Needle punching Process
A physical method of mechanically interlocking
fiber webs by using barbed needles to
reposition some of the fibers from a horizontal
to a vertical orientation.
Principle of Needlepunching Process
Effect of Needle penetration
Parts of Needle and Type
Types of needles
Fibre Parameters
– Fibre Type (Natural or Synthetic)
– Linear density or denier
– Length
– Crimp level
– Tensile Properties
– Cross-sectional Shape
– Surface [email protected]
Needle Penetration
Depth of barb penetration is defined as the longest distance that the first barb travels below the lower surface of the web
Effect of Needle Penetration
Effect of Needle Penetration (Cont.)
Effect of Needle Penetration on Fabric PropertiesNeedle Penetration (in.)
Fabric Weight (g/m2)
Fabric Density (g/cm3)
Initial Modulus (g/tex)
Tenacity (g/tex)
Breaking Extension (%)
1/8 230 0.042 0.3 0.25 45
1/4 240 0.044 0.42 0.40 43
3/8 195 0.046 0.55 0.50 441/2 195 0.047 0.68 0.71 355/8 160 0.043 0.74 0.66 30
3/4 160 0.043 0.59 0.45 30
Needlepunching Process Parameters
– Arrangement of needles in needle-board
– Effective length of needle-board
– Punch density
– Depth of needle penetration
– Diameter of the holes in stripper and bed plates
– Distance between the two plates at entrance and exit
Direction of Needling
– Passing the same side of the web and second by feeding
alternating sides of the web in consecutive passes.
– Alternating the side of the web facing the needles caused
less fibre breakage.
– Fibre stress caused by the previous needling pass was
superimposed by the subsequent pass.
– Significant strength reduction.
Punching ForceThe force which is generated as a result of the resistance offered by the fibres being transported (reoriented) by the penetrating barbs is defined as Punching Force.
Punch density
– The density of needles in the needle board (Nd)
– The rate of material feed
– The frequency of punching
– The effective width of the needle board (Nb T)
– The number of runs
– n= number of needles within a needleboard
– F = frequency of punching
– V = rate of material feed
– W = effective width of the needle board
Edpass = [n*F] / [V*W]
Applications– Shoe felts – Blankets– Automotive insulation– Carpet backing– Wall coverings– Composites– Geo textiles– Felts– Padding– Filters