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Article
Publication date: 10 August 2010

Gulcan Ozkan and Recep Eren

The purpose of this paper is to investigate warp and weft crimp distribution over the fabric width and how it is influenced by warp tension distribution over the warp width.

Abstract

Purpose

The purpose of this paper is to investigate warp and weft crimp distribution over the fabric width and how it is influenced by warp tension distribution over the warp width.

Design/methodology/approach

An experimental design in this research includes air jet loom, tension sensor, inductive sensor and personal computer.

Findings

It is found that warp crimp in the fabric on the loom is higher in the edge zones than the middle of the fabric and warp crimp in the middle is higher than warp crimp in edge zones of the grey fabric. Weft crimp in the edge zones is higher than in the middle of the grey fabric. The reason behind warp tension and warp and weft crimp variations over fabric width is that weft yarn slips towards inside fabric at selvedges and gets relaxed during beat up.

Originality/value

It is proved that reducing weft yarn slip and therefore weft yarn relaxation during beat up will reduce warp tension and warp and weft crimp variations and improve the uniformity of fabric properties over the fabric width.

Details

International Journal of Clothing Science and Technology, vol. 22 no. 4
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 1 June 2001

Darja Žunič‐Lojen and Jelka Geršak

The perfect interlacing of needle and bobbin thread in the stitch formation process and seam appearance depends first of all on correct pre‐tension of the tension

Abstract

The perfect interlacing of needle and bobbin thread in the stitch formation process and seam appearance depends first of all on correct pre‐tension of the tension regulator. Changes in the pre‐tension settings also have a direct influence on the tensile force during the sewing process. This contribution presents the influence of pre‐tension in a defined area on the tensile force in important phases of the stitch formation process. In addition the influence of the stitch velocity on tensile force was investigated. On the basis of statistic analysis it was ascertained in which pre‐tension area and stitch velocity the significant differences between tensile forces occurred.

Details

International Journal of Clothing Science and Technology, vol. 13 no. 3/4
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 1 March 1994

F.B.N. Ferreira, S.C. Harlock and P. Grosberg

A study of thread tensions on a lockstitch sewing machine was made, measuring simultaneously both the needle and bobbin thread tensions. Experiments were carried out under…

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Abstract

A study of thread tensions on a lockstitch sewing machine was made, measuring simultaneously both the needle and bobbin thread tensions. Experiments were carried out under specified sewing conditions, whereby needle and bobbin thread tensioner adjustment, sewing speed, number of plies, fabric quality and sewing thread quality were varied in order to investigate the effect of these factors on the needle and bobbin thread tensions. The patterns of the thread tension traces obtained were analysed as well as the effect of these factors on the peak tensions detected on both thread tension traces. Four significant peak tensions on the needle thread tension trace and two significant peak tensions on the bobbin thread tension trace were detected, during a stitch cycle. It was found that no significant variations occurred as far as the timing and shape of the peak tensions were concerned. However, variations were detected in the peak tensions according to the sewing conditions, as expected. From the analysis of the data obtained, multiple regression equations were derived to predict, with a good degree of accuracy, the peak tensions generated, according to the sewing conditions.

Details

International Journal of Clothing Science and Technology, vol. 6 no. 1
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 1 June 1952

W.A.P. Fisher, R.H. Cross and G.M. Norris

The prevention of fatigue in bolts by controlled pre‐tensioning is investigated theoretically. It is shown that the effect of pre‐tension is to reduce the alternating load…

Abstract

The prevention of fatigue in bolts by controlled pre‐tensioning is investigated theoretically. It is shown that the effect of pre‐tension is to reduce the alternating load in the bolt and that the stiffness of the fitting plays an important part in this reduction. Fatigue tests on ¾‐in. B.S.F. bolts with various amounts of pre‐tension show how this reduction in alternating load can prevent fatigue failure. A warning is given against relying on the benefits of pre‐tensioning without ensuring that pre‐tension is maintained in service.

Details

Aircraft Engineering and Aerospace Technology, vol. 24 no. 6
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 January 1995

Victor P. Janule

Formulators must control coating transfer and adhesion by developing formulations that perform well under widely varying application speeds and operating conditions. There…

Abstract

Formulators must control coating transfer and adhesion by developing formulations that perform well under widely varying application speeds and operating conditions. There are factors that can be controlled, and others that cannot be controlled. It is especially useful, and often essential, for the formulator to have an understanding of the principles and relationships of surface and interfacial tension, and surface energy or “wetting tension”. A review of these important principals and relationships, with a brief introduction to formulation variables sets the stage for introduction of an instrument that can easily measure the surface tension of coatings and the wetting tension of the surfaces or “substrates” to be coated.

