Engineering needle-punched nonwovens to achieve desired physical properties

41-48<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" calibri;mso-fareast-theme-font:minor-latin;mso-hansi-theme-font:minor-latin;="" mso-bidi-font-family:"times="" new="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">The influence of punch density, depth of needle penetration and fabric weight has been studied on the various physical properties of the needle-punched nonwovens made from polyester and polypropylene fibres. With increase in punch density and depth of penetration the weight per unit area and the thickness of the resultant fabric decrease, bulk density increases, and air and water permeabilities decrease due to the increased compactness of fabric. Specific stress and tear strength increase steeply with punch density up to a level and then slightly decrease. Bursting strength and cone puncture resistance decrease with increase in punch density and depth of penetration. Punch density also influences the compressibility and recovery properties of fabric. With increase in fabric weight the air and water permeabilities decrease while the tensile, tear and bursting strengths and cone puncture resistance increase.