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The essential properties of active sports fabrics are moisture management, quick-drying, body heat management and thermal regulations. Fibre type, blending nature, yarn and fabric structure and the finishing treatment are the key parameters that influenced the performance of the clothing meant for sportswear. This study aims to investigate the effect of fibre blending and structural tightness factors on bi-layer sport fabric's dimensional, moisture management and thermal properties.

In this study, 12 different bi-layer inter-lock fabrics were produced. Polyester filament (120 Denier) yarn was fed to form the backside of the fabric, and the face side was varied with cotton, modal, wool and soya spun yarns of 30sNe. Three different types of structural tightness factors were considered, such as low, medium and high were taken for sample development. The assessment towards dimensional, moisture management and thermal properties was carried out on all the samples.

The polyester-modal blend with a high tightness factor has shown maximum overall moisture management capability (OMMC) values of 0.73 and air permeability of 205.3 cm³/cm²/s. The same sample has shown comparatively higher thermal conductivity of 61.72 × 10^–3 W m^-1 °C^-1(Under compression state) and 58.45 × 10^–3 W m^-1 °C^-1 (under recovery state). In the case of surface roughness is concerned, polyester-modal blends have shown the lowest surface roughness, surface roughness amplitude and surface friction co-efficient. Among the selected fibre combinations, the overall comfort level of polyester-modal bi-layer knitted structure with a higher tightness factor is appreciable. Polyester-modal is more suitable for active sportswear among the four fiber blend combinations.

The outcome of this study will help to gain a better understanding of fibre blends, structural tightness factor and other process specifications for the development of bi-layer fabric for active sportswear applications. The dynamic functional testing methods (Moisture management and Thermal properties) were carried out to simulate the actual wearing environment of the sports clothing. This study will create a new scope of research opportunities in the field of bi-layer sports textiles.

This study was conducted to explore the influence of fibre blend and structural tightness factor on the comfort level of sportswear and to find the suitable fibre blend for active sportswear clothing.

The application of rinse cycle softener after the household laundry process has become more common in recent times. This study aims to understand the effect of repeated rinse cycle softener treatment on the mechanical and frictional properties of the cotton fabric.

Cotton-woven fabric is treated with commercial rinse cycle softener repeatedly for 15 times. After treatment, the fabric was evaluated for the changes in mechanical properties using the Kawabata evaluation system.

The results of this study revealed that the softener treatment reduces the tensile properties (41.25%) and increases the overall extensibility of the fabric up to 20.89%. The shear (34.57%) and bending rigidity of the treated fabric are reduced considerably than the untreated fabric (58.02%). The increment in the fabric softness and fluffiness was confirmed with the increment in the compression and the difference between the initial and final thickness at maximum pressure. Statistical significance (p < 0.05) is noted only in the case of bending and surface friction properties (dynamic friction).

The usage of rinse cycle softeners in the household laundry has a significant influence on the comfort characteristics of the cotton-woven fabric. Repeated usage of rinse cycle softener increased the fabric softness and fluffiness of the fabric and also reduced the tensile properties significantly.

The Nature of the Boundary Layer The changes of velocity in an air stream at points close to a surface past which it is flowing have been calculated by Blasius and von Karman for the surfaces of a thin plate placed edgewise to the stream; and they have also been directly measured by Fage and Falkner close to the surfaces of an aerofoil, by means of an arrangement of minute pitot tubes, down to distances of a few thousands of an inch from the surface.

Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Notes of the United States National Advisory Committee for Aeronautics and publications of other similar Research Bodies as issued

This paper aims to assess the relationships amongst the tearing strength of fabrics after each chemical processing stage and after finishing of plain-woven cotton fabric. An effort has been made to study the effect of different finishing chemicals (tear improver) and their different concentrations on the high-density fabric tear strength and its sub-component with respect to the co-efficient of friction value of yarns for all the fabric samples. It also aims to establish a statistical model for prediction of tear strength with identified parameters as yarn–yarn friction co-efficient, yarn pullout force and single yarn strength.

