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Call for Tender Pimpled Table Tennis Rubber Friction Measurement

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Call for tenders The ITTF welcomes individuals and organizations to submit tenders for development of a method to detect low-friction table tennis rubbers at competition sites. The tender shall be returned, only in English, to equipment@ittf.com, latest on 18th of October 2019; the tender shall document ability and academic or other titles of the tenderer. The ITTF will analyse all proposals, their scientific and financial background, and communicate its decision as soon as possible; ITTF may ask for additional information in a written way. It is the tenderer’s obligation to document his/her concept for achieving the research and getting conclusive results. The International Table Tennis Federation reserves the right to choose any of the tenders or decline all and re-open the call. We thank you in advance for your help and tender. Kind regards. Claudia Herweg Equipment Manager

08 Fall

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Pimpled Table Tennis Rubber Friction Measurement The ITTF has deemed low-friction pimples-out rubber to be damaging to the sport. The friction of pimples-out rubber is currently measured in a laboratory prior to granting ITTF authorisation for use; however this does not prevent aftermarket modification of authorised rubbers, which results in illegal rubber with low friction disguised as authorised rubber. In order to prevent usage of such rubbers, the ITTF would like to adopt a new method of testing friction which can be done at competition sites around the world, using small portable equipment. The test should be easy to use, and understandable by athletes with no technical or scientific knowledge. The test equipment must also be very low cost: Less than 1.000 EUR is mandatory; less than 10 EUR is ideal. An ideal test method should equally detect low-friction pimples-out rubbers of two types: those with uniformly low friction on the entire rubber material, and those with low friction only on the top of the pimple surface. The test method may provide either a quantitative measurement of friction, or a simple pass/fail indication. A quantitative measurement is preferred, but low cost is a higher priority.The test must be repeatable and non-destructive.Depending on the test method, it may also be necessary to establish a calibration process, or a sanity check process. The test method may use a traditional friction test, or any other method of material analysis. If a traditional friction test is used, then the following should be considered:

1. What material should be used? A table tennis ball must be round plastic, 40mm in diameter and 2.7g in mass, but there is no friction or texture standard. Using a ball in the test may or may not give consistent results. Using a different but standard material in the test will give consistent results, but may not give a reasonable ball-to-rubber frictional measurement.

2. What is the ideal normal force, or range of normal forces, which consistently detects such rubbers? Too high a force may result in measurement of the pimple sides or base sheet, which may have much higher friction. Too low a force may result in erratic measurement, and is very far removed from a typical table tennis ball impact.

The ITTF can help provide pimpled rubber with low friction, high friction, and minimally acceptable friction.