Corrugated board adhesive strength test principle and test

Corrugated board adhesive strength refers to the degree of firmness between corrugated paper and face paper, liner paper and core paper.

The test principle is to insert a needle-shaped peeling rack between the crepe paper and the facial tissue of the sample or between the crepe paper or the inner paper and the core paper, and then use a special compression instrument to pressurize the needle-shaped peeling rack with the sample inserted therein so as to make it The relative motion is performed until the separated parts are separated. At this time, the maximum separation force associated with the binding surface of the paper or the top sheet and the paper and the core paper is the adhesive strength value.

There are two methods for testing the adhesive strength in the testing experiment: one-side method and two-sided method; the single-side method is based on different corrugated type, and three kinds of steel pins with different diameters are used respectively, and the pins will be tested when testing. In order to insert, the single side of the corrugated space together with the support frame is peeled off. This method can accurately measure the adhesion between any combination of the peak and the paper or the peak and the paper and the core paper. The disadvantage is the operation comparison. Cumbersome, so less used in practice.

The double-sided method uses 14 types of comb-shaped pins with different diameters and different gauges according to different types of jaws. When the test is performed, the upper and lower comb needles are inserted from both sides of the specimen, and the two joint surfaces of the same dome layer are simultaneously peeled off. The strength of the combined surface with poor strength, this method is easy to operate and fast, so it has been widely used in corrugated box production and inspection units.

It should be pointed out that the bilateral stripping method is a non-standard method and none of the new and old standards of GB6548 have such provisions.

From the inspection practice, the comb pins used in the double-sided method are too thick and too tightly arranged when measuring B-type corrugated samples. When the corrugated fiber is inserted, the adhesion to the sample will occur. Different levels of artificial cracking occur. At the same time, the pin is supported by no support. After a certain period of time, the pin is bent and deformed, and is not parallel to the surface of the pressure plate. (Standard requires that the parallelism of the pressure plate is not allowed to vary. Greater than one-hundredth of a percent) causes uneven unilateral peeling of the specimen in the width direction, which seriously affects the test results. On the contrary, the single-sided method is equipped with separate pins of different diameters, and there is a corrugated space interval between the pins; there is a supporting attachment on the end face of the pins, so that the pins are not easily deformed after being subjected to force, so that they are better overcome. The former has defects.

This method is the standard method specified in the new and old standards of GB6548. It is also found in the test practice that the former is lower by 5% to 10% than the latter for the same sample under the same conditions using the two-sided method and the one-sided method. If the above analysis considers some other factors, the difference Even bigger.