Paper 6: Development of Faster Net Weighing Techniques to Match Higher Packaging Machine Speeds

The paper covers the development of net weighing of granulated sugar for small packets during the last forty years. Reference is made to the weighing of icing sugar where it is relevant.

The main influences have been:

(1)

Large increases in the proportion of prepacked sugar, compared with total sales to the domestic market.

(2)

Continual advances in the speeds of packing machines.

(3)

Company policy to maintain the highest possible weight standards.

In pre-war days, automatic net weighing machines were available which gave the required accuracy at a speed under 15 weighings per minute. During the next twenty years the advances in weigher speed were slight in comparison with the speeds obtainable on the packaging machines. The result was that larger and larger numbers of weighers were needed to feed one packaging machine, thus increasing the problems of putting the sugar into the packet.

The development of an electronic net weighing machine has restored the balance. In the late 1920's four compound beam weighers fed a 50 packets per minute filling and sealing machine; now four electronic weighers feed a 240 packets per minute unit, with similar weight accuracy.