The waterproof membrane requires excellent weathering resistance, ozone aging resistance, heat aging resistance and waterproof performance. EPDM rubber is the main rubber raw material in the production of waterproof membrane. EPDM reclaimed rubber has the basic performance characteristics of EPDM rubber, and has excellent high and low temperature resistance and aging resistance. It can replace EPDM rubber to produce waterproof membranes, and effectively reduce the cost of raw materials on the premise of ensuring product quality.
1. Application of EPDM reclaimed rubber in waterproofing membranes
In actual production, the waterproofing membrane can be completely produced with EPDM reclaimed rubber, or can be used in combination with EPDM rubber to further improve the physical and mechanical properties of the product. EPDM reclaimed rubber can also be used in combination with butyl rubber or butyl reclaimed rubber to improve the processing properties and adhesion properties of ethylene-propylene rubber compounds. The higher the rubber content, the greater the tensile strength and elongation at break of the EPDM reclaimed rubber, the better the elasticity, and the better the tear resistance and antifreeze performance of the waterproof membrane.
2. EPDM reclaimed rubber to produce waterproof membrane formulation optimization
(1) EPDM reclaimed rubber waterproofing membrane vulcanization system
When using EPDM reclaimed rubber or EPDM reclaimed rubber/ethylene propylene rubber combined with rubber to produce rubber waterproofing membranes, the peroxide vulcanization system is often used for vulcanization, which can appropriately increase the rate of slow accelerators such as thiazole 2ELYY224 accelerators. Dosage; it is recommended to use dithioformate super-accelerators, or use thiuram-type fast accelerators to promote the vulcanization of rubber compounds.
(2) EPDM reclaimed rubber waterproofing membrane reinforcement filling system
The EPDM reclaimed rubber waterproofing membrane can be reinforced with high wear-resistant carbon black or medium-super wear-resistant carbon black to improve the strength of the rubber compound and the performance of the calendering process. The use of coarse-grained calcium carbonate, or the combination of calcium carbonate and soft clay, can prevent air holes and needle-shaped bubbles in the waterproofing membrane and ensure the smooth progress of the calendering process. Appropriate addition of tackifying resin, such as coumarone resin, can improve the adhesiveness of waterproof roll material.
(3) EPDM reclaimed rubber waterproofing membrane softening system
If the volatile content of the operating oil for waterproofing membrane is too high, it will evaporate, which will lead to the shrinkage of the waterproofing membrane. Therefore, the amount of operating oil should be minimized in the production process of EPDM reclaimed rubber waterproofing membrane. It is recommended to use oil with low volatile content and high aniline point; it is recommended to add a small amount of calcium oxide when using hot air vulcanization to avoid rubber foaming. .
3. Common production methods of EPDM reclaimed rubber to produce waterproof membranes
When EPDM reclaimed rubber or EPDM rubber/reclaimed rubber is used to produce waterproof membranes, the commonly used production methods mainly include the following three: The most); the rubber material is vulcanized by hot air after being calendered or extruded; the semi-finished rubber sheet that has been calendered or extruded is directly used to make it naturally vulcanized.
At present, the combination of EPDM reclaimed rubber and EPDM rubber is the mainstream way to produce rubber waterproof membranes. Selecting appropriate reclaimed rubber, reasonably controlling the mixing ratio of reclaimed rubber and original rubber, and properly adjusting the formula can reduce costs. At the same time, it further optimizes the comprehensive indicators of the waterproof membrane and prolongs the service life. In actual production, with the continuous development of EPDM reclaimed rubber production technology, its application in waterproofing membranes has become more and more extensive, and the editor will continue to discuss related issues with you later.
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