BSI Education

Integrated Assignment 03

Soft, absorbent and strong?

Paper is used in kitchens and dining rooms everywhere. The most common uses are for kitchen towels and paper napkins.

Their quality depends on what paper pulp is used, how it is machined and the dyes that are used.

Consumers rate quality by softness, strength and how much liquid it can absorb and they expect the printing inks and dyes to be safe.

You can measure softness by qualitative analysis: compare people’s opinion with the type of fibres in the paper. The dyes can be checked by qualitative analysis, too. How many dyes are used?

Strength and absorbency are measured by quantitative analyses: you will end up with numbers rather than descriptions.

Major hotel chains buy enormous quantities of paper towels and napkins. If the purchasing manager asked you for advice on selecting the ‘best’ paper you would need some tests.

Your assignment is to develop three separate standard procedures to check the fibres, strength and absorbency of different papers. You should also investigate the dyes used in their manufacture.

What you have to do

Select five different kitchen towels or coloured paper napkins so that you have a variety of sample materials.

Fibre quality by microscopic examination

  1. Refer to SP 0001:2005 and SP 0002-1:2005.
  2. Ensure that your paper samples are dry.
  3. Prepare a specimen of paper: try different ways, for example separating the paper layers, so that the sheet is as thin as possible.
  4. Enclose the specimen on a microscope slide.
  5. Examine the slide under the microscope.
  6. List the features that you can see, for example, size, shape and the pattern of the fibres (use the scale in the eyepiece).
  7. Write a standard procedure for the observation of the kitchen paper features.

Strength

  1. Refer to SP 0012-1:2005.
  2. Make some preliminary trials with different specimen sizes. You may find that the specimen needs to be 50mm wide. Use the full thickness of the material (you are testing the product, not its constituent layers).
  3. Make both wet and dry specimens of your sample papers.
  4. Record the mass required to break each specimen.
  5. Write a standard procedure to measure the strength of kitchen towel/paper napkins.

Absorbency

  1. Refer to SP 0011-1:2005. You do not need to measure the thickness of the specimen, only its area.
    You can use the method below as a basis for your new procedure:
  2. Read through this method and write out an apparatus list. Assemble what you need.
  • Cut out specimens 200 mm x 50 mm.
  • Loosely push each of your paper samples into a separate funnel.
  • Weigh each of them and put the masses in a table like the one below.
  • Put each funnel into a separate conical flask.
  • Fill a 100 cm3 beaker with water.
  • Pour the water slowly through one of the funnels.
  • Repeat for the other funnels.
  • When all of the water has drained remove each funnel and shake gently (this should remove any surplus water).
  • Weigh each of the funnels again and complete your table.

 

Paper specimen
Mass of paper + funnel
(g) 		Difference (g) Mean difference (g)

(test 1+2+3) 3

 Absorbency g/mm2
mean difference/area
  Wet Dry      
1 test 1          
1 test 2          
1 test 3          
2 test 1          
2 test 2          
2 test 3          
etc.          
  1. Prepare a standard procedure to measure the absorbency of kitchen towel/paper napkins.

    Pattern and Colour
  2. Look at the procedure described in SP 0005:2005.
  3. Prepare specimens of each sample paper. If the kitchen towel is multi-coloured, cut out portions that are all the same colour
  4. Think about how to extract the dye. You may not need to use all the stages listed in SP 0005:2005.
  5. Make some trials to see which dyes are soluble in water. CAUTION: hot water.
  6. Carry out some tests on the water soluble dyes to find out how many are used.
  7. If you have food dyes available, you could find their Rf values and then see if any of your results match.
  8. Write a standard procedure to describe the colouring in kitchen towel/paper napkins.

What you need to think about

  • Before you start, write down what kitchen towel and paper napkins are used for. Think about what features are important. Some features will be more important than others, depending on what the paper is used for.
  • Do you need an opinion survey to judge what is acceptable for softness? Do the fibres affect softness?
  • For the strength test, use the same amount of water to dampen each of the specimens, so that the results are not affected by different absorbencies. You could repeat the test with the paper fully saturated. Record this separately.
  • Would it be useful to compare the impact resistance of the papers? Standard Procedure SP0012-2:2005 gives a method.
  • Should you test for absorbency using other liquids such as cooking oil?
  • If dye can be extracted easily, it should be of food quality. What common substances might the paper come into contact with? Could they cause the dye to come out?
  • Check that all your tests are fair.
  • Remember that the reason for all these tests is to find out which paper is the best for its intended purpose.

Presenting your conclusions

Present your conclusions as a list of quality checks necessary for the four features. Give details of the standard procedures that you have devised. Include the results of your tests, to show that your new procedures are valid. If you can, indicate what is good quality for softness, strength, absorbency and colouring.

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