Test Background
Freeze-thaw resistance refers to the changes in water absorption and compression behavior of a sample after it has been repeatedly frozen under humid conditions. The freeze-thaw test of rigid foam plastics can measure the change behavior of its mechanical properties and moisture content after multiple continuous cycles of dry conditions at -20°C and humid conditions at 20°C.
The purpose of the freeze-thaw test is to simulate the effects of freeze-thaw testing on insulating products exposed to moisture and low temperatures for a long time, such as inverted roofs and exposed ground insulation materials.
Zhongke Testing Reliability Experiment Center has the capability of reliability testing of various plastics and provides professional freeze-thaw testing services for rigid foam plastics and related products.
Scope of tests
The representative products of rigid foam are polystyrene foam, rigid polyurethane foam, phenolic, amino, epoxy, thermosetting acrylate resin and other foams, as well as rigid polyvinyl chloride foam. It can be used as thermal insulation materials, sandwich materials, packaging materials, sound insulation and shockproof materials, building materials, etc.
Test method
After the sample is continuously subjected to 300 cycles of freezing (-20°C, in dry conditions) and thawing (20°C, in water), its freeze-thaw resistance is characterized by measuring the water absorption and changes in compressive strength or compressive stress of the sample. The test at -20°C is carried out in air, and the test at 20°C is carried out in water.
The freeze-thaw cycle test must be carried out simultaneously with one of the following long-term immersion water absorption tests:
a) Long-term diffusion water absorption is carried out according to ISO 20393:2007;
b) Long-term immersion water absorption rate shall be carried out in accordance with GB/T 8810-2005. The selection of water absorption test method should be carried out in accordance with relevant product standards.
Test standard:
QB/T 5168-2017 Rigid foam plastics Freeze-thaw cycle test method
GB/T8810-2005 Rigid foam plastics - Determination of water absorption
GB/T 8813-2008 Rigid foam plastics - Determination of compression properties
ISO 20393-2007 Thermal insulation materials - Determination of long-term diffusion water absorption
