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Document Title Results of ageing followed by abrasion test
Reference Number IGPG-03-09
Date
28 Nov 2011
Source(s) Vinçotte
Rulemaking Area(s) UN R43 Safety Glazing
Meeting(s)
Downloads
UNECE server Document
Excerpts from session reports related to this document
IGPG | Session 3 | 21-22 Nov 2011

Dr. Buckel explained he had had numerous contacts with Taber Industries, which clarified that the last Round Robin test for the Taber test was performed in 2004, while last wheel types were delivered in 2008. Dr. Buckel was of the opinion that, according to the results of the round robin, the main influencing factors seem to be the nozzle gap and the wheel lot (tests performed with wheels coming from different wheel lots may provide different results).

The informal group held a telephone meeting with Taber Industries (TI):

The experts firstly discussed documents IGPG-03-06 (tracking card) and IGPG-03-05 (comments from TI about the round robin):

  • - As all equipments passed the test, it was proposed to pay attention primarily to the ones on the “borderline”.
  • - Lab 2: could be the flatness of the table, misalignment of the arm, age of the instrument (1989, bearing not replaced).
  • - Lab 3: 11 year old instrument, arm alignment. Arm re-alignement can be performed by Ericsson (EU) as having good relations with Taber.
  • - Lab 4, Lab 5: OK
  • - Lab 6: Test 1, 1-5 O’clock: OK, 6-9 o’clock quite deviated.
  • - Lab 7: TI definitely recommended improving the toe.
  • - About lab 9, there was no recommendation TI could provide.

Nozzle distance: document IGPG-03-09, the table of percentage light demonstrates the influence of the nozzle distance. TI made some tests showing a clear influence of the nozzle distance on the haze values recommended 0,8 mm as the correct value.

Lab 9 used wheels from 2 different lots. TI committed to investigate the difference between the lots DY22 and DW22.

Test data verification of MPA (IGPG-03-04):

Dr. Dümmler questioned how TI would avoid future problems like that described in document IGPG-03-04. TI said they contacted their supplier, identified the root cause of the issue, dealing with the raw material. TI added additional tests on the raw materials and indicated that they are produced overseas, yet the suppliers are in the USA, making the contacts relatively easy. Other wheels of that lot, manufactured 3 years ago, were also investigated, not showing any problem. Traceability of the raw material is well maintained by TI. TI had indeed no feedback about labs using the wheels for plastic glazing.

It was questioned whether TI provides recommendations for which material the Taber test is recommended (scope of the test) i.e. is there any restriction for certain materials.

TI clarified that CS10F is relevant for haze on coating material. But certainly not for e.g. acrylic or plastic, uncoated, with 1000 cycles. Not only is the material different (physics), but the preparation of the samples as well. TI also pointed out that different wheels can address different materials. TI did not expect the type of ranges the informal group encountered and hence committed to further investigate the issue.

It was questioned how can a lab verify the wheels before testing, instead of waiting for inappropriate results.

TI recommended to test the wheels with a material whose expected results are known (method used by TI). TI has a large bank of reference material. When questioned about an example of a reference material, TI suggested as a recommendation simply using a material with known results.

The informal group however could not accept such recommendation as the order of results with the 3 different materials is not consistent (the results for the three materials have no correlation). TI committed to further investigate this point.

Document IGPG-03-07:

TI confirmed they use a brush to reface the wheels after testing. TI confirmed that this could generate static electricity and that distance, state and cleanness of the nozzle are of high importance. The Taber test is sensitive and all details must be well calibrated. TI recommended abrading right away after cleaning.

Conclusion:

  • - TI welcomed any comment by email.
  • - Most influencing parameters were investigated.
  • - TI did not provide any indication of what material could be used as a reference, seeing the discrepancies between PC and PMMA. Dr. Dümmler and Mr. Helmich recommended continuing investigating the Taber test, at least up to the time ISO finishes its work.

A debate took place about the work ISO is currently conducting. Dr. Dümmler recalled that ISO is looking to clarify the standard for permitting any wheel supplier (Taber, Daiwa), i.e. finding a relevant abrasion (wheel) technical specification. The difficulty is to assess the wheels w/o destructing them. Yet the experts agreed that adding a new wheel supplier could add a new parameter (Taber wheel, Daiwa wheel, equipment).

The group was questioned whether including the combinations in the final text.

  • I. Resistance to Temperature changes followed by abrasion:
    • a. Report says it is reasonable.
    • b. Informal group experts’ opinion: seems not necessary as no negative experience was ever reported. Should the group decide not to use the Taber test for abrasion, it would have to be excluded as well from the combination.
    • c. Conclusion: combination seems not relevant.
  • II. Resistance to Temperature changes as a single test:
    • a. Informal group experts’ opinion: Some experts were of the opinion that the temperature resistance should be included, out of a combination. Side glass experience did not show any failure to this test: seems relevant not to include it. However the regulation addresses any kind of “plastics” hence safety could be ensured thanks to this test because some new materials could need such test
    • b. Conclusion: kept for the moment, subject to revision at next meeting.
  • III. 227g Ball drop followed by humidity test
    • a. Report Conclusion: no failure
    • b. Informal group expert opinion: aim was to assess the resistance to humidity after an impact.
    • c. Conclusion: combination seems not relevant
  • IV. 227g ball drop followed by “boil” test (high temperature)
    • a. Report Conclusion: no failure
    • b. Comments from the informal group: this test was not mentioned during the 2nd meeting. The number of samples and tests performed is not sufficient to draw a conclusion as providing insufficient data. Height of 8,5 m was debated. The experts acknowledged that this value is a copy/paste from the glass test.
    • c. Conclusion: not enough samples, neither coating or plastics, etc: no conclusion to the combination can be drawn to date. Yet the proposed height of 8,5 can be kept for plastics.
  • V. 2,26 kg ball drop test.
    • a. Report Conclusion: no failure detected
    • b. Informal group experts’ opinion: headform test with a 10 kg ball already exists, hence the experts did not find necessary an additional test with a 2,26 kg ball..
    • c. Conclusion: test deleted for the moment, Daimler to communicate a solid position for the next meeting.