IE85355B1 - Filter cloth - Google Patents

Abstract

ABSTRACT A filter cloth for deep bed filtration, which has mutually crossing warp and weft threads which are woven together in a specific type of weave, should be formed in such a way that it can be produced inexpensively and therefore economically. In so doing the requirement must be fulfilled that the particles to be filtered out are of a size less than 40um, preferably less than l0um. Furthermore, the filter cloth should be sufficiently stable. In accordance with the invention a portion of the warp and/or weft threads (11, 12) of the filter cloth (10) comprises monofilament and/or multifilament threads. The remaining portion of the warp and/or weft threads (11, 12) is formed from metal or synthetic material wires. The monofilament and multifilament threads comprise non-metallic materials. The filter cloth in accordance with the invention is particularly suitable for filtering solid particles with a relatively small surface area out of a substance. This substance can be, for example, air or liquid in the form of an emulsion.

Description

Filter cloth The invention relates to a filter cloth, preferably for deep bed filtration, which has mutually crossing warp and weft threads which are woven together in a specific type of weave.

The filter cloth in question is used for filters and filter devices in very different constructions or designs. However, it is preferably used when solid particles with a relatively small surface area have to be filtered out of a substance. This substance can be, for example, air or a liquid in the form of an emulsion. The use of filter cloths made from fine metal wires is known, for example, for cases where the size of the particles to be filtered out is smaller than 5 pm. These metal wires, which are correspondingly fine, are relatively weak so that the wires must be handled with great care. Furthermore, a filter cloth of this type is relatively expensive by reason of the use of the metal wires which must be regarded as extremely fine.

The object ofthe invention is to create a filter cloth of the type described in more detail in the introduction so that it can be produced inexpensively and therefore economically, wherein the requirement must be fulfilled that the particles to be filtered out are of a size smaller than 40pm, preferably smaller than 10pm. Furthermore, stability should be retained.

The stated object is achieved in that a portion of the warp and/or weft threads of the filter cloth comprises monofilament and/or multifilament threads and that the remaining portion of the warp and/or weft threads is formed from metal or synthetic material wires.

The filter cloth in question could also be designated as a mixed or hybrid cloth as it comprises threads of dual origin, i.e. it is formed from monofilament and/or multifilament threads.

"Endless" products with a relatively small diameter can be considered for use as the threads.

Thus. for example, a monofilament thread is regarded as a single filament with a diameter of at least (J.lmm. A multifilament thread is a filament bundle which comprises a plurality of filaments, wherein an elementary thread is always to be regarded as a filament.

In a further formation provision is made for the monofilament and multifilament warp and/or ‘.43 weft threads to be produced from non-metallic materials. In a further formation provision is made for the monofilament and/or multifilament threads to comprise synthetic or organic substances. These substances are selected according to, amongst other things, the respective intended use. Thus provision is made for the multifilament warp and/or weft threads to comprise synthetic fibre yarns or fibre ply yarns. In a preferred embodiment these multifilament threads can comprise polyester. However, it is also alternatively possible for the multifilament threads to be textured. Furthermore, they could also be produced from a worsted yarn or carded yarn. Provision is also made for the warp and weft threads which comprise metal to be produced from a stainless steel. The diameters of the warp and weft threads of the filter cloth depend on the intended use. They may be the same but they may also differ from each other.

The mutually crossing warp and weft threads made from a synthetic material can be fixed to each other at the crossing points, for example, by means of a heat treatment. This also applies for warp and weft threads produced from the other materials. For connection or fixing purposes suitable auxiliary agents such as adhesive and the like are then used. The diameters of the warp and weft threads should be less than 0.1mm in the filter cloth in accordance with the invention.

The sequence of warp and weft threads made from very different materials is then produced according to a preset design, for example in the warp direction the first thread could comprise metal, the second thread of a multifilament, the third also of a multifilament and the fourth thread once again ofa metal, wherein this arrangement is to be regarded as an example.

