adhesives - copy

Garima Goel

textile engineering

J.N Government Engineering college

The non woven fabric properties depends on the following particulars to an great extent,1) The choice of fibers.2) Technology which determines how the fibers are to be arranged.3) The bonding process and the bonding agents.

Fabric properties of nonwovens range from crisp to that soft-to-the-touch to harsh, impossible-to- tear to extremely weak. This leads to a wide range of end products such as filters, teabags, geotextiles, etc. some which are durable and others Are disposable

It is not necessary to use best fiber but required fiber

Virtually all types of fibrous material can be used to make nonwoven bonded fabric, the choice being dependent on:

1) The required profile of the fabric.

2) The cost / use ratio(cost effectiveness)

3) The demands of the further processing

The bonding agents are the glue as it binds the web firmly together to give the non woven fabric. These agents largely determine the wear properties of the non woven fabrics.Fabrics made from a combination of fibers and bonding agents is defined ass non woven bonded fabrics ( DIN61210- German Standards Committee)

Strength/stretch (resistance to pilling, tearing and ripping)

Elastic tenacity and bendability

Handle and draping qualities

Washing and dry cleaning fastness

Resistance to chemicals

Resistance to air and oxygen

Flame resistance property

Hydrophilic and hydrophobic properties

Bonding Fibers are usually made from thermoplastic polymers. The most important of the former kind are polyvinyl alcohol (PVA), co-polyamide, polyolefin, polyester and polyvinylchloride. Among the powders and pastes made from them, those used are co-polyamides, polyethylene and ethylene vinyl acetate (EVA) copolymers.

The construction of a nonwoven with suitable binders is to achieve improved characteristics such as strength, softness, adhesion, firmness, durability, stiffness, fire retardence, hydrophilicity, hydrophobicity, anti-microbial properties, organic compatibility, reduced surface tension, improved dimensional stability and solvent, wash and acid resistance

Strength Adhesion to Fibers Flexibility/handle Elastic Recovery Minimum film forming temperature Glass or brittle temperature Resistance to washing/ Drying cleaning Other special requirements

A binder is any material or substance that holds or draws other materials together to form a cohesive whole mechanically, chemically, or as an adhesive.

The binders available are mainly classified according to their chemical structures. There are three main kinds of binders viz.

Butadiene copolymers

Acrylates

Vinyl copolymers