2. Mechanical property tests

NB. All the samples tested have to be kept until "quality clearance". In case of failure, the tarpaulin (piece or roll) has to be kept for laboratory control.

Tear test in the sheet (see figure 2).

• The test has to be performed a minimum of 4 times on different samples. Cut 4 samples lengthwise and 4 samples crosswise into the sheet (outside of the reinforced bands!). The dimensions of samples must be 6 x 20 cm² and they must be pre-cut 8 cm down the middle. On each sample note "L" for lengthwise and "C" for crosswise plus the sample reference (Sample description: see figure 2).
• Hang the first clamp with the rope to any support about 2 m high. Insert the sample into this clamp.
• Fix the second clamp to the other end of the sample. Slowly hang a weight of 10 kg (including the weight of the clamp itself) on the second clamp. Release the weight very carefully.
• Each sample should resist the weight of 10 kg. If a sample tears off, do a laboratory test to confirm or to cancel this result. The laboratory test should be a test of tensile strength and tear strength.

Tear test in the band (see figure 3).

• The test should be performed on 3 samples per tarpaulin or roll. Cut 3 pieces on 3 different bands as shown in the drawing (Sample description: see figure 3).
• Roll one end of the sample around the wooden bar several times, clamp it with the second timber and nail it.
• Place both extremities of the wooden timber on a support in order to allow the sample to hang freely (e.g. the raised forks of a forklift).
• Punch a hole of 8 mm diameter in the middle of the band at 20 cm from the border.
• Place the hook in the hole you have punched, and hang a 70 kg weight on it, avoiding any shock. To make a weight of 70 kg you can use one bale of tarpaulins, plus the additional weight you had in the previous test.
• If one of the samples tears off, further laboratory testing is required

Peeling test of the bands.

• Pull off a corner of a band from the tarpaulin with the knife and try to peel the band off just by pulling it by hand. In most of the cases you should be able to peel off the bands. If this is not the case, it means that the band has been welded too strongly, report it into the "comment" column of the report form.
• To check that the resistance to peeling is not too low, you must check that black spots remains on the white side and white spots remaining on the black side. This means that the melting of the band and the base material has been correctly done.
• If one side remains completely white and the other completely black, this counts as a failure and further laboratory testing is required.
• Repeat the whole process on three different reinforced bands.

Peeling test of welding

• If the product has a weld in the middle, perform the same peeling strength control on the weld.

Peeling of the coating

• Try to pull off the white coating from the black fabric, it should be impossible to peel pieces larger than 1 cm² or ¼ square inch.