Low temperature bending instrument

First,overview

This instrument is designed and manufactured according to the requirements of standard GB12952-91 GB/T17671-1997 and JC500-92, which is suitable for low-temperature bending test of waterproof coil, and suitable for low-temperature flexibility measurement of waterproof coating.
 
Second,low temperature bending instrument structure
bending instrument is mainly made of castings made of the upper and lower plate, shaft and shaft bracket and adjusting screws, etc., plate spacing can be adjusted.

The bending instrument is suitable for coil size 50X100 or 100X50 or coating mold specimen 100X25 prepared by polymer waterproof coating.
1, in the standard environment, with thickness measurement to measure the thickness of the sample, the thickness resistance of the sample should have no obvious defects.
2, the weathering surface of the sample will be bent outward 180 degrees, so that the 50mm (or 25mm) wide edge coincides and is flush, and ensure that no misalignment occurs, the edge can be fixed with a fixed clip or stapler or 10mm wide tape. 
3, adjust the spacing between the upper and lower plates of the bending instrument to three times the thickness of the sample.
4,open the upper and lower plate of the bending instrument, place the sample flat on the upper and lower plate, and the overlapping side is toward the rotating shaft, and the distance from the rotating shaft is 20mm, (or 25mm)
5, put the bending instrument together with the sample in the low temperature box, keep it at the specified temperature for 1 hour (or 2 hours), and then press down the bending instrument on the plate within 1S to reach the adjusted spacing, and keep 1S. Take out the specimen.
6, after returning to room temperature, observe whether the bending part of the sample is broken, or use a magnifying glass to observe whether the bending tension surface of the sample is cracked.
7, when two or three samples are not broken or no cracks, it is assessed as no cracks.