Refined (crystal) sugar
Because most marine reference books are silent on the carriage of refined sugar, it is assumed that it is a relatively simple product to handle
The Committee is aware that although guidance on the carriage of raw or semi-refined sugar is readily available, little or no information has been published on the carriage of refined sugar.
Not infrequently, substantial claims have arisen on shipments of bagged refined sugar, where the complaint often relates to stickiness or caking of the product, sometimes wrongly attributed to conditions encountered during the voyage.
Unlike semi-refined or raw sugar, refined sugar is always carried in bags. In the past, jute outer bags were widely used with a polythene film inner bag. Nowadays the outer bags are often made from woven polypropylene. The purpose of the plastic inner bags is to keep out moisture but because the outer and inner bags are often stitched together, the seal is not always effective.
Refined sugar is normally a dry, free flowing commodity with very low moisture content.
If the sugar is found on delivery not to be free flowing, it is important to establish whether this is due to:
● Pressure compaction
● Adhesiveness (stickiness), or
● Caking (agglomeration).
Pressure compaction usually occurs as a result of static pressure exerted by the weight of the sugar itself, especially when bags are stacked high. This condition can readily be corrected when the bags are handled and transported. However, adhesiveness and caking of refined sugar are both the result of too high a moisture content and possibly, to some extent, the temperature of the cargo at the time of bagging.
Adhesiveness, resulting in poor flow characteristics, occurs as a result of high moisture content, either initially or after packing. Caking may occur when over-moist sugar dries out.