Search results

1 – 10 of 701
Article
Publication date: 1 September 1978

S. Chandra and D.K. Jindal

Polycarbonate, a polymer having extremely useful properties, was incorporated in linseed and DCO alkyds of various oil lengths. Compatibility of polycarbonate and alkyds…

Abstract

Polycarbonate, a polymer having extremely useful properties, was incorporated in linseed and DCO alkyds of various oil lengths. Compatibility of polycarbonate and alkyds has been investigated. It was found that though polycarbonate was compatible with glyceryl phthalate, it was not compatible with alkyds (oil modified) in general. However, small amounts (4 to 10%) of the polycarbonate could be successfully blended with alkyds particularly with the short oil alkyds. Film properties of these blends were examined and compared with plain alkyds and epoxy modified alkyds in order to determine the usefulness of the polycarbonate‐alkyd blends. It was found that polycarbonate modified alkyds, even with such a small amount of polycarbonate, were superior in film characteristics to both the plain as well as epoxy modified alkyds.

Details

Pigment & Resin Technology, vol. 7 no. 9
Type: Research Article
ISSN: 0369-9420

Article
Publication date: 1 March 1979

J.K. Vinaik, S. Chandra and A.K. Vasishtha

Polycarbonate was incorporated in castor oil and nigerseed oil alkyds of various oil lengths. Compatibility of polycarbonate with these alkyds was investigated. It was…

Abstract

Polycarbonate was incorporated in castor oil and nigerseed oil alkyds of various oil lengths. Compatibility of polycarbonate with these alkyds was investigated. It was found that only a small amount (4 to 10%) of polycarbonate could successfully be blended with these alkyds. Film properties of these blends were examined and compared with those of amino alkyd blends, in order to determine the usefulness of the polycarbonate alkyd blends. It was observed that polycarbonate modified alkyds, even with a small amount of polycarbonate were superior in film properties as compared to amino modified alkyds, especially with respect to chemicals and physical properties.

Details

Pigment & Resin Technology, vol. 8 no. 3
Type: Research Article
ISSN: 0369-9420

Article
Publication date: 1 August 1971

GEORGE L. WISER

POLYCARBONATE can now be considered among the select group of aircraft transparent plastics and it has several key properties that make it attractive to the aircraft…

Abstract

POLYCARBONATE can now be considered among the select group of aircraft transparent plastics and it has several key properties that make it attractive to the aircraft designer particularly because of its impact resistance and good strength at elevated temperatures, raw material suppliers and other manufacturers have struggled to overcome the chemical and physical shortcomings of this material. Optics have been improved both in a ‘cleaning‐up’ of raw resin and the extrusion proces‐sing, and also through optical flattening by pressure polishing of the surfaces. By this latter means, thicknesses greater than the normal sheet extrusion capacity can be built up from thinner gauges by simply welding them together without the use of adhesives or solvents. To summarise: Major Advantages:

Details

Aircraft Engineering and Aerospace Technology, vol. 43 no. 8
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 18 September 2017

Kanwal Jeet Singh, Inderpreet Singh Ahuja and Jathinder Kapoor

The purpose of this paper, an original research paper, is to study the optimization of material removal rate (MRR) in ultrasonic machining of polycarbonate bulletproof…

227

Abstract

Purpose

The purpose of this paper, an original research paper, is to study the optimization of material removal rate (MRR) in ultrasonic machining of polycarbonate bulletproof glass and acrylic heat-resistant glass. The machining of these materials is a very tough job. There are so many constraints which need to be taken into account while machining, but without proper knowledge of material properties and machining parameters, machining is not possible. This paper gives basic knowledge about polycarbonate bulletproof and acrylic heat-resistant glass and provides ways as to how these types of materials are processed or machined.

Design/methodology/approach

The Taguchi method was utilized to optimize the ultrasonic machining parameters for drilling these advanced materials. The relationship between MRR and other controllable process parameters such as concentration of slurry, type of abrasive, abrasive grit size, power rating, concentration of HF acid and type of tool material has been analyzed by using the Taguchi approach.

