Testing of a Large-Scale Mechanical Cottonseed Delinter: Results and Improvements

Traditionally, mechanically delinted seed retains 1-2% residual linters whereas acid removes all linters and is primarily used for production of planting seed. The need for a process that cleans the lint off cottonseed has been of interest to inventers and the cotton industry for some time. Most of the early inventions focused on mechanical processes such as reginning the seed or using abrasives, scraping, or scouring. Even though a majority of the early cottonseed delinting patents and inventions focused on mechanical methods, other processes were patented such as a flammable liquid and flame, a flame treatment apparatus or acid. The main arguments for using acid were that the mechanical processes damaged the seed (i.e. crushing or getting too hot and killing germination) and/or did not remove all of the lint. Consequently, acid delinting became, and still is, the primary means of producing planting quality seed. The use of an acid, for delinting cottonseed, may be desirable in removing lint for planting seed but is not a desirable process from an environmental perspective or if the seed is used as a protein source for humans.

Historically, cottonseed has not been a viable source of protein for humans due to gossypol. However, a researcher at Texas A&M University was able to silence the gene responsible for gossypol production in the cottonseed allowing for its potential use as human protein source. Simultaneously, cottonseed companies were expressing an interest in a non-acid delinting process due to regulatory (environmental), safety and maintenance issues (corrosiveness) with running acid delinting plants. Hence, the need to produce a non-acid delinting process had renewed interest from industry.

This research reports on data obtained from processing large volumes of cottonseed through a large-scale mechancial delinter based on the sucessuful bench-top archetype. Parameters measured include Lint Residue (%) and Germination (%).