(Correspondent: Yin Xueyu) A few days ago Shenyang Rubber Research & Design Institute (Shenyang Institute) completed the development of a high-performance waterproof rubber putty sealant. The product is mainly used in large amounts in neutrino experiments, where it serves as a waterproof sealant to isolate the photomultiplier, the core element, from water. Inside the photomultiplier are closely-connected electronic components; outside is a glass shell connected with a stainless steel case. Photomultipliers work in pure water at a constant temperature of 23℃; the maximum water depth is 40 meters; and their service life is required to be not less than 20 years. Therefore, photomultipliers’ sealing requirement is extremely strict.
To ensure normal experimentation the photomultiplier is protected by multiple seals from the outside to the inside: rubber putty, pouring sealant, and mechanical seal. Shenyang Institute is mainly responsible for the development of the rubber putty sealant. As the product is used as the outermost sealant in direct contact with water, it must have excellent water resistance, strong adhesion, and high plasticity.
After 8 months of hard work and more than 30 adjustments to the formula, the Southwest Development Department of Shenyang Institute eventually completed the development of the sealing putty of all specifications, with strength, viscosity, water resistance, and all other indicators meeting contract stipulations.