Box spring packaging method and apparatus

Abstract

Improved packaging materials for packaging multiple mattress spring cores together in a compressed stack, wherein the two ends of the stack are covered by end panels comprising a laminated paper stack panel that includes one or more layers of a stretchable paper called extensible kraft paper laminated together with a water soluble glue. The mattress spring cores are separated by an interleaving sheet comprising one layer of extensible kraft paper.

Claims

1. A package of compressed mattress spring coils comprising a plurality of mattress spring coils positioned in a stack having two end panels positioned on each end of an outer side of the stack wherein the stack is compressed and strapped in a compressed condition: wherein the mattress spring coils are each separated by a piece of interleaving paper; wherein the end panels comprise a laminated paper stack panel wherein the laminated paper stack panel includes at least one layer of an extensible kraft paper; wherein the laminated paper stack panel has a mullen from 200 psi to 600 psi; and wherein the piece of interleaving paper separating the mattress spring coils comprises a layer of the extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft.

2. The package of compressed mattress spring coils according to claim 1, wherein the extensible kraft paper has a basis weight of 35-150 pounds per 3000 sq. ft.

3. The package of compressed mattress spring coils according to claim 1, wherein the laminated paper stack panel comprises three layers of extensible kraft paper, each layer of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft.

4. The package of compressed mattress spring coils according to claim 1, wherein the laminated paper stack panel comprises two layers of the extensible kraft paper, each layer of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft., laminated with a water soluble glue to one layer of a linerboard having a basis weight of 10-90 pounds per 1000 sq. ft.

5. The package of compressed mattress spring coils according to claim 1, wherein the laminated paper stack panel comprises one layer of the extensible kraft paper having a basis weight of about 35-150 pounds per 3000 sq. ft. laminated with a water soluble glue to two layers of a linerboard, each layer of linerboard having a basis weight of 10-90 pounds per 1000 sq. ft.

6. A package of compressed mattress spring coils comprising a plurality of mattress spring coils positioned in a stack having two end panels positioned on each end of an outer side of the stack wherein the stack is compressed and strapped in a compressed condition: wherein the mattress spring coils are each separated by a piece of interleaving paper; wherein the end panels comprise a laminated paper stack panel wherein the laminated paper stack panel includes at least one layer of an extensible kraft paper with a basis weight of 35-150 pounds per 3000 sq. ft; and wherein the laminated paper stack panel has a mullen from 100 psi to 800 psi; and wherein the laminated paper stack panel includes at least two layers of the extensible kraft paper with a basis weight of 35-150 pounds per 3000 sq. ft.

7. The package of compressed mattress spring coils according to claim 6, wherein the laminated paper stack panel includes three layers of extensible kraft paper, each layer of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft.

8. The package of compressed mattress spring coils according to claim 6, wherein the laminated paper stack panel includes two layers of extensible kraft paper, each layer of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft., laminated with a water soluble glue to one layer of linerboard having a basis weight of 10-90 pounds per 1000 sq. ft.

9. The package of compressed mattress spring coils according to claim 6, wherein the laminated paper stack panel includes one layer of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft. laminated with a water soluble glue to two layers of linerboard, each layer of the linerboard having a basis weight of 10-90 pounds per 1000 sq. ft.

10. The package of compressed mattress spring coils according to claim 6, wherein the laminated paper stack panel has a mullen from 250 psi to 400 psi.

11. A package of compressed mattress spring coils comprising a plurality of mattress spring coils positioned in a stack having two end panels positioned on each end of an outer side of the stack wherein the stack is compressed and strapped in a compressed condition: wherein the mattress spring coils are each separated by a piece of interleaving paper; wherein the end panels comprise a laminated paper stack panel wherein the laminated paper stack panel includes at least one layer of an extensible kraft paper with a basis weight of 35-150 pounds per 3000 sq. ft; and wherein the laminated paper stack panel has a mullen from 100 psi to 800 psi; and wherein the laminated paper stack panel has a mullen from 250 psi to 400 psi.

12. The package of compressed mattress spring coils according to claim 11, wherein the laminated paper stack panel includes three layers of extensible kraft paper, each layer of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft.

13. The package of compressed mattress spring coils according to claim 11, wherein the laminated paper stack panel includes two layers of extensible kraft paper, each layer of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft., laminated with a water soluble glue to one layer of linerboard having a basis weight of 10-90 pounds per 1000 sq. ft.

