Popular science on the hardness of liquid silicone gel
When we use liquid silicone to make silicone mold products, we need to adjust the hardness of the silicone according to the characteristics of the product. The hardness we are talking about now refers to the hardness of the silicone product after the addition of liquid silicone and solidification. Silicone has a characteristic: it is very soft. But in some cases, it is necessary to harden it, and a common method of hardening is to add MQ resin to silicone rubber. There are many uses and different hardness requirements. For example, chocolate molds require a hardness of 20-25 degrees, while adult toys require a hardness of 0-0 degrees or less. In addition, the harder the silicone, the more brittle the product, the worse its performance, and it may crack open at the first break.
Below are some common hardness and applicable fields of additive liquid silicone, as well as corresponding products in daily life.
0-5 degrees (including below 0 degrees) plus molded liquid silicone, the product has a super soft touch and is similar in hardness to human skin. Suitable for adult products, breast pads, shoulder pads, patches, anti slip pads and other flexible silicone rubber products, simulating human facial molds, simulating human limb shapes. 5-degree addition molded liquid silicone is harder than 0-5 degree silicone, with a soft touch and similar hardness to rubber bands. Suitable for sugar molds, soap molds, transfer printing glue heads, etc.
Liquid silicone gel is formed at 10-20 degrees Celsius, with good flexibility and stretchability. It can be pulled continuously and is harder than rubber bands. Suitable for molding processes such as candle handmade soap, candy chocolate, gypsum line, handicrafts, etc.
Liquid silicone gel with a hardness of 25-35 degrees, which is relatively high and not easily deformed. It has good tensile properties and is similar in hardness to erasers, making it suitable for slicing brush molds. Such as cement products, cultural sandstone reliefs, resin crafts, tire molds, etc.
Liquid silicone gel with a hardness of 40 degrees is relatively hard and has poor performance, similar to the hardness of shoe soles. It is generally used for filling, such as electronic sealing glue, to seal, prevent dust, water, and shock, and is not recommended for mold making processes.
Liquid silicone gel formed at 45-60 degrees Celsius is very hard, similar to plastic, with almost no performance, very brittle, and can break at a touch, just like oxidized plastic products. The applicable range is similar to 40 degrees.