Ream Weight Paperboard in Reels
1. To calculate the total length of paper in a reel in meters where the net weight of the paper in kilograms, the reel width in centimeters and the substance of the paper in grams per square meter is known.
Weight of reel in kgs x 100000
Length of paper in meters = _____________________________________________
Reel width in cm x grams per sq. meter
FOR EXAMPLE: – The length of paper of substance 100 gsm in a reel of 75 cm width and weighing 150 kg
150 x 100000
________________ = 2000 Meters
75 X 100
2. To calculate the weight of a reel of paper in kilograms where the substance of the paper in grams per square metre, the total length of the paper in the reel and the reel width is known:
Weight of reel in kg = length in meters x reel width in cm x gsm x .00001
FOR EXAMPLE: – The weight of a reel with a total length of 1500 meters paper of 80 gsm with a reel width of 100 cm
1500 x 100 x 80 x 0.0001 = 120 kg.
3. To calculate the substance of paper in a reel where the total length of the paper in reel, width of the reel and its net weight is given
Weight of reel in kg x 100000
Substance in gsm = _____________________________________________________
Length of paper in meters x reel width in cm
FOR EXAMPLE: – The substance of paper in a reel of 250 cm width and which weighs 200 kg and contains a total length of 1000 meters of paper
200 x 100000
__________________ = 80 gsm
1000 x 250
4. To calculate the approximate number of sheets of a particular size which may be obtained from a reel of paper, the net weight of the reel and the substance of the paper being known and the width of the reel being known and the width of the reel being known and the width of the reel being equal to or exact multiple of the dimension of one side of the sheet.
Weight of reel in kg x 10000000
No. of Sheets =___________________________________________________________
Gsm x breadth of the sheets in cm x length of the sheets in cm
FOR EXAMPLE: – Approximate number of sheets of size 51 x 76 cms to be obtained from a reel of paper of 60 gsm substance and having a reel width of 255 cm and weighing 175 kg
175 x 10000000
____________________ = 7524 sheets
60 X 51 x 76
5. To find the approximate number of sheets of two different sizes to be obtained cut from a reel, the sizes filling the complete deckle (trimmed).
First the proportion of the deckle (trimmed) utilised to obtain the two different sizes is to be found out and consequently the proportion of the weights of the reel to get the two sizes equivalent to the above proportion of the reel utilised to get the two sizes is obtained and the approximate number of sheets for each size is then calculated from the previous formula No. 4, the substance of the paper being known.
FOR EXAMPLE: – To fill a deckle (trimmed) of 188 cm a reel of paper of 80 gsm substance is cut into proportions of 2 x 56 cm and 1 x 76 cm to obtain paper of two different sizes of 56 x 91 cm and 76 x 102 cm. Find out the approximate number of sheets of the two sizes obtained by cutting the full reel into sheets, the weight of the reel being 376 kg. Portions of the deckle utilised for sizes 56 x 91 cm and 76 x 102 cm are respectively.
2 x 56 1 x 76
________ And ________
Therefore weight of the portion of the reel utilised for the size 56 x 91 cm is
376 x 2 x 56
_____________ = 224 kg.
and the weight of the portion of the reel utilised for the size 76 x 102 cm is
376 x 1 x 76
_____________ = 152 kg.
Approximate number of sheets for size 56 x 91 cm
224 x 10000000
_________________ = 5494 sheets.
80 x 56 x 91
Approximate number of sheets for size 76 x 102 cm
152 x 10000000
_________________ = 2450 sheets.
80 x 76 x 102
N.B.: – For any specifications given in inches, first we should convert into cm by multiplying by 2.54 for getting the correct result.
i.e., if the size is 18″ (length) x 23″ (breadth) the sizes are to be converted as 18″ x 2.54 = 45.7 cm and 23″ x 2.54 = 58.4 cm and then only other multiplications are to be computed as above.