The pre-treatment of polyester yarn or fabric is generally based on oil removal, because polyester will add spinning oil during spinning. So, what oils are generally used in polyester spinning oil? ?
There are many types of polyester filament oils, including POY and DTY oils, conventional spinning oils, drawn yarn oils, and textured yarn oils agents and industrial silk oil agents, etc. They can all play a role in bundling, lubrication, reducing friction coefficient, antistatic, etc., but they have their own special functions and adaptability. Even for the same type of filament, due to different processing equipment and post-processing processes, the required oil agent The characteristics should also be different.
Polyester filament oils can be divided into two categories: spinning oils and finished oils. The basic properties of oils are the same, but they have different effects on spinning oils. The performance requirements of the agent are higher than those of the finished oil agent.
01
Basic properties of oils
1. Smoothness
Smoothness, or lubricity, is essentially the friction characteristic of oil . It is often expressed by the static friction coefficient (μs) and kinetic friction coefficient (μd) between wire and wire (F/F), wire and metal (F/M), and wire and rubber (F/R) after oiling.
Generally speaking, after a better oil is applied to the yarn, the static friction coefficient of F/F should be appropriately larger, so that the yarn has better bundling properties. , good winding shape and excellent unwinding properties. There are no special requirements for the dynamic friction coefficient of F/F, but during false twist deformation, if the wire slides, it will easily deform.
It is better for the static friction coefficient of F/M to be smaller, and the smaller the dynamic friction coefficient, the better. This can reduce the friction between the wire and the metal. , reduce wool and broken ends, reduce the wear of wire on metal, and improve the processing and weaving performance of silk. The static and dynamic friction coefficients of F/R are appropriate. Because during the processing, rubber parts are used to increase the holding force of the wire. If the friction coefficient is too small, it will easily slip. Smoothness is determined by the properties of each component of the oil and has a certain relationship with the lubrication condition.
Lubrication when the oil content is high (0.5% ~ 1.0%) is fluid lubrication. In fluid lubrication, the friction coefficient increases with the increase in oil viscosity and oil content.
The lubrication with the lowest oil content and the smallest friction coefficient is critical lubrication. At high speeds and high contact pressures, maintaining critical lubrication is of great significance. Under critical lubrication conditions, in addition to the viscosity of the oil agent affecting the friction coefficient, the oil film strength (interfacial adsorption force, intermolecular cohesion) also has a great influence on the friction coefficient. The oil film strength is high and the friction coefficient fluctuates little.
2. Antistatic properties
Polyester It is a good insulator. When it is rubbed during processing and use, negative static electricity will be generated due to the accumulation of charges.
Static electricity loosens the filament and deteriorates the processability. Therefore, oiled fibers should be antistatic. There are usually three antistatic mechanisms: enhancing the hygroscopicity of fibers; reducing friction; and neutralizing the generated charge. Three mechanisms can work simultaneously. The simplest method to measure the antistatic property of an oil is to measure the specific resistance of the wire after oiling. It can also measure the frictional charge of the wire.
Prevention method: See Dye Condensation and Oligomer Prevention.
8. Lining and abrasions
Produced Reasons and prevention methods: The diameter of the nozzle is too small, which causes the nozzle pressure to be too high. A nozzle of appropriate diameter should be selected according to the weight of the dye to make the spray pressure moderate and not too large; the cloth speed and the rotation speed of the cloth guide wheel are out of proportion. The two should be proportional; if the gray cloth or semi-finished product is scratched due to impact, the gray cloth or semi-finished product should be handled with care to prevent impact and scratches; if it is scratched when opening the width, manual opening should be used.
9. Stretch
Cause and reason Prevention and control methods: The cloth capacity is too low, which lengthens the transportation distance of the cloth and increases the tension. The cloth capacity should be controlled appropriately; the liquid level of the dye liquor is set too high, thus increasing the resistance between the water and the cloth. Keep the fluid level as low as possible.
07
Common defect repair technology
1. The dyeing is seriously uneven
In this case, the migration of the dye cannot be used to correct back and forth. , must be stripped before dyeing. If it is a light or medium color, it can be dyed into a dark color.
The stripping methods are:
①Oxidation and color stripping.
Recipe example: sodium chlorite 2~5g/L, acetic acid (98%) 2~3g/L, methylnaphthalene or Chlorobenzene 3~5g/L. The process is: start treatment at 30°C, raise the temperature to 98°C in 30 minutes, boil for 60 minutes, and wash with water. If necessary, use bleaching powder and acetic acid to bleach at boiling temperature.
② Restore color stripping.
Prescription example: caustic soda (flakes) 1g/L, insurance powder 5g/L, chlorobenzene 5g/L. Nonionic surfactant 2g/L. The process is: start treatment at 30°C, raise the temperature to boiling for 30 minutes, boil for 60 minutes, then wash with cold water and hot water. If the stripping is not sufficient, process it again, or use the oxidation stripping method again. Using the above methods may damage the feel of the fabric, so try to avoid it.
2. Wrinkles and mild uneven dyeing
Wrinkle treatment method: Put the fabric back into the jet dyeing machine, raise the temperature, the temperature should be a few degrees higher than the original dyeing temperature, and then slowly cool down.
For lightly dyed uneven fabrics, the migration property of the dye is generally used for counter-dying. The process flow: start dyeing at 60°C, and heat up to 90°C in 15 minutes. , then raise the temperature to 130°C for 40 minutes, keep it warm for 60 minutes, and then cool.
The repair formula is: disperse dye (determined after testing), leveling agent 1~2g/L, and the pH value is adjusted to 5~6.
When using dyes with poor dye migration, the dyeing temperature should be increased to 135~140℃, but the mechanical properties must be allowed and the feel of the fabric must not be affected. As a premise, the dispersion leveling agent includes a carrier (or repair agent).
3. Dyeing oil spots
①small Batch removal of local oil spots or dead oil spots. Usually non-ionic detergent, carbon tetrachloride, gasoline and other organic solvents are used, sprayed with a spray gun, washed manually, and then the fabric is washed.
②Removal of large-area oil spots. Use 2 to 3 g/L of degreaser and non-ionic detergent each, and treat it at 100°C for 20 minutes, or use 2 to 3 g/L of degreaser and non-ionic detergent, and 1 to 2 g/L of high-temperature dispersant at 130°C. Process for 20 minutes.
③ Oil spots that are difficult to remove. If the oil spots are serious and difficult to remove, you can consider changing them to dark sapphire blue or black to cover them. Sexy color.
pan style=”letter-spacing: 1px;”>When using dyes with poor dye migration, the dyeing temperature should be increased to 135~140℃, but it must be based on the mechanical properties and not affecting the feel of the fabric. The dispersion leveling agent includes a carrier (or repair agent).
3. Dyeing oil spots
①small Batch removal of local oil spots or dead oil spots. Usually non-ionic detergent, carbon tetrachloride, gasoline and other organic solvents are used, sprayed with a spray gun, washed manually, and then the fabric is washed.
②Removal of large-area oil spots. Use 2 to 3 g/L of degreaser and non-ionic detergent each, and treat it at 100°C for 20 minutes, or use 2 to 3 g/L of degreaser and non-ionic detergent, and 1 to 2 g/L of high-temperature dispersant at 130°C. Process for 20 minutes.
③ Oil spots that are difficult to remove. If the oil spots are serious and difficult to remove, you can consider changing them to dark sapphire blue or black to cover them. Sexy color.
