Acrylic yarn is made from Acrylic fibre / tow – which is a man made fibre basic derivative is acrylonitrile which is further made from crude oil . Acrylic fibre is available in various deniers ranging from 0.9 to 17 , most commonly used denier for Hand knitting yarns range from 2 to 6 , Lower the denier of the fibre softer is the yarn , higher the denier bulkier is the yarn , Hence right mix depending on end use of the yarn is needed , Example baby yarns will have lower denier mix , Latch yarns can have higher denier mix
Acrylic fibre started becoming popular in early on 1970s – it has a unique property when stretched on special machines it becomes shrinkable ( means will shrink when subjected to heat / steam ) therefore Acrylic tops ( basic form ) of acrylic fibre to spin yarn can be made as shrinkable Tops and Non Shrinkable Tops ( also called as Relaxed tops ) These 2 kinds of variants are mixed in order to make what is called Bulky Acrylic yarn ( most common type hand knitting yarn ) , when both fibres are mixed -the shrinkable fibres , shrink by 15% to 25% they make non shrinkable fibres to crimp around shrinkable fibres , hence provide very good volume / bulk to the yarn This bulk / crimping resembles the natural volume of wool caused by natural crimp of the wool fibres , Therefore Acrylic is the closest man made fibre that resembles wool in terms of bulkiness Acrylic bulky yarn can be High Bulk , Medium Bulk , Low Bulk, or No Bulk ( Called as Relax yarn ) Lower the bulk softer is the yarn , but weight per square knitting will also increase where as bulky yarns will result in Light weight garment Just to give an idea of the bulk of the yarn Bulky Acrylic hand knitting yarn . The volume would be double that of cotton or polyester yarn , example if One container / carton box can contain 10 kgs of cotton yarn it can only contain 5 Kgs of Acrylic yarn and 6 Kgs of wool yarn So the products made from Acrylic yarn will be half the weight of cotton ( light weight ) There are some acrylic yarns ( Relax yarns ) which are not bulky they will knit heavier
Acrylic is mostly spun on worsted / Semi worsted spinning system ( Long Staple spinning ) -as explained in All about yarns section , Acrylic yarns can be made by dyeing fibre first and then making the yarn ( called as Fibre / Tow dyed yarns ) or they can be dyed later after raw white yarn is made then yarn itself can be dyed – Normally on Hanks Acrylic can be easily mixed with any fibre , for example Acrylic Wool , Acrylic Merino, Acrylic Nylon ( Very soft yarns for babies ) , Acrylic Alpaca , Acrylic Tencel , while Acrylic will provide the bulk , and other fibre will provide the property it is intended for