Test Method for Stress Crack Resistance

Damage by stress crack formation arose occasionally in HOPE geomembranes in the past, in particular in weld seam areas (EPA 1992 Hsuan et al. 1993). Stress erack resistance is therefore a substantial criterion in the selection of polyethylene resins for geomembranes. For this reason, in the following, test methods used will be dealt with in detail. At the same time the phenomenon should be specified more precisely. Table 5.2 gives an overview of the test methods. 

Test method Standard Type Test conditions Test duration Test  

Pipe pressure DIN 8075 1999, Planar state of 10.000 h Hoop stress 

Notched ASTMD5397-95 Notched speci- lOOh Tensile force 

Long-term DIN EN ISO Tensile force. Depending Meantime- 

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A most efficient test method for stress-crack resistance of bottles was established by Mitsui Petrochemical Industries Ltd. The MPC-H2-A 312-2/ 709 method consists of deforming filled bottles and immersing them in a tensio-active medium. 

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