2 Tapio RQP: Measuring Principle The Measuring principle is tolaunch an impact body byspring force against the testsurface on which it rebounds.Velocity and distance aremeasured and processedto form the hardness profile.RQP measures 10 timesevery second.
3 Smooth hardness profile is of great importance for print houses
4 Profile resolution vs. measurement speed Fast1 m/s, 1measurement every 10 cmTypical0.5 m/s, 1measurement every 5 cmDetailed0.1 m/s, 1measurement every cm
5 Example of a bad hardness profile High Max-Minvalue causestension controlproblems on aprint machine.
6 Soft roll edge is a typical hardness profile problem Paper machineCustomer rollsFront edgeBack edgeWeb width in the paper machine
7 Local faults in hardness profile Tense areas: - Increase web breaks- Increase paper waste
8 Local faults in hardness profile Slack areas: - Increase web breaks- Increase paper waste- Slack area found10cm from theroll edgeWidth 2 cm,requires highresolutionmeasurement
9 Roll Hardness Profile, z-direction Example of hardnessprofile in z-direction !Hardness increasetowards the center ofthe roll. Measurement does not damage the roll.
10 Automatic vs. Hand Held Unit White line: Manual measurement, speed 20cm/sec.Red line: Automatic measurement, accelerating.Speed only effects the resolution, not level of values !
11 Tapio RQP – Complete System 2. Tapio RQP is portable.1. Tapio RQP system3. Tapio RQP uses tablet-PC.4. Tapio RQP measuring head.
12 Conclusions Uneven paper roll hardness profile is a major factor for a web break at the printing plant.RQP is the fastest and the most accurate systemto detect reels that need to be excluded in printing orconverting processes.RQP high resolution hardness measurement detectnarrow slack and tense areas.Hardness measurements in z-direction are possible.Roll hardness profiles are easily available for further usein mill system etc.