Polyethylene tape coating quality inspection
polyethylene tape coating quality inspection is divided into process quality inspection and anticorrosive pipe inspection.
the first quality inspection process basically has the following points:
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1, the quality of steel tube surface treatment shall be not less than SA2. 5 or ST3 level, metal surface clean, no dust.
2, check whether the primer coating is continuous, no defects such as leakage besmear, flow mark, whether primer to table dry again after winding plastic sticky tape.
3, check whether the tape seam in the process of winding is parallel, glue sticks with distortion, fold, if there is a cock with end.
anticorrosive pipe inspection mainly include the following:
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1, appearance inspection. PE anticorrosive tape shall be smooth, uniform pressure side, without permanent bubbles, fold and damaged. Reserve anticorrosive pipe length conforms to specified requirements.
2, leakage check. Electricity spark leak detector to continuous inspection by root, anticorrosive pipe without funnelled as qualified.
3, the thickness of the inspection. Using nondestructive thickness measuring instrument for testing, every 20 1 root tube sampling, each random sample 3, 4 o 'clock every place is uniformly distributed along the circumference measurement, unqualified another two root of spot check, if one root is unqualified, is judged not qualified.
4, peel strength test. Along the pipe circumferential direction with a knife slit width 10 mm, length is greater than 100 mm of anticorrosive coating, should be thoroughly until the pipe body. Pry up one end and in the end, with the spring balance and demand pull direction and tube wall form an Angle of 90 degrees, open rate not greater than 300 mm/min.