The bonding strength of corrugated cardboard refers to the maximum separation force that the surface paper, lining paper or core paper and the corrugated peak can withstand after the corrugated cardboard is bonded. GB/T6544-2008 Appendix B specifies that the adhesive strength is the force required to separate the unit flute length of corrugated cardboard under the specified test conditions. Also known as peel strength, expressed in Newtons per meter (Leng) (N/m). It is a key physical quantity that reflects the quality of corrugated cardboard bonding, and is one of the important technical indicators for evaluating the physical properties of corrugated boxes. Good bonding quality can improve the compressive strength, edge compressive strength, puncture strength and other physical indicators of corrugated boxes. Therefore, the correct test of bonding strength has become an important part of the quality inspection of corrugated boxes, and it is necessary to emphasize this, so as to ensure a correct judgment on whether the quality of corrugated boxes is qualified or not.
The testing principle of corrugated cardboard bond strength is to insert the needle-shaped accessory between the corrugated cardboard and the surface (inner) paper of the sample (or between the corrugated cardboard and the middle cardboard), and then press the needle-shaped accessory inserted with the sample. , make it perform relative motion until it is separated by the separated part. At this time, the maximum separation force that the corrugated peak and the face paper or the corrugated peak and the lining paper and core paper are combined with is calculated by the formula, which is the bond strength value. The applied tensile force is generated by inserting the upper and lower sets of the corrugated rods, so this experiment is also called the pin bonding strength test. The instrument used is a compressive strength tester, which shall meet the technical requirements of the compressive strength tester specified in GB/T6546. The sampling device shall comply with the cutter and requirements specified in GB/T6546. The attachment is composed of the upper part of the attachment and the lower part of the attachment, and it is a device that applies uniform pressure to each adhesive part of the sample. Each part of the attachment consists of a pin-type piece and a support piece that are equidistantly inserted into the center of the corrugated cardboard space, and the parallelism deviation between the pin-type piece and the support piece should be less than 1%.
Test method for adhesive strength: Carry out the test in accordance with the requirements of Appendix B “Determination of Adhesion Strength of Corrugated Cardboard” in the national standard GB/T 6544-2008. The sampling of samples shall be carried out according to GB/T 450. The handling and testing of samples and environmental conditions shall be carried out according to the requirements of GB/T 10739, and the temperature and humidity shall be strictly determined. The preparation of the sample should cut 10 single corrugated cardboard, or 20 double corrugated cardboard or 30 triple corrugated cardboard (25±0.5) mm × (100±1) mm sample from the sample, and the corrugated direction should be the same as the short side direction. Consistent. During the test, first put the sample to be tested into the accessory, insert the needle-shaped accessory with two rows of metal rods between the surface paper and the core paper of the sample, and align the support column, taking care not to damage the sample, as shown in the figure below. Show. Then place it in the center of the lower platen of the compressor. Start the compressor and press the attachment with the sample at a speed of (12.5±2.5) mm/min until the peak and the face paper (or lining/middle paper) are separated. Record the displayed maximum force to the nearest 1N. The separation shown on the right in the figure below is the separation of the corrugated paper and the lining paper. A total of 7 needles are inserted, effectively separating 6 corrugations. For single corrugated cardboard, the separation force of top paper and corrugated paper, and corrugated paper and lining paper should be tested 5 times respectively, and a total of 10 times; The separation force of paper, medium paper and corrugated paper 2, corrugated paper 2 and lining paper is measured 5 times each, a total of 20 times; the three-corrugated cardboard needs to be measured 30 times in total. Calculate the average value of the separation force of each adhesive layer, then calculate the adhesive strength of each adhesive layer, and finally take the minimum value of the adhesive strength of each adhesive layer as the adhesive strength of the corrugated board, and keep the result to three significant figures. .
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Post time: May-23-2022