The amount of rubber oil used in reclaimed rubber products is not small, ranging from 5 or 6 parts to more than 40 parts, which directly affects the dispersion of fillers such as carbon black in reclaimed rubber. There are many varieties of rubber oils, including petroleum-based rubber oils, coal tar-based rubber oils, and vegetable oil-based rubber oils. Factors such as the type of rubber oil, refueling sequence and refueling time during the mixing process of reclaimed rubber will affect the dispersion of carbon black and other fillers in the reclaimed rubber, which in turn affects the quality of reclaimed rubber products.
1. Types of rubber oil and mixing dispersity
During the mixing process of reclaimed rubber, the more aromatic structural components in the rubber oil, the better the dispersibility. Aromatic hydrocarbon rubber oil has the best compatibility with rubber; at the same time, it is similar to the aromatic structure or quinoid structure of carbon black, and the two have great compatibility, and it is easy to make carbon black under the action of the shearing force of the rubber mixer. dispersion. Aromatic oils have the highest degree of dispersion, followed by naphthenic oils, and paraffinic oils are the lowest. In actual production, aromatic oils have poor color, and light-colored reclaimed rubber products should not be used.
2. The order in which the rubber oil is added during the mixing of reclaimed rubber affects the degree of dispersion
During the mixing process of reclaimed rubber, under the condition of the same amount of carbon black, the final refueling dispersion is higher, and the initial refueling dispersion is low; if the rubber softening oil is added at the end, the more carbon black is used, the higher the dispersion. Generally, the addition of oil operating agent 2ELYY221 will reduce the viscosity of the rubber compound, which is not conducive to the dispersion of carbon black; adding carbon black first and then adding oil, adding carbon black and oil separately can effectively improve the dispersion.
3. The addition time of rubber oil during reclaimed rubber mixing affects the degree of dispersion
Adding rubber rubber oil after adding carbon black is an important principle in the mixing operation. On the basis of following this principle, when the rubber softening oil is added too early during the mixing of reclaimed rubber, the problem of poor dispersion of carbon black will occur; if the oil is added too late, a slippery phenomenon will occur inside the rubber compound, which will prolong the mixing time and cause mixing. Bad; especially in reclaimed rubber products that use small particle size carbon black such as high wear-resistant carbon black, super wear-resistant carbon black and the dosage is more than 50 parts. If the oil is added too early (less than 0.25min), the dispersion will be poor; when the oiling time is longer than 0.5min, the dispersion degree will be significantly improved; but if the oiling time is delayed to 2min, the dispersion degree will not change.
4. The method of adding rubber oil during reclaimed rubber mixing affects the degree of dispersion
In the production of reclaimed rubber products, if the amount of rubber oil is large, it is recommended to add it in batches to improve the dispersion of fillers such as carbon black and shorten the mixing time. During the mixing process of reclaimed rubber, some oil softeners can also be added together with some fillers. The specific addition timing needs to be determined according to actual needs. Later, the editor will have the opportunity to discuss related issues with you.
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