HYDROCARBON ABSORBENT STRUCTURES

Abstract

A method of manufacturing a hydrocarbon absorbent structure comprises providing a lower sheet of material and dispensing a hydrocarbon absorbent polymer mixture thereon. The polymer mixture is then preheated so as to at least partially melt the polymer mixture. An upper sheet of material is then provided onto the at least partially melted polymer mixture on the lower sheet of material. The lower sheet of material, polymer mixture and upper sheet of material are then laminated together to form a hydrocarbon absorbent laminate structure.

Claims

1. A method of manufacturing a hydrocarbon absorbent structure, the method comprising: providing a lower sheet of material; dispensing a hydrocarbon absorbent polymer mixture onto the lower sheet of material; preheating the polymer mixture on the lower sheet of material so as to at least partially melt the polymer mixture; providing an upper sheet of material onto the at least partially melted polymer mixture on the lower sheet of material; and laminating the lower sheet of material, polymer mixture and upper sheet of material together to form a hydrocarbon absorbent laminate structure.

2. A method as claimed in claim 1, wherein at least one of the lower sheet of material and the upper sheet of material is substantially permeable to hydrocarbon-based compounds.

3. A method as claimed in claim 1, wherein at least one of the lower sheet of material and the upper sheet of material comprises a stitch-bonded material.

4. A method as claimed in claim 1, wherein the polymer mixture comprises one or more hydrocarbon absorbent polymers or one or more hydrocarbon solidifying polymers.

5. A method as claimed in claim 1, wherein the polymer mixture comprises one or more adhesives.

6. A method as claimed in claim 5, wherein the one or more adhesives comprise one or more elastomeric polymer adhesives.

7. A method as claimed in claim 5, wherein the one or more adhesives comprise one or more hot melt adhesives.

8. A method as claimed in claim 1, wherein the polymer mixture is dispensed under gravity.

9. A method as claimed in claim 1, wherein the preheating comprises heating the polymer mixture to a temperature of at least 50° C.

10. A method as claimed in claim 1, wherein the laminating comprises applying heat at a temperature of at least 50° C.

11. A method as claimed in claim 1, wherein the laminating comprises applying a pressure of at least 120 kPa (1.2 bar).

12. A method as claimed in claim 1, further comprising conveying the laminate structure through the laminator with one or more conveyors.

13. A method as claimed in claim 12, wherein at least one of heat and pressure is provided via one or more of the conveyers.

14. A method as claimed in claim 1, wherein the dispensing speed of a lower sheet dispenser is controlled to at least one of: regulate the thickness of polymer mixture deposited onto the lower sheet of material; and regulate the amount of heat transferred to the polymer mixture during the preheating.

15. A method as claimed in claim 1, further comprising forming a layered structure using the laminate structure.

16. A method as claimed in claim 15, wherein forming the layered structure comprises assembling the laminate structure together with one or more other functional layers.

17. A method as claimed in claim 16, wherein the one or more other functional layers comprise one or more layers of wicking material configured to at least one of: draw in hydrocarbon-based compounds; and hold hydrocarbon-based compounds adjacent to the laminate structure.

18. A method as claimed in claim 17, wherein the wicking material comprises a needle-punched material.

19. A method as claimed in claim 16, wherein the one or more other functional layers comprise one or more layers of outer material configured to protect the laminate structure.

20. An apparatus for manufacturing a hydrocarbon absorbent structure, the apparatus comprising: a lower sheet dispenser configured to provide a lower sheet of material; a polymer mixture dispenser configured to dispense a hydrocarbon absorbent polymer mixture onto the lower sheet of material; a heater configured to preheat the polymer mixture on the lower sheet of material so as to at least partially melt the polymer mixture; an upper sheet dispenser configured to provide an upper sheet of material onto the at least partially melted polymer mixture on the lower sheet of material; and a laminator configured to laminate the lower sheet of material, polymer mixture and upper sheet of material together to form a hydrocarbon absorbent laminate structure.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0024] By way of example only, embodiments of the invention will now be described in detail with reference being made to the accompanying drawings in which:

[0025] FIG. 1 is a schematic illustration of an apparatus for manufacturing a hydrocarbon absorbent structure according to an embodiment of the present invention;

[0026] FIG. 2 is a partial cross-section through a hydrocarbon absorbent structure according to an embodiment of the present invention;

[0027] FIG. 3A is a plan view of a product incorporating the hydrocarbon absorbent structure of FIG. 2;

[0028] FIG. 3B is a side view of the product of FIG. 3A;

[0029] FIG. 4A is a plan view of another product incorporating the hydrocarbon absorbent structure of FIG. 2; and

[0030] FIG. 4B is a side view of the product of FIG. 4A.

