Synthesis and Characterization of Homo Polymer of Acrylate of Mixed Alcohols (Decyl,Dodecyl, and Myristyl Alcohol)—A Potential Pour Point Depressant for Lubricating Oils

Polymer of the acrylate of a mixture of three different alcohols, decyl alcohol, dodecyl alcohol, and myristyl alcohol, and the respective homopolymers, poly(decylacrylate), poly(dodecylacrylate), and poly(myristylacrylate), were synthesized, characterized, and evaluated for their performances (oil thickening and pour point depression property) as lube oil additive. The viscosity measurements of the synthesized polymers in the toluene solution at 313 K were performed and compared.     

Comparative analysis of in vitro ultraviolet radiation protection of fabrics woven from cotton and bamboo viscose yarns

Ultraviolet protection factor (UPF) of fabrics made of 100% cotton and 100% bamboo viscose yarns were studied and a comparative analysis carried out using curve fitting technique. Bamboo viscose fabrics showed higher shrinkage, cover percentage, areal density and UPF compared to its cotton counterpart woven with identical yarn counts and fabric sett. However, the predictive model of cotton fabric UPF using fabric areal density as the input was able to estimate the UPF of bamboo viscose fabrics with very good accuracy. Furthermore, the 100% cotton and 100% bamboo viscose fabrics showed the same UPF if their cover percentage and areal density is similar. It is inferred from the analysis that the apparently higher UPF of bamboo viscose fabrics can be attributed to their higher cover percentage and areal density instead of bamboo’s inherent UV protective property which has been claimed in various literatures.     

Study on thermal resistance of multilayered fabrics under different compressional loads

In this work, the thermal resistance of multilayered fabric ensembles meant for cold weather conditions were studied under different compressional loads. An instrument has been developed to study the thermal resistance of fabrics under different compressional loads. The instrument consists of a test plate, guard plates and a bottom plate. The test plate and guard plates were assembled together as a single entity, which can be moved up and down with a screw shaft. A load cell was connected to the plate assembly to apply the required compressional load on the fabric specimen. Thermal resistance of multilayered fabrics was studied in the developed instrument under different loading conditions. Single-jersey knitted fabric, needle punched fabric and polytetraflouroethylene (PTFE) coated fabrics were used in the inner, middle and outer layer, respectively. Twenty different multilayered fabric ensembles with the same inner and outer layers were studied. The middle layers, i.e. needle punched nonwoven fabrics, were produced from polyester hollow fibres, with varying linear density of fibre, mass per unit area and punch density. The thermal resistance of multilayered fabrics obtained from the developed instrument was compared with the thermal resistance of instruments, namely sweating guarded hot plate (SGHP) and Alambeta. Regression equations were developed and the contour plots were drawn to analyse the effect of the fibre, fabric and process parameters. ANOVAs were conducted to find the significance of the compressional load, linear density of fibre, mass per unit area and punch density on the thermal resistance of fabrics. It was found that the thermal resistance obtained from the instrument follows the same trend as that of thermal resistance obtained from SGHP and Alambeta. Mass per unit area was found to have significant effect on the thermal resistance of multilayered fabrics under different compressional loads. The effect of punch density decreases with the increase in compressional load on the thermal resistance of multilayered fabrics. The thermal conductivity of multilayered fabrics was observed to increase with the increase in the compressional load.     

Impact properties of thermoplastic composites

The excellent properties exhibited by thermoplastic composites at much reduced weight have attracted attention in the development of products in different sectors. Thermoplastic (TP) composites, because of their distinctive properties as well as ease of manufacturing, have emerged as a competitor against the conventional thermoset resin-based composites. Depending on the application, these composites may undergo impact events at various velocities and often fail in many complex modes. Hence, the development of TP composites having high energy-dissipation at (the desired) much-reduced weight has become a challenging task, but it is a problem which may be alleviated through the appropriate selection of materials and fabrication processes. Furthermore, fibre surface modification has been shown to increase fibre-matrix interfacial adhesion, which can lead to improved impact resistance. Textile preforms are helpful in acting as a structural backbone in the composites since they offer a relatively free hand to the composite designer to tailor its properties to suit a specific application. Additionally, hybrid textile composite structures may help in achieving the desired properties at much lower weight.

Simulation software can play a significant role in the evaluation of composites without damaging physical samples. Once the simulation result has been validated with actual experimental results, it should be possible to predict the test outcomes for different composites, with different characteristics, at different energy levels without conducting further physical tests. Various numerical models have been developed which have to be incorporated into these software tools for better prediction of the result.

In the current issue of Textile Progress, the effects of various materials and test parameters on impact behaviour are critically analyzed. The effect of incorporating high-performance fibres and natural fibres or their hybrid combination on the impact properties of TP composites are also discussed and the essential properties of TP polymers are briefly explained. The effects of fibre and matrix hybridization, environmental factors, various textile preform structures and fibre surface modification treatments on the impact properties of thermoplastic composites are examined in detail. Various numerical models used for impact analysis are discussed and the potential applications of TP composites in automobile, aerospace and medical sectors are highlighted.     

Modelling of yarn shrinkage due to washing

Yarn shrinkage due to washing is modelled using the idea of helical model of yarn. The derived theoretical relation between yarn shrinkage and yarn twist intensity is experimentally verified. It is proved that yarn shrinkage increases non-linearly with the increase in yarn twist intensity.     

