Unexpected Glossiness in Matte Silicone After Curing: Causes and Solutions
Matte silicone (Matte Silicone) may develop unexpected glossiness after curing due to material characteristics, process parameters, or operational factors. Below are the possible causes and solutions:
1. Silicone Material Characteristics
Causes:
Some matte silicone formulations may have insufficient or unevenly dispersed matting agents (e.g., silica, matting powders).
Prolonged storage can cause sedimentation of matting components, reducing the matte effect.
Solutions:
✅ Choose specialized matte silicone from reputable brands (e.g., certain models of Fibre Hidden Silicone or Matte Finish Silicone).
✅ Stir the silicone thoroughly before use to ensure even distribution of matting agents.
2. Excessive Curing Temperature or Time
Causes:
High temperatures or prolonged curing can lead to excessive surface leveling, diminishing the matte texture.
In heat press printing (such as foil stamping or transfer printing), temperatures exceeding 160°C may cause silicone to become glossy.
Solutions:
✅ Follow the manufacturer's recommended curing temperature and time (e.g., 150-160°C for 15-20 seconds).
✅ Use an infrared thermometer to calibrate actual equipment temperature and avoid deviations.
3. Excessive Pressure or Improper Pressing Method
Causes:
Excessive pressure can compress the silicone too much, making the surface smoother and shinier.
Using a mirror-finish steel plate or overly smooth release paper during foil stamping may also lead to reflections.
Solutions:
✅ Adjust the pressure to a moderate level (e.g., 4-5 kg/cm²).
✅ Use matte release paper or a matte-finish steel plate to assist with pressing.
4. Insufficient Silicone Coating Thickness
Causes:
A thin silicone coating may not form enough matte surface texture.
Solutions:
✅ Use a lower mesh screen (e.g., 120-160 mesh instead of 200 mesh) to apply a thicker layer.
✅ Print two layers of matte silicone (allow the first layer to semi-dry before applying the second).
5. Fabric Influence
Causes:
Synthetic fabrics (e.g., polyester) have inherent sheen, which may reflect through the silicone layer.
Extremely smooth fabric surfaces (e.g., chiffon, nylon) may reduce the matte effect.
Solutions:
✅ Preferably use matte silicone on cotton fabrics.
✅ For synthetic fabrics, apply a matte base coat before adding the silicone layer.
6. Other Factors
Additive Contamination: Mixing with glossy silicone or solvents (e.g., thinning agents) may affect the matte finish.
Curing Equipment Issues: Some ovens or heat presses may have uneven temperatures, causing localized glossiness.
Quick Remedies
If the silicone has already cured with a glossy finish, try the following:
Lightly spray a matte fixing agent (e.g., textile matte spray).
Lightly sand the surface with fine sandpaper (600 grit or higher) (only for thick coatings).