14. The package of compressed mattress spring coils according to claim 11, wherein the laminated paper stack panel includes one layer of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft. laminated with a water soluble glue to two layers of linerboard, each layer of the linerboard having a basis weight of 10-90 pounds per 1000 sq. ft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic side view of a stack of mattress coil springs separated by interleaving sheets prior to being compressed together;

(2) FIG. 2 is a schematic side view showing a compressed stack of mattress cores separated by interleaving sheets and having end panels on the outer sides thereof and being bound together in compressed form for shipping;

(3) FIG. 3 is a perspective view showing the compressed and bound stack of mattress cores; and

(4) FIG. 4 is a chart showing various alternative end panel constructions feasible in the present invention.

DETAILED DESCRIPTION

(5) Referring to the drawings, FIG. 1 shows a stack 10 of mattress spring cores 12 or mattress spring coils 12 separated by interleaving paper 14 and having end panels 16 on the outer ends of the stack. The individual mattress spring cores 12 each comprise a plurality of spaced coil spring elements 18 fastened together to form a spring coil mat. The coils 18 in overlapping mattress cores 12 are in general alignment.

(6) The stack 10 or plurality of mattress spring coils 12 can comprise 4-15 mattress spring coils, 6-12 mattress spring coils, 8-10 mattress spring coils, about 6 mattress spring coils, about 7 mattress spring coils, about 8 mattress spring coils, about 9 mattress spring coils, about 10 mattress spring coils, about 11 mattress spring coils, or about 12 mattress spring coils.

(7) The term extensible kraft paper, as used herein refers to fully extensible kraft paper, semi-extensible kraft paper, and any other specialty grades of extensible kraft paper known to one with ordinary skill in the art.

(8) The term linerboard, as used herein refers to linerboard, natural kraft paper, high performance linerboard, and any other specialty grades of linerboard known to one with ordinary skill in the art.

(9) In one embodiment, the interleaving paper 14 is a single layer or piece of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft. In another embodiment, the interleaving paper can be two layers of non-laminated extensible kraft paper, each layer or piece of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft. In another embodiment, the interleaving paper can be three or more layers or pieces of non-laminated extensible kraft paper, each layer or piece of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft.

(10) In some embodiments, the extensible kraft paper may have a basis weight of 30-150 pounds per 3000 sq. ft. In other embodiments, the extensible kraft paper may have a basis weight of 50-100 pounds per 3000 sq. ft. In other embodiments, the extensible kraft paper may have a basis weight of 50-75 pounds per 3000 sq. ft. In other embodiments, the extensible kraft paper may have a basis weight of about 50 pounds per 3000 sq. ft., about 55 pounds per 3000 sq. ft., about 60 pounds per 3000 sq. ft., about 65 pounds per 3000 sq. ft., about 70 pounds per 3000 sq. ft., or about 75 pounds per 3000 sq. ft.

(11) After the stack 10 of mattress cores 12 has been formed with the interleaving papers 14 and end panels 16 in place, a plurality of spears 20 (FIG. 2) are inserted through the coils 18 and through the end panels 16 and interleaving sheets 14 in order to hold the coils in alignment for compression. The coils 18 are shown in their uncompressed state in FIG. 1. Wood boards of panels 22 (FIG. 3) are then placed against the outer sides of the stack 10 and the stack 10 is compressed in a press, generally a horizontal hydraulic press. The mattress spring cores 12 are shown in a compressed bundle in FIG. 2. When the bundle of mattress spring cores 12 and coil spring elements 18 are fully compressed, the bundle is bound together in the compressed state by conventional bands, straps, or tie wires 24 (FIG. 3). The bundle is thereafter shipped to its destination, where the mattress spring cores 12 are then unbundled and decompressed, and the individual mattress spring cores 12 are thereafter covered with padding and fabric in order to complete the mattress construction.

(12) One important feature of the present invention is that the end panels 16 positioned on the outer sides of the stacks are relatively thin, easily pierceable members formed of a lamination or a laminated paper stack panel comprising at least one and up to three layers of extensible kraft paper laminated together with water soluble glue. Other types of glue known in the art for adhering paper layer may be used. The use of extensible kraft paper instead of the conventional linerboard is important. Extensible kraft paper is a specific type of relatively thin paper that has been subjected to additional processing during manufacture that makes the paper somewhat stretchable. This type of paper is generally used in cement bag or bag applications with a single ply or two plies of a non-laminated paper which benefits from being somewhat stretchable. Generally, extensible kraft paper is not used in laminated paper products. The stretchability and thinness of extensible kraft papers generally make them undesirable for use in laminated paper products, because thin and stretchy paper cannot be used in known automated laminating machinery and can only be processed in smaller batches. Notwithstanding the increased material cost on a unit weight basis and notwithstanding the added manufacturing cost of a non-automated laminating process, the use of laminated extensible kraft paper in the end panels provides cost savings and performance benefits in the present invention. Likewise, the use of extensible kraft paper for the interleaving paper provides desirable strength and tear resistance while retaining desirable pierce-ability attributes.

