ASTM D3344 Standard Test Method for Total Wax Content of Corrugated Paperboard
7. Procedure
7.1 Weigh the two board specimens together to the nearest 1 mg and record the combined weight of sample in grams. Cut each specimen into small pieces, each measuring about 25 mm square, being careful to retain all of the trimmings, and being careful that no surface wax is lost during handling of the specimens. Place all pieces in a 1000 cm3 beaker.
7.2 To the cut pieces, add 250 cm3 of solvent 1,1,1-trichloroethane (Warning - May cause irritation. Avoid contact with the eyes, skin, and clothing. Use only with adequate ventilation. Avoid prolonged breathing of vapor or spray mist. Avoid prolonged or repeated contact with skin. Do not take internally.) and cover the beaker with a watch glass. Heat to 75 °C (167 °F) then maintain at 75 °C for 1 h on a steam bath or hot plate in a hood. Pour off the solvent, passing it through the stainless steel screen in the funnel to remove fibers, and collect the solvent in a clean, tared 1000 cm3 beaker. Rinse the extraction beaker and the extracted paper chips with 50 cm3 of hot solvent, filter this rinsing, and add it to the solvent in the tared beaker.
7.3 Repeat the solvent extraction using 250 cm3 of fresh solvent, boiling for 1 h and rinsing with 30 cm3 of hot solvent. Combine all extracts and rinsings in the same tared beaker.
7.4 Evaporate the combined solvent extracts on a steam bath or, optionally, overnight in the air current of a hood. Evaporation may be hastened by use of a stream of nitrogen. For the final stages of evaporation, place the beaker on a hot plate at about 300 °F to completely dissipate solvent vapors or moisture. Confirm that evaporation is complete when no solvent odor can be detected. Cool and reweigh the tared beaker. Record the weight of wax extracted, to the nearest 1 mg.
NOTE 4 - If it is not possible to tare the 1000 cm3 beaker because of space limitations on the analytical balance, evaporate most of the solvent in the 1000 cm3 beaker and then quantitatively transfer the residue with rinsings to a smaller tared beaker, and continue the evaporation to dryness as described in 7.4.
NOTE 5 - Use of a Soxhlet extraction technique may result in improved precision.
8. Calculations
8.1 Calculate the basis weight of waxed combined board at start, Bw, in grams per square metre, as follows:
Bw = (b/a) x 10 000
where:
a = specimen area, total, cm2, and
b = specimen weight, total, g.
8.2 Calculate the total wax content, T, in grams per square metre, as follows:
T = (c/a) x 10 000
where:
c = weight of extracted wax, total, g
8.3 Calculate the basis weight of unwaxed board, Bu, in grams per square metre, as follows:
Bu = Bw - T
8.4 Calculate the weight percent total wax content, W, based on unwaxed board, as follows:
W = (T/Bu) x 100
