Rieter

Chemical deposits (sticky substances)

Index

The best-known sticky substance on cotton fibers is honeydew. Strictly, this is a secretion of white fly or aphid, but today all sticky substances are incorrectly called honeydew. Schenek  [1,7] identifies these sticky substances as:

Secretions
honeydew;
Fungi and bacteria
decomposition products;
Vegetable substances
sugars from plant juices, leaf nectar,
overproduction of wax;
Fats, oil
seed oil from ginning;
Pathogens
Synthetic substances
defoliant, insecticides, fertilizers,
oil from harvesting machines.

 In the great majority of cases, however, the substance is one of a group of sugars of the most variable composition, primarily, but not exclusively, fructose, glucose, saccharose, melezitose, trehalose and trehalulose, as found, in sticky cottons  [26].

These saccharides are mostly, but not always, produced by insects or the plants themselves, depending upon the influences on the plants prior to picking.

Whether or not a fiber will stick depends, however, not only upon the quantity of the sticky coating and its composition, but also upon the degree of saturation as a solution  [1] and the working temperature in the spinning mill. Accordingly, conclusions regarding stickiness in the production process cannot be drawn automatically from the determination of quantity. Elsner  [8] states that the sugars are broken down by fermentation and by microorganisms during storage of the cotton. This occurs more quickly, the higher the moisture content. During spinning of sticky cotton, however, the relative humidity of the air as well as the ambient temperature in the production area should be kept as low as possible.