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Performance assessment of lapinus–aramid based brake pad hybrid phenolic composites in friction braking

Singh T., Patnaik A.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 1

151--161

EN

The brake pad hybrid phenolic composites based on lapinus–aramid fibre combination are designed, fabricated and characterized for various physical, chemical, mechanical, thermo-mechanical and tribo-performance. The physical properties such as water absorption, compressibility, void and ash contents increase with increase in lapinus fibre, whereas mechanical (such as hardness, impact energy, tensile and flexural strengths) and thermo-mechanical (loss-tangent, storage and loss modulus) properties increase with increase in aramid fibre. The assessment of braking performance is done using a standard test protocol conforming to ECE R-90 regulation on the Krauss friction testing machine. Comprehensively, it is found that incorporation of higher metallic-silicate lapinus fibre in formulation relative to aramid enhances the overall frictional response. The same successfully arrests highest rise in the disc temperature even though wear losses are maximized. The same show lowest fading and excellent recovery performance. Optimally the formulation having lapinus-to-aramid proportion 25:5 experimentally optimizes the overall braking performance. The SEM micrograph study justifies the overall braking tribology and the associated wear mechanisms.

2

Reducing yarn hairiness in winding by means of jets: optimisation of jet parameters, yarn linear density and winding speed

Rengasamy R. S., Kothari V. K., Patnaik A., Ghosh A., Punekar H.

Autex Research Journal

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2005

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Vol. 5, no. 3

127--132

EN

Reducing yarn hairiness during yarn winding by the use of air jets is a new approach, since the production rate of winding is very high and the process itself increases yarn hairiness. The Box & Behnken factorial design approach has been used to optimise the jet angle, the jet diameter, yarn linear density and the winding speed in order to reduce the yarn hairiness. A jet angle of 450, a jet diameter of 2.2 mm, 10 tex yarn and a winding speed of 800 m/min give the optimal results in terms of reducing the hairiness. A CFD (computational fluid dynamics) model has been developed to simulate the airflow pattern inside the jets with the use of Fluent 6.1 software. The air velocity around the core of the jet is the influencing factor in wrapping the hairs on the yarn body.

3

Predictive models for strength of spun yarns: an overview

Ghosh A., Ishtiaque S., Rengasamy S., Mal P., Patnaik A.

Autex Research Journal

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2005

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Vol. 5, no. 1

20--29

EN

Over the past century or so, determining the predictive models of yarn strength has been the subject of a number of investigations, because yarn strength is a principle component of yarn quality. The aim of these models is to enable the yarn strength to be predicted from the properties of its component fibres as well as other parameters. The development of predictive modelling of yarn strength is always significant both in theory and in practice. In this article, a review of various predictive models of yarn strength is presented.

4

The mechanism of end breakage in ring spinning: a statistical model to predict the end break in ring spinning

Ghosh A., Ishtiaque S., Rengasamy S., Patnaik A.

Autex Research Journal

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2004

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Vol. 4, no. 1

19--24

EN

The mechanism of end breakage in ring spinning is a complex phenomenon, and is entirely different from the yarn failure mechanism during a tensile test. In this paper a possible mechanism of end breakage is reported. A statistical model is developed for predicting the likely end breakage rate in ring spinning. The important factors in governing end breaks are the mean yarn strength, yarn strength variation, mean value of the peak spinning tensions and the variation of yarn mass irregularity. Some practical aspects have also been discussed to tackle the problem of when the breakage rate suddenly increases.