Needle punching technique by Vignesh Dhanabalan

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Transcript of Needle punching technique by Vignesh Dhanabalan

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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.

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Principle of Needlepunching Process

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Effect of Needle penetration

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Parts of Needle and Type

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Types of needles

Fibre Parameters

– Fibre Type (Natural or Synthetic)

– Linear density or denier

– Length

– Crimp level

– Tensile Properties

– Cross-sectional Shape

– Surface Finishvigneshdhanabalan@hotmail.com

vigneshdhanabalan@hotmail.com

Web Parameters

– Web area density

– Thickness

– Orientation of fibres

– Web type

Needle Penetration

Depth of barb penetration is defined as the longest distance that the first barb travels below the lower surface of the web

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vigneshdhanabalan@hotmail.com

Effect of Needle Penetration

Effect of Needle Penetration (Cont.)

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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

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vigneshdhanabalan@hotmail.com

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.

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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.

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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

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