Packing of micro-porous yarns: Part I. Optimization of yarn characteristics

The present paper deals with the factors affecting the packing of a micro-porous yarn, namely proportion of PVA fibre content, yarn twist multiplier (TM) and spindle speed at ring frame, and with their combined effect on various properties of the yarn. The micro-pores within the structure of the yarn have been created by dissolving the PVA fibres using washing treatment in hot water. A three-variable factorial design technique proposed by Box and Behnken is used to investigate the combined interaction effect of the above variables on the properties of the yarn. The present experiment variables, namely proportion of PVA fibre, yarn twist multiplier (TM) and spindle speed, were found to have significant impact on various properties of yarns before and after wash. For yarns before wash, the specific volume reduces with the increase in the PVA content, yarn twist and spindle speed. In the case of yarns after wash, there is reduction in the yarn specific volume with the increase in TM and spindle speed, but with the increase in the PVA percentage the yarn specific volume increases. The tenacity of yarns before wash increases with the increase in the PVA content, but for yarns after wash, the proportion of PVA content has comparatively less influence. The compressibility of yarns before wash reduces with the increase in the PVA content, but a reverse trend is observed in the case of yarns after wash. The design variables were optimized for all the yarn properties by using the response surface equations.     

Clothing comfort and yarn packing relationship: Part II – Transmission characteristics of fabrics

The effects of ring frame process parameters affecting the packing of yarn, namely yarn twist, spindle speed and draft at ring frame, on fabric transmission characteristic have been reported in the present paper. The detailed results on the yarn characteristics and low-stress mechanical properties, due to change of these ring frame parameters, have been reported in Part I of this series. It has been observed that there is very strong evidence that by changing the above ring frame process parameters, which affect the packing factor of yarn, the transmission characteristics of the fabrics can be manipulated. The yarn packing factor is directly related with the yarn diameter. All the studied ring frame process parameters have direct relationship with air permeability, thermal conductivity and relative water vapour permeability, i.e. with the increase in these ring frame parameters the above fabric transmission parameters increase, but water retention characteristics show opposite trend. Thermal absorptivity was found to be related with the fabric surface roughness.     

Study on spliced yarns of different spinning technologies. Part II: structural characteristics

A detailed study on structural parameters of splices of viscose staple fiber yarns made from ring, rotor, and air-jet spinning technologies are reported in this paper. All the yarns each had six different color tracers with 0.3% of total fibers. A three variable three-level factorial design approach proposed by Box and Behnken has been used to study the interactive effect of splicing parameters. The splicing parameters, such as splicing length, duration of splicing air blast, and splicing air pressure were varied to prepared spliced yarn samples. Splices were introduced at all these levels for the three different technologies. This paper deals with the structural characteristics of splice portions, i.e. splice diameter, helix angle, splicing coefficient of fiber (SCF), and fiber overlapping coefficient (FOC). The structural characteristics, such as splice diameter, helix angle, SCF, and FOC, are significantly affected by the different splicing parameters (i.e. splice length, duration of the opening air blast, and splicing air pressure). Different types of yarns (ring-, rotor-, and air-jet-spun) show different trends of structural characteristics with splicing parameters. Part I of this paper deals with the mechanical characteristics of spliced portion.     

Establishment of a stable Amaranthus tricolor callus line for production of food colorant

This study aimed at demonstrating the effects of fermentation time (24, 48, 72, 96, and 120 h) and water activity (0.943, 0.970, and 0.985) on the production of cellulolytic enzymes by solid-state fermentation of purple mombin (Spondias purpurea L.) residue using Aspergillus niger. The fermentation was carried out at 35°C and the enzyme production was measured as endoglucanase and total cellulose activities. The optimum condition for endoglucanase was water activity 0.974 and 93.8 h of fermentation, reaching a production of 3.21 U/g of residue; whereas for total cellulase it was 0.958 and 79.4 h achieving 12.1 U/g of residue. Fermentation time had a greater effect on the endoglucanase activity, while water activity had a more significant influence on the total cellulase activity. Endoglucanase had optimum activity at temperature of 50°C and pH 5.0. Although cellulase total optimum activity was also at pH 5.0, the maximum activity was at 60°C.     

Production of Vegetable Protein from Rapeseed Press-Cake Using Response Surface Methodology,Weighted Multivariate Index,and Desirability Function: A Way to Handle Correlated Multiple Responses

The majority of present day industrial processes/products are defined by several quality characteristics, for which the process variables need to be precisely modulated to meet the required specifications. Hence, the multi-response process optimization has become an increasingly important and demanding task. In practice, many of these quality characteristics under consideration show conflicts among themselves, which need to be simultaneously satisfied. This situation is aggravated when the quality characteristics show correlation. To remedy this shortfall, we present a novel multi-objective process optimization approach, based on weighted principal components (principal component scores weighted by their respective eigen values), response surface methodology and desirability function. The implementation of the suggested approach is presented on a study that discusses the optimization of light-colored and reduced phytate containing protein extraction process from rapeseed press-cake. The effectiveness of the said approach was confirmed by performing additional confirmatory experiments at the predicted optimal condition. Furthermore, this study suggests the feasibility of the exploitation of the waste oilseed cake for extraction of high quality vegetable protein, using viable process and simple computational procedure. This study also briefly highlights performance analyses in cross-flow batch extraction scheme using optimized condition.