BS 2782-6:Method 632A:1993

Specifies a method for the determination of the "free length" of a roll of plastics film or sheeting. Meant to be used with rolls of length up to 100 m as a reference method with which other methods may be checked. Also specifies a method for the determination of the average width of a roll and the width of a sample of plastics film or sheeting not less than 5 mm wide. Coverage includes apparatus, procedure and precision.

1.1 This International Standard specifies a method for the determination of the “free?? length of a roll of plastics film or sheeting (see clause 2).

This method is intended for use with rolls of length up to 100 m as a reference method with which other methods may be checked. Any other method of determining the length may be used, provided that it gives the same result as the specified method. If automatic measuring devices are used, it is necessary that they be checked by measurements made in accordance with the specified procedure for each type of film or sheeting.

Because the method is laborious it is permissible, in the case of long rolls, to check the other methods of measurement referred to above on an approximately 100 m length of film and sheeting measured by the specified method.

1.2 This International Standard also specifies a method for the determination of the average width of a roll and the width of a sample of plastics film or sheeting not less than 5 mm wide (see clause 3). If the width is only slightly greater than 5 mm, the accuracy of the method is only 2 %. Two procedures are specified, their application depending on the width of the material.

The method determines the “free?? width of a roll of film or sheeting.

This method is intended for use as a reference method with which other methods may be checked. Any other method of determining the width may be used, provided that it gives the same result as the specified method. If automatic measuring devices are used, it is necessary that they be checked by measurements made in accordance with the specified procedures for each type of film or sheeting.