AS 1301.405:2021 pdf Methods of test for pulp and paper
1 Scope
This document specifies a method for determining the grammage of paper and board.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 186, Paper and board — Sampling to determine average quality
ISO 187, Paper, board and pulps — Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples
ISO 287, Paper and board — Determination of moisture content of a lot — Oven-drying method
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1 grammage
mass per unit area
mass of a unit area of paper or board determined by a specific method of test
Note 1 to entry: Grammage is expressed in grams per square metre.
4 Principle
The area of the test pieces and their masses are determined and the grammage is calculated.
For details regarding the test method precision, see Annex B.
5 Apparatus
5.1 Cutting device, capable of repeatedly cleanly cutting test pieces to within ±1,0 % of the same nominal area, for most paper and board products. This shall be checked frequently by measurement. Provided that the above accuracy is attained, the nominal area shall be used for calculating grammage. With certain types of paper and board it will be found, after carrying out this determination of area, that test pieces cannot be cut to within ±1,0 % of the nominal area. In such instances the dimensions of each test piece shall be determined to the nearest 0,5 mm and its area calculated.
5.2 Balance, sufficiently accurate, over the range of mass for which it is used, to measure the test piece mass to within 0,5 % of the actual mass. It shall be sensitive enough to detect a change of ±0,2 % in the mass to be weighed and, if the balance is of the direct-reading type, it shall be graduated so that readings may be taken to this degree of accuracy.
5.3 Special sheet-weighing balances, designed to weigh test pieces of a given size and which indicate grammage directly, may be used, provided that the above conditions for determination of mass are fulfilled and that the area of each test piece on a single weighing is not less than 50 000 mm 2 (500 cm 2 ) and not more than 100 000 mm 2 (1 000 cm 2 ) (see Clause 8 and 9.2). When in use, the balance shall be shielded from air currents.
6 Sampling
The selection of units and sheets and the taking of specimens shall be carried out in accordance with ISO 186. If tests are made on another type of sample, make sure that the specimens taken are representative of the sample received. If possible, take at least five specimens and take an area sufficient for at least 20 test pieces. If the “as taken” grammage is to be determined, the influence of the ambient atmosphere on the moisture content of the specimens shall be minimised (see A.2).
8 Procedure
For the determination of conditioned grammage, prepare and weigh the test pieces in the same atmospheric conditions as used to condition the specimens. For the determination of conditioned grammage and oven dry (see A.1) grammage, using the cutting device (5.1), cut test pieces from conditioned specimens. If possible, cut at least 20 test pieces from at least five specimens, taking the same number from each specimen. For the determination of “as- taken” grammage, follow the same procedure, minimising the influence of the ambient atmosphere on the moisture content of the test pieces (see A.2). Whenever possible, each test piece shall have an area of not less than 50 000 mm 2 (preferably 200 mm × 250 mm) and not more than 100 000 mm 2 . If necessary, it may be composed of several smaller pieces.
AS 1301.405:2021 pdf Methods of test for pulp and paper
