Recently, Futek was experiencing difficulty assembling some of its load cells to specifications. By performing several tests and controlling for different variables, this manufacturer and supplier of load cells, torque and pressure sensors found fluctuations in clamping pressure to be a significant factor.
Futek’s sensors incorporate metal foil strain gauge technology. The adhesive used to bond gauges to sensors requires a clamping pressure of 50-75 psi. However, by using Pressurex®, mechanical engineer James Meiselbach could see that the pressure fluctuated from 50 psi to upwards of 200 psi in some of their production runs. Following this discovery, Futek used Pressurex in redesigning several clamps to incorporate silicone die springs to regulate the pressure more precisely.
“A sample pack of Pressurex with film that revealed different surface pressure ranges allowed our production to continue,” said Meiselbach.
This thin flexible film from Sensor Products Inc is a versatile NDT tool for quality control and machine component inspection. Its ability to easily and rapidly show inconsistencies in surface pressure between mating or contacting surfaces has lowered scrap rate and aided in the design and manufacture of many industrial and electronic products.
A Simple Solution
Pressurex reveals surface pressure from 2 - 43,200 psi (0.14 - 3,000 kg/cm2). No training or instrumentation is required; it is ideal to assess surface contact inconsistencies in virtually any industrial or electronic application, including gaskets, clamps, bolted joints, connectors, heat sinks, heat sealing elements, welding heads, and plastic and composite manufacture, among others.
Using Pressurex is simple -- to measure the surface pressure of a clamp around the outside of a load cell, Meiselbach cut Pressurex in the configuration of the clamp surface area, placed it in between the clamp and the load cell, applied force, unclamped it, and removed the Pressurex. He then compared the film, which changes color depending on how much pressure is exerted, to an accompanying color calibration chart.
Meiselbach first became aware of Pressurex when he was working for an aerospace company.
“We were having a problem with the main rotor blade of a helicopter. Interference was causing a fatigue crack in one of the inner spar tubes of the rotor blade. We put a large sheet of Pressurex in the bonding tool, bagged it up, and pressurized it in the autoclave. When we removed the film, we were able to identify the exact amount of pressure causing the crack.”
Contact Sensor Products for a free sample.