As we all know, white ink digital direct printing has a high demand on fabrics. Good fabrics directly affect the effect and color fastness of white ink digital direct printing, so the most basic requirement we usually see is not to contain too much silicone oil and cloth wool. Today, Xiaobian will tell you some basic techniques and processes for singeing cloth, that is, how to remove cloth wool.
In general, before the pretreatment of cotton fabric, the fluff on the cloth surface should be burned to make the cloth surface bright and clean, and to prevent the existence of fluff in dyeing, white ink digital direct printing from causing coloring and poor printing effect.
Fabric singeing is to quickly pass the open fabric through the flame or brush the red hot metal surface. At this time, the fluff on the cloth surface will soon heat up and burn, while the cloth body is relatively close and the temperature rises slowly. When it does not rise to the ignition point, it has left the flame or the red hot metal surface, so as to achieve the purpose of not only burning the fluff but also damaging the fabric.
The quality assessment of singeing is divided into 5 levels, general fabric requirements are 3-4, fabrics with high quality requirements are 4 levels, or even 4-5, and thin fabrics can reach 3 levels. In addition, singeing must be even, otherwise, after dyeing and digital printing, the color will be uneven, and singeing needs to be done again.
Before singeing, first pass the fabric through the brush box, which is equipped with a number of pairs of brush hairs that rotate reversely with the fabric, so as to brush off the gauze head, sundries and dust on the cloth surface, and make the fluff on the fabric stand up to facilitate singeing. After the fabric is singed, it is often stained with sparks. If it is not extinguished in time, it will cause combustion. Therefore, after singeing, the fabric should be immediately passed through the fire chute or fire extinguisher to extinguish the remaining sparks. There is a pair of rolling liquid spokes in the fire extinguishing tank, and there is hot water or desizing liquid (enzyme liquid or dilute alkali liquid) in the tank. When the tank is opened, Mars will be extinguished. The fire extinguisher is steam spray extinguishing.
The types of singeing machine include gas singeing machine, cylinder singeing machine, copper plate singeing machine, etc. At present, the most widely used is gas singeing machine, its main parts are burner. Generally, there are 2-4 burners in the gas singeing machine. The number of times that the front and back sides of the fabric pass through the burners depends on the variety and requirements of the fabric, which can be one positive and one negative, two positive and two negative or three positive and one negative, etc. There are three kinds of combustion gases: gas, LPG and gasoline. In order to make the combustion gas play a good role in combustion, it is necessary to mix the combustion gas and air in proper proportion. The normal flame should be bright and powerful light blue. The speed of gas singeing machine is generally 80-150m / min.
The contact cylinder singeing machine is commonly used for singeing Khaki cotton fabrics. The rotation direction of the cylinder is opposite to the running direction of the fabric, so as to make full use of the red hot cylinder surface. The number of singeing cylinders varies from 1 to 3, and the fabric with more than two cylinders can be singed on both sides. Cylinder singeing can improve the surface finish of thick cotton fabric, hemp fabric and low-grade cotton fabric. The operation speed of the cylinder singeing machine is 50-120m / min.
matters needing attention:
1. In order to improve the singeing efficiency, the fabric should be dried evenly before singeing to keep the moisture content below 5%, but if the drying is uneven or the drying effect is not good, the singeing effect will be affected.
2. In addition to the thin and jacquard fabrics, they should be brushed before singeing.
3. The bristle root shall be cleaned regularly to prevent the yarn head from binding the surface and affecting the bristle effect.
4. Fabric into the machine should not make left and right skew, curl, wrinkle, to prevent uneven singeing defects.
5. When using gas singeing machine to singeing, the flame color shall be checked frequently. In case of flame beating and shaking or abnormal color, it indicates that the proportion of air and combustible gas is improper, and the proportion of both shall be adjusted.
6. Often check the fabric quality, mainly the fabric singeing effect, but also pay attention to local or continuous defects, such as uneven singeing, holes and so on. Polyester blended fabric should pay more attention to fabric falling temperature, hand feeling and fabric shrinkage. If the singeing is excessive, the hand will be hard, the cloth will shrink too much, and the breaking strength, especially the tearing strength, will decrease significantly.