Cellulosic chemical fibres of all lengths and degrees of refinement and with clearly different properties, are at the disposal of the industry of nonwoven bonded fabrics. They are all characterised by the ability to absorb a fairly high amount of moisture. That recommends their use wherever this property is useful for the production of nonwoven bonded fabrics and/or the use of nonwoven bonded fabrics is even a precondition.
Nonwovens are textile fabrics consisting of separated fibres which are arranged properly by means of enduse-oriented technologies. In order to guarantee serviceability of the finished product, they are bonded. For this reason the choice of fibres and possibly bonding materials is of special importance: This relates to fibre raw materials and fibre dimensions. As a rule they have a greater share in creatng the specialities of the nonwovens than this is the case in textile fabrics made of yarns. The bonding agents can also have an impact on the quality of the non-wovens.
Fibrous materials used for Non-wovens
Virtually all kinds of fibres can be used to produce nonwoven bonded fabrics. The choice of fibre depends on:
- the required profile of the fabric and
- the cost effectiveness to produce nonwoven bonded fabrics
- chemical fibres of both cellulosic and synthetic origin as well as
- natural fibres and
- inorganic fibres are mainly used
Vegetable fibresThe most important constituent of vegetable fibres is cellulose, which is hydrophilic and hygroscopic. Apart from cellulose, vegetable fibres also consist of several other substances which affect their properties. Cotton is the most important vegetable fibre used to produce nonwoven bonded fabrics.
Animal fibres Sheep’s wool (Ovis aries)Of all the animal wool and hair, only sheep’s wool is of any importance for the production of nonwoven bonded fabrics. As its price is high, it is used mainly in the form of reclaimed wool or cuttings. The variations in quality and the impurities in reclaimed wool as well as the chemical and physical properties determined by its provenance impose restrictions on its use.
Man-made fibres from synthetic polymersThe field of nonwoven bonded fabrics has become so broad that it includes nearly all kinds of existing fibres to some extent. However, specific fibre types have become predominant in certain areas within this field.
The two main types of fibre are polyamide 6, usually known as Perlon, and polyamide 6.6, which is generally called Nylon to distinguish it from Perlon. The number or numbers after the word ‘polyamide’ indicate how many carbon atoms there are in each molecule making up the polyamide.