Compression Resistance Testing of Medical Polyethylene/Aluminum/Polyethylene Composite Tube

1. User’s Testing Demand
The tube to be tested is shown in Fig.1. The sealing performance of the tube cup and the weld are to be tested. It’s required to screw down the cup with a certain torque force; then, purge from the tube tail testing gas of a certain pressure, and immerse into the water for leakage observation.

Fig.1. Tube Structure

2. Requirements in Standards
It’s required in YBB00252005 to screw down the tube cup with a torque force of 30N.cm—90N.cm. Purge compressed air into the tube from tube tail. The pressure of compressed air is 0.2MPa. Then, put the tube into a water bath at 20±2℃, and go on purging for 30 seconds. The tube should not burst, and the weld should not produce bubble.

3. Test Design
Since testing gas with a certain pressure is purged in from the tube tail, inferior sealing would lead to leakage easily, and correspondingly influence the testing results. Thus, the following measures should be taken: clamp the tube on to the cone-shape injector firmly.

4. Testing Procedure
Immerse the clamped tube as shown in Fig. 2 into water. Testing gas purges into the tube and stops purging when the preset pressure has reached. Observe if there are bubbles in the water as well as the decrease of the pressure value of the control system.

Fig.2. Testing Structural Drawing

5. Conclusion
It’s proved to be effective and can satisfy testing demands. Such testing method can be applied to varied tube testing.