The so-called paper thread refers to the texture of the paper fiber structure, that is, the arrangement direction of the fiber structure. Where the paper roll is parallel to the paper machine's running direction during papermaking, it is the longitudinal direction of the paper, and perpendicular to the paper machine's running direction is the transverse direction of the paper. Generally, the width direction of the roll paper is transverse fibers, the circumferential direction of the roll paper is longitudinal, and the longitudinal tensile strength of the paper is high, which can meet the tension requirements of the printing press at high speed and is not prone to breakage. The width direction of the flat paper is also transverse fibers, and the slitting direction of the length of the roll paper is the longitudinal direction. Under normal circumstances, 787 * 1092mm; 850 * 1168mm; 889 * 1194cm and 880 * 1230mm, etc., write the front is the horizontal direction of the paper, such as 787 specifications is the horizontal direction of the paper. Because different papers have different directivities, affected by the temperature and humidity of the environment, there are obvious differences in the amount of expansion and contraction. Generally, the longitudinal expansion and contraction amount of paper is small, the lateral expansion and contraction change range is large, and it is easy to curl and deform. Therefore, the directionality of the paper will have a direct impact on the printing registration and packaging quality. For example, if the direction of the beer label is wrong, it will easily cause wrinkling and warping of the label. It can be seen that it is very important to correctly understand the threads of paper. There are many methods for identifying paper strands, such as mechanical identification methods, but more routine identification is based on experience. 1. Tear method When the paper has no creases, both hands will tear the paper in the opposite direction naturally. The straight cracks are longitudinal filaments, and the obvious ripples are horizontal filaments. 2. Pull method Use both hands to squeeze the two sides of the paper and pull outwards. The horizontal paper is easy to tear, and the vertical paper is not easy to tear. 3. Hand law enforcement cut the paper strips of about 100mm × 10mm in different directions of the paper, pinch one end with your fingers and let the plane of the paper stick out horizontally to see its free bending state. The horizontal wires are more severely bent, and the longitudinal wires are straighter. 4. Turn over the law. On the entire stack of paper, turn the edges of the paper in different directions to the opposite side respectively, and release the hand to naturally reset the paper edge. After the paper edge is reset, the horizontal paper edge is kept tight; on the contrary, the vertical paper edge is the one with larger gap. [next] 5. Water drop method For paper without sizing, you can put the paper flat on the table and drop a drop of water onto the paper. The shape of the water droplets after spreading is elliptical. The long axis direction of the ellipse is the longitudinal paper edge, and the vertical direction is the horizontal paper edge. 6. Wet the paper and tear it into a round or square shape, put it in water to soak it, and it will curl when the paper absorbs moisture. The curled side is a horizontal thread, and the non-curled side is a longitudinal thread. 7. Nail gliding method: Use nails to slide along the up and down and left and right directions of the paper once. If the up and down directions are wavy and there is no change in the left and right directions, the paper is a longitudinal thread; otherwise, it is a horizontal thread. 8. The mechanical measurement method cuts the paper strips of different paper directions according to the rules respectively, and uses the paper detection instrument to test the ring pressure strength, folding endurance, tensile strength, etc. of the paper sample. The paper with the larger test value is a longitudinal thread; otherwise, it is a horizontal thread. Correct understanding and discrimination of paper threads, scientific and reasonable use of paper grains for printing, will improve the accuracy of product overprinting and trademark labeling process quality, will play a better effect. White Paper Bag,Brown Kraft Paper Bags,Small Kraft Paper Bags,Kraft Paper Gift Bags JINAN XINSHUNYUAN PACKING CO., LTD , https://www.xsy-packaging.com