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the names and their roles of primary sizing ingredients are given below:
this is untreated starch powder. Mainly maize starch, sago starch, wheat starch, potato starch are used as adhesive agents in sizing. The viscosity of sizing liquor with untreated starch is always high. It gives poor penetration in the warp yarn. This starch is suitable for sizing a coarse count of yarn up to 20s count.
it is chemically treated starch. It has a lower viscosity than untreated starch. It easily penetrates the yarn. When warp count increases, the size pick-up percentage is also increased thus the concentration of liquor is also increases but the viscosity of liquor is kept almost the same by using thin boiling starch. It may be successfully used in the sizing of the medium count of warp yarn. It is a little expensive than untreated starch.
it chemically modified starch. It has a very low viscosity. It gives the best penetration effect in the yarn. It is suitable for all types of yarn count. It can be used for sizing of warp of high-speed loom. Good quality of fabric results with this adhesive. Maximum efficiency can be achieved by using this adhesive. This is much expensive so that it is used in the sizing of a fine count of warp yarn only.
The secondary sizing ingredients of sizing agents are given below:
A braking system is attached to each pair of rollers. Beam tension is adjusted by loosening or tightening the handwheel. The alignment of the beam is also done with help of this handwheel. The yarn guiding rollers are fitted in the creel which guides the warp of each beam. Zigzag or vertical creel is used in the sizing machine. Zigzag creel occupies more space than vertical creel.
the sow box has a stainless steel tub. The sizing liquor is filled in this tub.
it is mounted just before the immersion rollers, it guides the warp sheet during the process.
the warp sheet passes under the immersion rollers. Two pairs of immersion rollers are used in a sow box, immersion rollers help to immerse the warp sheet into the sizing liquor. The warp sheet first passes under one pair of immersion rollers then between the nip of stainless steel and squeezing rollers. Now warp sheet again passes under another pair of immersion rollers and finally warp sheet passes between the nip of other stainless steel and squeezing rollers.
When the warp immerses into the sizing liquor, it has an excess amount of sizing liquor with it. There is a need to eliminate this excess amount of sizing liquor from the warp. The warp coming out of immersion rollers passes between the nips of the squeezing roller, which is mounted just over the stainless steel roller. Two squeezing rollers are used in a sow box. The squeezing roller applies the pressure on the warp sheet and eliminates the excess amount of sizing liquor from it.
This is mounted in the circulation box or tub. It is perforated and connected to the steam line. The main function of this perforated steam pipe is to maintain the temperature of sizing liquor in the sow box. A steam valve is fitted in the steam line which regulates the temperature of the sow box.
The pneumatic cylinders are fitted at both ends of squeezing rollers. These cylinders perform up and down movement of squeezing rollers. The squeezing pressure is maintained by these cylinders. The compressed air is supplied continuously to these pneumatic cylinders.
A pressure gauge is fitted between the pneumatic cylinders and the air supply line. This pressure gauge reads the pressure during the process.
An air pressure regulator is used to control the squeezing pressure. By rotating the air regulator valve the squeezing can be increased or decreased according to requirement.
The temperature sensor is immersed in the sizing liquor. This sensor senses the liquor temperature and sends the signal to the control panel.
The circulation system mainly consists of a geared feeding pump. When the tub of sow box is filled with sizing liquor, it begins to fall into the circulation box. The liquor from here passes into the inlet of the feeding pump. The outlet of the pump is connected to a sow box. The feeding pump continuously circulates the sizing liquor.
some drying cylinders are driven negatively. These cylinders are revolved due to warp tension over the cylinder. The last three or four cylinders are driven positively. A steam trip is mounted on each cylinder which releases an excess amount of steam pressure. The steam valve fitted with each cylinder regulates steam pressure in the cylinder. The temperature sensors fitted with each cylinder reads the temperature of the cylinder and sends the signal to the control panel.
comes out from the drying unit, the ends are stuck to each other. The yarn separators are inserted into the warp sheet in a definite sequence. The number of yarn separators depends upon the number of warper’s beams to be used. The number of yarn separators is always one short of a number of warper’s beams. The yarn separators are fixed on their brackets. The warp sheet moves toward the headstock of the machine. This movement of the warp sheet helps to separate the ends from each other.
The warp sheet again passes over another pressure roller. The pressure of these rollers is controlled by pneumatic cylinders. These cylinders also help to lift upward the pressure rollers. A metallic cover is mounted over the drag rollers which prevents to fall off any foreign material between the pressure roller and the drag roller. A protection grid is mounted just in front of the drag roller which protects the operator’s hand.
A handwheel is used to reduce or increase the reed width. The width can be adjusted by rotating the handwheel in a clockwise or anticlockwise direction. There is another mechanism attached with this reed that helps to move it left and right direction.
The one flanged toothed pulleys connected to the gear transmission system and the other end is connected through a chain sprocket to the receiving device. When the diameter of driver pulleys is increased, the diameter of driven pulleys reduces simultaneously. Therefore the speed of the motion receiving device is increased. When the diameter of the driver is reduced, the speed of the motion receiving device is decreased. The diameter adjustment is achieved by rotating the handwheel.
Steam is used to maintain the temperature in the vessel. A temperature meter and pressure gauge are fitted in this cooking vessel to reed temperature and cooking pressure. Normally the volume of the cooking vessel is 1000 litres. One inch height of the cooking vessel contains 20 litres of the volume of liquor.