FILTER ELEMENT

Abstract

A filter element comprising two layers of weft (1) interlaced with warp (2). Additionally laid-in (3) yarns are provided in-between the two weft layers. The laid-in yarns (3) are not interlaced with the weft.

Claims

1. A filter belt comprising interlaced weft and warp yarns, and laid-in yarns, wherein: the filter belt comprises two layers of weft yarns, with the laid-in yarns located between said layers of weft yarns; the laid-in yarns do not interlace with the weft yarns and run substantially parallel to the warp yarns, the laid-in yarns having a linear density of 150 to 4400 dtex (grams/10,000 m); the weft yarns run substantially perpendicular to the warp yarns, and wherein; the ratio of the laid-in yarns to warp yarns is at least 1:4 and the weft yarns comprise an abrasion resistant material.

2. A filter belt according to claim 1, wherein the abrasion resistant material comprises polyamide.

3. A filter belt according to claim 1, wherein the weft yarns are the predominant yarn on both the top and bottom surfaces of the filter belt.

4. A filter belt according to claim 1, wherein the weft yarns are woven in a double-faced sateen construction.

5. A filter belt according to claim 1, wherein the ratio of laid-in yarns to warp yarns is approximately 1:1.

6. A filter belt according to claim 1, wherein the laid-in, warp and/or weft yarns comprise any of the following either alone or in combination:PP, PET, PE, PBT, PPS and/or aramid materials.

7. A filter belt according to claim 1, wherein the weft yarns consists essentially of polyamide.

8. A filter belt according to claim 1, wherein the filter belt additionally comprises an abrasion resistant coating.

9. A horizontal chamber filtration apparatus, such as a tower press, comprising a filter belt according to claim 1.

10. Use of a filter belt according to claim 1 in a horizontal chamber filtration apparatus such as a tower press.

11. A filter belt according to claim 1, wherein the laid-in yarns have a linear density of 1100 to 2200 dtex (grams/10,000 m).

Description

[0021] The present invention will now be illustrated, by way of example only, by reference to FIG. 1 which shows a schematic diagram of a filter element according to the invention.

[0022] In FIG. 1, two layers of weft yarns 1 and warp yarns 2 are interlaced to create a fabric, wherein the weft yarns run perpendicular to the machine direction and the warp yarns run parallel to it. Although not shown in FIG. 1, the warp yarns 2 interlace weft yarns 1 in the two weft layers to link the two weft layers. Laid-in yarns 3 placed in-between the two weft layers also run parallel to the machine direction. There is a laid-in yarn present between each pair of warp yarns, such that the ratio of laid-in yarns to warp yarns is 1:1. The weft yarns 1 comprise an abrasion resistant material such as NYLON.

[0023] In FIG. 2, two layers of weft yarns 1 and warp yarns 2 are interlaced to create a fabric, wherein the weft yarns run perpendicular to the machine direction and the warp yarns run parallel to it. The warp yarns 2a, 2b and 2c interlace the weft yarns 1 to link the two weft layers. Laid-in yarns 3 placed in-between the two weft layers also run parallel to the machine direction. In this embodiment, the ratio of laid-in yarns 3 to warp yarns 2 is 1:1. The weft yarns 1 comprise an abrasion resistant material such as NYLON.

[0024] A filter element according to the invention, labelled V6 in the below tables, has been tested for abrasion resistance and extension resistance against standard Clear Edge and competitor (Tamfelt) materials.

[0025] The abrasion resistance was tested using a NuMartindale Abrasion Tester with single line test mode with a pressure of 12 kPa with 50 cycles per minute. The sandpaper used was Klingspor PSIIC (240 grain), and circular test samples of 140 mm in diameter were used. Samples were loaded in such a way that the cake side was in contact with the sandpaper. The results achieved were as follows in Table 1:

TABLE-US-00001 TABLE 1 Clear Edge After After After After After After After After After After After After product 100 500 2000 5000 8000 11000 13000 17000 19000 24000 30000 35000 ref cycles cycles cycles cycles cycles cycles cycles cycles cycles cycles cycles cycles 98430F Fine Hairy Hairy Hairy Hairy Fine Fabric dust surface surface surface surface dust failed and warp and and flattens fine hairy up. dust surface Fine dust 25330B Fine Hairy Hairy Hairy Wefts Pin Fabric dust surface surface surface exposed. holes in failed and Failure one row. hairy appear Fabric surface fails 98320K Fine Hairy Hairy Hairy Hairy Hairy Hairy Fabric dust surface surface surface surface surface surface failed. and Warp hairy completely surface abrades off 97770F Fine Hairy Hairy Hairy Hairy Fine Hairy Fabric dust surface surface surface surface dust surface failed and and warp and hairy flattens hairy surface up. surface Fine dust V6 (fabric Fine Fine Fine Fine Fine Fine Fine Fine Hairy Fine Fine Fabric of the dust dust dust dust dust dust dust dust surface dust dust failed invention) and and and and and and and and and weft and and hairy hairy hairy hairy hairy hairy hairy hairy appears hairy hairy surface surface surface surface surface surface surface surface on the surface surface surface

[0026] As can be seen, the V6 (which is the product according to the invention) shows the highest abrasion resistance as compared to the other standard Clear Edge Fabrics.

[0027] The extension resistance of the V6 product was tested as compared to competitor's products (by Tamfelt) and as compared to other Clear Edge products. Testing was done by measuring (i) how much load must be attached per tensile metre in the warp direction to achieve 2% elongation, and (ii) the % elongation in the warp direction at a load of 400 N. As can be seen from table 2, the V6 (product according to the invention) has most favourable load characteristics.

TABLE-US-00002 TABLE 2 (i) Low Load Reference N/5 cm @ 2% (ii) Low Load % @ 400 N Tamfelt 600 1.6 S 2206-L1 K4 Tamfelt 1000 1.1 S 2106-L1 Tamfelt 1000 1.1 S 2102-L1 K4 Tamfelt 1000 1.1 S 2104-L1 Tamfelt 1200 1.0 S 2123-L1 Tamfelt 850 1.3 S 2110-L1 Tamfelt 900 1.0 S 2209-L1 Clear Edge 1600 0.7 98320F Clear Edge 1400 0.7 97630F Clear Edge 900 1.2 97770F Clear Edge 1200 0.9 18830F Clear Edge 1600 0.7 98320F Clear Edge 1900 0.45 V6

[0028] It is to be understood that the above described embodiment is by way of illustration only. Many modifications and variations are possible. For example three or more layers of weft may be provided in the filter.