We will see how to find out GSM of different types of papers and understand the significance of GSM Testing.
- Different types of papers like-
- Wrapping paper-
- Baking paper
- Butter paper
- Freeze paper
- Kraft paper
- A4 paper (Letter sized paper)
- A Squared size template of size 10 cm
- Weighing Machine
- Climate Chamber
- 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-
- Wrapping paper– Used 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.
- 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.
- Butter paper– A greaseproof paper used for wrapping butter, lard etc.
- 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.
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.
6. Cardboard– A material made from cellulose fiber ( such as wood pulp) like paper, but usually thicker.
- 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)
- Bursting strength
- Cut all the 7 types of paper with a squared template of area=100cm2. So, we get 7 square pieces of papers.
- Take weights of all types of papers on the electronic weighing balance (in grams).
- Calculate their GSM values individually with the formula
GSM (g/m2) = weight in g/ area of paper in m2
- Find the averages of individual GSMs.
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)|
Table 1.1- GSM of different type of papers
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-
- The surface should be smooth, on which the papers are measured and cut.
- Use of inks on papers for labeling should be avoided to prevent minor weight fluctuations in the measurement.