In case of woven fabrics, it cannot be assumed that only yarn friction plays the role in deciding fabric-tearing strength. Whether the static or kinetic frictions need to be considered or the linear or capstan frictions have to be analyzed, to incorporate the results of friction analysis in the tearing behavior, need to be assessed. In the present work through a fabrication of yarn–yarn friction measurement, under a synchronized slow speed as that of actual fabric tearing (50 mm/min), has been carried out. After each wet processing stage, surface characteristics of yarns have been changed. Surface of yarns becomes smoother after finishing and rough after dyeing, which affects the co-efficient of friction of yarns, accordingly.

After each wet processing stage, the surface characteristics of yarns are changed. Surface structure of yarns becomes smooth after finishing and rough after dyeing, which affects the co-efficient of friction of yarns. For all the fabrics, the weft-way tearing strength is always higher than warp-way tearing strength. It is also observed that yarn pullout force is not the only responsible factor for tearing strength of such fabric. It is because of the combined action of yarn–yarn friction, yarn pullout force and single yarn strength for a given structure.

A more extensive investigation with respect to concentration as well as further variety of chemicals requires to be identified for the optimum concentration level for each chemical. A mathematical model based on the three parameters as yarn–yarn co-efficient of friction, yarn pullout force and yarn strength for all woven fabric structure to achieve optimum strength level has been established which could be further extended for each fabric structures.

The problem has been identified from the day-to-day exercise of the commercial textile industry. The whole of the sample preparations have been done in the industry by using commercial machines under standard industrial conditions. The findings have been discussed and suitably introduced in the industry.

The whole of this paper has been unique in idea origination, sample preparation and execution of tests. The findings are very important for the researchers as well as for textile industry.

The purpose of this paper is to study the wear behavior of as‐cast (AC) and heat treated (HT) triple particle size (TPS) silicon carbide (SiC) reinforced aluminum alloy‐based metal matrix composites (SiC_p/Al‐MMC).

Al‐MMCs were prepared using 20 vol.% SiC reinforcement into aluminum metal matrix and developed using a stir casting process. Stir casting is a primary process of composite production whereby the reinforcement ingredient material is incorporated into the molten metal by stirring. The TPS composite consist of SiC of three different sizes viz., coarse, intermediate, and fine. The solution heat treatment was done on AC composite at 540°C for 4 h followed by precipitation treatment. The wear test was carried out using a pin‐on‐disc type tribo‐test machine under dry sliding condition. A mathematical analysis was also done for power factor values based on wear and friction results. The wear morphology of the damaged surface was also studied using optical microscope and scanning electron microscope (SEM) in this investigation.

The test results showed that HT composite exhibited better wear resistance properties compared to AC composite. It is anticipated that heat treatment could be an effective method of optimizing the wear resistance properties of the developed Al‐MMC material.

This paper provides a way to enhance the wear behavior of automotive tribo‐components such as brake rotor (disc and drum), brake pad, piston cylinder, etc.

This paper compares the wear behavior of AC and HT TPS reinforced Al‐MMC material under dry sliding condition.

In this study the microstructure and wear characteristics of Multilayer AlCrN coated AISI 410 stainless steel with the physical vapor deposition technique.

The friction and wear performance of the ML-AlCrN-coated AISI410 steel and uncoated AISI410 steel sliding against with high carbon steel were investigated by the ball cratering test at room temperature. The tribological characteristic of coated AISI410 steel was determined by applying constant sliding velocity of 0.3927 ms⁻¹ and total sliding distance of 353.43 m over various normal loads of 2, 3 and 4 N.

The AlCrN-coated AISI410 steel showed excellent wear performance up to 4 N load. The uncoated AISI410 steel showed good to acceptable wear resistance up to 2 N load. The wear tracks and worn surface were examined by scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDS) attachment for explaining the differences in wear mechanism.

The ability of coating to delay substrate oxidation, with an excellent wear resistance, was identified under different parameters on worn areas.

