68% high-solid amino silicone emulsion works perfectly for improving softness and smoothness of pillow wadding, and it is the preferred option for factories to cut storage and transportation costs. However, compared with conventional emulsions with 30% solid content, it has stricter dilution requirements and different performance between microemulsion and coarse emulsion types.
1. Two Types of 68% High-Solid Amino Silicone Emulsion & Recommended Selection for Pillow Wadding
1.1 Translucent / Slight Blue-tint High-Solid Microemulsion (Recommended for white cotton, maternity & infant pillows, high-end pillow wadding)
- Amine value: 0.3～0.6 mmol/g. It features low yellowing tendency. With fine particle size, it can fully penetrate into hollow polyester fibers, delivering uniform softness and smoothness both inside and outside the cotton instead of only forming surface coating.
- Ionic type: Weak cationic / non-ionic. It has excellent dilution stability and rarely causes demulsification or oil spots when contacting residual adhesive on spray-bonded cotton.
- Application: White polyester stuffing, Class A infant pillows, high-resilience pillow fillings.
1.2 Milky viscous coarse-particle high-concentration emulsion (Only for low-grade colored/dark cotton)
This type has large particle size and only adheres to the fiber surface. It provides good surface smoothness but leads to stiff inner cotton and impaired bulkiness. It is highly likely to cause local oil accumulation and fiber agglomeration. It is strictly forbidden for white cotton, and tends to turn yellow under high-temperature drying.
Key reminder: Prioritize 68% microemulsion type during procurement. Coarse high-solid emulsion is only applicable to low-cost fillings.
2. Accurate Dilution Ratio (Calculated based on 68% solid content, for two mainstream processes)
2.1 Continuous padding process (for mass production of spray-bonded wadding)
Industry standard effective silicone content of working solution: 20 g/L
Required dosage of raw emulsion per 1000 L padding liquor: approx. 29.4 kg
Control pick-up rate at 65%～72%; drying temperature: 120～135℃. Avoid temperature over 150℃ to prevent yellowing.
2.2 Atomized spraying for bulk cotton (most commonly used for finished pillow fillings)
Effective silicone content of working solution: 5～8 g/L
- Minimum dosage (5 g/L): approx. 7.35 kg raw emulsion per ton of clean water
- Maximum dosage (8 g/L): approx. 11.76 kg raw emulsion per ton of clean water
Practical formula: Add 7.5～12 kg of 68% silicone emulsion into 1 ton of warm water. You may also compound with 2～4 kg fatty acid softener to balance bulkiness and smoothness.
3. Critical Rules for Diluting 68% High-Solid Emulsion (Prone to demulsification and oil floating)
- Strict feeding sequence: First add warm soft water (30～40℃), then slowly pour in the silicone emulsion under continuous stirring. Reversing the order will immediately cause demulsification, oil floating and sticky cotton.
- For water with high hardness: Add 0.1～0.2 kg chelating agent per ton of water to prevent silicone precipitation and oil spots caused by calcium and magnesium ions.
- Do not dilute the stock solution with large amount of water at one time; dilute step by step.
4. Advantages & Disadvantages: 68% High-Solid Emulsion vs. Conventional 30% Solid Content Emulsion
Advantages
- Higher solid content means lower addition rate, greatly reducing costs on storage, transportation and packaging barrels.
- Less water consumption for solution preparation, saving energy for drying.
Disadvantages
- Very low error tolerance during dilution; improper operation will directly result in oil stains and cotton agglomeration.
- Some commercial 68% high-solid products are formulated with high amine value (＞0.8 mmol/g), which will cause severe yellowing on white cotton after high-temperature drying. Test the amine value before purchasing.
5. Compounding Formula for Better Bulkiness & Anti-Collapse Performance
Mix 68% amino silicone emulsion with fatty acid softener (by effective content) at the ratio of 1 : 0.3 ～ 0.4
- Fatty acid softener enhances bulkiness and relieves fiber stiffness;
- Amino silicone provides superior surface smoothness. This formula reduces the total dosage of silicone and cuts production costs.
6. Formula Adjustment for Special Applications
- Hydrophilic fillings for infant pillows: Choose 68% hydrophilic modified amino silicone emulsion with polyether grafting. It is water permeable, breathable and sweat-absorbent without stuffy feeling. Conventional amino silicone is hydrophobic and not suitable for direct-contact infant products.
- Wash-resistant pillow fillings: Add 0.3～0.5 kg silicone crosslinking agent per ton of working solution to fix the silicone film, so the cotton will not lose softness and smoothness after repeated washing.
7. Incompatibility Notes
68% cationic amino silicone emulsion must not be mixed with anionic auxiliaries (e.g. anionic softeners, anionic optical brighteners) in the same bath, otherwise demulsification and layer separation will occur. Apply different functional auxiliaries in separate processes.
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