Thesis Details

Thesis Title: An investigation of different sizing agents and size pick-up levels on sized yarn physical properties and weavability of a 35/1 polyester/cotton ring spun yarn sized on the Reed-Chatwood foam size applicator
Thesis Author: Steven W. Josey
Abstract: Sizing is a process that applies a film forming solution to warp yarns to enable them to withstand the complex forces encountered during weaving. The sizing process has proven to be beneficial, however, it is also an energy-intensive process. The majority of the energy is used to dry the moisture from the warp sheet after the size is applied to the yarn. The moisture content (wet pick-up) of conventionally sized yarns is typically in the range of 80% to 110%. with the need to reduce the energy cost associated with the sizing process, new sizing systems have been developed to reduce wet pick-up, therefore, the amount of energy to dry the yarns is reduced. One such system is the Reed-Chatwood foam sizing applicator. This sizing system replaces the majority of the water in the size formulation with air. Past research has shown that foam sizing does reduce the amount of energy needed to dry the yarns, and certain conventional sizing agents can be used as foam sizing agents. However, an in-depth comparative study of foam sized and conventionally sized yarns physical properties and weavability has not been conducted. Therefore, this study compares the sized yarn physical properties and weavability of yarns sized on the Reed-Chatwood applicator to yarns sized conventionally on the Callaway Laboratory Slasher. During the slashing trials, all sizing variables were held as constant as possible except for sizing agents and size pick-up levels. Three foam sizing agents were used to access the physical yarn properties and weavability of the foam sized yarns and to determine what the best foam sizing agent was. The three foam sizing agents were 100% PVA, PVAjPVAC blend, and Val foam which is an acrylic based resin. The inventionally sized yarns were sized with a 100% PVA solution. Conditions were sized at three size pick-up levels. The pick-up levels ranged from 7-9%, 11-13%, and 15.5-17.5%. After all conditions were sized, the yarns were examined for 'their change in physical yarn properties from foam to conventionally sized yarns. The weavability of the yarns were accessed by weaving each condition on a Dornier Rapier Weaving Machine under accelerated tension levels. The tension of the sample warps were four times greater than the recommended tension for the particular machine and style. The results of this investigation indicated that the Reed-Chatwood foam size applicator can be a viable method to size spun yarns. Most of the physical yarn properties of foam sized yarns proved to be as good or better to the conventionally sized yarns. However, the size application quality of the foam sized yarns was not as good across the width of the warp sheet as the conventionally sized yarns. Also, a test to access the yard-to-yard size pick-up variability of foam sizing revealed some inconsistency. From the weaving trials, Valfoam, the acrylic based resin, had the best overall weaving performance.