Use of rubber mixt. for prodn. of rollers, esp. platens

摘要

The use of a rubber mixt. (I) for the prodn. of rollers,esp. typewriter platens, is claimed. Mixt. (I) is based on styrene/butadiene rubber (SBR), nitrile rubber (NBR), natural rubber (NR), isoprene, butadiene or acrylate rubber (IR, BR, ACM), epoxidised NR (E-NR) or blends thereof, pref. SBR/NBR or NBR/NR blends, contg. fillers, plasticisers, antioxidants and other additives etc. The mixt. is used for the prodn. of rollers with high noise damping, a good grinding pattern and well-defined print image, and a vulcanisation hardness of not less than Shore 80A. These rollers are produced by injection moulding, with a fill time of 0.5-3 (pref. 1-2) mins. and an injection temp. and pressure of 50-100 (pref. 60-70) deg C and 100- 250 (pref. 120-150) bar, and with a vulcanisation time of 5-15 (pref. 8-10) mins. at not less than 150 (pref. 160-165) deg C. The moulding system used is designed to enable annular injection directly onto the outer sheath of the axle in the direction of and parallel to the axis, in order to fill the voids without any turbulence and prevent radial loads on one side of the roller axis. Also claimed is a rubber mixt. (I) for this application, with a rubber content of 30-70 (pref. 40-50) wt%.