| Needle punched filter material as an efficient, low resistance and low cost filter material inenvironment protection has been wildly used. Since the strength of the web is relatively low andthe filter requires a certain strength in the actual work, base fabric was usually placed between thewebs to improve the strength.In the needle punching process the base fabric always damagedunavoidably, leading the strength of filter material decline.In order to reduce the damage to the base fabric and improve filter’s strength, we use the neweliptical needle and choose the optimum parameters to reduce the base fabric’s damage andimprove the quality of filter material.By reviewing a lot of papers and doing needle punchingexperiments, we researched the effect of elliptical and triangle needle on the damage of basefabric. At the same time,we use the best process parameters to finish some product filter. Throughcomparative analysis of elliptic needle to research the low damage characteristics.This paper obtains the following conclusions from these researches:(1) To triangle and elliptic needles, the base fabric’s damage changes not very large when theneedle depth increased from7mm to9mm while the hook teeth increased from3to4. For triangleneedles increased by about7%and for elliptical needles increased by4%-5%.(2) When the needling depth is7mm and the needling density is1200, the elliptic needle’sbase fabric strength increased by31%compared with the triangle needle. When the needling depthis9mm and the needling density is1200, the elliptic needle’s base fabric strength increased by33%compared with the triangle needle.(3) The PTFE Fabric and filter processed by different hook depth(0.05mm and0.07mm)exhibit different strength,.The deeper the depth, the greater the damage.(4) The filter’s strength is provided by the surface fiber net and fabric, The strengthcontribution rates were approximately20%and80%.It shows that the strength of needle punched material is mainly depended on the base fabric. |
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