1Wash and clean molds with detergents,dry the molds and use an air gun if necessary,and apply a film of mold release. 2Determine the normal proportion of pad printing silicon and silicon oil on the basis of customer requirements.Add more silicon oil if a larger area of printed pattern and therefore soft rubber head is needed by the customer.0therwise,add less or no silicon oil for better hardness.For normal pad printing rubber head, hardness between 15A°-25A°will be appropriate.If excessive amount of silicon oil is added,the number of printing will be limited by an extremely soft rubber head,and the molecular weigtht of silicon of however supreme quality will be destboyed by silicon oil,and therefore,the phenomenon of compromised resistance to abrasion,solvent and aging. 3The normal proportion is as follows100g silicon admixed with 30g silicon oil for a hardness of 20A°will be suitable for pad printing for alloy toy cars and products with small patterns and contact area.If larger pressure contact surface or soft rubber head is required,the silicon and silicon oil proportion can be adjusted to 10030,10050 and so on.Remember,the more silicon oil is added,the softer the rubber head will be,and the number of pad printing,resistance to abrasion and solvent will be undermined,and hence,heightened cost and more material waste. 4Admixture amount of curing agent and chemical reaction of silicone.g., mix 100g of silicon with 50g of silicon oil,after they are sufficiently and evenly mixed,add curing agent as per 2 of the total weight of silcon and silicon oil,mix again for 23 minutes before exhausting. Generally exhausting duration can not exceed 10 minutesotherwise,the silicon will harden quickly to anffect the quality of molding 5 Admixture amount of curing agent and silicon reaction 5.1Added with 1 of curing agent,silicon can still flow within 2.5 hours,mold can be released in 68 hours. 5.2Added with 2 of curing agent,silicon can still flow within 50 minutes to 1 hour,mold can be released in 23 hours. 5.3Added with 3 of curing agent,silicon can still flow within 2830 minutes,mold can be released in 1.52 hours. 5.4Added with 4% of curning agent,silicon can still flow within 1015 minutes,mold can be released in 11.5 hours. 5.5Curing agent reaction rate is related with weather and temperature.Under 25 degree,they can be added according to the instruction or at double amount in winter or under subzero temperature. (Notecuring agent can not be added above the 4 maximum level and the normal proportion is 2.If more than 4 is applied,the silicon will condensate too fast for normal usage).Above is the mixing data for silicon and curing agent,the precise result of hundreds of times of our experiments.Provided that you arrange production according to our instruction,you are sure to manufacture first class products and maximize your profitthis is not only the need of,but also our responsiblity for and a satisfactory answer to our customers. We may not be the first,but we will trv to be the best.The customers need is what we pursue! |