sectional view of an exemplary pallet column and deck
- FIG. 4 is a cross sectional view of an exemplary pallet corner
- FIG. 5 is a cross sectional view of an exemplary pallet deck
- FIG. 6 is a cross sectional view of an exemplary pallet component mold.
- thermoplastics such as high density polyethylene (HDPE) or polypropylene, among others.
- Components of such articles e.g., pallets, may be constructed according to any convenient method, for example by injection molding.
- Solid particulate fire retardants may also be included in the thermoplastic compositions, for example Grafguard graphite intumescent material, aluminum trihydrate, magnesium hydroxide or antimony trioxide (often used with bromine compounds), among others.
- the solid fire retardants may be used in combination with other types of fire retardants, for instance, brominated hydrocarbons. It will be appreciated that the invention may be applied to the inclusion of other ingredients, solid particulate or not, in a pallet and to other articles.
- the present invention recognizes that addition of fire retardants in quantities sufficient to impart minimal to good fire resistance, which in one embodiment, and depending on the material, ranges from 10 to 30 weight percent retardant, correspondingly decreases the fracture toughness of that article.
- the pallet becomes too prone to breakage, particularly around the edges of the pallet where the shanks of the tines of a forklift truck may impact the pallet. Accordingly, an improved article is described, wherein fire resistance of the article is selectively tailored with regard to the geometry and/or position of a component of the article.
- exemplary pallet 20 comprises a deck 22 , which is welded to the columns 26 of base 24 .
- the deck includes a plurality of holes (the deck may take other configurations, e.g., solid or grid-like, among others).
- the columns 26 which have hollows at their top ends, are interconnected by rails 30 .
- Hollow square cross section metal beams 28 are within the rails.
- deck 22 of pallet 20 has a higher concentration of retardant relative to the frame 24 .
- HDPE deck has 10% intumescent composition, and the frame has 5%. (All concentrations are by weight unless otherwise indicated.)
- exemplary pallet 22 A wherein beam 28 is covered by a floor plate 29 .
- the plate 29 is configured to incorporate of the beam 28 within the base and comprises no or low fire retardant relative to other portions of the pallet.
- the beam 28 is strategically engineered to fail in the event of a fire. This is due to the lack of significant fire retardant in the plate 29 .
- the beam 28 will be subjected to heat and will fail according to engineered design.
- An exemplary pallet 20 B is illustrated, wherein such pallet lacks base rails.
- An exemplary deck is a two-layer composite structure, which may be made for example by co-extrusion, by joining one sheet to another, or by injection molding, among other methods.
- the underside layer 27 comprises a first composition with a large amount of fire retardant relative to the top layer 25 .
- Such exemplary configuration provides durability for the top of the deck, but at the same time provides fire protection to the pallet (oftentimes flames will rise up from below, and the lower deck layer provides a lower barrier relative to heat sources from above as well).
- Other layers may also be interposed between the top and bottom layers, for other properties or fire resistance.
- the layers may also be contoured to create cavities therebetween, and the cavities may be filled with foam, such as urethane.
- deck 22 D has an inner portion comprising a first material having fire retardant (and thus diminished impact or other properties) and an integral edge portion 42 with less fire retardant and better impact properties.
- the edge portion that has minimal or no fire retardant at least spans the openings that are between columns 26 D, through which forks enter the space under the pallet for transport.
- a top view of exemplary pallet 20 C is illustrated, wherein deck 22 C has a central area 34 with higher retardant content than a periphery portion 32 .
- the dashed boundary line 33 is one exemplary indication of where the composition changes. Depending on the manufacturing technique that is used, and the objective, the demarcation of composition change may be definite or gradual. While the periphery of the deck may be thin and thus should have fire retardant in accord with another teaching herein, the volume of plastic, which has the inferior fire retardant, is a small fraction of the total pallet. Thus, while burn test performance might be somewhat reduced the performance can still be acceptable, and the “give up” is well traded against durability and strength, in considering the total pallet design.
- FIG. 6 a simplified cross section view of an exemplary mold for a pallet other dual property object is illustrated.
- the exemplary cavity parts 26 CC, 32 CC and 34 CC are illustrated as corresponding to numeral parts of exemplary pallet 20 C.
- the mold comprises two mating parts 36 , 38 .
- injection mold nozzles feed molten plastic through ports 54 , 56 .
- Two different material compositions, one with high retardant content, the other with low or no retardant content are provided by two different sets of nozzles, fed by appropriate injection extruders and supplies.
