EXPLANATION
Blocking of waxed paper, because of the relatively low temperature at which it may occur, can be a major problem to the paper coating industry. The wax picking and blocking points indicate an approximate temperature range at or above which waxed surfaces in contact with each other are likely to cause surface film injury.
The wax blocking point is the lowest temperature at which film disruption occurs across 50 % of the waxed paper surface when the test strips are separated.
TEST SUMMARY
Paper test specimens are coated with the wax sample, folded with the waxed surfaces together, and placed on a blocking plate which is heated at one end and cooled at the other to impose a measured temperature gradient along its length. After a conditioning period on the plate, the specimens are removed, unfolded, and examined for film disruption. The temperatures of corresponding points on the blocking plate are reported as the picking and blocking points or as blocking range.
TEST PRECISION
This test method has no bias.