Measurements of inverse creep in polyester multifilament yarns
Creep and Inverse creep are the important fundamental properties of textile materials. These properties determine the relaxation behaviour of the product. We have designed and fabricated an instrument which can measure the creep and inverse creep. The instrument consists of a Trans - Receiver unit interfaced with Embedded System along with the Personal Computer. Existing technique for measuring inverse creep does not measure the instantaneous extension or contraction. The newly fabricated instrument, can measure the instantaneous extension and contraction of the yarn up to an accuracy of 0.02%. This can be measured after every 500 μs. The position of the yarn, which is to be hanged, is vertical. The 'Electronic Timer Unit', replaces a meter scale. Set up is improved by using electronic utilities. The capability is enhanced to next level of time and distance resolutions. Automation enables to have flexibility of time from microseconds to minutes. Data is stored in different text files. Different samples of Polyester multifilament yarn were used in the experiment. The length and the load were altered. Change in stress lead to instantaneous extension or contraction followed by creep or inverse creep. This can sensed by the sensor and further stored in the memory of the Computer. The percentage creep and inverse creep were measured and have been reported in this present paper
A study of inverse relaxation in some textile fibers
This article discusses the phenomenon of inverse relaxation in some textile fibers, namely cotton, ramie, wool, polyester, and viscose. If anextended viscoelastic specimen is allowed to recover a part of the deformation given to it, such that its tension has not become zero, the stress in it tends to increase. This phenomenon is termed as “inverse relaxation.” This property is measured in terms of an index referred to as the inverse relaxation index. The values of this index at various extension and retraction levels for the above materials are presented and discussed in this article.
Adsorption of immunoglobulin Y in supermacroporous continuous cryogel with immobilized Cu(2+) ions.
The influence of temperature, pH and ionic strength on the adsorption of Immunoglobulin Y (IgY) in IDA-Cu(2+) cryogel system was studied by batch equilibrium measurements. The adsorptive equilibrium data were obtained at 17 and 27°C, pH 5.0 and 6.5, and at ionic strength of 50 and 200mmolL(-1) NaCl. Langmuir, Freundlich and Langmuir-Freundlich models were fitted to equilibrium data, while the enthalpy of adsorption of IgY in IDA-Cu(2+) cryogel system was calculated through Van't Hoff analysis. The binding of IgY on cryogel was stronger at 27°C and lowest pH and ionic strength values, with apparent maximum adsorption capacity of 27mgg(-1). The adsorption of protein in the resin was spontaneous in all analyzed cases. The results provide valuable information to enable the improvement of IgY purification processes.