Amino silicone emulsion is the preferred and mainstream auxiliary for enhancing softness and smoothness of pillow wadding including spray-bonded cotton, hollow polyester filling cotton and toy stuffing cotton. It features excellent applicability and serves as a standard solution for the finishing of home textile filling cotton. However, it is necessary to select the proper silicone type and control the amine value and processing parameters. Wrong selection will result in yellowing, cotton agglomeration and collapse, as well as decreased bulkiness.
1. Reasons why amino silicone emulsion matches the requirements for softness and smoothness of pillow wadding
Most pillow wadding is made of hollow polyester staple fiber. Polyester fiber has an inert surface and high friction coefficient, so raw cotton feels harsh and prickly and generates a large amount of static fly lint.
The amino polar groups on amino silicone molecules firmly adhere to the surface of polyester fibers, while the long polysiloxane chains face outward to form a continuous lubricating silicone film.
The silicone film greatly reduces static and dynamic friction between fibers, and endows the cotton with a soft inner texture and silky surface. It is different from ordinary fatty acid softeners, which only provide softness without slipperiness and tend to create a dull hand feel.
When used at a proper dosage, it will not block the hollow cavities of polyester fibers. The key bulkiness and resilience of pillow wadding can be maintained, and static fuzzing and fiber shedding can also be effectively reduced.
2. Selection of dedicated amino silicone emulsion for pillow wadding (core part, three types for different applications)
-
First choice: Low-amine-value amino silicone microemulsion (ideal for regular adult pillows and white cotton)Amine value: 0.3～0.6 mmol/g. This is a critical indicator. Products with an amine value higher than 0.8 mmol/g will easily cause yellowing of white cotton after high-temperature drying and are prohibited for white pillow wadding.Particle size: 50～100 nm. It has strong permeability, enabling the silicone film to penetrate deep into fibers for uniform softness and smoothness throughout the cotton with no free oil on the surface.Ionic property: Weak cationic or non-ionic microemulsion. It has good compatibility and rarely causes demulsification and oil spots when contacting residual spray adhesive on cotton.
-
Premium option for Class A maternity and infant pillows: Polyether-modified hydrophilic amino silicone emulsionPolyether chains are grafted onto the amino silicone molecular structure.This product is hydrophilic, breathable, sweat-permeable, low-yellowing and oil-free, which is essential for infant pillows for direct skin contact. It overcomes the drawbacks of conventional amino silicone emulsion such as hydrophobicity and poor moisture absorption, and delivers both excellent slipperiness and hydrophilicity.
-
Not recommended: Conventional coarse-particle amino silicone emulsionWith a particle size larger than 500 nm, the silicone only attaches to the fiber surface. The cotton feels smooth on the surface but stiff inside with poor bulkiness. It is only used temporarily for low-cost low-grade filling cotton.
Warning: Pure dimethyl silicone emulsion (without amino groups) offers good slipperiness but extremely poor adhesion. The silicone will peel off after washing and rubbing, and the cotton will turn harsh after several uses. Hydroxyl silicone oil cannot provide sufficient softness and slipperiness, so it shall not be used alone for the smoothing finishing of pillow wadding.
3. Two common application processes and dosages for pillow wadding
-
Continuous padding process (for mass production of spray-bonded cotton grey fabric)Dilute the neat silicone emulsion with water to an active silicone content of 15～30 g/L, and control the pick-up rate at 65%～75%.Drying: Perform staged curing at 120～140℃. Avoid instant temperature above 155℃ to prevent yellowing.
-
Atomized spraying for bulk finished cotton (for small-batch pillow core filling cotton)Dilute the silicone emulsion with warm water at a ratio of 1:8 to 1:15. Spray the mixture evenly over the cotton via high-pressure atomization, then air-dry at a low temperature of 80～110℃.
Problems caused by over-dosage: Excessive silicone accumulation will lead to fiber adhesion and agglomeration, cotton collapse and stiff pillow cores.
4. Compounding optimization solution (cost reduction and balance between bulkiness and softness)
Compound amino silicone emulsion with a small amount of non-ionic fatty acid softener at a ratio of 1:0.3 to 1:0.5.
The fatty acid softener provides fluffy softness for the cotton, while amino silicone emulsion delivers surface slipperiness. This combination can greatly reduce the dosage of silicone and cut production costs, and it is the most widely used formula in cotton processing plants.
For wash-resistant pillow cores, add a tiny amount of epoxy silicone crosslinking agent to fix the silicone film, so the cotton will not lose softness and slipperiness after repeated washing.
5. Compatibility restrictions
Most amino silicone emulsions are cationic. Do not add anionic softeners, anionic optical brighteners or anionic flame retardants in the same working bath. Coexistence will cause demulsification, layer separation, oil spots and sticky cotton. Apply different functional auxiliaries in separate processes.
6. Summary of advantages and disadvantages
| Advantages | Disadvantages (Controllable) |
|---|---|
| Provides both softness and slipperiness; improves the prickly feel of chemical fibers; reduces static electricity and fiber fly | High-amine silicone causes yellowing under high temperature → Use low-amine or modified silicone to avoid this issue |
| Does not damage hollow fiber structure and retains bulkiness and resilience | Over-dosage leads to fiber agglomeration and cotton collapse → Strictly control dilution ratio and application dosage |
| Higher cost performance than special silicone softeners | Conventional amino silicone is hydrophobic → Adopt polyether-modified hydrophilic type for maternity andinfant products |
Links