Pressure cookers, blenders, insulated cups... The sealing rings in these small household appliances endure extreme tests of 1,000 cycles of "thermal expansion and contraction + oil immersion" every year, while ordinary rubber turns pale and sticky within three months. Recently, a "secondary vulcanization-free" liquid silicone rubber has gained popularity in sealing ring factories—jokingly called the "fitness coach" by workers because its "muscles" are too strong.
A 2 mm rubber film placed in a 200°C oven for 168 hours—equivalent to taking a continuous seven-day sauna—still retains a tensile strength of over 9 MPa, an elongation rate of 500%, and almost no loss in hardness. The tear resistance test is even more impressive: a tear strength of 35 kN/m allows a 1 cm-wide rubber strip to withstand a "tearing force" of 35 kg, making the 5 kg force from daily pot lid openings nothing more than a "warm-up."
"Before, making sealing rings required two hours of secondary vulcanization, which produced strong odors and high energy consumption. Now, molding at 150°C for 45 seconds allows direct packaging," calculated a household appliance supplier. "For a workshop with 20 machines, this saves 380,000 yuan in electricity annually while increasing production capacity by 30%."
Moreover, it is immune to "seasonings." After 24 hours of immersion in soy sauce, vinegar, and chili oil, its weight increases by less than 1%, with no deformation in volume. When tested for "total migration," the results were one-tenth below the national limit, truly achieving "retaining only the aroma, not the taste."
From coffee machines to baby food processors, from hot water kettles to medical sterilization pots, this "fitness coach"-grade sealing material is quietly replacing traditional black rubber rings. Consumers may not notice the change visually, but with every pot lid they open, they experience the small joy of "perfect tightness and no peculiar odor."
—Don’t underestimate that transparent ring; it’s conquering all the heat and grease in the kitchen.
