5. Nonwoven

DEFINITIONS

Nonwoven fabrics:

Techniques by which fabrics are made direct from fibers ,by passing both spinning and weaving.The textile structure are produced by bonding or interlocking fiber, by chemical ,mechanical ,thermal or solvent means and combination theoref.[1](ASTM 1998)

Figure 1

MANUFACTURING PROCESS OF NONWOVENS

FIBER SELECTION ->WEB FORMATION ->WEB BONDING ->FINISHING

FIBRE SELECTION

Characteristics of the fiber in term of  :

Figure 2

NATURAL FIBERS

Figure 3

MAN MADE FIBERS

[2]

Figure 3

WEB FORMATION

Nonwoven manufacture starts by the arrangement of fibres in a sheet or web. The fibres can be staple fibres packed in bales, or filaments extruded from molten polymer granules.There are several ways to form the web. It can be done in term of mechanical, chemical ,and thermal .

Figure 4 [1]

PICTURE A-dry laying

Web forming by carding. Fibers from the bale are comb by the fine wires and teeth into the parallel arrays.

PICTURE B –air laying

Fibers from opened bales are suspended in air and then collected on a screen.

PICTURE C-wet laying

Fibers are uniformly suspended in the water and collected to form a sheet by filtering it onto the screen.

WEB BONDING

Web bonding of nonwovens are typically manufactured by putting small fibres together in the form of a sheet or web (similar to paper on the paper machine), and then binding them either mechanically (as in the case of felt, by interlocking them with serrated needles such that the inter-fibre friction results in a stronger fabric), with an adhesive, or thermally (by applying binder (in the form of powder, paste, or polymer melt) and melting the binder onto the web by increasing temperature).Figure below show the examples of web bonding using the adhesive methods.

Figure 5 [1]

PICTURE A-saturation bonding

PICTURE B-gravure printing

PICTURE C-screen printing

FINISHING

After the web formation and web bonding, the final stage is finishing. Finishing processes as a means of enhancing fabric performance or aesthetic properties. Performance properties include functional characteristics such as moisture regain and transport, absorbency, or repellency, flame retardancy, electrical responce, abrasion resistance and frictional behavior. Aesthetic properties include various attributes such as appearance, surface texture, color, and odor. There is a lot method to do the finishing which are:[3]

Figure 4

END PRODUCTS

INDUSTRIAL / TECHNICAL USES

Focus on strength ,modulus,durability,dimensional stability and functions.

—  Examples :

Figure 5

  • Filtration media
  • Geotextiles
  • Roofing materials
  • Automotive parts
  • Packaging

MEDICAL APPLICATION

—  Focus on the barrier properties, strength, sterilisation stability , breathability &

comfort.

—  Examples:

Figure 6

  • Face  mask
  • Disposable isolation gowns
  • Bouffant caps
  • Surgical drapes and wraps

HOUSEHOLDS & UPHOSLTERY

Examples :

Figure 7

  • Pillow and bolster cases
  • Table Cloths
  • Carpet Underlay
  • Curtains
  • Laundry Bags

APPARELS

Examples :

Figure 8

  • Disposable Underwear
  • Protective & Working Clothes
  • Interlinings

CONCLUSION

As conclusion,there is lot of development in nonwoven area.For example is an innovation about the additives from mineral sources that will be apply in nonwoven production. The statemant below is about the product:

FiberLink 101S Mineral Additives for Nonwovwn Application

FiberLink™ 101S is the latest development in nonwoven and mineral technology. This product has been specifically designed to enable the amount of resin used in nonwoven production to be substantially reduced.[4]

REFERENCES

[1]Billie J. Collier, University of Tennessee & Phyllis G. Tortora, Queens College. Understanding Textiles Book, (Sixth Edition).

[2]Lecturer’s note by Miss Atiyyah Bt Musa & En Mohd Iqbal Bin Misnon

[3]http://www.andritz.com/nonwoven-finishing-technology

[4]www.nonwovens.imerys.com

 

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