Viscometric Studies of Cellulose in Cotton in Relation to Mechanical Processing

A study was undertaken at the Southern Regional Research Laboratory to determine whether or not the mechanical processing of cotton fibers into yarn causes any chemical degradation to the cellulose. The study seemed timely in view of a report [22] indicating that the mechanical processing of cotton into yarn by conventional textile machinery causes as much as 30% average reduction in intrinsic viscosity. Studies were made on four sets of samples which had been treated as follows: (1) powdered in a Wiley mill; (2) processed a number of times through a new type of textile cotton opener developed at the Southern Regional Research Laboratory; (3) mechanically processed in essen tially the same manner as in the study referred to above; and (4) portions of the same samples used by Krieble and Whitwell [22]. The viscosity measurements determined by the methods employed at the Southern Regional Research Laboratory failed to show any demonstrable chemical damage to the cellulose which could be associated with processing. When the new method described by Krieble and Whitwell was applied to the viscosity data, the linear plots depended upon for extrapolation could not be obtained. It was concluded that the damage previously reported to have been found is not fully supported by a statistical treatment of the data; also, that chemical damage is not produced in ordinary cotton textile processing to any appreciable extent, although it might conceivably become notice able in excessively processed cotton. Some suggestions are given to explain the failure to secure linear plots by the suggested new method.