- the low content material is injected in the ports 54 while the high content material is injected in the ports 56 .
- the deck parts 34 , 32 may be separately fabricated and then joined together, as by welding.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Pallets (AREA)
Abstract
The parts of a pallet or other article have different tailored thermoplastic composition to provide fire resistance according to the shape, location and function of the part in the pallet. In one embodiment, the high surface area to volume deck has high fire retardant content, whereas the heavier portions of the pallet, such as the base and columns have lower content. In another embodiment, the periphery of the deck that is prone to impact damage has low retardant content, compared to the rest of the deck and or the rest of the pallet.
Description
- The present application claims priority to U.S. Provisional Patent No. 60/657,678, filed Mar. 1, 2005, the entire contents of which are specifically incorporated herein by reference.
- There are a variety of thermoplastic articles that benefit from fire-resisting properties. One method of imparting fire-resisting properties to a plastic is inclusion within the plastic of a fire-retardant component. However, inclusion of such fire retardants, even in minimally effective amounts, often carries adverse side effects. More specifically, such fire retardants can decrease mechanical properties and moldability, increase weight and cost, and be environmentally undesirable.
- Fire resistant coatings may also be used, however such coatings are subject to wear and degradation. Once the coating layer is penetrated, particularly with objects having large relative mass, there is little effect.
- Plastic pallets are an example of plastic articles, which might incorporate fire-retardant components therein. An important criterion for all pallet uses is that the pallet has adequate fire resisting properties. Indeed, all pallets must pass tests that determine how fast and with what heat evolution pallets burn in a simulated warehouse fire. These same pallets must also pass durability and impact tests.
- Plastic pallets have not gained wide acceptance due in large measure to the failure to satisfactorily meet fire resistance criteria, while additionally meeting the structural and durability standards of Grocery Manufacturers of America (GMA). Pallets should have fire resistance sufficient to not exceed the heat release set by Underwriters Lab Standard 3435. In a test under the standard, pallets are subjected to a fire in a test facility, to simulate a warehouse fire. Any fire resisting pallet also must be strong enough to carry specified loads, must not be too heavy, and must be durable in resisting damage during use, as measured by certain tests and field use.
- Because the heat and rate of combustion of the typical polyethylene or polypropylene pallet material are inherently high compared to wood and many other materials, it is, in one sense, desirable to include fire retardant components within the plastics of the pallet. However, while inclusion of fire retardants in plastic pallets may increase the chances of passing fire resistance tests, such inclusion at the same time generally decreases the chances of passing durability and impact tests.
- One partial solution is to construct the deck of a pallet can from metal, while constructing the rest of the pallet as plastic. That has the effect of reducing the amount of plastic in the pallet and the favorably improving the burn test characteristics, and reducing the gross amount of fire retardant in the pallet. However, it may not always be desirable to have a metal deck on a pallet.
- What is needed is a thermoplastic article that is satisfactorily fire resistant, and that is also satisfactorily impact resistant or durable.
- The above described and other disadvantages of the prior art are overcome or alleviated by the presently disclosed thermoplastic article, comprising plastic parts that having differing fire resistances. In one embodiment, with regard to the rate of heat evolution is concerned compared to the total heat evolution, those portions of a plastic pallet having a higher surface area or those portions of the pallet that are more exposed have higher heat resistances relative to those portions having lower surface areas or those portions that are less exposed.
- In another exemplary embodiment, a pallet's thermoplastic material has different fire retardant content (composition) is tailored according to the portion of the pallet that the material forms. In one such embodiment, thinner and higher surface area to volume ratio sections have higher fire retardant content than do other sections. In another such embodiment, the edges of the top deck of the pallet, or like areas of some other article that are prone to impact damage, have lower fraction of retardant than those portions not prone to impact damage. In another embodiment, the deck of a pallet has higher fire retardant content than the columns upon which the deck is mounted. In another embodiment, part of, or all of, the periphery of the deck has less retardant or no retardant, compared to the interior of the deck which has fire retardant.
- In another exemplary embodiment, a pallet's differing components include a fire resistant coating or layer on portions having a higher surface area or on portions that are more exposed. In one such embodiment, the deck is formed of two or more layers of material that are joined together, wherein the deck comprises a top layer having less fire retardant than a bottom layer.
- The above-described and other features will be appreciated and understood by those skilled in the art from the following detailed description, drawings and appended claims.
