This document discusses sizing of synthetic yarns. It defines sizing as applying a protective adhesive coating to yarn surfaces. Sizing is needed to provide strength and abrasion resistance for weaving. The document describes various synthetic yarns including acrylic, aramids, basofi, chlorofibers, modacrylic, nylon, olefin/polypropylene/polyethylene, sulfar PPS fibres, PBI. Common synthetic sizing agents are listed as polyacrylates, modified polyesters, polyvinyl alcohols and styrol/maleic acid copolymers. Polyvinyl alcohol is described in more detail. Characteristics and applications are

1. SIZING OF
SYNTHETIC YARN

2. Sizing:
 The process of apling proctive adhesive coating the tarn surface is called
Sizing.
 In the weaving of yarns into fabrics, most yarns lack the strength and abrasion
resistance necessary to weave efficiently under typical weaving conditions. To
overcome these deficiencies, yarns are impregnated with a material called
size.

3. Synthetic Yarn
 Synthetic yarns are produced entirely from
chemicals obtained from petroleum's. Each type
of fiber will yield characteristics proper to the
chemicals used. Some fibers are soft others do
not burn or melt, some resist to chemicals while
others are super strong etc.

4. Types of Synthetic Yarn
 ACRYLIC
 ARAMIDS
 BASOFIL
 CHLOROFIBERS Rhovyl
 MODACRYLIC
 NYLON
 OLEFIN/POLYPROPYLENE/POLYETHELENE
 SULFAR PPS fibres Torcon, Procon
 PBI

5. Synthetic Sizing Agent
1. Polyacrylates
2. Modified polyester
3. Polyvinyl alcohols (PVA)
4. Styrol/maleic acid copolymers

6. PVA (Polyvinyl alcohols)
 PVA is the second largest film former used in sizing. It is
mostly used on synthetic yarns such as polyester and
poly/cotton blends. PVA coating is strong, abrasion resistant
and can easily be desized in hot water. Its strength is greater
than starch and also more flexible than most standard
starches. PVA is less prone to setup in the size box compared
to starches. PVA can form foam in the size box which is
controlled with a deformer. PVA may be too strong for some
sizing applications. In this case, some weaker film forming
polymers such as starch are added to modify the mixture,
which also reduces the cost, since PVA is more expensive
than starch.

8. ACRYLIC
 Soft and warm
 Wool-like
 Retains shape
 Resilient
 Quick-drying
 Resistant to moths, sunlight, oil and chemicals
 Dyes well and has excellent color fastness
 Tendency to pill
 Apparel: Dresses, infant wear, knitted garments, lingerie, linings,
shirts, slacks, sportswear
 Fabrics: Fleece and pile fabrics, face fabrics in bonded fabrics,
simulated furs, jerseys
 Home Furnishings: Blankets, carpets, draperies, upholstery
 Other: Auto tops, awnings, hand knitting and craft yarns,
industrial and geotextile fabrics

9. CHLOROFIBERS Rhovyl
 Thermal insulation
 Wicking of moisture
 Flame retardancy
 Resistance to meldew and fungi
 Resistance to acids, bases, reducing and oxidizing agents
 Apparel: Underwear, hosiery, sports wear, fleece and fake fur, chi
 Fabrics: Drapes, wall coverings, curtains, trimmings and upholstery
 Other: filtration, hygiene, bedding, Fire and cold protection

10. MODACRYLIC
 Soft
 Resilient
 Abrasion and flame resistant
 Quick drying
 Resists acids and alkalies
 Retains shape
 Apparel: Deep pile coats, trims, linings, simulated furs, wigs and hairpieces
 Fabrics: Fleece fabris, industrial fabrics, knit pile fabric backings, non-woven
fabrics
 Home Furnishing: Awnings, blankets, carpets, flame resistant draperies and
curtains, scatter rugs.
 Other: Filters, paint rollers, stuffed toys

11. NYLON
 Exceptionally strong
 Supple
 Abrasion resistant
 Lustrous
 Easy to wash
 Resists damage from oil and many chemicals
 Apparel: Blouses, dresses, foundation garments, hosiery, lingerie and under
wear,raincoats, ski and snow apparel, suits, windbreakers
 Home Furnishing: Bedspreads, carpets, draperies, curtains, upholstery
 Other: Air hoses, conveyor and seat belts, parachutes, racket strings, ropes
and nets, sleeping bags, tarpaulins, tents, threads, tire cord, geotextiles.

12. OLEFIN/POLYPROPYLENE/POLYETHELENE
 Unique wicking properties that makes it very comfortable
 Abrasion resistant
 Quick drying
 Resistant to deterioration from chemicals, mildew, perspiration, rot and weather
 Sensitive to heat
 Soil resistant
 Strong; very lightweight
 Excellent color fastness
 Apparel: Pantyhose, underwear, knitted sports shirts, men’s half hose, men’s knitted
sportswear, sweaters
 Home Furnishing: Carpet and carpet backing, slipcovers, upholstery
 Other: Dye nets, filter fabrics, laundry and sand bags, geotextiles, automotive
interiors,cordage, doll hair, industrial sewing thread.

13. PBI
 Highly flame resistant
 Outstanding comfort factor combined with thermal and chemical stability
 Will not burn or melt
 Low shrinkage, when exposed to flame
 Suitable for high performance protective apparel such as firemen’s
turnout coats, astronaut space suits and applications where fire
resistance is important.

14. THANK YOU!!