The variety of natural and man made fabrics available today, offers a wide selection of fibres for use. But all fabrics are not perfect in one way or other. They all have some good, fair and poor charcteristics. Man's desire, to produce perfect fabrics resulted in the production of blended fabrics. An intimate mixture of two or more fibres spun together is a blend. The individual yarns contain two or more different fibres.
Blending of cellulosic fibres with man made fibres to produce fabrics with improved characteristics has long been accepted throughout the world. The use of blended fabrics have been tremendously increased even in India. The price structure and multi fibre policy of government have increased the use of cellulosic blended fabrics.
The properties of the fibres blended are combined and made into a modified state in blended fabric. If blending is done carefully the good qualities of the fibres are emphasized minimising the poor qualities. Blending requires knowledge of both fibre sciene and art. It enables the technician to produce a perfect fabric for perfect use.
Reasons why fabrics are blended
- The important reason for blending fibres is to produce better performance. By blending we can improve the characteristics that are poor in one fibre, by blending it with another type of fabrics that excel in those characteristics For example polyester when blended with cotton, the resultant fabric has moderate absorbancy which is almost nil in polyester.
- To improve the texture, hand or feel and appearace of fabrics blending of wool fibres with polyester produces the desired texture for suiting materials. Viscose when blended with cotton improves it's lusture and softness and there by enhances it's appearance.
- To reduce the cost This is sometimes one of the important reasons for blending of fibres. The cost of a very expensive fabric can often be reduced by blending with another cheap fibre. For example expensive wool is blended with cheaper polyester to reduce the cost.
- To produce cross dyed efffects Fibres with unlike dye affinity are combined and dyed together so that it produce interesting cross dyes effects as one fibres take up the colour and the other retains its original colour.
- To improve the spinning, weaving and finishing efficiency for example the spinning efficiency of polyester is improved by blending with cotton to produce spun yarns.
Blending may be done before or during spinning. It can be done at the opening and blending stage. though it facilitates perfect blending it poses problems and so it is not in much use. Even at the sliver stage over drawing or roving or spinning frames blending can be done. Blending over drawing frame is most commonly used today. slivers of different fibres are combined over drawing frame depending on blend ratio. They are drawn to get a single silver which is later processed into yarn.
Types of Blended Fabrics
Among the various tyes of blends available today, the most popular fabrics are terry cotton, terry wool, polyester viscose. Polyester cotton viscose blends are most common. Various effects and combinations of properties are produced from these blends depending on the fibres used and the percentage of these fibres used in each blend.
Fabrics of various blend ratios are available in the market today. A blend of 65% polyster and 35% cotton is common. The other blend ratios are 67/33, 70/30, 50/50, 45/55, 52/48, 80/20 polyester and cotton respectively are also available.
A blend of 65/35 polyester and cotton produces satisfactorily a fabric for daily wear. 59/50 blend produces more softer and more absorbent fabric. Polyester when blended with cotton contributes more strength wrinkle resistance and shape; retention, cotton produces comfort as it provides absorbency and heat conduction. The polyeste r cotton blend is most suited for not only India but also for other tropical countries.
Terry-wool Suiting Fabrics
The excellend shape retention of polyster is the foremost contribution to worsted fabrics which show poor shape retention. Polyester provides excellent wrinkle resistance and crease retention that contributes to shape retention whether wet or dry. Depending on the blend ration polyester increases the strength of wool fabrics. Wool provides warmth resiliency, drapability and absorbency depending on the blend ratio.
Blends of polyester and wool are available in ranges from 65% polyster and 35% wool to 60/50, 55/45, 5/50 respectively. A blend of 65/35 will be suitable to produce a light weight, all season suiting. for medium worsteds 60/40 blend is suitable. When more warmth is required 50/50 blends should be opted.
Polyster Viscose Rayon
The blend of polyester with viscose contributes durability, resiliency and shape retention. The wet strength of the resultant fabric is also improved, viscose provides absorbency, soft texture and variety of colour. Blend of polyester and viscose generally ranges from 65% of polyester and 35% viscose to 55/45, 45/55, 48/52 respectively. Among these blend levels 48/52 and 65/35 are commonly used for school uniforms and suiting materials.