Influence of oiling emulsion concentration on rupture properties of twisted threads from high-melting alumina

Abstract

The optimum concentration of emulsion for oiling thread from high-melting alumina fibres is established. The electrokinetic potentials of the fibre surface and oiling emulsion of the optimum concentration are determined. The optimum oiling agent concentration and rupture (tearing) properties of thread are found to be correlated.In order to facilitate textile processing, threads from chemical (synthetic) and natural fibres are submitted to treatment with textile-ameliorating agents. One of such methods is oiling dry thread before twisting. Oiling agents can be used as water-free oil composites (blends) or as aqueous emulsions.Several works were dedicated to the study of the influence of oiling composites on the thread strength [1-4]. The formulas and the methods of application of oiling composites for complex threads from high-melting (refractory) ceramic fibres, cited in patents [5][6][7], are of a descriptive nature; specific information about the composition and conditions of application are not provided.The purpose of this work was to determine the influence of the concentration of the preparation AVIV-B, UN 3082 (Technical Specification 2484-054-17965-829−2005) produced by the research and production firm Traskon on the strength of twisted threads from high-melting alumina fibres and to find the optimum oiling emulsion concentration. This oiling agent is a blend of mineral oils and surfactants. It is intended not only for enhancing the strength of twisted complex thread, but also for rendering elementary fibres selective. Since the oiling agent contains surfactants, we considered it expedient to determine their critical concentration for micelle formation (CCM) because precisely at this concentration emulsion drops are absorbed best on the hard fibre surface and the emulsion itself is most stable.The physical and chemical characteristics of oiling agent solutions of various concentrations are adduced in Table 1. Since the surfactants contained in the oiling agent exhibit their properties to the maximum at critical concentration for micelle formation (CCM), it was established by conductometric method that for the studied composition CCM comprises 8 wt.%.The correlation between the specific electric conductivity of the emulsion of the oiling compound AVIV-B and the concentration is depicted in Fig. 1. This micelle-forming concentration of 8 wt.% was confirmed also by the methods of CCM determination in terms of the dependence of the viscosity of the emulsion solutions and their surface tension on the concentration (Fig. 2).