Determination of GSM ( Gram per meter square) of different papers

 

We will see how to find out GSM of different types of papers and understand the significance of GSM Testing.

Materials required-

  • Different types of papers like-
  1. Wrapping paper-
  2. Baking paper
  3. Butter paper
  4. Freeze paper
  5. Kraft paper
  6. Cardboard
  7. A4 paper (Letter sized paper)
  • A Squared size template of size 10 cm
  • Scissors
  • Weighing Machine
  • Climate Chamber

Theory-

  • GSM stands for Gram per meter square, i.e., it is the weight of the paper of one square meter.
  • We can compare the strength and weight of different types of paper with the help of GSM.
  • Its unit is g/ m2.
  • GSM is also called the GRAMMAGE of the Paper. This measure is widely used in most comparisons.
  • Another measure to compare the Weight/area ratio of the papers is by the use of BASIS WEIGHT.
  • Basis weight is the weight of 1 ream of paper divided by the number of sheets in one ream.
  • Here 1 Ream= 500 sheets)

 

Description of different type of papers used in this experiment-

  1. Wrapping paperUsed for wrapping stored food to retain the moisture inside food. It keeps the freshness of different foods like sandwiches, pretzels etc. along with keeping them non-greasy.

    Wrapping paper

  2. Baking paper– They are cellulose-based papers used in Baking processes as a disposable non-stick surface. It is capable to withstand temperatures involved in baking, or sometimes roasting.

    Baking paper     Source- JMP Holdings

  3. Butter paper– A greaseproof paper used for wrapping butter, lard etc.

    Butter paper

  4. Freeze paper– It is a coarse and sturdy paper. Low-density polyethylene is laminated on one side for strength, leak resistant and for prevention of freeze burn up to a year. Ideal for wrapping noodles, pasta.

    Freeze paper

Used for storing fresh fish, poultry, cheese etc. Used for maintaining freshness, both in refrigerator and freezer. One may use ink for communication on the outer layer of the packaging, i.e. the poly coating.

         5. Kraft paper– Also called Butcher paper, is a coarse, sturdy paper ideal for wrapping meat and fish, most commonly used among the fishmongers, butchers etc.

Kraft paper- Source-Sunkea

        6. Cardboard– A material made from cellulose fiber ( such as wood pulp) like paper, but usually thicker.

Cardboard paper- Source www.biopac.co.uk

  1. A4 Paper– A commonly used letter sized paper having a dimension (210x 297mm)

Significance for GSM testing-

Most of the papers are bought and sold with respect to the GSM. GSM is the basis of comparing the strength of papers. Used for determining-

  • Quality of papers (or other substances like textiles in another context)
  • Strength
  • Bursting strength

 

Procedure-

  1. Cut all the 7 types of paper with a squared template of area=100cm2. So, we get 7 square pieces of papers.
  2. Take weights of all types of papers on the electronic weighing balance (in grams).
  3. Calculate their GSM values individually with the formula

         GSM (g/m2) = weight in g/ area of paper in m2

  1. Find the averages of individual GSMs.

Observations-

Here all GSM values are in g/m2

S No. Paper type GSM-Ist sample GSM-IInd sample GSM-IIIrd sample GSM-IVth sample Average GSM (g/m2)
1 Wrapping paper 41.53 41.32 41.62 41.26 41.4325
2 Baking paper 43.26 42.74 43.32 43.38 43.175
3 Butter paper 50.28 50.52 51.25 51.21 50.815
4 Freeze paper 67.97 67.55 67.67 67.24 67.6075
5 Kraft paper 147.83 106.63 108.35 144.56 126.8425
6 Cardboard 509.6 511.8 515.62 506.73 510.93
7 A4 paper 78.83 77.25 75.31 76.75 77.035

Table 1.1- GSM of different type of papers

Conclusion-

From Table 1.1, Cardboard has the highest GSM value among all the 7 types of papers, whereas, wrapping paper has the least GSM. So, it means that Cardboard and wrapping paper have the maximum and minimum strength respectively for the area of 100cm2.

 

 Below Precautions should be taken while performing the experiment-

  1. The surface should be smooth, on which the papers are measured and cut.
  2. Use of inks on papers for labeling should be avoided to prevent minor weight fluctuations in the measurement.

 


 

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