Add-on Materials on Sizing Ingredients | Binders | Lubricants

Add-on materials:

In addition to a film former polymer various additives are added to a size mix. Additives may be included in the size mix depending on the particular weaving machine requirements or if a particular type finishing is required after the fabric is woven. A huge variety of additives are used. Most common of them are as follows:

Binders:  

There are a number of polymeric materials that can be used in sizing as binder materials. Binders are true film formers but are generally not used alone for sizing; some sizes are useful as both a primary size and as a binder. Binders are typically used to increase weave ability by promoting the adhesion of the primary film forming size to a specific fiber substrate while reducing the cohesion between sized yarns. By judicious selection of a binder, additional sizing advantages can be realized.Most commonly there are three types of binders used;

1. Acrylics:
2. Pearl corn starch
3. Modified starch
4. Starch derivatives.
5. Polyvinyl alcohol.
6. CMC.
7. Polyester resin binders.
8. Vinyl acetate resins.

Lubricants: 

Lubricant is almost always added to increase abrasion resistance of the yarn which is especially useful for rapiers and projectile machines. Lubricants with anti-sticking agents (lecithin) also prevent sticking of PVA to dry cans. Emulsifiers are added to the wax to improve desizablity. Paraffin or marine glycerides are added to harden the wax and better lubricate the yarns; however, if not removed properly during desizing some lubricants can cause problems in later operations.

Various other additives include humectants, anti-static and anti-foam agents, removable tints (for warp or style identification), preservatives (if the warp or the fabric is to be stored for long periods of time), penetrating agents (to allow the size to penetrate into tightly constructed styles), weighting agents (to make cloth heavier), anti-mildew.

Softeners such as lubricants, soaps and waxes are used to make the yarn sufficiently extensible, they also prevent cracking of size during weaving.

Humectants, such as urea, sugar and glycerin are used to retain moisture in the size product. Moisture makes the size film more flexible and less brittle.