2Tapio 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.
3Smooth hardness profile is of great importance for print houses
4Profile resolution vs. measurement speed Fast1 m/s, 1measurement every 10 cmTypical0.5 m/s, 1measurement every 5 cmDetailed0.1 m/s, 1measurement every cm
5Example of a bad hardness profile High Max-Minvalue causestension controlproblems on aprint machine.
6Soft roll edge is a typical hardness profile problem Paper machineCustomer rollsFront edgeBack edgeWeb width in the paper machine
7Local faults in hardness profile Tense areas: - Increase web breaks- Increase paper waste
8Local faults in hardness profile Slack areas: - Increase web breaks- Increase paper waste- Slack area found10cm from theroll edgeWidth 2 cm,requires highresolutionmeasurement
9Roll Hardness Profile, z-direction Example of hardnessprofile in z-direction !Hardness increasetowards the center ofthe roll. Measurement does not damage the roll.
10Automatic 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 !
11Tapio RQP – Complete System 2. Tapio RQP is portable.1. Tapio RQP system3. Tapio RQP uses tablet-PC.4. Tapio RQP measuring head.
12Conclusions 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.