Long-lasting pad printing silicone with no oil seepage or sticky residue, offering extended service life and high print counts

Applications of Pad Printing Silicone:

Pad printing silicone is specifically used for manufacturing pad printing pads. It is primarily applied in printing on plastic toys, electroplated products, electronic toys, trademarks, and irregular patterns. The pad printing pad acts as a carrier to transfer patterns from the steel plate onto toy products.

Features of Pad Printing Silicone:

1); Low viscosity, good fluidity

2); No shrinkage, easy ink application, clear printed patterns

3); Fine texture, excellent rebound, high number of printing cycles

4); Professional-grade pad printing silicone is designed for manufacturing printing pads. It requires a fine texture, free of impurities and particles, with good rebound. Made from high-quality raw materials and enhanced with DuPont's high-temperature resistant new material, it offers advantages such as wear resistance, high-temperature tolerance, and excellent printing results.

Operation of Pad Printing Silicone:

① First, clean the mold thoroughly with detergent, then wipe or blow dry any moisture, and apply a layer of release agent.

② The standard ratio of pad printing silicone to silicone oil is determined based on customer requirements. If the customer needs to print large patterns and requires a softer pad, more silicone oil should be added. Conversely, for a harder pad, little or no silicone oil should be added. Generally, the hardness of a pad printing pad should be between 15A° and 25A°. Excessive silicone oil will make the pad too soft, limiting the number of prints. Even the highest quality silicone can be compromised by excessive silicone oil, leading to reduced wear resistance, solvent resistance, and accelerated aging.

③ A typical ratio is as follows: 100g of silicone with 30g of silicone oil, resulting in a pad hardness of 20A°, suitable for printing small patterns on alloy car models and products with small contact areas. For larger contact areas or softer pads, ratios such as 100:30 or 100:50 can be used. However, note that higher silicone oil content softens the pad, reducing the number of prints, wear resistance, and solvent resistance. This increases costs and wastes materials.

④ The curing agent ratio and chemical reaction of silicone are as follows: Take 100g of silicone and 50g of silicone oil, mix thoroughly. After ensuring even distribution, add 2%–3% of the total weight of silicone and silicone oil as curing agent, then stir for another 2–3 minutes. Proceed to degassing, which should not exceed 10 minutes. Excessive degassing time may cause premature curing, affecting the quality of the silicone.

Principles of Pad Printing Pad Manufacturing:

a.; The vulcanization system of rubber is the foundation of significant advancements in the rubber industry. Pad printing pads are made using the principle of room-temperature vulcanized silicone rubber cross-linking into a network-structured elastomer under the action of vulcanizing agents.

b.; Rubber consists of large molecular chain hydrocarbons. Rubber with only carbon atoms in the main chain is called carbon-chain rubber; rubber with other atoms besides carbon in the main chain is called heterochain rubber. If the main chain contains organic groups with atoms like silicon (Si), tin (Sn), or boron (B), it is termed an elemental organic polymer. Silicone rubber is an elemental organic polymer with organosilicon groups in its main chain. There are two vulcanization processes for silicone rubber: high-temperature vulcanization, corresponding to high-temperature vulcanized silicone rubber (HTV), and room-temperature vulcanization, corresponding to room-temperature vulcanized silicone rubber (RTV). RTV silicone rubber is further divided into addition-type and condensation-type.

c.; Condensation-type silicone rubber contains terminal hydroxyl groups (-OH), which easily react with silanes containing hydrolyzable groups (-OCH3, -OCOCH3) for room-temperature vulcanization. The cross-linking agent is ethyl silicate, and the catalyst is dibutyltin dilaurate. Addition-type silicone rubber typically contains -CH=CH terminal groups and usually uses polysiloxane with Si-H bonds as a cross-linking agent for self-addition reactions to form an elastomer.