- Referring now to the accompanying FIGURES, which are meant to be exemplary and not limiting:
-
FIG. 1 is a cross sectional view of an exemplary pallet; -
FIG. 2 is a cross sectional view of an exemplary pallet column; -
FIG. 3 is a cross sectional view of an exemplary pallet column and deck; -
FIG. 4 is a cross sectional view of an exemplary pallet corner; -
FIG. 5 is a cross sectional view of an exemplary pallet deck; and -
FIG. 6 is a cross sectional view of an exemplary pallet component mold. - The present disclosure relates to articles comprising thermoplastics, such as high density polyethylene (HDPE) or polypropylene, among others. Components of such articles, e.g., pallets, may be constructed according to any convenient method, for example by injection molding.
- Solid particulate fire retardants may also be included in the thermoplastic compositions, for example Grafguard graphite intumescent material, aluminum trihydrate, magnesium hydroxide or antimony trioxide (often used with bromine compounds), among others. The solid fire retardants may be used in combination with other types of fire retardants, for instance, brominated hydrocarbons. It will be appreciated that the invention may be applied to the inclusion of other ingredients, solid particulate or not, in a pallet and to other articles.
- The present invention recognizes that addition of fire retardants in quantities sufficient to impart minimal to good fire resistance, which in one embodiment, and depending on the material, ranges from 10 to 30 weight percent retardant, correspondingly decreases the fracture toughness of that article. In the example of plastic pallets, the pallet becomes too prone to breakage, particularly around the edges of the pallet where the shanks of the tines of a forklift truck may impact the pallet. Accordingly, an improved article is described, wherein fire resistance of the article is selectively tailored with regard to the geometry and/or position of a component of the article.
- Referring now to
FIGS. 1-4 , partial vertical cross sections of portions of exemplary thermoplastic pallets are illustrated. Referring toFIG. 1 ,exemplary pallet 20 comprises adeck 22, which is welded to thecolumns 26 ofbase 24. In this exemplary embodiment, the deck includes a plurality of holes (the deck may take other configurations, e.g., solid or grid-like, among others). Thecolumns 26, which have hollows at their top ends, are interconnected byrails 30. Hollow square crosssection metal beams 28 are within the rails. In one exemplary embodiment,deck 22 ofpallet 20 has a higher concentration of retardant relative to theframe 24. As an example, HDPE deck has 10% intumescent composition, and the frame has 5%. (All concentrations are by weight unless otherwise indicated.) - Referring now to
FIG. 2 , a portion ofexemplary pallet 22A is illustrated, whereinbeam 28 is covered by afloor plate 29. In an exemplary embodiment, theplate 29 is configured to incorporate of thebeam 28 within the base and comprises no or low fire retardant relative to other portions of the pallet. In such embodiment, thebeam 28 is strategically engineered to fail in the event of a fire. This is due to the lack of significant fire retardant in theplate 29. At an early stage in a fire, thebeam 28 will be subjected to heat and will fail according to engineered design. - Referring now to
FIG. 3 , an exemplary pallet 20B is illustrated, wherein such pallet lacks base rails. An exemplary deck is a two-layer composite structure, which may be made for example by co-extrusion, by joining one sheet to another, or by injection molding, among other methods. In one embodiment, theunderside layer 27 comprises a first composition with a large amount of fire retardant relative to thetop layer 25. Such exemplary configuration provides durability for the top of the deck, but at the same time provides fire protection to the pallet (oftentimes flames will rise up from below, and the lower deck layer provides a lower barrier relative to heat sources from above as well). Other layers may also be interposed between the top and bottom layers, for other properties or fire resistance. The layers may also be contoured to create cavities therebetween, and the cavities may be filled with foam, such as urethane. - Referring now to
FIG. 4 , opposing edges of an exemplary pallet 20D is illustrated, wherein deck 22D has an inner portion comprising a first material having fire retardant (and thus diminished impact or other properties) and anintegral edge portion 42 with less fire retardant and better impact properties. In another exemplary embodiment, the edge portion that has minimal or no fire retardant at least spans the openings that are between columns 26D, through which forks enter the space under the pallet for transport. - Referring not to
FIG. 5 , a top view of exemplary pallet 20C is illustrated, wherein deck 22C has acentral area 34 with higher retardant content than aperiphery portion 32. The dashed boundary line 33 is one exemplary indication of where the composition changes. Depending on the manufacturing technique that is used, and the objective, the demarcation of composition change may be definite or gradual. While the periphery of the deck may be thin and thus should have fire retardant in accord with another teaching herein, the volume of plastic, which has the inferior fire retardant, is a small fraction of the total pallet. Thus, while burn test performance might be somewhat reduced the performance can still be acceptable, and the “give up” is well traded against durability and strength, in considering the total pallet design. - Referring now to
FIG. 6 , a simplified cross section view of an exemplary mold for a pallet other dual property object is illustrated. The exemplary cavity parts 26CC, 32CC and 34CC are illustrated as corresponding to numeral parts of exemplary pallet 20C. The mold comprises twomating parts ports ports 54 while the high content material is injected in theports 56. In another exemplary manufacturing alternative, with reference toFIG. 5 , thedeck parts - While exemplary embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. It is to be understood that the present invention has been described by way of illustration and not limitation.
