Paper 5: Check Weighing: A Review of the Weight Control Problem and its Solution

Abstract

Producers of consumer products are increasingly turning their attention to the use of automatic machinery for filling, wrapping, and packing operations under the stimulus of improving productivity and of planning for reduced availability of labour.

To an extent progress is hampered by demands made by the recent Weights and Measures legislation which has extended the area in which certain legal requirements regarding packed weight must be observed. One immediate effect has been to make packers more aware of limitations in present filling and checkweighing equipment and of the need, in some cases, for further development of more accurate high speed equipment if legislation is to be met economically. Such equipment takes time to develop, particularly when it must be of approved design. The development of automatic checkweighing machines has had a chequered career but a number of approved models are now available. Such machines can be used successfully in weight-control schemes designed to protect the packer from producing underweights and, where possible, to prevent excessive over-pack. However, the installation of a checkweighing machine does not automatically guarantee success.

The paper reviews some of the problems involved and discusses in some detail factors—such as weight distribution from filling machines—which have to be considered in determining where and how automatic checkweighers can be usefully applied. A brief review of some of the more recent developments is included.