If the specimen melted or sintered / shrinked, reduce the temperature by 10 degrees and repeat the test with a new specimen. Repeat the procedure till the "melting point" is clearly determined.
Any thermo-analytical method may be used, e.g. DTA or TGA.
Tack free time of foams: a suitable amount of the material is extruded in to a beaker. Every 2 seconds the surface of the foam is touched by means of a wooden spatula. The tack free time is reached when no foam sticks on the spatula.
The thickness of products in the form of plates, sheets, boards, strips, fabrics, foils etc. is determined by means of a suitable gauge to the nearest 0.1 mm at 5 locations of the specimen. The minimum size of the specimen is 100 mm x100 mm or a minimum length of 500 mm in case of strips.
The dimensions shall be determined to an accuracy of 0,5% by means of a suitable gauge.
Particle size distribution
The method described for dry material in EN 1015-1 may be used.
Dimensional stability is a measurement of a cured foam’s resistance to shrink or post expand after curing as measured in this test. Excessive shrinkage may adversely affect the foam's ability to provide an effective air seal if the shrinkage forces exceed adhesive forces. Excessive post expansion can result in unacceptable deflection. The following protocol describes how to measure dimensional stability in a controlled testing environment.
The application tool (e.g. dispenser) that belongs to the tested system
Spacers (minimum 100 mm x (15 mm ± 1 mm) x 20 mm, made of dimensionally stable material (for example: PE, PTFE,...), on which polyurethane does not adhere.
AC grade plywood, about 130 mm x 100 mm, so that a net foam area of 100 mm x 100 mm remains. The thickness of the plywood should be minimum 9.5 mm.
Climatic chamber (controlled environment test equipment)
Heating chamber, dry but unspecified relative humidity
The foam, the application tool, and the substrate shall be conditioned to constant mass in accordance with EN 13238. Three specimens shall be made according to Figure B.1 and B.2. Be sure that the clamps sit directly on the spacers so as not to compress the assembly. The specimen shall have a gap with the required width of approximately 20 mm. The net foam space shall be an area of approximately 100 mm x 100 mm. Figure B.3 shows how the assembly should be oriented during foaming and how the foam should be applied. Again, make sure that the clamps sit directly on the spacers. After 24 hours, remove the hand clamps and the spacers. Cut the excess foam that has expanded from the interior of the assembly so that it is flush with the plywood edges. Measure the initial, inner plywood to plywood board dimensions. After taking the measurements, store the assemblies in the required test climates.
The test climates are:
(40 ± 2) ºC / (90 ± 5) % relative humidity
(30 ± 2) ºC / (30 ± 5) % relative humidity