Claims (13)
1. A thermoplastic article comprising a plurality of thermoplastic portions, wherein at least two of said portions have differential fire resistance, by virtue of compositions or coatings, according to the position or geometry of said portions.
2. A thermoplastic article in accordance with claim 1 , wherein at least one said portion is thinner or has a higher surface area to volume ratio relative to another of said portions.
3. A thermoplastic article in accordance with claim 1 , wherein said thermoplastic article is a plastic pallet.
4. A thermoplastic article in accordance with claim 3 , wherein a deck of the pallet has higher fire retardant content than columns upon which the deck is mounted.
5. A thermoplastic article in accordance with claim 3 , wherein part or all of the periphery of a deck has less retardant or no retardant, compared to the interior of the deck which has fire retardant.
6. A thermoplastic article in accordance with claim 3 , wherein said pallet has a top deck spanning columns, wherein said deck comprises a top layer having less fire retardant than a bottom layer.
7. A thermoplastic article in accordance with claim 3 , wherein part of all of the sides of said pallet has less retardant or no retardant, compared to an interior portion of said pallet.
8. A thermoplastic article in accordance with claim 7 , wherein those portions of a pallet that are configured adjacent contact points for the tines of a forklift have less fire retardant than other portions of the pallet.
9. A thermoplastic article in accordance with claim 3 , wherein a first portion of said pallet has fire retardant content of between about 0 and 10 weight percent, and a second portion has a fire retardant content of between about 10 and 30 weight percent.
10. A thermoplastic article in accordance with claim 4 , wherein said deck has between about 8 to 12 weight percent fire retardant, and wherein said columns have between about 3 to 7 weight percent fire retardant.
11. A thermoplastic article in accordance with claim 3 , wherein the pallet includes a plate covering a reinforcing cross beam, and wherein said plate contains little or no fire retardant compared to other portions of the pallet.
12. A thermoplastic article in accordance with claim 3 , wherein an interior portion of a pallet deck has a first level of fire retardant, which is higher than the level of fire retardant in an edge component, such that the edge component has higher impact resistance relative to the interior portion.
13. A thermoplastic article in accordance with claim 3 , wherein a pallet deck has a gradually varying fire retardant composition across a horizontal section of the pallet deck.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/358,867 US20070000415A1 (en) | 2005-03-01 | 2006-02-21 | Thermoplastic article having portions with different fire resistances |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US65767805P | 2005-03-01 | 2005-03-01 | |
US11/358,867 US20070000415A1 (en) | 2005-03-01 | 2006-02-21 | Thermoplastic article having portions with different fire resistances |
Publications (1)
Publication Number | Publication Date |
---|---|
US20070000415A1 true US20070000415A1 (en) | 2007-01-04 |
Family
ID=37588000
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/358,867 Abandoned US20070000415A1 (en) | 2005-03-01 | 2006-02-21 | Thermoplastic article having portions with different fire resistances |
Country Status (1)
Country | Link |
---|---|
US (1) | US20070000415A1 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080141912A1 (en) * | 2006-12-19 | 2008-06-19 | Valentinsson Anders L | Transport pallet |
US20080143514A1 (en) * | 2006-12-19 | 2008-06-19 | Schoeller Arca Systems Services Gmbh | Transport pallet |
