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Article
Publication date: 13 September 2011

V. Geža, A. Jakovičs, U. Krieger and B. Halbedel

The purpose of this paper is to investigate the outlet of a special glass melting system, which is used to control melt flow and modify flow pattern.

Abstract

Purpose

The purpose of this paper is to investigate the outlet of a special glass melting system, which is used to control melt flow and modify flow pattern.

Design/methodology/approach

Numerical calculations in ANSYS and ANSYS CFX were used to study electromagnetic, thermal, hydrodynamic and chemical mixing processes, results are validated by comparison with experimental data.

Findings

Obtained results show that investigated approach can improve glass melt chemical homogeneity significantly – Lorentz force driven melt movement in conjunction with diffusion process ensures good mixing quality.

Research limitations/implications

The mixing in glass melt is present only in azimuthal direction (in cylindrical coordinate system associated with outlet tube axis) but the radial homogenization is determined by diffusion only.

Practical implications

The experiments in JSJ GmbH with soda lime glass were successful and showed mixing effect in output material, thus providing additional method for glass production.

Originality/value

Although the electrical conductivity of glass is very low, the melt motion is generated by EM forces in this equipment, thus this approach is innovative in glass production technology where typical motion source is buoyancy or mechanical mixing.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 7 March 2008

Laetitia Jacoutot, Emilien Sauvage, Annie Gagnoud, Yves Fautrelle, Patrice Brun and Jacques Lacombe

This paper aims to report on a vitrification process based on direct induction that has been developed by the French Atomic Energy Commission (CEA, France). This process…

Abstract

Purpose

This paper aims to report on a vitrification process based on direct induction that has been developed by the French Atomic Energy Commission (CEA, France). This process is characterized by currents directly induced inside the molten glass and by the cooling of all the crucible walls. In addition, a mechanical stirring device is used to homogenize the molten glass. This paper presents a global modelling of coupled phenomena that take place within the glass bath.

Design/methodology/approach

Electromagnetic, thermal and hydrodynamic phenomena are modelled. The aim of this study is to develop strategy of coupled modelling between these aspects. The thermohydrodynamic calculations are achieved with the Fluent software (distributed by Fluent France) and the electromagnetic aspects are solved by the OPHELIE program based on integral methods (developed in EPM laboratory).

Findings

Two configurations are considered: the first deals with thermal convection in an unstirred bath and the second takes into account the mechanical stirring.

Research limitations/implications

The main limitation is that repartition of the Joule power density within the molten glass is supposed to be not perturbed by the intrusive elements like the thermocouples or the stirrer. This assumption allows us to perform only axisymmetric calculations of induction effect.

Originality/value

This paper present different strategy of coupling the thermohydrodynamic and direct induction phenomena taken place in the molten glass.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 27 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 August 1999

Jaroslav Mackerle

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the…

Abstract

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1977‐1998. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, ferrites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

Details

Engineering Computations, vol. 16 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 1 February 1987

N.M. Davey and F.W. Wiese

Silver‐glass die attach materials represent a significant advance in silicon packaging technology and are expected to displace gold‐silicon eutectic bonding as the…

Abstract

Silver‐glass die attach materials represent a significant advance in silicon packaging technology and are expected to displace gold‐silicon eutectic bonding as the preferred method of die attachment for high reliability applications. In this paper the rle of the glass in the adhesion mechanism of silver‐glass to gold and chromium/gold backed die has been determined using thermal analysis and X‐ray diffraction in addition to scanning electron microscopy and electron probe microanalysis of the sintered film. An adhesion mechanism is proposed in which the glass of the silver‐glass system migrates to the die interface during the firing cycle and chemically bonds to the silicon which is present at the surface of the gold‐silicon eutectic. Adhesion between the die back and the silver of the die attach material is by means of a simple mechanical bond between ‘fingers’ of glass and the sintered silver matrix. Thermodynamic and kinetic considerations suggest that insufficient silicon dioxide may be formed using chromium/gold backed die for acceptable adhesion. Processing changes are proposed which resolve this adhesion problem.

Details

Microelectronics International, vol. 4 no. 2
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 18 April 2017

Swee Leong Sing, Wai Yee Yeong, Florencia Edith Wiria, Bee Yen Tay, Ziqiang Zhao, Lin Zhao, Zhiling Tian and Shoufeng Yang

This paper aims to provide a review on the process of additive manufacturing of ceramic materials, focusing on partial and full melting of ceramic powder by a high-energy…

Abstract

Purpose

This paper aims to provide a review on the process of additive manufacturing of ceramic materials, focusing on partial and full melting of ceramic powder by a high-energy laser beam without the use of binders.

Design/methodology/approach

Selective laser sintering or melting (SLS/SLM) techniques are first introduced, followed by analysis of results from silica (SiO2), zirconia (ZrO2) and ceramic-reinforced metal matrix composites processed by direct laser sintering and melting.

Findings

At the current state of technology, it is still a challenge to fabricate dense ceramic components directly using SLS/SLM. Critical challenges encountered during direct laser melting of ceramic will be discussed, including deposition of ceramic powder layer, interaction between laser and powder particles, dynamic melting and consolidation mechanism of the process and the presence of residual stresses in ceramics processed via SLS/SLM.

