SCIENTIFIC SERVICES SD INC

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• SCIENTIFIC SERVICES S/D INC
• October 2004
• ASTM D 3556 RESEARCH
• Deposition on Glassware During Mechanical
  Dishwashing
• Background 1
• Preliminary Soil Exp. 3-5
• 3 Soils,2Levels, ½ Factorial 6-12
• Precision of Evaluation 13-20
• Preparation of Standards 20-24

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BACKGROUND
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PRELIMINARY EXPERIMENT - SENSITIVITY TO CURRENT
D 3556 SOILS
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Preliminary Test of Soil Effect - 2 Level
Factorial Design Main Effects OnlyLiquid and
Powder commercial Detergents at recommended use
levelEqual Amounts of Tallow/Lard/Margarine
Greasy Soil 16 or 48g OatmealDry Milk ASTM
Soil - 16g or 48g165 ppm in Maytag MDB3700AWX
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Conclusions from Preliminary Experiment

• All three variables have significant effects.
• Liquid and powder detergents react differently to
  soil kind and amount. Liquid Detergent gave more
  more spots than powder. Powder gave more film.
• Higher amounts of grease reduced film but had no
  effect on spots.
• Higher amounts of oatmeal reduced both film and
  spots.
• Additional work was done with more realistic
  levels of soils and the three soils fat, starch
  and protein were each investigated.

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INVESTIGATION OF EFFECTS OF THREE SURFACE
ACTIVE SOILS

• Variables
• Liquid and Powder Commercial Detergents at
  Recommended Dosage
• Hi and Low Levels of
• Grease
• Dry Milk
• Oatmeal
• Levels chosen to approximate household amounts
• Maytag Model No. MDB3700AWX inexpensive model
• 165 ppm 2/1 Ca/Mg synthetic hard water
• Evaluate after 1,2 3 Cycles by Rating and by
  Ranking

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Experimental Design Half Factorial 4
Variables 2 levels
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Fractional Factorial Structure

• Factor Confounding Rules
• Dry Milk Detergent X Grease X Oatmeal
• Aliasing Structure
• Detergent
• Grease
• Oatmeal
• Dry Milk
• Detergent X Grease Oatmeal X Dry Milk
• Detergent X Oatmeal Grease X Dry Milk
• Detergent X Dry Milk Grease X Oatmeal

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3rd Cycle Main Effects of 4 Variables from
Experimental DesignEvaluation by Ranking and by
Rating against Standards
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1st, 2nd 3rd Cycle Main Effects from 4 variable
Experimental Design
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Interactions from 4 Variable Design - Data from
Evaluation by Ranking
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Conclusions from study of three separate soils
with Liquid and Powder DetergentsRanking results
used. Ranking vs Rating Discussed Later

• At the lower levels of soil significant effects
  were still seen and interactions between the
  variables were important. Also, there were
  differences after 1, 2, and 3 cycles.
• Evaluation of 3rd cycle glasses only show more
  grease gave more spots. More oatmeal caused more
  film. More dry milk gave less film. With Liquid
  Detergent there were more spots and Powder
  resulted in more film
• Including evaluations from all three cycles gives
  similar, but not identical, results. Grease
  causes both film and spots to increase. Oatmeal
  gives fewer spots. Dry Milk still gave less
  film. Powder detergent is preferred for less
  spotting but Liquid Detergent is better for less
  film.
• There are many significant two way interactions
  between the variables. But, there is
  confounding because of the half-factorial
  experimental design, so dont know whether
• the effects shown are soil-to-soil synergisms of
  their soil-detergent counterparts. The
  importance is that soil type and amount affect
  Detergent Performance differently and need to be
  taken into account.

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Precision of Evaluation

• Comparison of evaluation of sets of glasses by
  ranking best to worst versus rating against ASTM
  Standards.
• Three Operators
• Three separated Sessions
• Analysis by JMP Statistical Software

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Evaluation by Ranking and against Standards by 3
Observers 3 Times24 Miscellaneous FL Glasses
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Evaluation of Glasses by 3 Observers 3 Times 24
FL Glasses - Statistics
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Effect of 3 Operators and 3 Sessions on
Evaluation of 24 Glasses from Experimental Design
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Statistics by Ranking and vs Stds. for 2 Level 4
Variable Partial Factorial Experimental Design
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Interactions Data from 4 Variable Design by
Evaluation Against Standards
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Interactions 3rd Cycle Results from 4 Variable
Design Vs Standards and by Ranking
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Conclusions about Rating vs Ranking

• Operator differences cause less error when
  relative performance is evaluated by a procedure
  to rank an experimental set of glasses than when
  assignment of ratings against standard glasses is
  used.
• Either procedure will allow for the measurement
  of significant differences in performance. And
  the operator error introduced by ranking is of
  low or significance.
• Ranking is less stressful than Rating.
• New data show that elapsed time before evaluation
  can be a factor and should be controlled.

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Preparation of Spot and Film Standard Glasses

• After much effort to select glasses from actual
  laboratory runs as spot and film standards, we
  developed methods for making spotted and filmed
  glasses synthetically. Spots were made by
  spraying natural hard water. Film was made by
  applying a pigment dispersion.
• To relate the ASTM 1- 5 scales to household usage
  we conducted a consumer acceptance test.
  Twenty four glasses with a wide range of deposits
  from various laboratory runs and including
  synthetically spotted and filmed glasses. The
  synthetic glasses had deposits that were typical
  of laboratory runs. Deposit amounts were related
  to concentration of applied so that the final
  scale would be linear with amount applied.
• The consumer test was run in the panelists
  dishwasher. There were 12 panelists. The
  glasses were loaded into the dishwasher rack.
  The panelist was requested to remove the glasses
  and put them away or set them aside for
  rewashing. Acceptance or rejection was recorded.
  Data from the 10 synthetic filmy and spotty was
  plotted on Pareto Charts which follow.
• From the charts we estimated the concentration at
  which all panelists would reject the glass as too
  spotty or filmy for use. This concentration was
  divided by four to give five levels of soil
  related to the ASTM Scale.
• ASTM 1 No Deposit
• ASTM 2 25 of Unacceptable Level
• ASTM 3 50 of Unacceptable Level
• ASTM 4 75 of Unacceptable Level
• ASTM 5 100 of Unacceptable Level
• We are currently perfecting our techniques and
  measuring reproducibility. We plan to repeat the
  consumer study to confirm our initial results.

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FILM ACCEPTABILITY vs AMOUNT OF PIGMENT
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ACCEPTABILITY OF SPOTS VS NUMBER OF APPLICATIONS
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Future Work

• Use the information about soil effects to conduct
  further performance evaluations
• Refine the procedures to produce sets of standard
  spotted and filmed glasses to use as standards to
  rate dishwashing performance.