Findings

Through the Taguchi analysis, it is concluded that types of abrasive and HF acid concentrations have a significant role to play in MRR for both materials; in which, type of abrasive have 72.91 and 72.96 percent contribution in MRR for polycarbonate bulletproof and acrylic heat-resistant glass, respectively. Similarly, HF acid concentration has 14.70 and 14.65 percent contribution in MRR for polycarbonate bulletproof and acrylic heat-resistant glass, respectively. The MRR was improved by 34.44 percent in polycarbonate bulletproof glass and 29.25 percent in acrylic heat-resistant glass.

Originality/value

After experimental investigation, the results of the Taguchi modal are validated.

Details

Multidiscipline Modeling in Materials and Structures, vol. 13 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 14 April 2014

Nevin Hill and Mehrdad Haghi

– The purpose of this study is to explore the dependence of material properties and failure criteria for fused deposition modeling (FDM) polycarbonate on raster orientation.

1483

Abstract

Purpose

The purpose of this study is to explore the dependence of material properties and failure criteria for fused deposition modeling (FDM) polycarbonate on raster orientation.

Design/methodology/approach

Tension, hardness and density measurements were conducted on a range of specimens at raster angles between 0 and 90° at 15° intervals. Specimens were manufactured so the raster angle was constant throughout each specimen (no rotation between adjacent layers). The yield strength, tensile strength, per cent elongation, elastic modulus, hardness and density of the material were measured as a function of raster angle. The orientation dependence of the properties was then analyzed and used to motivate a failure mechanism map for the material.

Findings

The properties of the material were found to be highly orientation-dependent. The variations in mechanical properties were explained to first order using a failure mechanism map similar to those generated for fiber-reinforced composites.

Originality/value

In addition to providing valuable experimental data for FDM polycarbonate, the study proposes micro-mechanisms of failure that appear to explain and capture the angular variation of strength with raster orientation. The fact that analysis methods which have been used for composites appear to apply to FDM materials suggests rich areas for future exploration.

Details

Rapid Prototyping Journal, vol. 20 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 16 August 2019

Sai Krishna Chitturi, A.A. Shaikh and Alpesh H. Makwana

A growing response in the development of hybrid composites to conquer the deficiency of neat composites has provoked doing this work. Thermoplastic Polycarbonate material…

Abstract

Purpose

A growing response in the development of hybrid composites to conquer the deficiency of neat composites has provoked doing this work. Thermoplastic Polycarbonate material offers better impact toughness with low structural weight. There is a little/no information available over the selected sandwich hybrid composite prepared from woven E-Glass and polycarbonate sheet. The purpose of this paper is to understand the response of the novel hybrid structure under tensile, flexural, interlaminar shear and impact loading conditions.

Design/methodology/approach

The hand-layup technique is used for fabricating the hybrid composites in the laminate configuration. The hybrid composites are prepared with a total fiber content of 70 percent weight fractions. The effect of the percentage of reinforcement on mechanical properties is evaluated experimentally as per American society for testing materials standard test methods. The damaged mechanisms of failed samples and fractured surfaces are well analyzed using vision measuring system and scanning electron microscopy.

Findings

A decline in densities of hybrid composites up to 22.5 percent is noticed with reference to neat composite. An increase in impact toughness up to 40.73 percent is marked for hybrid laminates owing to the ductile nature of PC. Delamination is identified to be the major mode of failure apart from fiber fracture/pull-out, matrix cracking in all the static loading conditions.

Originality/value

The response of novel hybrid composite reported has been explored for the first time in this paper. The outcome of experimental work revealed that hybridization offered lightweight structures with improved transverse impact toughness as compared to conventional composite.