THE VERY TITLE of this talk is something which is always quite exciting to an Engineer—that is the thought of completely dry lubrication and the possibility of dispensing with such unpleasant necessitites as grease cups, nipples, oil sumps etc. Unfortunately, films of dry lubricants do have co‐efficients of friction and are therefore subject to wear, so the ideal of “life time lubrication” is still in the far and distant future. However new materials are constantly being discovered and/or developed which offer some technical advantage over the previous best, and as each of these materials comes to light it does mean that there are a few more engineering units that at one time were dependent on grease or fluid film lubrication that may now be dry lubricated. It is really the technical‐cum‐commercial development of dry lubricants that this paper discusses. For many years the use of Lamellar solids was limited to such materials as talcum, mica and graphite, the last being by far the most popular and possibly still the most widely used today. In more recent years, molybdenum disulphide has come very much to the fore, and because of certain technical advantages (which will be discussed later) will probably replace graphite if and when it becomes more economical to produce and if it in turn does not first become replaced by other lubricating solids such as boron nitride, tungsten disulphide and cadmium oxide. Of these “new” names in dry lubrication, tungsten disulphide looks very promising and has been selected as the third dry lubricant to discuss.

THE drag of a streamline body, such as an airship hull or an aeroplane fuselage, with its axis in the direction of the relative wind, is almost entirely due to skin friction. The drag component clue to surface pressure is, in general, small and relatively unimportant. Unfortunately, in the range of Reynolds numbers obtainable in most wind tunnels, the drag due to skin friction is abnormally sensitive to the degree of initial turbulence in the wind tunnel stream and to the shape of the model, particularly near the bow. Wind tunnel tests on models of airship hulls at a Reynolds number RL= U0L/v (where L is the length of the model and Uo the velocity in the free stream) of the order of 10° show wide variations in the values obtained for the drag coefficients of the same model in different wind tunnels or for different models in the same tunnel. At Reynolds numbers of about 4 × 108, appropriate to a full‐scale airship, it is impossible to carry out a reliable series of tests, but there is reason to believe that careful streamlining is not important and that a shape which is usually considered a “poor” streamline will have as low a resistance on the full scale as the shapes adopted for “R100” and “R101,” which, in the wind tunnel, appeared to be the best obtainable. From the structural point of view the “good” streamline shape proved to be a distinct disadvantage owing to the restricted gas volume in the bow and stem and the consequent lack of lift to balance the weights of fins and mooring gear, which produced increased bending moments throughout the ship.

Oil‐in‐water (O/W) emulsion has been used in industrial rolling mills for many decades, but its lubrication mechanism is still not adequately understood. There is a need to understand the role of chemical ingredients and emulsifier in lubrication and tribological characteristics of rolling oil. With this purpose, the authors selected three commercially available O/W emulsions of different generations and of known industrial performance. The aim is to understand the lubrication mechanism of these rolling oils and to correlate the laboratory findings with that of industrial rolling mills.

The lubrication mechanism has been studied with the help of an ultra thin film interferometry EHD test rig, an advanced experimental rolling mill and a Coulter LS 230 instrument. Film thickness, rolling parameters and droplet size were measured. The coefficient of friction was computed with the help of the measured values of rolling parameters. Emulsion stability and saponification value (SAP) of the selected emulsions were also determined. The results of film thickness, rolling parameters and droplet size have been presented. The lubrication mechanism of the emulsions has been explained on the basis of film thickness, droplet size, emulsion stability, SAP value and coefficient of friction.

Results of the present study reveal that chemistry of O/W emulsions plays an important role in their film forming and tribological behavior. Rolling emulsions of relatively low stability, higher droplet size and high SAP value are found to provide better lubrication and lower coefficient of friction. The results of the present study correlate well with the actual industrial experience except those obtained on EHD test rig.

Coulter LS 230 instrument was available with M/s LUBRIZOL CORP., USA. Only limited study on droplet size was carried. Although the study carried out has given good information but it would have been more practical if the emulsion samples taken from the experimental mill stand would have been studied for droplet size.

From understanding point of view of lubrication mechanism of O/W emulsion, it will be useful for oil technologists, tribologists and rolling mill users.

The study is original in nature and gives information on lubrication mechanism of O/W emulsions in steel cold rolling of steel strips.