CHAPTER 2 SIZING OBJECT OF SIZING TYPES OF

CHAPTER 2: SIZING • • OBJECT OF SIZING TYPES OF SIZING FUNCTION OF DIFFERENT SIZING INGREDIENTS SIZE COOKING & STORAGE EQUIPMENTS, USE OF PRESSURE COOKER AND ITS ADVANTAGES

OBJECT OF SIZING • To hold together the individual fibres of yarn and to bind them together firmly so that the yarn becomes sufficiently strong to bear the stress and strain of weaving operation. • To give sufficient cover , feel , appearance to the yarn. • To cover minor yarn defects and weaving faults. • To add some extra weight to the cloth.

SIZE INGREDIENTS • • Adhesives Softeners Hygroscopic agents Weighting agent Antiseptics Binding agent Tinting agent

PREPARATION OF SIZING PASTE • • • Pure Sizing Light Sizing Medium Sizing Heavy Sizing Extra Heavy Sizing

PURE SIZING • The size that is used only for weaving purposes , i. e. only to protect the yarn from temporary strain and rubbing action during weaving, is called pure sizing. The amount of size in this type of size does not exceed 15% on the wt. of the warp. This size, in most cases, are subsequently removed from the cloth by scouring if later intended for bleaching or dyeing. • The ingredients used in pure sizing are adhesive, softener , antiseptics and water.

LIGHT SIZING • Besides protecting the yarn from temporary strain and rubbing action during weaving, the object of light sizing is to give a slight fuller appearance and to add some wt. to the cloth. • The amount of size put on the yarn is upto 25%. • The ingredients used in light sizing are adhesive , softener, deliquescent in small percentage, antiseptics and water.

MEDIUM SIZING • The object of medium sizing is same as that of light sizing plus to add comparatively more wt. to the warp. The wt. added in medium sizing does not exceed 50% on the wt. of the yarn. • The ingredients used in medium sizing are adhesive, softener, deliquescent , antiseptics weighting material and water.

HEAVY SIZING • The purpose of heavy sizing is same as that of medium sizing except that a considerably much more wt. is added and a much fuller appearance is given to the cloth. The wt. added in heavy sizing is from 50 to 100%, on the wt of the warp. The quantity of weighting material is much more than all other materials put together. A small percentage of tinting material is often used in heavy sizing

EXTRA HEAVY SIZING • The purpose of extra heavy sizing is same as that of heavy sizing except that a considerably much more wt. is added and a much fuller appearance and to impart a special feel to the cloth. The wt. added in extra heavy sizing is from 100 to 200 %on the wt. of material.

SLASHER SIZING DIFFERENT TYPES OF CREEL: • Horizontal Creel • Inclined Creel • Vertical Creel

SIZE BOX (OR SOW BOX) • Direct or Indirect Heating of Size • Immersion Rollers • Sizing and Squeezing Rollers

DRYING ZONE • Shirley Hood: A vapour exhaust system which removes the moisture laden air from above the cylinder drying section and the size box to accelerate the drying capacity of the slasher. • Cooling Fan: It is used to circulate air though the warp sheet and cool the yarn.

FEATURES OF MULTI CYLINDER SIZING M/C • A number of small diameter cylinders heated internally by high pressure steam for drying • The diameter of the cylinder about 28 -311/2 inch depending on different manufacturer models • No. Of cylinders used may vary from 5 to 13 depending on the drying capacity required. • Teflon coating is given to first few cylinders to prevent the wet size from sticking • Automatic temperature control of cylinders. • A hood having an exhaust fan fitted to its top for removing moisture laden air from over the cylinder

MULTI-CYLINDER SIZING MACHINE ADVANTAGES OVER TWO-CYLINDER MACHINE: • The cylinders being smaller in size can be made with a greater accuracy, and enable higher steam pressure to be used , resulting faster drying rate. • Heat losses are reduced because smaller end plates compared to two cylinder machine. • Increased drying efficiency. • Reduced chances of charring.

CONTROL ARRANGEMENTS TYPES: • Size Level Control • Viscosity Control • Tension Control • Stretch Control