Product Detail:
This method describes procedures for obtaining a sample for testing. It should
be recognized that in an ideal situation the samples selected should represent a
lot of paper or paperboard, container board, or related product, including
converted paper products (all hereafter referred to as “paper”). However, in
some situations the sample may be as small as a single sheet of paper that has
been provided to the laboratory for testing and may not represent the lot from
which it is obtained.
Procedures are described (see Section 4) for establishing the lot of paper to
be sampled.
The rules for selecting a represen-tative sample for testing from this lot
are described in Sections 5.1 and 5.2. Specific sampling procedures are
described (5.3) for large rolls or skids.
Specific procedures are described (5.4) for sampling from a single roll of
containerboard for basis weight and burst strength.
A procedure is described (5.5) for the sampling and testing of a continuous
strip of paper. In evaluating the performance of a process there may be
advantages in measuring the cross or along machine variation in the product. An
example could be the cross machine caliper profile to determine the processing
variation caused by calendar roll loadings or crown. The evaluation of machine
direction strips can provide information of performance of equipment, i.e.,
blocked couch roll.
A procedure is described (5.6) for handling a sample that may consist of
limited a quantity of paper; or, may be as small as a single sheet of paper.
Situations may arise where the testing laboratory has no control of the quantity
of paper that is supplied for testing. An example could be the return of a piece
of paper that the customer perceives to be defective and the testing laboratory
has been asked to quantify its properties. It must be recognized that in these
situations the laboratory may not have control of the sampling procedure; and,
the samples supplied and tested may not represent the lot of material from which
they came.
Prior to purchase, there should be agreement between buyer and seller on the
size of the lot to be sampled (3.1), on details of the sampling procedure, the
required physical and chemical properties, dimensional tolerances, etc., and the
testing methods to be employed.
The appendices, which provide useful, statistical criteria for accepting
individual lots of paper on the basis of the number of defective test units, can
assist the buyer and the seller in selecting an agreed upon sampling and
acceptance procedure.
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