Development of portable auto peel strength tester for 3PE coating

Peel strength is a key performance index for 3PE coatings. However, on-site testing of the peel strength is susceptible to impacts of surrounding conditions and testing techniques. Currently, spring scales or dynamometers are used extensively to measure the peel strength of 3PE coatings manually. These techniques are characterized by incapability in accurate control over peeling velocities and angles, missing of testing curves, limited testing areas and poor safety performances. With consideration to principles related to structural design with isosceles triangle, holder can be maintained around the central axis of the isosceles triangle to maintain the angle between the peeling and the pipe surface at 90°. In addition, by using the worm gear and speed reduction motor, the peeling speeds can be controlled accurately. With infrared devices deployed to monitor changes in temperatures in real time, temperatures around the peeling operations can be recorded continuously. In this way, the entire peeling process can be performed automatically with testing curves recorded to output on site. The new system can significantly enhance accuracy, repeatability and safety of on-site peeling operations, eliminating problems related to low accuracy and poor safety performances of manual operations. On-site performances of the proposed system are satisfactory.