Silicone spots on fabric surfaces appear as small oil stains ranging from the size of a pinhead to a grain of rice, and in extreme cases may be larger. Sometimes, due to floating dyes, these spots may have a slight coloration. The spots resemble tiny damp patches, feel soft to the touch with no granular texture, and are extremely difficult to detect and remove before drying. These spots typically result from silicone oil demulsification and oil flotation, commonly occurring after finishing or water-washing softening processes.
Causes of Silicone Oil Spots 
1. Alkalinity issue: 
During the pretreatment of cotton fabrics, a relatively high concentration of alkali is typically used to remove impurities (especially higher amounts for mercerizing), and alkali tends to penetrate into the fiber interior, making it difficult to wash out completely. Since alkali is also added during dyeing with reactive or vat dyes, the fabric surface may remain alkaline during finishing processes. 
After dyeing, synthetic fiber fabrics must undergo reduction washing. Currently, printing and dyeing mills still use sodium dithionite and caustic soda for this process. If the subsequent washing is incomplete, alkaline residues may remain on the fabric surface before softening treatment. Ordinary silicone oils are not alkali-resistant and can break emulsion under alkaline conditions—this is why rollers become sticky after several kilometers during padding softening in factories. Therefore, it is essential to thoroughly remove alkali agents from the fabric surface prior to softening, or alternatively, add acetic acid to the working solution to maintain a pH of 5–6 in the padding bath. 
2. Coagulation issues: 
On fabrics containing short fibers (such as cotton, T/R fabric, and velvets), some short fibers inevitably shed during processing. These shed fibers accumulate in the nip roll gap, where they agglomerate with conventional silicone oil. As the finishing liquor rises to the rollers, the combined mixture adheres to the rollers when the silicone oil is sheared and emulsified, resulting in roller sticking or silicone spots. Poor water quality can also cause similar aggregation with regular silicone oil, leading to roller adhesion. Additionally, similar issues may occur with hairy fabrics. Therefore, thorough cleaning should be performed before starting up the machine, and any loose fibers should be removed immediately upon detection. 
3. Charge stability issue: 
Most dyes and optical brighteners used for cotton fabrics are anionic, and cotton whitening is typically carried out on the finishing machine. Additionally, when the color shade of dyed fabric is not correct, slight color correction is required, which usually involves adding a small amount of dye or pigment during the application of softener. However, factories generally use conventional silicone oils (weakly cationic), which can cause electrostatic attraction between anionic and cationic charges, leading to coagulation and roller sticking. On the other hand, anionic silicone oils do not provide sufficient softness, creating confusion in production. Therefore, charge compatibility must be carefully considered during processing. 
4 Temperature issue: 
Fabrics dyed on long cotton machines must be dried using drying cylinders and then stored in large rolls or stacked in fabric boxes. If not adequately cooled—especially when stored in large rolls—the surface temperature of the fabric may remain high during softening treatment, causing the working liquid temperature in the padding mangle to rise (particularly in summer), sometimes exceeding 60°C. This can lead to roller sticking, especially when conventional silicone oils have poor heat resistance. 
It is preferable that the temperature in the rolling groove does not exceed 40 ℃. 
5. Standardized speed issue: 
When producing thin fabrics, the setting machine operates at very high speeds—sometimes reaching 60 meters per minute. Due to poor penetration, conventional silicone oils tend to backflow on the rollers, causing roller sticking. Be sure to replace the working fluid in the calendering slot regularly and frequently wipe the rollers. 
6. Glue tank issue: 
Many factories experience issues during impregnation softening, where regular silicone oil adheres to the drum walls. Over time, this leads to black oil stains forming on the drum walls, which then transfer onto fabrics as silicone oil spots. It is essential to strengthen cleaning procedures. 
7. Handling Issues 
As market demands for fabric hand feel continue to rise, different fabrics require diverse styling characteristics depending on season and customer requirements—such as smooth drape, slippery flexibility, fluffy softness, or simple elasticity. Typically, a single silicone oil can only achieve one specific style, leading many manufacturers to use numerous types of silicone oils, resulting in production chaos. Sometimes, they cannot find the right silicone oil to meet customer specifications and are forced to abandon orders, causing losses. By selecting amino silicone oils with varying amine values and controlling molecular weight and distribution through end-group modification, we can synthesize amino silicone oils with differing amine values, viscosities, and reactivity, thereby meeting various fiber requirements for softness, smoothness, and elasticity. 
8 Cost Issues 
The biggest challenge currently facing dyeing and printing factories is cost management. With rising prices for water, electricity, and steam, while processing fees continue to decline, many factories end up working hard throughout the year yet barely making any profit. Therefore, controlling costs has become a critical issue that these factories must address. 
Removal of Silicone Oil Stains 
1. Fabric not heat-set at high temperature: 
① Acetic acid washing 
② High-temperature treatment of solvent-based degreaser. 
2. The fabric has been heat-set: treated with a specialized fluorine- and silicone-based remover under alkaline conditions. 
The main principle involves hydrolyzing the fluorosilicone chains through boiling under alkaline conditions, then promptly emulsifying and dispersing the hydrolyzed fluorosilicone segments using the emulsifying and dispersing capabilities of the fluorosilicone remover to seal them off. This process effectively removes silicone oil stains and water-repellent spots. 
For stubborn stains that are difficult to remove, you can add degreaser or hydrogen peroxide to alkaline or fluorine-based stripping agents. Additionally, depending on the severity of water spots and silicone oil stains, the amount of stripper may be increased accordingly. If complete removal is not achieved in a single treatment, increasing the number of stripping steps can help achieve thorough stain removal. 
For regenerated cellulose fibers or protein fibers, which have poor alkali resistance, it is recommended to use soda ash to adjust the pH of the treatment bath to 8.5–9.5 in order to avoid strength damage or excessive protein loss. 
Silicone oil floating 
Why does silicone spot formation sometimes occur when amino silicone emulsion is used together with fixatives and softening oils, but not when used alone? 
Amino silicone oil is incompatible with fixatives, softening agents, and other auxiliaries, causing silicone oil to float. 
Amino silicone emulsion is a cationic (or weakly cationic) surfactant, while many chemicals used in the dyeing process are anionic surfactants, such as dyes (some of which are anionic), leveling agents, dispersants, and fixing agents. If these chemicals are not thoroughly rinsed out before softening treatment after dyeing and finishing, the cationic amino silicone softener may react electrostatically with the anionic substances in the dye bath, causing the cationic amino silicone emulsion to break and oil to float, resulting in softness spots or silicone spots. The most effective solution is to ensure thorough washing prior to softening treatment, preferably avoiding softening in the same dyeing machine. After dyeing and rinsing, remove the fabric and carry out the softening process in a padding mangle.