BS EN ISO 7263:2011 pdf free download – Corrugating medium – Determination of the flat crush resistance after laboratory fluting (ISO 7263:2011).
5.4 Pressure-sensitive adhesive tap, for example 3M grade 410 tape1), at least 15 mm wide.
The tape shall be of low stretch and have good adhesion properties and it shall not transfer moisture to the substrate during the test.
5.5 FIat crush tester, motor-driven, fixed-platen type in accordance with ISO 13820.
6 Sampling
If the tests are being made to evaluate a lot, the sample shall be selected in accordance with ISO 186. If the tests are made on another type of sample, make sure that the specimens taken are representative of the sample received.
7 Conditioning
When using the reconditioning procedure (see 9.3), before preparation of the test pieces, condition the sample for at least 4 h in one of the conditioning atmospheres specified in ISO 187.
8 Preparation of test pieces
If the flat crush resistance index is required, determine the grammage of the conditioned specimens (before the preparation of test pieces) as described in ISO 536.
Cut at least 10 test pieces having a width of 12,7 mm ± 0,1 mm and a length between 150 mm and 160 mm, the length being cut in the machine direction. Care should be taken not to damage the edges of the test pieces and they should not be handled more than is necessary.
A test piece width of 15,0 mm ± 0,1 mm may be used, provided that the corrugating roll width is greater than the test piece width. If a test width of 15 mm is used, the force between the corrugating rolls, as defined in 5.2, is to be adjusted to 118 N ± 10 N. The use of a 15 mm test piece width is not to be considered as being in accordance with this International Standard and its use is to be stated in the test report.
9 Procedure
9.1 General
The compression test may be carried out immediately after fluting (see 9.2) or after reconditioning (see 9.3).
9.2 Testing immediately after fluting
If the test is to be carried out immediately after fluting, the total time between discharge of the fluted test piece from the fluting rolls and the initial application of the crushing force shall be 5 s to 8 s. Arrange all equipment to facilitate completing the operations in the specified time.
For the most reliable results, the times shall be maintained within the 5 s to 8 s time limit from the discharge of the fluted test piece from the fluter to the initial application of force in the compression tester. To do this expeditiously, pre-cut the adhesive tape (5.4) that is to serve as the facing to its prescribed length (at least 120 mm long) and adhere one end of each strip lightly to the workbench.
Uniform meshing of fluting rolls can be checked by using, for example, National Cash Register Tape2), (CB white NCR paper and CR green tinted NCR paper C2R).
Run a 12,7 mm wide strip of each type of paper through the fluting rolls. The pressure pattern will appear on the green tinted strip. The pressure lines should be uniform and extend the full 12,7 mm width of the strip. If there is more impression at the top or bottom of the rolls, they are not in the same plane. This means that the heating plate has warped, is worn unevenly, or that the bearings are worn. In any case, the fluter should go back to the manufacturer for repair.
The rolls should ride flat on the heating plate. If the drive roll is not flat on the heating plate, loosen the collar directly above the bottom-bearing housing and tap the roll lightly until it is lying flat. It may be necessary to loosen the bottom bearing also. Make this adjustment only when the fluter is up to normal operating temperature. When the roll is flat, tighten all bolts and set screws. Remove the driven roll by taking out the centre bolt and lifting the roll up by bolts inserted in the thread holes provided. Inspect the heating plate for wear of the chrome plating. If worn, a new heating plate should be installed by the manufacturer. The roll can also be inspected for smoothness and wear on the bottom. The spring-loaded post slide can be checked for freeness of movement and lubricated with powdered graphite, if necessary. When the roll is replaced, powdered graphite should be added to the lubricating hole while the roll is turning. Graphite should be added until the grooves under the roll are completely filled. The same holds true for the drive roll.