The Damage Mechanism Analysis On Base Fabric In Needle Punched High Temperature Resistant Filter Material

High temperature resistant needle punched filter material as an efficient, low resistance and low cost filter material in environment protection has been wildly used. High temperature resistant filter material usually places woven fabric as the base fabric to improve the filter material strength. However, the base fabric organization structure always be damaged in the needle punching process, leading the strength of filter material decline and reducing its service life. Mechanical reasons and process reasons are the two main reasons leading the strength damage of the base fabric. Mechanical reasons induces the performance of acupuncture machine, needle type; process reasons induces needle punching depth, needle punching density and needle punching times.It surveys the bag filter's damage mechanism, inquires a large number of literatures, learns the process of filter material methods in plant, research the filter material damage cases in the actual use condition. Those efforts guide to change process parameters in the experiment, optimize process of acupuncture and improve the quality of filter material.This paper obtains the following result from these researches:(1) With the needle vibration frequency and needle punching density increasing, the percentage of needle broken increase exponentially. With the material density and thickness increasing, the percentage of needle broken increases.(2) The changes of needle punching depth and needle punching density will affect the filter material performance, especially for the base fabric becomes more apparent.The base fabric has an apparent effect of air permeability in the front needle punching because of its sparse structure. With the needle punching times increases, the structure of the surface fiber net becomes more closely, the base fabric will reduce the role for the air permeability.(3) Material apertures mainly depend by the type of surface fiber, the thickness and structure of this material. With the same fiber used in the needle punching process, the needle punching density has the greatest impact to material apertures.(4) In the angle between needle teeth arranged direction and the material forward direction is 45°or 135°, the needle punched material has the highest strength. The angle between needle teeth arranged direction and the material forward direction has a greater damage to the horizontal strength and a slighter damage to longitudinal strength. After two times of needle punched, the base fabric longitudinal strength remained at 73%.(5) The surface fiber net has a low strength at the material broken point. The strength of needle punched material is mainly depended on the base fabric.