The invention will be explained in more detail with the aid of the attached drawings in which: Figure l is a section of the filter cloth in accordance with the invention shown in a plan view, Figure 2 shows the filter cloth in accordance with Figure l in a cross-sectional view taken at a right angle to the warp threads, and Figure 3 shows a cross-sectional view in parallel with the warp threads.

For purposes of illustration the filter cloth 10 illustrated in the figures is shown in a greatly Lu ‘J1 enlarged form. The warp threads 11 extend in parallel and spaced apart from each other. The warp threads 11 are crossed by the weft threads 12 which extend transverse thereto. In a manner which is not shown in more detail the crossing points can be connected to each other, wherein the connection can also be dependent upon the material, for example, the mutually crossing synthetic material fibres are welded to each other by the effect of heat. The warp and weft threads 1 1, 12 can be woven together in known weave types.

The diameters ofthe warp and weft threads 11, 12 can be the same or different. In Figure 1, for example, a section of a woven cloth is shown in which the weft threads 12 have the same diameter and the diameters of the warp threads 11 are greater than the diameters of the weft threads 12. Furthermore, the warp and weft threads 11, 12 can be connected to each other in weave styles which are known per se. As already explained, the warp and weft threads 1 1, 12 formed from the different materials can be combined with each other according to a specific design when seen in the warp and weft direction.

Figure 1 illustrates one possible embodiment of the filter cloth. In this embodiment the spaces between the individual warp threads 11 are larger than those between the individual weft threads 12. In the illustrated embodiment they are even larger by a multiple. Furthermore, Figure 1 shows that the diameters of the warp threads 11 are larger than those of the weft threads 12.

This is advantageous since the stability of the filter cloth is at least predominantly dictated by the warp threads 11 so that the filtering effect is principally achieved by the weft threads 12.

The diameters of all the warp threads 11 and of all the weft threads 12 are the same as each other. In contrast to the illustration, both the warp threads 11 and the weft threads 12 could each have differences with respect to each other.

The invention is not limited to the illustrated exemplified embodiment. It is essential that a certain portion of the warp and/or weft threads 11, 12 is formed by monofilament and/or multifilament threads and/or yarns and/or ply yarns, wherein in particular the multifrlament threads comprise synthetic or organic substances.

Claims (2)

CLAIMS Filter cloth (10), preferably for deep bed filtration, which has mutually crossing warp and weft threads (11, 12) which are woven together in a specific type of weave, characterised in that a portion of the warp and/or weft threads (11, 12) of the filter cloth (10) comprises monofilament and/or multifilament threads and that the remaining portion of the warp and/or weft threads (11, 12) is formed from metal or synthetic material wires. Filter cloth as claimed in claim 1, characterised in that the monofilament and multifilament threads comprise non-metallic materials. Filter cloth as claimed in claim 1 or 2, characterised in that the monofilament and/or multifilament threads comprise synthetic and/or organic substances. Filter cloth as claimed in claim 3, characterised in that the multifilament warp and/or weft threads (11, 12) comprise synthetic fibre yarns or fibre ply yarns. Filter cloth as claimed in claim 3 or 4, characterised in that the multifilament threads comprise polyester, worsted yarn, carded yarn or similar materials. Filter cloth as claimed in any one or several of the preceding claims 1 to 5, characterised in that the warp and weft threads (11, 12) which comprise metal comprise a stainless steel. Filter cloth as claimed in any one or several of the preceding claims 1 to 6, characterised in that the diameters of the warp and weft threads (1 1, 12) are the same or different. Filter cloth as claimed in any one or several of the preceding claims 1 to 7, characterised in that the warp and weft threads (11, 12) comprising a synthetic material are connected to each other at the crossing points, preferably by means of a heat treatment. Filter cloth as claimed in any one or several of the preceding claims 1 to 8, characterised in that the warp and weft threads (1 l, 12) comprising an organic or synthetic substance are at least partially connected to each other at the crossing points. Filter cloth as claimed in claim 7, characterised in that the diameters of the warp threads (1 l) are larger than those of the weft threads (12). Filter cloth as claimed in any one or several of the preceding claims l to 10, characterised in that the spaces between the individual warp threads (1

1. ) are larger than those between the individual weft threads (1

2. ).