Originality/value

Despite the challenges, SLS/SLM still has the potential in fabrication of ceramics. Additional research is needed to understand and establish the optimal interaction between the laser beam and ceramic powder bed for full density part fabrication. Looking into the future, other melting-based techniques for ceramic and composites are presented, along with their potential applications.

Details

Rapid Prototyping Journal, vol. 23 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

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Article
Publication date: 1 February 1987

B. Herod and D. Lusniak‐Wojcicka

Manufacturing of thin film potentiometers involves using very special substrates, usually with complicated shapes and explicit dimensional tolerance. Commonly, such…

Abstract

Manufacturing of thin film potentiometers involves using very special substrates, usually with complicated shapes and explicit dimensional tolerance. Commonly, such substrates should possess holes and recesses for assembling of the terminals as well as for mounting into housing. Particular difficulties are connected with the labour and time consumption necessary for forming of the molten glass, and limited utilisation of the glass substrates for potentiometer bodies. On the other hand, this material is the best one for the thin film elements. To solve these problems with the objective of producing inexpensive glass substrates for potentiometers, different tests were carried out with moulded elements made from glass powder. The aim of this research was the optimisation of a glass frit granulation and composition of the softening agent (plasticiser) as well as a choice of the temperature profile of firing of the moulded pieces to guarantee the precise structure of the substrate, essential for its application in thin film technology.

Details

Microelectronics International, vol. 4 no. 2
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 1 April 1986

J.M.A. Cesar de Sa

Application of the finite element method to the simulation of glass forming processes is described. The forming process results in a coupled thermal/mechanical problem…

Abstract

Application of the finite element method to the simulation of glass forming processes is described. The forming process results in a coupled thermal/mechanical problem with interaction between the heat transfer analysis of the temperature distribution in the glass and the viscous flow formulation describing the deformation of molten glass being a dominant factor. Particular attention must be given to derivation of the appropriate non‐linear thermal boundary conditions and also to monitoring of the mechanical contact between the glass and mould. The technique described provides both the glass and temperature distribution at each instant of the forming process and thus can provide invaluable information for mould and plunger design, optimum operation times, etc. Numerical examples are provided for both wide neck and narrow neck press and blow forming processes and the results obtained compare well with commercial observations.

Details

Engineering Computations, vol. 3 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 26 January 2010

Olavi Uusitalo and Toni Mikkola

The purpose of this paper is twofold. First and most importantly, the paper aims to explain how Pilkington is able to revolutionize the flat glass industry. The modified…

Abstract

Purpose

The purpose of this paper is twofold. First and most importantly, the paper aims to explain how Pilkington is able to revolutionize the flat glass industry. The modified design envelope model is applied to demonstrate the technological competence and especially strategic thinking concerning to understanding of the markets and positioning the product. Second, the paper demonstrates the entrepreneurship within a large‐scale manufacturing firm.

Design/methodology/approach

The paper applies a longitudinal, historical, and contextual approach. The paper uses multiple case study method and multiple data sources. This is done because creation of an innovation does not take place in vacuum, it is context bound.

Findings

The float glass fulfills the requirements of two industries: the plate and sheet glasses. Within both industries, short‐sighted competitors concentrate on technologies applicable only in other industry. Pilkington positions the float glass first clearly in the plate glass industry and after further development introduces the technology to sheet glass industry as a total surprise. Based on the case, the paper argues that positioning should be part of the corporate strategy.

Practical implications

In addition to complex systematic technologies, the example shows that the design envelope model is applicable also for simple non‐assembled products like flat glass. The model is useful for companies to build scenarios for responses if new unexpected innovations will be introduced in its own or related industries.

Originality/value

This paper offers a novel insight to the old but still viable case of dominant design. In addition, the thorough case description allows reader to go deeply into a classic example of process innovation.

Details

European Journal of Innovation Management, vol. 13 no. 1
Type: Research Article
ISSN: 1460-1060

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Article
Publication date: 1 November 1970

R.A. Nicholson

In the fabricating and finishing operations of glass, various lubricant type processing aids are employed to achieve the high production and quality which has…

Abstract

In the fabricating and finishing operations of glass, various lubricant type processing aids are employed to achieve the high production and quality which has characterized the mechanization and revolutionary progress in the glass industry since 1900.

Details

Industrial Lubrication and Tribology, vol. 22 no. 11
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 January 1998

M. Owen, E. Roelants and J. Van Puymbroeck

In the last two years, laser drilled microvias have become the dominant method for producing blind vias smaller than 150 mm, with over 100 laser drilling machines with a…

Abstract

In the last two years, laser drilled microvias have become the dominant method for producing blind vias smaller than 150 mm, with over 100 laser drilling machines with a variety of laser types installed worldwide. Only a few of these systems have been qualified for drilling blind holes in standard glass reinforced FR4. Details a production line at Siemens AUT LP in Karlsruhe, Germany, involving the successful evaluation, introduction, and full production of laser drilling of FR4/glass. An ESI 5100 with Ultraviolet Nd:YAG laser operating at 355nm was chosen for all copper structuring and all microvias less than 150 mm in diameter in thin materials, and a TEA CO2 laser was chosen for thicker constructions, where at least 250 mm holes were required. Production has been running since November 1996. Details the process modifications, design rules, qualified materials, reliability tests, and production experiences.

Details

Circuit World, vol. 24 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

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