ISO/TR 8285:1990 pdf free.Plain bearings — Evaluation of the tribological properties of polymer-based materials.
This Technical Report deals with the tribological testing of bulk plastic specimens under specified working conditions, i.e. load, sliding velocity and temperature, without lubrication. From the Wet results, data are obtained about the tiibu(uyical b&iavluui of steel-plastic rubbing pairs which can be used in practice for predicting the working capacity of a friction unit.
It specifies the test conditions, equipment and programmes that allow reproducibility of the results at particular conditions of the specimen preparation and testing.
This Technical Report specifies the specimen shape, conditions of the rubbed surfaces of the plastic and steel, tolerable run-out of the rotating counterface, heat transfer between the device housing and counterface, the range of variations in the friction process parameters in order to reach the reproducibility of the results In the trlbologTcal testing of plastics. It proposes tochnical solutions for tho standard oqulpmont usod for tho tribological testing of plastics.
4.1 Plastic block
The block can be made by moulding, injection moulding, turning or by milling, making use of the near surface structure effects formed by moulding or machining (see figures 2 and 3).
The block Is 10 mm high, 10 mm wide and 20 mm long (see figure 2).
The roughness of the plastic block depends on the machining conditions; In case of moulding or injection moulding, It dupnds on the roughness of thu moulding parts.
4.2 Test roller
A test roller complying with this Technical Report Is a combination of a steel bushing and a heat-Insulating bushing. The heat-insulating bushing Is made of textolite and is pressed Into the steel bushing. The dimensions of the mating parts are shown In figure 4.
The steel bushing Is made of steel with a carbon content of between 0,45 % and 0,8 %, of hardness 45 HRC to 50 HRC, for example steel complying with iSO 683 (all published parts).ISO/TR 8285:1990 pdf free download.