In a study of the long term natural

In a study of the long term natural ageing of rubbers, nineteen compounds were naturally aged for forty years at three sites classified as temperate (Shawbury, UK), hot dry (Cloncurry, Australia) and hot wet (Innisfail, Australia). The specimens were stored in specially constructed aluminium boxes which allowed free circulation of ambient air around the test pieces but excluded direct light and rain. After 40 years ageing, the use of microhardness measurements was investigated as a means of determining the degree of ageing as a function of material thickness. Compression set test pieces were sliced into 1 mm thick sheets and hardness determined.

The procedure proved effective for determining hardness profiles. Significant differences were observed between skin and bulk suggesting that differential ageing had taken place. However, only the net effect of scission and crosslinking reactions is detected and differences can be due to differences in cure before exposure to ageing. After consideration of the known macro hardnesses of these materials and differences found at the centres of test pieces from the different exposure sites, it is suggested that the ageing process had not been greatly restricted by the rate of oxygen diffusion.

ผลลัพธ์ (อังกฤษ) 2:

In a study of the long term natural ageing of rubbers, nineteen compounds were naturally aged for forty years at three sites classified as temperate (Shawbury, UK), hot dry (Cloncurry, Australia) and hot wet (Innisfail, Australia). The specimens were stored in specially constructed aluminium boxes which allowed free circulation of ambient air around the test pieces but excluded direct light and rain. After 40 years ageing, the use of microhardness measurements was investigated as a means of determining the degree of ageing as a function of material thickness. Compression Set test pieces were sliced ​​Sheets Into 1 mm thick and Hardness Determined. The proved Effective Procedure for determining Hardness profiles. Significant differences were observed between skin and bulk suggesting that differential ageing had taken place. However, only the net effect of scission and crosslinking reactions is detected and differences can be due to differences in cure before exposure to ageing. After consideration of the known macro hardnesses of these materials and differences found at the centres of test pieces from the different exposure sites, it is suggested that the ageing process had not been greatly restricted by the rate of oxygen diffusion.

ผลลัพธ์ (อังกฤษ) 3:

In a study of the long term natural ageing, of rubbers nineteen compounds were naturally aged for forty years at three. Sites classified as, temperate (Shawbury UK), hot dry (Cloncurry Australia), and hot wet Innisfail Australia (,).The specimens were stored in specially constructed aluminium boxes which allowed free circulation of ambient air around. The test pieces but excluded direct light and rain. After 40 years ageing the use, of microhardness measurements was investigated. As a means of determining the degree of ageing as a function of material thickness.Compression set test pieces were sliced into 1 mm thick sheets and hardness determined.

The procedure proved effective. For determining hardness profiles. Significant differences were observed between skin and bulk suggesting that differential. Ageing had taken, However place.Only the net effect of scission and crosslinking reactions is detected and differences can be due to differences in cure. Before exposure to ageing. After consideration of the known macro hardnesses of these materials and differences found at. The centres of test pieces from the different, exposure sitesIt is suggested that the ageing process had not been greatly restricted by the rate of oxygen diffusion.