DETAILED DESCRIPION OF THE FIGURES

[0031] FIG. 1 shows an apparatus 10 for manufacturing a hydrocarbon absorbent structure. The apparatus 10 comprises a lower sheet dispenser reel 11 which provides a lower sheet of material 2. In this embodiment, the lower sheet of material 2 comprises a permeable non-woven stitch-bonded material formed of polyester or viscose. The apparatus 10 further comprises a polymer mixture dispenser hopper 12 having an elongate opening which dispenses a hydrocarbon absorbent polymer mixture 4 under gravity onto, and across the width of, the lower sheet of material 2. The dispensing rate is fixed by the size of the opening of the hopper 12. In this embodiment, the polymer mixture 4 comprises a mixture of hydrocarbon absorbent polymers and EVA adhesive. The apparatus 10 further comprises an infrared heater 13 that preheats the polymer mixture 4 on the lower sheet of material 2 so as to at least partially melt the polymer mixture 4. In this embodiment, the heater 13 operates at around 200° C., but is spaced from the lower sheet of material 2 so as to heat the polymer mixture 4 to around 90° C.-100° C. The apparatus 10 further comprises an upper sheet dispenser reel 14 which provides an upper sheet of material 6 onto the at least partially melted polymer mixture 4 on the lower sheet of material 2. In this embodiment, the upper sheet of material 6 also comprises a permeable non-woven stitch-bonded material formed of polyester or viscose. The apparatus 10 further comprises a laminator 15 which laminates the lower sheet of material 2, polymer mixture 4 and upper sheet of material 6 together to form a hydrocarbon absorbent laminate structure 8. The laminator 15 comprises a first (lower) conveyer 16 and second (upper) conveyer 17 which convey the laminate structure 8 through the laminator 15, with the laminate structure 8 passing between the conveyers. In this embodiment, the laminate structure 8 takes around 25 seconds to pass through the laminator 15. In this embodiment, the laminator 15 operates at around 175° C. and 300 kPa (3 bar). The apparatus 10 further comprises a laminate structure receiver reel 18 which receives the laminate structure 8. In this embodiment, the receiver reel 18, first conveyer 16 and second conveyer 17 are directly rotated by motors, with the lower sheet dispenser reel 11 and upper sheet dispenser reel 14 being indirectly rotated. The motors operate at an appropriate speed to regulate the thickness of polymer mixture 4 deposited onto the lower sheet of material 2 and to regulate the amount of heat transferred to the polymer mixture 4 from the heater 13. In this embodiment, the thickness of the layer of polymer mixture 4 is around 5 mm

[0032] The laminate structure 8 can then be cut to size and assembled together with other functional layers to form a layered hydrocarbon absorbent structure. FIG. 2 shows (not to scale) a partial cross-section through a layered hydrocarbon absorbent structure 20, which comprises the lower sheet of material 2, polymer mixture 4, and upper sheet of material 6 of the laminate structure 8. The structure 20 further comprises a wicking layer 22 that draws in and holds hydrocarbon-based compounds adjacent to the laminate structure 8. In this embodiment, the wicking layer 22 is formed of a non-woven needle-punched sheet of polypropylene. A second wicking layer may also be provided under the laminate structure 8 if desired. The structure 20 further comprises a first outer layer 24. In this embodiment, the first outer layer 24 is formed of a perforated sheet of PVC that allows hydrocarbon-based compounds to enter the structure 20 from above in use. The structure 20 further comprises a second outer layer 26. In some embodiments (e.g. that of FIG. 3), the second outer layer 26 is formed of an impermeable sheet of polyethylene coated polyester that prevents hydrocarbon-based compounds from passing straight through the structure 20. However, in other embodiments (e.g. that of FIG. 4), the second outer layer 26 is formed of a perforated sheet of PVC that allows water to pass through the structure 20, with hydrocarbon-based compounds having been filtered out.

[0033] FIGS. 3A and 3B show a hydrocarbon absorbent product 30 which incorporates the structure 20. In this embodiment, the product 30 comprises a planar pad product in which the first (upper) outer layer 24 is joined to the second (lower) outer layer 26 about the periphery by overstitching 32. The product 30 can be placed on the ground or a floor under machinery and/or containers which are prone to leaking or spilling hydrocarbon-based compounds.

[0034] FIGS. 4A and 4B show another hydrocarbon absorbent product 40 which incorporates the structure 20. In this embodiment, the product 40 has a substantially hollow conical section 41 comprising the structure 20 joined to itself at a stitched seem 42. The hollow conical section 41 has an open end 43 configured to receive waste liquids and a closed end 44 which is placed in a drain 45. The product 40 also comprises an impermeable planar section 46 surrounding the open end 43 which is placed on the ground or a floor surrounding the drain 45. Waste liquids can flow across the planar section 46 and into the hollow section 41, with the hollow section 41 preventing hydrocarbon-based compounds in the liquids from entering the drain 45 whilst still allowing water to soak into the drain 45.