Silicone, epoxy, polyurethane and other materials are used in the field of potting materials. Performance comparison

1. Epoxy resin glue: mostly hard, with a small amount of soft. The biggest advantage is that it has good adhesion to hard materials, cannot be opened after potting, high hardness, and good insulation performance. The ordinary temperature resistance is 100, the temperature resistance for heating and curing is about 150 degrees, and there are also temperatures above 300 degrees. , but the price is very expensive and mass production is generally not possible. Restorability is not good.

2. Silicone resin potting glue: mostly soft after curing, with poor adhesion; advantages: high and low temperature resistance, can be used at 250 degrees for a long time, the heating curing type has higher temperature resistance, and the insulation performance is better than that of environmental protection Oxygen resin is good, can withstand a voltage of more than 10,000V, is moderately priced, and has good repairability.

3. Polyurethane potting glue: The adhesiveness is between epoxy and silicone, the temperature resistance is average, generally not exceeding 100 degrees, and there are many bubbles, so it must be poured in a vacuum. Advantages: good low temperature resistance

With the vigorous development of electrical products in recent years, electronic manufacturers are using various materials for potting electrical appliances to ensure waterproofing, moisture-proof, insulation and confidentiality of electrical products. Currently, the most widely used materials are epoxy resin, organic resin, etc. Silicone, polyurethane (PU) and hot melt. This article only briefly introduces the characteristics of the above materials to facilitate electrical engineers to use them as a reference.

Cost:

Silicone resin>Epoxy resin>Polyurethane>Hot melt;

Note: Among silicone resins, the cost of the condensation type is close to that of epoxy resin, and the cost of modified epoxy resin is also close to that of PU;

Manufacturing:

Epoxy resin>Silicone resin>Hot melt>Polyurethane;

Note: Because of its hydrophilicity, PU must be vacuum dried to obtain a better cured product. If vacuum and drying are not required, the cost is too high. Therefore, although the hot sol is heated and dissolved for pouring, overall its The operability is still much simpler than that of PU;

Electrical performance:

Epoxy resin>Silicone resin>Polyurethane>Hot melt;

Note: Some electrical properties of addition-type silicone or paraffin hot melt are even higher than those of epoxy, such as surface resistivity;

Heat resistance:

Silicone resin>Epoxy resin>Polyurethane>Hot melt;

Note: The heat resistance of low-priced PU is not much better than that of hot sol;

Cold resistance:

Silicone resin>Polyurethane>Epoxy resin>Hot melt;

Note: The low-temperature properties of many hot melts are actually very good, so in many cases, epoxy is ranked last;

After the liquid chemicals are potted into the electrical products, they solidify and become solid, thus serving the functions of protection, insulation, sealing, waterproofing, and confidentiality.