EN 17333-3-2020 pdf download.Characterisation of one component foam – Part 3 Application.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 923 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso,org/obp/ui
— IEC Electropedia: available at http://www.electropedia.org/
3.1
one component foam
(OCF)
moisture curing or water drying foam as well as self-curing activatable foam dispensed from a single pressurised foam container
3.2
pressurised foam container
pressurised can according to EN 14847 and EN 15006
3.3
test container
pressurised can according to EN 14847 and EN 15006 used for testing purposes
3.4
fully cured ordried foam
cross-linked foam which reaches its serviceable properties as claimed by the manufacturer
3.5
cutting time
time necessary after application to achieve a stage in which the bead of the foam could be cut without deforming the structure
3.6
tack tree time
time that surface tack is no longer detectable
3.7
straw foam
one component or two component foams for the extrLlsion with an aaapter tube
3.8
gun foam
one component foams for the extrusion with a foam application gun
3.9
sagging
tendency of freshly applied foam to collapse in or flow out of the joint before reaching its cured stage
Note ito entry: Sagging behaviour is dependent on temperature of both the canister, the environment and the dimensions of the joint. particularly vertical joints.
4 Test methods
4.1 Method 1- Cutting time
4.1.1 Principle
The liquid foam is dispensed in defined beads on a horizontal surface. After a certain time for curing, the bead is cut. The cutting time is reached when the cut surface is not sticky anymore, the knife remains clean without foam residues and the foam is not squeezed.
NOTE The measured value depends strongly on the dispensed bead diameter as well as the humidity, temperature and the processing and tools. The cutting time gives an Indication about the water transport inside the foam body, therefore about the foam quality.
4.1.2 Equipment
4.1.2.1 Sharp and clean knife blade.
4.1.2.2 Stopwatch.
4.1.3 Sampling
4.1.3.1 Conditioning
Bring the test container to the test temperature for at least 24 h.
4.1.4 Test procedure
a) Shake an unused test container vigorously 20 times.
b) Discard the first (40 ± 10)gof foam.
c) Extrude at least 3 beads of fresh foam on the paper or cardboard and start the stopwatch, maintaining at least 50 mm between each bead and a maximum bead height of 30 mm (see Figure 2).
d) Indicative times after which it Es recommended to start the measurements are 15 mm for moisture curing foam, 5 mEn for self-curing activatable foam and 24 h for water drying foam.
e) Test conditions: (23 ± 2) °C and (50 ± 5) % RH. The test may also be performed under other conditions. The selected test conditions shall be part of the report.
1) Find 30 mm diameter bead by template (see Figure 3) and cut it in this place. Do not saw the foam, cut it in one or two steps at a fast pace.
g) If fresh foam remains on the knife, or the foam is crushed, the foam is still not cured.
h) Clean the knife.
i) Wait for another five minutes and try to cut again, but in another bead to avoid impact on the foam due to the cut surface.
j) Repeat steps b) to e), until the foam is not crushed by the knife. Also the bead shall stay in shape.
NOTE Flexible foams may he difficult to assess.
3) test conditions,
4) any deviation from procedure in 41; g) results of test:
1) test results,
2) observations (if any).
4.2 Method 2 – Tack free time
4.2.1 Principle
The foam is extruded as a bead on a horizontal surface. After a certain time for curing, the surface of the head is touched with a small rod or adapter tube. The tack free time is defined as the point at which the rod or tube does not stick to the foam surface.
4.2.2 Equipment
4.2.2.1 Paper or cardboard.
4.2.2.2 Rod or adapter tube (e.g. polyethylene (PE) tube).
4.2.2.3 Stopwatch.
4.2.3 SamplIng
4.2.3.1 Conditioning
Bring the test container to the test temperature for at least 24 h.
4.2.3.2 Test Pieces preparation
a) Test conditions: (23 ± 2) °C and (50 ± 5) % RH. Any deviation from these conditions shall be noted in the test report.
b) An unused test container is shaken at least 20 times before application. Discard the first (40 ± 10) g of foam.
c) Cylindrically shaped beads with diameter of 20 mm to 30 mm are extruded on the cardboard and the stopwatch is started.EN 17333-3-2020 pdf download.