Summary of Standard D464

Grammage of Paper & Paperboard

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• Test method to determine the weight (or mass per unit area of paper & paperboard)
• Basis weight for paper - Mass per unit area for paperboard
• ASTM prefers grams per square meter (g/m2)

Safety

• Follow all safety rules

Reference

• ASTM standards D585 & D685

Method

• Area is a linear measurements
• Mass is a weight
• Grammage is calculated from the ratio of the mass to the area (convert to metric units)

Apparatus

• Weighing device (accurate to within .25% of the applied load)
• Cutting device - accurate parallelism
• Scale (accurate to within .20%)

Sampling

• Obtain sample per ASTM D585
• Cut sample at least 500cm2 (800 in2)
• Select # of sheets to give the required weighing accuracy

Calibration

• Check accuracy of weighing device
• Check cutting device
• Determine frequency of checking

Conditioning

• Condition & test in accordance with Practice D685
• Test specimens so moisture content is in drier state

Procedure

• Measure dimensions of each sheet
• Make correction if not within .2% (G = G’ x (A’/A)
• Weigh each test specimen to within .25%

Calculation M = mass A = area

• Calculate the mass per unit area of each test specimen G = K x (M/A) K from conversion table 1
• Calculate the mean of the results for each test unit & express in grams per square meter to 3 s.f.
• To convert grammage to mass in pounds for paperboard BW = Q x G

Report

• Grammage in grams per sq. meter to 3 s.f. for each test unit

Precision & Bias

• Repeatability in a lab = 94%
• Reproducibility between labs = 2.84%
• No bias because the value of grammage is defined only in terms of the condition stated

1. Obtain samples Lot #________________

Mill to take & send samples per lot of paper. (standard D585 5.2.1)

2. Cut samples _______________check when done

From at least 10 sample sheets cut test specimen with template - near center of sample

3. Condition test specimen for a minimum of 24 hrs. Handle as little as possible & keep out of direct sunlight, extreme temp. & relative humidity above 58%. Place test specimen in cabinet with circulating air, at 10 to 35% relative humidity & 71.6 F to 104 F (22 to 40 C) _________________check when done

4. Temperature of room for testing_____________Relative Humidity of testing room________________

(to be 50.0 +/- 2% rel. humidity & 73.4 +/- 1.8 F or 23.0 +/- 1.0 C)

5. Calibrate scales (shield from air current) Record weight of :

_____________1 gram

_____________3 grams

Adjust scales if more than .25% off of standard weight.

6. Weigh test specimen to 3 significant figures ___________________grams

7. Calculate test specimen results to determine grammage

_____________ Weight in grams divided by Area in m

(Sq " x # of sheets) 841.5"sq x 2.54 x 2.54 = 5429 10000 10000 = .5429

841.5"sq is 8.5" x 11" paper multiplied by the number of sheets (93.5"sq x 9)

SO:

____________gms gms

.5429 = _______________ m

8. Determine what a ream will weigh. (500 sheets)

_________lbs. weight in gms / # of sheets * 500 sheets / 454 gms (to change to lbs.)