Details

Pigment & Resin Technology, vol. 24 no. 1
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 August 2015

E.A.S.K. Fernando and T.S.S. Jayawardana

The tension variations across the width of the weaver's beam cause uneven tension in the fabric formation zone. As a result of the tension variation, the woven fabric…

Abstract

The tension variations across the width of the weaver's beam cause uneven tension in the fabric formation zone. As a result of the tension variation, the woven fabric tends to have fabric defects, such as non-uniform fabric density and differential dye take–up at various places on the fabric. As the warp ends are continuously subjected to varying tensions, warp breakage frequently occurs. As a result, the quality of the fabric produced suffers and there is reduced loom efficiency. However, uniformity in the fabric density is crucial, especially for technical and smart textiles. In this paper, the authors have attempted to model the varyingtensions across different segments of a warp sheet under a set of assumptions and derived a linear model. Furthermore, a prototype of an automatic tension control device is instrumentedwith two different positions which are located one meter apart and allows the tension variations across the warp-sheet to be practically observed. The measured average tension shows that variations in the internal tension on different segments of the warp-sheet can be minimized or even completely eliminated over time. With the implementation of a related experiment, the authors have shown the effectiveness of this automatic tension controller and its strong implications for the industry.

Details

Research Journal of Textile and Apparel, vol. 19 no. 3
Type: Research Article
ISSN: 1560-6074

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Article
Publication date: 1 June 2015

Xinjin Liu, Xuzhong Su and Hong Zhang

Spinning triangle is a critical region in the spinning process of staple yarn, which geometry influences the distribution of fiber tension and determines the qualities of…

Abstract

Purpose

Spinning triangle is a critical region in the spinning process of staple yarn, which geometry influences the distribution of fiber tension and determines the qualities of yarn directly. Therefore, the purpose of this paper is to investigate the fiber tension distribution at the twist point.

Design/methodology/approach

First, one theoretical model of fiber tension distributions at the twist point is given according to the motion law of fibers in the spinning triangle. Then, one calculation method of fiber tension at the twist point is given by two steps. First, the initial tension of each fiber at the front nip line caused by the yarn load should be calculated according to the models obtained based on the principle of minimum potential energy. Second, the fiber tensions at the twist point can be calculated using the obtained model in this paper. Finally, as an application of the proposed method, spinning triangles of a modified ring spinning system with a pair of offset device which can change the horizontal offset of the twist point to the symmetric axis of nip line of the spinning triangle continuously are studied. The fiber tension distributions are simulated numerically.

Findings

It is shown that the fiber tension distributions at the twist point can be determined by fiber feeding into and out the spinning triangle speed, the initial tension of each fiber at the front nip line, fiber tensile Young’s modulus and cross-sectional area, the number of fibers at spinning triangle and the individual fiber angle with the center fiber. The spinning experiment shows that taking appropriate right or left offset of the spinning triangle can help to improve the spun yarn qualities.

Originality/value

In this paper, the fiber tension distribution at the twist point is investigated. One theoretical model of fiber tension distributions at the twist point is given according to the motion law of fibers in the spinning triangle first. Then, one calculation method of fiber tension at the twist point has been given under the assumption that the initial tension of each fiber at the front nip line is caused by the yarn load.

Details

International Journal of Clothing Science and Technology, vol. 27 no. 3
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 30 August 2021

Lifeng Wang, Huijiang Qu, Longlong Sun, Ziwang Xiao, Long Liu and Sharf Shajib Ahmad

Due to the deformation between the pylon and the girder caused by single tension of cables, the previously tensioned steel strands have stress relaxation, resulting in the…

Abstract

Purpose

Due to the deformation between the pylon and the girder caused by single tension of cables, the previously tensioned steel strands have stress relaxation, resulting in the actual cable forces being less than the design cable forces. To compensate the stress loss caused by the single tension of cables, this paper aims to present a practical compensation algorithm of stress relaxation during the construction period.

Design/methodology/approach

From the perspective of the essential cause of the stress relaxation, finite element analysis is used to solve the tension control force of each steel strand after a rigorous theoretical formula derivation.

Findings

The deformation and tension control force of each steel strand decrease with the advance of the tension sequence, and the decline rate drops gradually. However, the calculated force values of the steel strand are in good agreement with the measured value as the cable length decreases.

