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Toxics Use Reduction Institute




Surface Solutions Laboratory

Trial Report



Trial Number 27

(Client Number 244, Project Number 1)

Trial Purpose: To determine the coefficient of friction for sealer and coating combined.

Date Run: 09/14/05

Experiment Procedure:
Control of Moisture Content and Temperature
The moisture content at the time of testing will influence results due to the hydroscopic nature of the base materials. Therefore, efforts must be taken to ensure that the moisture content and temperature remain constant during the evaluation period. Ideally, the sample floor should be kept at 65+/-1% relative humidity and 68+/-6 F.

During laboratory testing, conditions were slightly drier, 40% relative humidity, but the temperature was within the given temperature range ~70 F).

Sample Preparation
The flooring material supplied was Hardwood flooring made from Red Oak. The boards were ?? thick, 2 ?? wide and cut into 8? sections. Some pieces of the flooring had to be sanded prior to making initial thickness readings to remove residual packing tape adhesive. With the boards cut into 8? coupons, three readings were made using a Brown & Sharpe Micrometer to measure each coupons initial board thickness. Each reading was made to 0.001? and the three values were averaged to give a baseline thickness for the coupons. In addition to the thickness baseline, baselines were established for Gloss, Coefficient of Friction, Impact, Small Area Loads. Procedures for each baseline measurements followed the procedures to be outlined.

Following the establishment of the baselines, three coupons were coated with a supplied floor finish according to the manufacturers? specifications. The finish was applied using a 1? Pure Bristle 1500 paint brush. To ensure consistent coating application, the finish was leveled off using a 10 mils Precision Gage & Tool Co Dow Film Caster. Three coats were used for each floor finish as this was common number of coating layers suggested by the various manufacturers. Each coating layer was allowed to dry for 2 hours prior to the application of the next coat. Completed coupons were allowed to sit for a minimum period of 24 hours before performance evaluations were conducted.

Coefficient of Friction
The ASTM specified apparatus was replaced with an IMASS, Inc SP-102B-3M90 Slip/Peel Tester (Figure 1). Two types of friction coefficients were measured using this instrument. The first, Static CoF, was determined by obtaining the force required to move the specimen from a stationary position. The second, Sliding CoF (or Kinetic), was found by measuring the average force required to maintain movement at a certain rate. Measured forces will have peaks and valleys in the amount of force needed to keep moving. Average these values results and dividing by the weight of the object will result in the desired coefficient.

The Slip/Peel tester was first adjusted to ensure that the device was properly calibrated for the sled weight being used. A coupon was then placed and clamped onto the bed of the device. The speed of the bed was set to 45?/min. The instrument records two values, the peak, the valley and calculates the average. The device was run three times per coupon for measuring the Static CoF and three times to measure the Kinetic CoF. Each coupon?s value was averaged and then the values for each finish (three coupon averages) were averaged to get one value for the Static Coefficient of Friction and one value for the Kinetic Coefficient of Friction. These values for coated samples were compared to the CoF for the same uncoated coupons.

Coefficient of Friction = Ratio of tractive (pulling) force to the normal force (sled weight): CoF = F/N = (Tractive force)/(Normal Force) = (meter reading)/(sled weight)

Trial Results
Initial CoF  Static                  Kinetic     
Coupon #     Peak    Valley  Ave     Peak    Valley  Ave
a            653     562     566     597     578     586
             781     577     588     586     571     578
             699     573     585     609     588     592
b            711     583     594     588     562     568
             714     576     586     607     568     572
             721     572     575     595     557     565
c            763     626     626     595     561     582
             696     592     593     583     555     568
             704     572     588     584     566     570

Coated CoF   Static                  Kinetic     
Coupon #     Peak    Valley  Ave     Peak    Valley  Ave
a            877     617     670     762     637     672
             898     616     673     734     607     674
             819     617     669     749     618     676
b            915     643     692     779     675     698
             127     671     703     738     682     704
             970     676     701     741     678     697
c            829     658     666     722     629     662
             891     640     662     689     639     664
             819     650     668     689     641     666

Averages                         
     Static             Kinetic     
Peak    Valley  Ave     Peak    Valley  Ave
711     571     580     597     579     585
715     577     585     597     562     568
721     597     602     587     561     573
716     581     589     594     567     576

      Static            Kinetic     
Peak    Valley  Ave     Peak    Valley  Ave
592     411     448     499     415     449
620     644     688     755     658     693
897     658     676     717     649     674
703     571     604     657     574     605


Final - Initial                                      Static                  Kinetic     
                                                     Peak   Valley   Ave     Peak    Valley  Ave
Capitol Polyurethane Gloss                           136     182     216     248     212     223
Pro Finisher Water Based Polyurethane for floors     381      65     183     317      74     156
Pro Finisher Water Based Sanding Sealer               -8      43      62      77      46      54
Quide SA Aqua Deva Metro                              24      25      48      52      36      49
Capitol Hydro 202 Satin                              348     331     398     477     349     419
SafeCoat BP Satin                                    158      40      78     114      63      71
SafeCoat BP Gloss                                    306     103     212     414     169     238
Kiilto                                              -337    -266    -268    -277    -254    -271
Kiilto + Primer                                       63     -31      71     123     -50      48
Pro Finisher Water Based 
Sanding Sealer & Polyurethane                        195      65      93     146      82     107


Success Rating
A follow up test, usually based on company input.

Conclusion
The combined sealer and coating performed better than the sealer alone and about as well as the coating alone.