What is BS 6712-2 - Hygroexpansivity measurement of paper and board about?
The measurement of dimensional changes in paper and board with changes in the ambient humidity is necessary for accurate control of printing and similar processes. The change in length, or hygroexpansivity, is due to stress relaxation of the paper fibres and swelling or contraction of the fibres by absorption or desorption of water. The proportion of the two mechanisms effective to produce hygroexpansivity depends upon the upper limit of relative humidity of the environment.
BS 6712-2 is identical to ISO 8226-2. BS 6712-2 specifies a method for the determination of the hygroexpansivity of paper and board when subjected to a change in the relative humidity with which it is in equilibrium from (33 ± 2) % to (84 ± 2) %. The method provided in BS 6712-2 is applicable to paper and board generally.
Note: BS 6712-2 is not suitable for crêpe papers and corrugated fibreboard.
Who is BS 6712-2 - Hygroexpansivity measurement of paper and board for?
BS 6712-2 on hygroexpansion measurement of paper and board is useful for:
- Paper mills
- The pulp and paper industry
- Paper manufacturers
- Research laboratories
- Paper testing laboratories
- Paper quality assurance authorities
Why should you use BS 6712-2 - Hygroexpansivity measurement of paper and board?
The hygroexpansion of the paper is a major concern for any producer of paper, print or packaging. For a long time, no method has been available for measuring the hygroexpansion in a flexible, effective and accurate manner. Moisture-induced dimensional changes have a significant effect on the runnability of paper and paperboard in converting operations. BS 6712-2 provides you with guidance on the measurement of hygroexpansivity of paper and board.
BS 6712-2 covers applications of paper and board intended to be used in high humidity conditions, e.g., as found in tropical countries. BS 6712-2 is useful for determining the effect of excessive moisture to which paper may be subjected for short periods during some printing processes, e.g., offset printing.
BS 6712-2 guidelines help to predict dimensional changes of paper when the moisture changes, e.g., during printing or end-use.
