(1) Check the whole production process such as dehumidification, de-oilremoval, rust removal, steel pipe heating, powder coating spraying, adhesive and polyethylene heat shrink sleeve winding or cladding, reserved end cleaning and dressing, etc.
(2) Steel pipe surface treatment quality should not be lower than SA2.5 grade, metal surface clean, dust-free, anchor depth of about 40-100 microns.
(3) The heating temperature of the steel pipe before coating shall conform to the numerical requirements set by the process.
(4) Check whether the powder supply system is working properly, whether the underlying coating of epoxy powder is uniform, and whether the anti-corrosion layer is well leveled.
(5) Extruding adhesive, polyethylene should be plasticized well, polyethylene heat shrink sleeve winding layer number in line with the process regulations, anti-corrosion layer appearance is flat, no bubbles.
Polyethylene heat shrink sleeve coating inspection process is mainly the above several, in order to ensure the accuracy of the inspection, must be carried out in accordance with the relevant provisions, at the same time, because the polyethylene heat shrink sleeve inspection includes the production process inspection, finished product inspection, etc., in order to facilitate the subsequent use of inspection results, for the inspection records must be kept.