What is the standard for paper clearance? How to test?

Add Time：2023/8/22    Clicks：3371

About this question
4, technical requirements
4.1 General requirements
Paper angle should be in accordance with the requirements of this standard, and should be approved by the prescribed procedures for customer drawings or samples produced samples.
4.2 appearance requirements
4.2.1 Surface quality
      The surface of the paper should be flat, no tear, broken, no burr and serious contamination. Paper angle cutting edge should be neat, and paper angle longitudinal direction at right angles, the tilt is not allowed to more than 1.5 degrees. Do not allow bending deformation.
4.2.2 Material requirements
      The outer edge of the paper corridor is a whole wooden paddle jam or imitation cattle cardboard, the middle layer of paper for the sand tube paper. Outside the use of cattle cardboard or imitation kraft paper wrapping.

The longitudinal maximum pressure of the paper angle is determined as follows:
       Take the sample length of 300mm ± 0.5mm, the sample incision must be smooth, straight and perpendicular to the edge of the longitudinal axis, the sample no obvious defects, such as twisting, indentation marks, tear and so on.
       Test equipment using universal tester, the test machine measured at each level of full scale between 10% to 90%, the reading indication error should be within ± 1%. Adjust the no-load speed of the test machine to 7 ± 2 mm / min. The sample is placed between the two plates, and the sample axis and the two plates on the surface of the center line coincidence, to ensure that both ends of the sample and the pressure plate surface parallel. Turn on the test machine to apply pressure to the specimen until the specimen is crushed.