(13) While some embodiments of the present invention employ end panels 16 formed of three layers of extensible kraft paper laminated together with a water soluble glue, other constructions are feasible. For example, the end panels can be formed by gluing two layers of extensible kraft paper with one layer of linerboard, or the end panels can be formed by gluing one layer of extensible kraft paper with two layers of linerboard. Multiple examples of feasible laminate constructions are shown in FIG. 4. FIG. 4 is not meant to be limiting since other combinations of laminate layers in light of this disclosure could be determined.

(14) When the laminated end panels or laminated paper stack panel comprises three layers of extensible kraft paper, the individual weights of the three different paper layers may all vary. As shown in FIG. 4, the first layer or ply of the three layers of extensible kraft paper can have a basis weight of 35-150 pounds per 3000 sq. ft. In some embodiments the first ply can have a basis weight of about 65 pounds per 3000 sq. ft., a basis weight of about 70 pounds per 3000 sq. ft., a basis weight of about 75 pounds per 3000 sq. ft., or a basis weight of about 80 pounds per 3000 sq. ft. The second layer or ply of the three layers of extensible kraft paper can have a basis weight of 35-150 pounds per 3000 sq. ft. In some embodiments the second ply can have a basis weight of about 50 pounds per 3000 sq. ft., a basis weight of about 55 pounds per 3000 sq. ft., a basis weight of about 60 pounds per 3000 sq. ft., a basis weight of about 65 pounds per 3000 sq. ft., a basis weight of about 70 pounds per 3000 sq. ft., a basis weight of about 75 pounds per 3000 sq. ft., a basis weight of about 80 pounds per 3000 sq. ft., a basis weight of about 85 pounds per 3000 sq. ft., a basis weight of about 90 pounds per 3000 sq. ft., a basis weight of about 95 pounds per 3000 sq. ft., or a basis weight of about 100 pounds per 3000 sq. ft. The third layer or ply of the three layers of extensible kraft paper can have a basis weight of 35-150 pounds per 3000 sq. ft. In some embodiments the third ply can have a basis weight of about 65 pounds per 3000 sq. ft., a basis weight of about 70 pounds per 3000 sq. ft., a basis weight of about 75 pounds per 3000 sq. ft., or a basis weight of about 80 pounds per 3000 sq. ft.

(15) When the laminated end panels or laminated paper stack panel comprises two layers of extensible kraft paper and one layer of linerboard, the individual weights of the three different layers may all vary. As shown in FIG. 4, the first layer or ply of extensible kraft paper can have a basis weight of 35-150 pounds per 3000 sq. ft. In some embodiments the first ply can have a basis weight of about 50 pounds per 3000 sq. ft., a basis weight of about 55 pounds per 3000 sq. ft., a basis weight of about 60 pounds per 3000 sq. ft., a basis weight of about 65 pounds per 3000 sq. ft., a basis weight of about 70 pounds per 3000 sq. ft., a basis weight of about 75 pounds per 3000 sq. ft., or a basis weight of about 80 pounds per 3000 sq. ft. The second layer or ply made of linerboard can have a basis weight of 10-90 pounds per 1000 sq. ft. In some embodiments the second ply can have a basis weight of about 26 pounds per 1000 sq. ft., a basis weight of about 30 pounds per 1000 sq. ft., a basis weight of 33 pounds per 1000 sq. ft., a basis weight of 38 pounds per 1000 sq. ft., a basis weight of 42 pounds per 1000 sq. ft., a basis weight of 56 pounds 1000 sq. ft., or a basis weight of 69 per 1000 sq. ft. The third layer or ply of extensible kraft paper can have a basis weight of 35-150 pounds per 3000 sq. ft. In some embodiments the third ply can have a basis weight of about 50 pounds per 3000 sq. ft., a basis weight of about 55 pounds per 3000 sq. ft., a basis weight of about 60 pounds per 3000 sq. ft., a basis weight of about 65 pounds per 3000 sq. ft., a basis weight of about 70 pounds per 3000 sq. ft., a basis weight of about 75 pounds per 3000 sq. ft., or a basis weight of about 80 pounds per 3000 sq. ft.