US20080210140A1 (en) * | 2006-12-19 | 2008-09-04 | Schoeller Arca Systems Gmbh | Transport pallet |
WO2011056956A1 (en) | 2009-11-04 | 2011-05-12 | Colgate-Palmolive Company | Microfibrous cellulose and alkaline earth metal ion structured surfactant composition |
US20120309869A1 (en) * | 2009-12-24 | 2012-12-06 | Bromine Compounds Ltd. | Flame retarded compositions |
US10118731B2 (en) | 2015-06-08 | 2018-11-06 | Rehrig Pacific Company | Pallet assembly |
US20180350696A1 (en) * | 2016-07-22 | 2018-12-06 | Magnachip Semiconductor, Ltd. | Method of manufacturing a cmos transistor |
US10322847B2 (en) | 2011-07-15 | 2019-06-18 | Chep Technology Pty Limited | Pallet with support elements configured as one-piece skids and related methods |
Citations (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3212462A (en) * | 1964-02-03 | 1965-10-19 | Pasquier Panel Products | Pallet |
US3330228A (en) * | 1966-07-01 | 1967-07-11 | Clement F Donnelly | Plastic pallet supporting unit |
US4972782A (en) * | 1987-11-27 | 1990-11-27 | Pallet Handling Ltd. | Pallet |
US5057350A (en) * | 1989-08-10 | 1991-10-15 | Jean-Marie J. Gezels | Pallet chock |
US5137777A (en) * | 1990-12-11 | 1992-08-11 | Ametek | Fire-retardant polymer foam composites |
US5766681A (en) * | 1995-06-22 | 1998-06-16 | Styro-Stop, Inc. | Insulation barrier and a method of making an insulation barrier |
US6418861B1 (en) * | 1999-11-18 | 2002-07-16 | Masco Corporation | Modular pallet construction |
US20030079660A1 (en) * | 2001-10-26 | 2003-05-01 | Bruce Torrey | Fire blocking method and apparatus |
US6742460B2 (en) * | 2002-07-08 | 2004-06-01 | Lyle Meyer | Molded pallet made of recycled materials |
US6955129B2 (en) * | 2000-08-24 | 2005-10-18 | The Engineered Pallot Company, Llc | Plastic pallet design |
US20060011108A1 (en) * | 2004-07-13 | 2006-01-19 | Abu-Isa Ismat A | Fire resistant plastic pallet |
US7105234B2 (en) * | 2001-03-30 | 2006-09-12 | Schlegel Systems, Inc. | Flame retardant corrosive resistant conductive fabric article and method |
US20060236903A1 (en) * | 2000-08-24 | 2006-10-26 | Moore Roy E Jr | Thermoplastic pallet having foam-filled or foam-coated structural parts |
US20060249058A1 (en) * | 2000-08-24 | 2006-11-09 | Moore Roy E Jr | Fire resistant thermoplastic pallet |
US20060254475A1 (en) * | 2005-02-18 | 2006-11-16 | Moore Roy E Jr | Fire-collaspible cross-beamed pallet |
US20070051283A1 (en) * | 2000-08-24 | 2007-03-08 | Moore Roy E Jr | Plastic pallet with sealed deck to frame joint |
US20080053342A1 (en) * | 2000-04-11 | 2008-03-06 | Nextreme, L.L.C. | Fire resistant plastic pallet with low frequency resistivity |
-
2006
- 2006-02-21 US US11/358,867 patent/US20070000415A1/en not_active Abandoned
Patent Citations (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3212462A (en) * | 1964-02-03 | 1965-10-19 | Pasquier Panel Products | Pallet |
US3330228A (en) * | 1966-07-01 | 1967-07-11 | Clement F Donnelly | Plastic pallet supporting unit |
US4972782A (en) * | 1987-11-27 | 1990-11-27 | Pallet Handling Ltd. | Pallet |
US5057350A (en) * | 1989-08-10 | 1991-10-15 | Jean-Marie J. Gezels | Pallet chock |
US5137777A (en) * | 1990-12-11 | 1992-08-11 | Ametek | Fire-retardant polymer foam composites |
US5766681A (en) * | 1995-06-22 | 1998-06-16 | Styro-Stop, Inc. | Insulation barrier and a method of making an insulation barrier |
US6418861B1 (en) * | 1999-11-18 | 2002-07-16 | Masco Corporation | Modular pallet construction |
US20080053342A1 (en) * | 2000-04-11 | 2008-03-06 | Nextreme, L.L.C. | Fire resistant plastic pallet with low frequency resistivity |
US20060236903A1 (en) * | 2000-08-24 | 2006-10-26 | Moore Roy E Jr | Thermoplastic pallet having foam-filled or foam-coated structural parts |
US6955129B2 (en) * | 2000-08-24 | 2005-10-18 | The Engineered Pallot Company, Llc | Plastic pallet design |
