Classification Of Filter Materials

First, non-woven filter

Compared with traditional weaving technology, non-woven technology has the advantages of simple process flow, fast production speed, high output and labor productivity, low cost, wide range of available fiber sources, easy process change, and many types of products that can be produced. Sales are growing fast.

Nonwovens can be divided into hydroentangled nonwovens and needlepunched nonwovens according to processing methods. The spunlace method uses a plurality of water jets generated by high pressure to spray the web. The fibers in the web are displaced, intersected, entangled and entangled by the water jets in different directions, so that the web can be strengthened; The puncture method is a barbed needle containing a barb to mechanically puncture the fibers in the web, so that the web can be reinforced. The fibers in the spunlace nonwoven web are flexible winding structures. In contrast, the needlepunched nonwovens are rigid winding structures. Water is consumed by spunlace. Although wastewater can be recycled after treatment, it must also be supplemented with 5 percent of clean water. Currently, most of the non-woven filter materials for bag filters are needle felts.

Second, weaving filter

Woven filter materials are mostly used in woven fabric filter materials, in addition to knitted fabric filter materials, three-way fabric filter materials and braided fabric filter materials. Woven fabric is made by weaving warp and weft yarns that are plied and twisted. Because the warp and weft yarns are twisted, the density of the yarn itself and the interweaving points are relatively large, and the filter can almost only pass through the gap between the warp and weft threads. Generally, the porosity of woven filter materials is only 30% to 40%, and it is straight through.

Compared with non-woven filter media, woven filter media has better dimensional stability and is suitable for making large diameter and long filter bags. The use of woven filter material can be made into a filter material with greater strength and can withstand greater pressure, which is easy to form a flat and smooth surface or a thin and soft fabric, which is conducive to the cleaning of the filter bag, and it is also convenient to adjust the tightness of the fabric. It can be made into looser filter material or highly compact filter material.

Third, the composite filter

In order to give play to the characteristics of the material, to avoid strengths and weaknesses, two or more different materials can be used to process a filter material. This filter material is called a composite filter material. In view of the different shapes of the materials used in composite filter media, it can be divided into two types: material composite and structural composite.

Material composite is a composite method that uses two or more materials to produce a woven filter material or a non-woven filter material using a woven or non-woven process. For example, some high-temperature-resistant short synthetic fibers are mixed with glass short fibers, a fiber web is made by a non-woven process, and a glass fiber composite felt is needle punched onto a glass fiber base cloth. The addition of synthetic fibers improves the entanglement strength of the fibers in the needle felt and the bonding strength between the felt layer and the base cloth, increases the compactness of the needle felt, and improves the filtration performance of the needle felt. However, if the temperature resistance of the synthetic fiber added is low, the overall temperature resistance of the needle felt filter material will be reduced. According to the different high-temperature resistant synthetic fibers, the material composite needle felt can be divided into P84 glass fiber composite needle felt, PTFE glass fiber composite needle felt, and Nomex glass fiber composite needle felt.