The embossed silicone process is widely used in fabric decoration such as clothing and bags, but it often faces two major problems: glue seepage and washing collapse. The following is a detailed analysis and solution for these two problems:
1. Glue seepage problem
The glue seepage phenomenon is mainly manifested as blurred edges of silicone patterns and glue seepage on the reverse side, which affects the aesthetics of the product. The main causes and solutions are as follows:
Silicone formula and viscosity
Problem: The viscosity of the silicone is too low or the curing agent ratio is improper, resulting in excessive fluidity.
Solution:
Use high-viscosity silicone (such as screen filtration above 170 mesh) to reduce the fluidity of the colloid.
Adjust the ratio of silicone to curing agent (such as 10:1) to ensure rapid curing.
Add thickener to increase the consistency of silicone.
Fabric characteristics
Problem: Thin fabrics (such as mercerized cotton and knitted fabrics) are prone to glue seepage.
Solution:
Pretreat the fabric to increase its surface tension.
Use high-hardness silicone (such as hardness above 45-50 degrees) to reduce the risk of penetration.
Process parameters
Problem: Excessive scraping pressure and insufficient temperature lead to prolonged curing time.
Solution:
Control the scraping pressure to avoid excessive accumulation of colloid.
Control the vulcanization temperature at 160-180℃ to shorten the curing time.
Optimize the mold design to ensure uniform distribution of silicone.
2. Washing collapse problem
Washing collapse refers to the loss of three-dimensional sense or even deformation of silicone pattern after multiple washings. The main causes and solutions are as follows:
Silicone hardness and toughness
Problem: Ordinary silicone has insufficient hardness (such as 45-50 degrees), poor toughness, and is easy to deform after washing.
Solution:
Select high-hardness and high-toughness concave-convex embossed silicone (such as hardness above 55-60 degrees).
Develop a special silicone formula that takes into account hardness and elasticity.
Vulcanization process
Problem: Insufficient vulcanization temperature or time leads to incomplete curing of silicone.
Solution:
Extend the vulcanization time (such as 150℃ for a few seconds) to ensure that the silicone is completely cured.
Optimize the mold cooling system to avoid temperature fluctuations.
Fabric and silicone bonding
Problem: Insufficient adhesion between silicone and fabric, and delamination after washing.
Solution:
Pre-treat the surface of the fabric to improve the adhesion of the silicone.
Use environmentally friendly silicone to avoid environmentally unfriendly fabrics affecting the bonding effect.
Mold design
Problem: Insufficient mold precision leads to uneven silicone filling.
Solution:
Use high-precision molds (such as copper molds or aluminum alloy molds) to ensure uniform silicone filling.
Coat the mold surface with a release agent to prevent silicone adhesion.
3. Comprehensive solution
Material selection
Use special embossed silicone with high viscosity, high hardness and high toughness.
Ensure the accurate ratio of silicone to curing agent to avoid poor curing.
Process optimization
Control the scraping pressure and temperature to shorten the curing time.
Optimize the mold design to ensure uniform distribution of silicone.
Post-processing
After the silicone pattern is cured, perform secondary reinforcement treatment (such as hot pressing).
Test the bonding strength between silicone and fabric to ensure water washability.
4. Precautions
Testing and verification
Before mass production, conduct a small sample test to verify the water washability and three-dimensional sense of the silicone.
Simulate actual water washing conditions to evaluate the durability of the silicone.
Equipment maintenance
Regularly check embossing machines, molds and other equipment to ensure their accuracy and stability.
Avoid uneven silicone filling due to equipment wear.
Environmental control
Keep the production environment clean to avoid dust and impurities affecting the quality of silicone.
Control temperature and humidity to ensure the curing effect of silicone.
5. Summary
By optimizing the silicone formula, adjusting process parameters, and improving mold design, the problems of glue seepage and water collapse of concave and convex embossed silicone can be effectively solved. It is recommended to use special high-hardness and high-toughness silicone, and strictly control the production process to ensure stable product quality.