How to solve the problems encountered when using silicone oil to soften textile products?

I believe everyone has encountered many problems when doing textile silicone oil softening and finishing in their daily lives, such as yellowing, fluorescence degradation, temperature issues, etc. Often, some printing and dyeing factories overlook these issues due to various reasons such as cost. So how can we solve these problems that cannot be ignored? I have compiled some common problem-solving solutions for everyone, as follows:

01. Alkalinity issues

During the pre-treatment of cotton fabrics, a higher concentration of alkali is usually used to remove impurities (especially with a higher amount of mercerized alkali). Alkali entering the fiber is not easy to clean, and alkali is also added during dyeing (reactive vat dyes), so the fabric surface may become alkaline during post-treatment. After dyeing, chemical fiber fabrics need to undergo reduction cleaning. Currently, printing and dyeing factories are still using insurance powder and caustic soda for cleaning. If the cleaning is not done thoroughly afterwards, it can also cause alkali on the fabric surface before softening. However, ordinary silicone oil is not alkali resistant and will break under alkaline conditions, which is the reason why the factory sticks to the roll after several thousand meters of immersion and rolling softening. Therefore, before softening, the fabric surface must be washed with alkaline agent or acetic acid added to the working solution to maintain the rolling groove pH 5-6.

02. Cohesion issues

On fabrics containing short fibers (cotton cloth, T/R cloth, velvet), it is inevitable that some short fibers will fall off during the processing. The short fibers that fall off the cloth accumulate in the rolling groove, forming adhesion with ordinary silicone oil. As the finishing liquid rises to the rolling roller, it binds with the silicone oil that has been crushed and broken, forming adhesion roller or silicon spot. When the water quality is relatively poor, it will also condense with ordinary silicone oil to produce sticky rolls. In addition, there may be similar situations with fluffy fabrics. Before driving, do a good job of cleaning, and if you find any burrs, clean them at any time.

03. Charge stability issues

Most of the dyes and brighteners used in cotton fabric are anionic, while cotton whitening is mostly done on the setting machine. In addition, when the color light of the dyed fabric is not correct, fine adjustments are needed for color correction. Usually, a small amount of dye or coating is added when applying a soft finishing agent. However, factories usually use ordinary silicone oil (weak cation), which will generate a negative and positive charge attraction reaction, causing condensation and sticking to the roller. However, anionic silicone oil cannot meet the requirements for hand feel softness, causing confusion in the factory. Charge consistency must be considered during processing.

04. Temperature issues

The fabric dyed from cotton long carts needs to be dried through a drying drum, packaged in large rolls or stacked in a cloth box. If it is not fully cooled, especially for the fabric packaged in large rolls, the surface temperature of the fabric may be high when it is soft, causing an increase in the temperature of the rolling groove working fluid (especially in summer), sometimes reaching over 60 ℃. However, ordinary silicone oil with poor heat resistance can also cause roller sticking. The temperature in the rolling groove should not exceed 40 ℃.

05. Fixed speed issue

When the factory is making some thin fabrics, the shaping speed is very fast, sometimes reaching a speed of 60 meters per minute. Due to poor permeability of ordinary silicone oil, it causes the silicone oil to flow back on the rollers, causing sticking to the rollers. Pay attention to replacing the working fluid in the rolling groove and frequently wipe the rolling rollers.

06. Problem with cylinder contamination

Many factories use ordinary silicone oil to soak and soften the cylinder walls. Over time, some black oil spots will form on the cylinder walls, and when it touches the cloth surface, it will form silicone oil spots to strengthen cleaning work.

07. Feel issues

Due to the increasing demand for the texture of fabrics in the market, and due to different seasons and customer requirements, various fabrics need to display various style requirements, such as smooth and drape, smooth and lively, fluffy and soft, and simple elastic. A silicone oil can generally only reflect one style. Therefore, many factories have to use many types of silicone oil, resulting in production chaos. Sometimes, they cannot find silicone oil that meets customer requirements and can only give up business, causing losses. We can synthesize amino silicone oil with different ammonia values, viscosity, and reactivity by selecting different amino silicone oil end groups to control molecular weight and molecular distribution, meeting the requirements of various fibers in terms of softness, smoothness, and elasticity.

08. Cost issues

At present, the biggest confusion for printing and dyeing factories is the cost issue. Due to the continuous increase in water, electricity, and gas prices, while printing and dyeing processing costs are decreasing, many printing and dyeing factories have been busy for a year, but their profits are basically non-existent. Therefore, cost control is the problem that printing and dyeing factories need to solve. The cost of finishing aids is a major burden for printing and dyeing factories, so reducing the cost of finishing aids is an urgent problem that printing and dyeing factories need to solve.

09. Yellowing problem

Heat yellowing:

Long periods of downtime during operation cause fabric retention and yellowing, while the amino hydrogen in amino silicone oil is prone to oxidation by air to form chromophores, resulting in yellowing. The product turns brown, which makes the white fabric appear as if it has lost its most basic white or simply turned yellow. If the pH is too high and the temperature is too high during drying, the accompanying substances of cotton fabric will turn yellow. Strengthen process control. Storage turns yellow. Caused by contaminated gases during storage.

10. Fluorescence degradation

The interaction between anionic brighteners/cationic softeners leads to agglomeration, which should be divided into two processes for processing.

Greening: If the whitening agent is sensitive to acid or excessive, acid resistant fluorescent whitening agent should be chosen.

Light damage: Fluorescent whitening agents have poor light fastness, and the light effect turns the fabric brown. Therefore, a reasonable choice of fluorescent whitening agents should be made.

Water quality impact: The content of impurities such as microorganisms and seaweed is too high, which can be filtered and precipitated to remove impurities.