US20060249058A1 (en) * | 2000-08-24 | 2006-11-09 | Moore Roy E Jr | Fire resistant thermoplastic pallet |
US20070051283A1 (en) * | 2000-08-24 | 2007-03-08 | Moore Roy E Jr | Plastic pallet with sealed deck to frame joint |
US7105234B2 (en) * | 2001-03-30 | 2006-09-12 | Schlegel Systems, Inc. | Flame retardant corrosive resistant conductive fabric article and method |
US20030079660A1 (en) * | 2001-10-26 | 2003-05-01 | Bruce Torrey | Fire blocking method and apparatus |
US6742460B2 (en) * | 2002-07-08 | 2004-06-01 | Lyle Meyer | Molded pallet made of recycled materials |
US20060011108A1 (en) * | 2004-07-13 | 2006-01-19 | Abu-Isa Ismat A | Fire resistant plastic pallet |
US20060254475A1 (en) * | 2005-02-18 | 2006-11-16 | Moore Roy E Jr | Fire-collaspible cross-beamed pallet |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080141912A1 (en) * | 2006-12-19 | 2008-06-19 | Valentinsson Anders L | Transport pallet |
US20080143514A1 (en) * | 2006-12-19 | 2008-06-19 | Schoeller Arca Systems Services Gmbh | Transport pallet |
US20080210140A1 (en) * | 2006-12-19 | 2008-09-04 | Schoeller Arca Systems Gmbh | Transport pallet |
US7779763B2 (en) | 2006-12-19 | 2010-08-24 | Schoeller Arca Systems Services Gmbh | Transport pallet |
US7841281B2 (en) | 2006-12-19 | 2010-11-30 | Schoeller Arca Systems Services Gmbh | Transport pallet |
WO2011056956A1 (en) | 2009-11-04 | 2011-05-12 | Colgate-Palmolive Company | Microfibrous cellulose and alkaline earth metal ion structured surfactant composition |
US20120309869A1 (en) * | 2009-12-24 | 2012-12-06 | Bromine Compounds Ltd. | Flame retarded compositions |
US8991321B2 (en) * | 2009-12-24 | 2015-03-31 | Bromine Compounds Ltd. | Flame retarded compositions |
US10322847B2 (en) | 2011-07-15 | 2019-06-18 | Chep Technology Pty Limited | Pallet with support elements configured as one-piece skids and related methods |
US10118731B2 (en) | 2015-06-08 | 2018-11-06 | Rehrig Pacific Company | Pallet assembly |
US20180350696A1 (en) * | 2016-07-22 | 2018-12-06 | Magnachip Semiconductor, Ltd. | Method of manufacturing a cmos transistor |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20070000415A1 (en) | Thermoplastic article having portions with different fire resistances | |
US20060249058A1 (en) | Fire resistant thermoplastic pallet | |
CA2463064C (en) | Pallet assembly with fire retardant properties | |
US6955128B2 (en) | Reinforced pallet | |
CA2824161C (en) | Pallet assembly | |
US8584599B2 (en) | Plastic pallet | |
CA2702957C (en) | Plastic pallet system | |
US20060236903A1 (en) | Thermoplastic pallet having foam-filled or foam-coated structural parts | |
US10118731B2 (en) | Pallet assembly | |
CA2717517C (en) | Shipping pallet post reinforcement | |
WO2016154260A1 (en) | Apparatus and methods directed towards a plastic pallet | |
WO2006094046A2 (en) | Fire resistant thermoplastic pallet | |
CN105270778A (en) | Systems and methods for protection of floorings in shipping containers | |
US20060254475A1 (en) | Fire-collaspible cross-beamed pallet | |
JPH0272048A (en) | Synthetic resin pallet | |
JP4059436B2 (en) | Plastic pallet | |
WO2006094045A2 (en) | Thermoplastic pallet having foam-filled or foam-coated structural parts | |
AU2016204316A1 (en) | Pallet assembly | |
AU2002347939A1 (en) | Pallet assembly with fire retardant properties | |
JPH0698984B2 (en) | Plastic pallet | |
MX2010008709A (en) | Improved plastic platform. | |
JPH02151423A (en) | Preparation of pallet made of synthetic resin |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ENGINEERED PALLET COMPANY LLC, THE, CONNECTICUT Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MOORE, ROY E. JR.;REEL/FRAME:019672/0815 Effective date: 20060705 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |