[en] γ- and electron doses, inducing optimal change of parameters of irradiated PA66, PA6, PP and PE plastic granulates during injection molding were determined. Cold water absorbing capacity decreases, softening point, crystalline structure stability and limit temperature of bearing force increase. The crystalline texture gets finer. Mechanical characteristics, save impact bending strength, improve. (author)

[en] Structural modifications of polymers caused by ionizing radiation were investigated both by post-irradiation of the end products and by pre-irradiation of the plastics grains. The absorbed dose dependence of the mechanical and thermal properties of gamma and electron irradiated polyamides and polyolefins were investigated. The fine structure of the irradiated samples changed also and, as a consequence, the application possibilities can be extended. (Sz.J.)

[en] Studying the effects of electron and gamma irradiation on polyamides (Ultraamide A3K, Ultraamide B3K) and polyolefins (Pro-fax 6523, Liten 7006) in granular form or as final products has shown that optimum radiation doses offer economic advantages. The mechanical parameters like tensile strength, modulus of elasticity, the flow limit under pressure, and hardness could be improved in both cases

[en] Cross-linking and breakdown taking place upon the effect of high-power radiation change the structure and mechanical characteristics of the material. The changes in the properties of materials and manufactured products irradiatied in different ways were investigated. (author)

[en] A new complex device has been elaborated for the investigation of the duration of bearings in the Institute of Isotopes of the Hungarian Academy of Sciences. The simultaneous determination of wear by an isotopic method the coefficient of friction by means of a Wheatstone bridge and the bearing temperature by means of a thermoresistor is described. Dynamic loading and variable revolution per minute are applied to produce a forced wear of the bearings. The isotopically labelled wear products are removed by oil and the collected sample is measured by a scintillation detector. Wear of a steel axle in plastic housing and plastic coated axle in cast iron housing was determined. (V.N.)