company news about How to Control the Quality of Paperboard by Measuring the Viscosity and Strength

Corrugated cardboard is made up of face paper and core paper bonded into a whole and play a role, so the bonding state of face paper and core paper is very important. The bonding of corrugated cardboard is not that the stronger the bonding force is, the better the bonding force is, but that the proper bonding force is required to maintain the normal state of corrugated cardboard. If excessive pursuit of bonding strength and excessive use of adhesives, corrugated top will be deformed, so although the bonding force is great, the overall strength of corrugated cardboard will be reduced. Therefore, in the production process of cardboard, to master the bonding strength of corrugated cardboard, combined with the actual situation of production, flexible application, reduce costs, can produce greater economic benefits.

To measure the bonding strength of corrugated cardboard is to test the bonding tightness between the papers of corrugated cardboard with instruments. The principle is to insert a needle-shaped attachment between the corrugated paper and the face paper (or core paper) of the corrugated board sample, and then apply pressure on the attachment with the sample to make it move relatively until the bonding part is separated. It uses "Newton per square metre" (N/m2) as a unit to indicate the bonding strength.

The test instrument used for measuring the bond strength of corrugated board is the pressure plate type pressure strength tester. The size of the pressure plate meets the selected size of the sample, so that the sample does not exceed the pressure plate, the parallelism deviation of the pressure plate is not more than 1:1000, the horizontal movement is not more than 0.05 mm, and the moving speed of the dynamic pressure plate is 12.5 (+2.5 mm/min). The test attachment is composed of the upper attachment and the lower attachment. Its function is to exert uniform external force on the adherent parts of the sample. Each accessory consists of needle parts and supporting parts inserted equidistantly into the space center of corrugated cardboard. The parallelism between needle parts and supporting parts should be less than 1%. According to the different insertion positions of steel needles, the test methods can be divided into two kinds: bilateral test and unilateral test. The corrugated cardboard of bilateral test is peeled off at first on the side of bad bonding, so the bond strength of the weaker side can only be measured by bilateral test. Therefore, the bond strength of corrugated cardboard can not be measured comprehensively by bilateral test, and the bond strength of both sides of corrugated cardboard can be measured reliably only by unilateral test.