The Specific Heat of Hygroscopic Textiles

A comparison between the qualities of open-end- and ring-spun yarns produced from Egyptian cottons is reported. Yarns of different counts and twist factors were produced on both the BD 200 open-end-spinning machine and a conventional ring-spinning machine, and their quality was studied by determining their strength, uniformity, and number of imperfections. The quality of open-end-spun yarn relative to that of ring-spun yarn is expressed in terms of the relative quality factor.

It is shown that the percentage reduction in strength of open-end-spun yarns compared with that of ring-spun yarns can be minimized by spinning them to coarser counts from shorter cottons. This is attributed to the different interactions between the fibre properties and the mechanism of yarn formation when different types of cotton are used.

It is also shown that the relative quality of open-end-spun yarns can be considerably increased by spinning them to coarser counts from Ashmouni cotton. The quality of open-end-spun yarn can exceed that of ring-spun yarn when Ashmouni cotton is spun to a linear density exceeding 30 tex.

It is concluded that the BD 200 open-end-spinning machine cannot be recommended for spinning fine yarns from long-staple Egyptian cottons.