(16) When the laminated end panels or laminated paper stack panel comprises one layer of extensible kraft paper and two layers of linerboard, the individual weights of the three different layers may all vary. As shown in FIG. 4, the first layer or ply of linerboard can have a basis weight of 10-90 pounds per 1000 sq. ft. In some embodiments the first ply can have a basis weight of about 26 pounds per 1000 sq. ft., a basis weight of about 30 pounds per 1000 sq. ft., a basis weight of 33 pounds per 1000 sq. ft., a basis weight of 38 pounds per 1000 sq. ft., a basis weight of 42 pounds per 1000 sq. ft., a basis weight of 56 pounds 1000 sq. ft., or a basis weight of 69 per 1000 sq. ft. The second layer or ply of extensible kraft paper can have a basis weight of 35-150 pounds per 3000 sq. ft. In some embodiments the second ply can have a basis weight of about 50 pounds per 3000 sq. ft., a basis weight of about 55 pounds per 3000 sq. ft., a basis weight of about 60 pounds per 3000 sq. ft., a basis weight of about 65 pounds per 3000 sq. ft., a basis weight of about 70 pounds per 3000 sq. ft., a basis weight of about 75 pounds per 3000 sq. ft., or a basis weight of about 80 pounds per 3000 sq. ft. The third layer or ply of linerboard can have a basis weight of 10-90 pounds per 1000 sq. ft. In some embodiments the third ply can have a basis weight of about 26 pounds per 1000 sq. ft., a basis weight of about 30 pounds per 1000 sq. ft., a basis weight of 33 pounds per 1000 sq. ft., a basis weight of 38 pounds per 1000 sq. ft., a basis weight of 42 pounds per 1000 sq. ft., a basis weight of 56 pounds 1000 sq. ft., or a basis weight of 69 per 1000 sq. ft.

(17) The laminated end panels or laminated paper stack panel are made of paper layers comprising extensible kraft paper and/or layers of linerboard. The strength and/or weight of the laminated end panels or laminated paper stack is normally the cumulative value of the individual layers laminated together plus any residual strength or weight added by the glue. For example, a single layer of extensible kraft paper having a basis weight of 100 pounds per 3000 square feet laminated with a single layer of linerboard having a basis weight of 270 pounds per 3000 sq. ft. would yield a laminated end panel or laminated paper stack panel of 370 pounds per 3000 sq. ft.

(18) In some embodiments, the ordering or layering of the individual layers in the laminated end panels or laminated paper stack panels do not matter. For example, if the laminated paper stack panel comprises two layers of an extensible kraft paper and one layer of a linerboard, the layering could be the linerboard sandwiched between the two extensible kraft paper layers or the layering could be a layer of extensible kraft paper on top of a layer of extensible kraft paper with the layer of linerboard added last to the top or bottom. In some embodiments, the ordering or layering of the individual layers in the laminated end panels or laminated paper stack panels are not limiting and may be in any order.

(19) In one embodiment of the invention, the laminated end panels each comprise three layers of extensible kraft paper, each layer of extensible kraft paper having a basis weight of 35-150 pounds per 3000 square feet.

(20) In another embodiment, the end panels comprise a laminated paper stack panel of at least one and up to two layers of extensible kraft paper, each layer of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft., in combination with a layer of linerboard having a basis weight of 10-90 pounds per 1000 sq. ft.

(21) In another embodiment, the end panels comprise a laminated paper stack panel of one layer of extensible kraft paper having a basis weight of 35-150 pounds per 3000 sq. ft. in combination with two layers of linerboard, each layer of linerboard having a basis weight of 10-90 pounds per 1000 sq. ft.

(22) Mullen is a measure of the bursting strength of paper or paperboard. In a Mullen test (also called a pop or burst test), the paper sample is placed between two ring-like clamps in a device called a Mullen tester, and hydraulic pressure is used to inflate a rubber diaphragm, which expands against the sample stretching it. The measure of the total hydraulic pressure expanding the diaphragm at the time the sample ruptures (usually expressed in either pounds per square inch or kilopascals) is its bursting strength. Mullen tests are performed for each side of a paper or paperboard, and the bursting strength can be expressed as the average of both sides.

(23) In one embodiment, the laminated paper stack panel has a mullen from 100 psi to 800 psi. In another embodiment, the laminated paper stack panel has a mullen from 200 psi to 600 psi. In another embodiment, the laminated paper stack panel has a mullen from 300 psi to 500 psi. In another embodiment, the laminated paper stack panel has a mullen from 250 psi to 400 psi. In another embodiment, the laminated paper stack panel has a mullen of about 300 psi, about 350 psi, about 400 psi, about 450 psi, or about 500 psi.

(24) In one embodiment, the interleaving paper has a mullen from 30 psi to 270 psi. In another embodiment, the interleaving paper has a mullen from 50 psi to 175 psi. In another embodiment, the interleaving paper has a mullen from 70 psi to 100 psi.

(25) It should be understood that the foregoing is merely exemplary of the preferred practice of the present invention and that various modifications may be made in the arrangements and details of the construction of the present invention without departing form the spirit and scope of the present invention.