EPDM recycled rubber is processed from EPDM head adhesive, unvulcanized EPDM rubber or waste EPDM rubber products (waste EPDM sealing strips, washing machine sealing rings, etc.) as raw materials, with excellent high and low temperature resistance, ozone resistance, weather resistance, can be used alone or in combination with EPDM rubber to produce high-performance and low-cost EPDM rubber products. When using EPDM recycled rubber to produce rubber products, the compounding process and compound selection are crucial.
1. Key points of EPDM recycled rubber compounding process
Compounding is an important process in the production process of rubber products, and the quality of compounding rubber directly affects the mechanical strength, processing performance and durability of rubber products. When using EPDM recycled rubber to produce rubber products, the compounding process can be carried out in the open and mixing machines, and the order of adding the compound and the mixing temperature must be paid attention to the parameters such as the mixing agent.
(1) EPDM recycled rubber mixing skills in the refinery
When EPDM recycled rubber is mixed in the refinery, the mixing temperature is generally controlled among 35°C-55°C, and the general principle of feeding is: the compound with a small amount and difficult to disperse E5LYY818 be added first, and the large amount and easy to disperse should be added later; Sulfur and speeding accelerator are added at the end to prevent scorching. The dosing sequence usually used in EPDM recycled rubber refiner is as follows: recycled rubber→ accelerator, active agent, anti-aging agent→ reinforcing agent, filler→ liquid softener→ sulfur, and overspeed accelerator.
(2) EPDM recycled rubber mixing skills in the mixer
When EPDM recycled rubber is mixed in the mixer, the mixing temperature is generally controlled among 105°C-120°C; Reasonable arrangement of feeding sequence can effectively reduce mixing time and improve mixing efficiency. The dosing sequence usually used in EPDM recycled rubber mixer mixture is: recycled rubber→ active agent, solid softener→ anti-aging agent, ordinary accelerator→ carbon black→ liquid softener→ sulfur and overspeed accelerator.
2. Selection of EPDM recycled rubber product compounds
When using EPDM recycled rubber or EPDM rubber/EPDM recycled rubber as the main raw materials for the production of rubber products, commonly used compounding agents include vulcanizing agents, vulcanization accelerators, softeners, anti-aging agents, reinforcing agents, foaming agents, colorants and other special-purpose compounding agents.
In actual production, the commonly used vulcanizing agents for EPDM recycled rubber products are sulfur and peroxide, and the commonly used main accelerators are autumn ram accelerators (such as TMTD, TMTM, etc.) and dithiocarbamate metal salts, and thiazole accelerators can be used as auxiliary accelerators. High wear resistance carbon black and medium super wear resistance carbon black are the most commonly used reinforcers in EPDM recycled rubber products, silica, calcium carbonate, terracotta and talcum powder also have a certain reinforcing effect, a small amount of silica can improve the viscosity and hardness of the rubber material; Petroleum-based oils (aromatic oils, naphthenic oils and paraffin oils) are commonly used softening plasticizers for EPDM recycled rubber products, paraffin oil is the most suitable, and coumaron resin, pine tar, esters and low molecular weight polymers can also be used.
When using EPDM recycled rubber to produce rubber products, the performance of recycled rubber, the ratio of recycled rubber, the selection of compounding agents, the mixing process, the vulcanization process, etc. will affect the performance and life of the finished product.
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