How to make screen printing silicone more transparent?
Here are some ways to make screen printing silicone more transparent:
Raw material selection
Select high-quality base polymers:
Selecting high-transparency silicone base polymer raw materials is the key. High-quality polysiloxane raw materials themselves have better optical properties, regular molecular structure, and low impurity content, which can fundamentally guarantee the transparency of silicone finished products. For example, some well-known brands have developed and produced silicone base rubbers specifically for high-transparency products, which perform better in terms of light transmittance.
Matching suitable additives:
Catalysts: Choose catalysts that will not have adverse effects on transparency, such as platinum catalysts, which have high catalytic activity and will not introduce colored impurities during the reaction process, which helps screen printing silicone to maintain good transparency after curing.
Plasticizers: Use colorless, transparent, and compatible plasticizers, such as some high-molecular-weight silicone oil plasticizers, which can improve the flexibility of silicone and will not make silicone turbid, which is conducive to improving overall transparency.
Production process
Precisely control the stirring process:
Stirring speed and time: When stirring and mixing the various components of silicone, the stirring speed and time should be reasonably controlled. Too fast speed and too long time will easily lead to too much air to form bubbles, which will make the silicone products look opaque and foggy. It is generally recommended to use moderate low-speed stirring, and the time should be controlled to make the ingredients fully and evenly mixed. For example, stir at a speed of 30-50 revolutions per minute for about 5-10 minutes (depending on the formula and amount).
Degassing treatment: After stirring, be sure to perform effective degassing operations. You can use vacuum degassing to put the silicone in a vacuum box and keep it at a suitable vacuum degree (usually about - 0.08 to - 0.1MPa) for a certain time (such as 5-15 minutes) to allow the mixed air bubbles to be fully discharged, making the silicone texture more uniform and transparent.
Strictly control the curing conditions:
Temperature control: Operate according to the curing temperature range recommended in the silicone product manual, generally curing at room temperature or appropriate heating temperature (such as 60-100℃, depending on the product). Too high a temperature may cause changes in the internal structure of the silicone, produce local yellowing and other problems, and affect transparency; too low a temperature may lead to incomplete curing and poor transparency.
Humidity management: It is also important to keep the humidity of the curing environment low. If the humidity is too high, moisture may participate in the curing reaction or condense on the surface of the silicone to form mist and reduce transparency. The ideal humidity of the curing environment should be controlled at around 40%-60%.