K. Raghunathan’s research while affiliated with Anna University, Chennai and other places

The mechanical properties of knitted jute inlaid reinforced composites with different stacking sequences and number of layers have been studied. Flat rib knitted preforms have been produced in manual flatbed knitting machine followed by composite laminate preparation using simple hand lay-up technique. It is observed that the mechanical properties are dependant upon the stacking sequence and number of layers.

Impact of mass of kapas on quality of ginned lint has been studied using MCU-5 variety. It is found that with the increase in mass of kapas, the quantity of lint and its length increase. The other physical properties of lint are also found to be superior with the increase in mass of kapas. Irrespective of the mass of kapas, the ginning machine setting shows significant impact on fibre properties. The strength and elongation of fibre vary significantly with varying length of oscillation of beater knife from the edge of fixed knife. This is because the removal of fibres from the seed is accomplished by a fixed knife held tightly against a single ginning roller and a moving (reciprocating) knife that co-operates with the roller and fixed knife to separate the fibre from the seeds. The range of increase in short fibre content and nep (content/g) is found to be significantly higher in the sample below 100 mg. If feeding is done in the form of locule in the ginning machine, the fibre deterioration is significantly lesser as compared to feeding as kapas.

The effects of picking periods and average mass of seed on fibre properties have been studied using MCU-5 Indian cotton variety, collected from three different locations at various picking periods. It is observed that there is a significant impact due to the average mass of seed in a particular picking period on fibre quality. In general, the mass of seed plays a vital role in deciding the quality of fibres.

The mechanical properties of knitted jute reinforced composites with different stacking sequences have been studied. Flat rib knitted preforms have been produced in manual flat bed knitting machine followed by composite laminate preparation using simple hand lay-up technique. It is observed that the mechanical properties are dependent upon the stacking sequence. The improvement in course-wise mechanical properties of the laminates has been observed with [00/±450/00] and [00/900/900/00] lay-up sequences compared to [0°]4 lay-up sequence which shows improvement in properties in wale-wise direction.

The picking periods and their combinations on fibre and yarn properties have been studied using MCU-5 variety of Indian cotton which was collected from four different locations at various picking periods. It is observed that the picking periods affect the fibre and yarn qualities. Better fibre and yarn can be achieved by excluding the fibres from the last few picking periods.

The effects of fibre dyeing, drying, opening and carding during milange yarn preparation on length and tensile properties of fibres have been studied using three different varieties of Indian cottons. namely S6, DCH32 and MCU5. It is observed that the dyeing, drying, opening and carding affect the fibre quality; the effect however varies with the fibre variety.