Non-wovens - Application and Types of Non-wovens

NON-WOVEN:

Non-wovens are defined as fabric structures produced directly from fibers by bonding or entangling the fibers or filaments by mechanical, thermal or chemical means. Use of adhesive heat, fusion or entanglement of the fiber may be carried out. The input material for non-wovens are 1. Any fibers 2. Some kinds of Bonding Agent. 3. Any Auxiliary agent (added for special effects, e.g., surface texture, etc.)

Non-wovens may be categorized into 1. Durables2. Non-durables or Disposables 3. Semi-Durables.

Durables are those which are manufactured for intention of longer use, e.g., furnishing, carpets (Numdhas), carpet backing. Mostly nylon, polyester and rayon, etc., are used.

Disposables are those that are intended to use only for a limited application. Throw away after use. It should not be very expensive. Cost of manufacture and material in this case should not be too high, e.g., Diapers, Tissue paper, surgeons gloves, gowns, filters, etc. Rayon is the fiber which is most commonly used. Semi Durables are used to make products as table mats. Can be used more than one time.

1. Non-wovens

          Made directly from fibers

          Variation can be made by using different ways of bonding fibers together.

          They show good to excellent resilience.

          Good shock absorbers.

          Easy to shape

          Will not ravel

          Edges need not finish

          Sound absorbent

          Have good insulation properties with resultant warmth

          Will not tear

          Breaking load is low

          Holes cannot be mended very satisfactorily

          There is little or no elastic recovery nor elongation in felt fabrics Should be laundered carefully.

          Should not be subjected to pulling or twisting.

Wovens

Yarn are made out of fibers which are then interwoven to form the fabric Variations can be made by using plain, novelty or textured yarns and may be by weaving them in different ways.

Normal resilience

They are not until the woven structure is quite thick.

Not easy to shape

Ravel most in case of man-mades

Edges needs to be finished

Are not sound absorbent

Only in few cases as worsteds

Will tear

Breaking load is high as compared with some general thickness and weight Can be mended

They have fair to good elastic recovery and elongation

Depends on what kind of fiber, yarn and weave used for the construction

2. Application of Non-wovens:

Non-woven fabrics appear in a wide variety of products for apparel, home-furnishings, business, industry and specialized applications such as aerospace. The list of products made from non-woven fabrics is long and growing each year. Some typical end-use items include diapers, handkerchiefs, shirts, dresses, apparel interfacings, bandages, curtains, decontamination clothing, garment bags, industrial apparel, lampshades, map backing, napkins, place mats, ribbons, upholstery backing, window shades, hospital gowns, hospital sheets and many more.

Durable non-wovens have wide applications. these include apparel, such as for caps, interlinnings and interfacings home furnishings, such as for draperies furniture, upholstery, mattress padding, and carpet backing, industrial uses, such as filters, insulation and roadbed stablization sheetings.

Disposable non-wovens are essentially made for one time use; such as dust cloths, may be laundered and reused a few times. General applications include diapers, sanitary napkins, surgical and industrial masks, bandages and towels.

3. Types of Non-wovens:

There are many types of non-woven but basically two types of non-wovens are very common: (a) Felts (b) Bonded fabrics

a. Felts:

Felts as defined by ASTM are: 'A structure build up by the interlocking of fibers by a suitable combination of mechanical work, chemical action, moisture and heat without spinning, weaving or knitting.' They may consist of one or more classes of fibers (main fiber type is wool).

b. Bonded fabrics:

Bonded fabrics constitue a larger area of non-wovens and this word is used as a constituent of non-wovens.