Originality/value

The previous rough calculation methods for the tension force of steel strands cannot meet the accuracy, and the accurate calculation methods often include the solution of nonlinear equations, which complicate the calculating process. Otherwise, there are few studies on the compensation of stress loss by calculating the deformation of the steel strand during the tension process. So, it developed an accurate and efficient algorithm to determine the tension control forces.

Details

Multidiscipline Modeling in Materials and Structures, vol. 17 no. 6
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 7 September 2021

Wen Pan Fagerlin and Yueqi Wang

The purpose of this study is to map different kinds of tensions in product innovation and investigate how top managers use communication to shape subordinates' attention…

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1819

Abstract

Purpose

The purpose of this study is to map different kinds of tensions in product innovation and investigate how top managers use communication to shape subordinates' attention and thereby respond to these tensions.

Design/methodology/approach

This study adopted an embedded case study of four innovation centers within a Nordic multinational firm.

Findings

This study identifies three kinds of tensions that reside in product innovation, namely dilemma, paradox and trade-off. Further, this study reveals how joint attention (among top managers and subordinates) as a response to tensions can be achieved through different aggregates of top managers' communication efforts.

Originality/value

In opening the black box of tensions in product innovation and identifying multiple tensions, this study contributes to advancing the understanding of the attention-based view. Different from previous studies that simply consider communication as channels for information processing, the findings indicate that the contents and practices of communication can help top managers to shape subordinates' attention and thereby respond to tensions. This study also extends the research focus of attention from top managers to the whole organization, by revealing the importance of building a joint pattern of attention among top managers and subordinates.

Details

Baltic Journal of Management, vol. 16 no. 1
Type: Research Article
ISSN: 1746-5265

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Article
Publication date: 16 August 2021

Nobin Thomas, Rajesh Kaduba Mokale and Patturaja Selvaraj

Organizational scholars are intrigued about stakeholders who propose multiple and conflicting ideas about what is good for their organization. Such contradictions are…

Abstract

Purpose

Organizational scholars are intrigued about stakeholders who propose multiple and conflicting ideas about what is good for their organization. Such contradictions are called paradoxical tensions. Although researchers have singled these out for analysis, focusing only on individual tensions prevents scrutiny of multiple paradoxical tensions that simultaneously emerge and how effectively organizations can manage them. In complex environments – especially during an organizational restructuring – multiple and interrelated tensions occur. Therefore, the objective in this paper is to investigate how organizations create multiple paradoxical tensions and how the combined effect of such tensions can constrain organizations during restructuring. The authors thus aim to help managers think reflectively and to plan interventions to deal with issues arising from restructuring through the lens of paradox theory.

Design/methodology/approach

The authors adopted purposive sampling for an archival research-based case study of a major restructuring of a leading IT firm in India in the decade 2009–2019. This study focused on the types of paradoxes created and the response of the organization to these during the restructure. The authors identified key events using public documents and news reports from that decade. They drew on two sources of data: mainstream media coverage and third-party documents about the company. The latter included monographs and academic publications written by critics, business historians and design and management scholars.

Findings

The findings address the gaps in the literature about how reorganizing during a restructure shapes the contradictions that lead to tensions and coexisting conflicting dualities, creating paradoxes. This study provides the reader with deeper insights into belonging, organizing, learning and performing tensions – core to paradox theory – along with their short- and long-term implications for organizational restructuring. The study demonstrates organizational responses to paradox and its practical implications for managers. The paradoxical nature of cultural–structural tensions in Indian organizations continues to be researched but, by focusing on paradox theory, the authors have opened doors for future research.

Originality/value

Although there is no dispute that effective management of tensions can facilitate organizational performance, contradictory demands that lead to tensions have only intensified as organizational environments become more global, dynamic and competitive. Paradox theory is thus valuable for understanding tensions between equally valid principles, inferences and insights. Although this paper is based on a case study, the framework proposed here can form the basis for theoretical generalizability within certain limitations. Because organizations face similar paradoxical situations under competing demands during restructuring and because paradoxes are becoming increasingly prevalent in organizations, the authors expect their propositions to apply in other cases of restructuring. However, the authors would like to caution that the model developed here should be tested and refined in other contexts to more fully establish its validity and generalizability.

Details

Journal of Organizational Change Management, vol. 34 no. 5
Type: Research Article
ISSN: 0953-4814

Keywords

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