Paper Abrasion
"Taber test" uses CS-10P wheels to evaluate paper abrasion
Situation:
For over 50+ years, manufacturers of paper and paperboard have followed test methods such as Tappi T476 to measure abrasion resistance properties. Utilizing the Taber Rotary Platform Abraser, paper specimens are subjected to dry or wet abrasion to determine the amount of paper fiber loss. This test is one of many to ensure acceptable paper construction and has been employed as a means to evaluate the amount of “fiber shedding” that might occur in copier machines during the photocopying process.
In late 2002, the paper industry ran into an unanticipated dilemma after Taber Industries released an improved version of our CS-10 resilient type wheels. The improved wheel formulation offered longer shelf life, a higher level of repeatability & consistency, and less color transfer to the test specimen. Yet despite Taber’s efforts to ensure the wheels matched expected historic performance, paper manufacturers reported differences in their test results. With the improved wheel, weight loss figures were only 30% of the anticipated value and the wheels only seemed to “polish” the paper specimen.
Analysis:
A thorough review of Taber’s preliminary data on paper test did not reveal any explanation for the performance differences. However, after interviewing each company who reported differences, the root cause became evident.
As standard test protocol, Taber recommends the abrasive wheels be refaced prior to each test. The purpose of this step is to remove any debris that adheres to the wheel surface and “standardize” the wheels prior to testing. Taber’s validation data was based on refacing the wheels before each test. However, Tappi T476 states that refacing should be conducted “after testing a fiber surface containing fillers or coating, or after each 1000 revolutions”. All of the companies reporting a difference in expected results performed tests 100 cycles in duration and refaced the wheels after every 10 tests!
An in-depth study confirmed paper debris generated during testing had a greater tendency to adhere to the outer periphery of the improved wheel. The initial two test results were comparable, however, for tests 3 – 10 the abrasion characteristics of the wheels changed dramatically and results showed a decreasing amount of weight loss.
The easy solution to remedy this dilemma was to reface the CS-10 wheels prior to each test. Recognizing this extra step would add both cost and time to a customer’s testing protocol, Taber investigated a custom wheel.
Benefit:
Tappi T476 allows the interested parties to select the wheel they wish to test with. This clause allowed Taber to design an abrasive wheel that provided the desired abrasion characteristics, without the paper debris adhering to it. The CS-10P was developed and after having the industry validate its performance, the wheel was released as an alternative to the CS-10. Specifically designed for paper, the CS-10P wheel provides equivalent test results and permits the operator to run ten consecutive 100 cycle tests without the need to reface between each test.