Details

International Journal of Structural Integrity, vol. 11 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Case study
Publication date: 20 January 2017

Gal Raz, Tim Kraft and Allison Elias

This case is used in Darden's Supply-Chain Operations elective. The field-based case gives supply-chain educators the ability to teach the newsvendor model with pricing…

Abstract

This case is used in Darden's Supply-Chain Operations elective. The field-based case gives supply-chain educators the ability to teach the newsvendor model with pricing under a capacity constraint using real-life decisions. By 2005, Eastman Chemical Company, based in Tennessee, had created a new specialty plastic, Tritan, which demonstrated heat resistance and durability properties that might allow Eastman to compete in the lucrative polycarbonate plastics market. Development of this product was a major breakthrough for both Eastman and the broader chemical industry. The Eastman specialty plastics team had to contend with numerous challenges, however, before producing Tritan at full scale. First, Eastman had to commercialize a completely new material that only had been produced in the lab; second, the team had to develop a supply chain to manufacture a new component (monomer) and a new product (polymer) simultaneously; and finally, it had to analyze market entrance options given capacity constraints. Thus, the specialty plastics team faced several dilemmas: who should the initial launch partners be, given Eastman's limited manufacturing capacity, and how aggressively should Eastman price Tritan, given that price would drive demand in the launch markets and in new markets?

Details

Darden Business Publishing Cases, vol. no.
Type: Case Study
ISSN: 2474-7890
Published by: University of Virginia Darden School Foundation

Keywords

Article
Publication date: 11 June 2018

Francesco De Luca, Raimo Simson, Hendrik Voll and Jarek Kurnitski

Electric lighting accounts for a large share of energy consumption in commercial buildings. Utilization of daylight can significantly help to reduce the need for…

Abstract

Purpose

Electric lighting accounts for a large share of energy consumption in commercial buildings. Utilization of daylight can significantly help to reduce the need for artificial lighting, increase workers productivity, customers’ satisfaction and consequently improve sales. However, excessive use of glazing and absence of lighting controls can contribute greatly to higher energy need for heating and cooling and cause undesired glare effects. Thus, optimizing the size, position and materials of external glazing, with the addition of deflectors and dynamic artificial lighting, can become key aspects in the design of sustainable low energy buildings. The purpose of this paper is to analyze daylight potential and energy performance of a hall-type commercial building, situated in the cold climate of Finland, by utilizing different combinations of skylights, windows and lighting controls.

Design/methodology/approach

The authors have used computer simulations to estimate daylight and energy performance of a single floor commercial building in relation to various combinations of skylights and windows with variable glazing materials, light deflectors and zonal lighting controls.

Findings

The results show that electric light energy saving potential ranges from a negligible 1.9 percent to a significant 58.6 percent in the case of glass skylights and wall windows using multi-zone lighting control. Total delivered energy ranges between increase of 1.5 and 21.2 percent in the cases with single zone lighting control and between decrease of 4.5 percent and increase of 4.5 percent in the cases with multi-zone control. The highest decrease in primary energy consumption was 2.2 percent for single zone and 17.6 percent for multi-zone lighting control. The research underlines the significant potential of electric light energy savings using daylighting strategies that, including the control of direct solar access for glare and internal gains, can be more than 50 percent.

Originality/value

This research combines accurate daylight and energy assessment for commercial hall buildings based in cold climate region with multiple design variations. The novelty of this work is the consideration of interior elements, shelves and deflectors, in the calculations. This is made possible through the combined use of validated simulation platforms for detailed annual daylighting and electric lighting calculation (Radiance and Daysim) and energy analysis (IDA-ICE, Equa Simulation AB). This method allows to obtain a reliable assessment of the potential of using natural light sources in buildings.

Details

Management of Environmental Quality: An International Journal, vol. 29 no. 4
Type: Research Article
ISSN: 1477-7835

Keywords

Case study
Publication date: 5 April 2013

Allison Elias, Tim Kraft and Gal Raz

This case is used in Darden’s Supply-Chain Operations elective. The field-based case gives supply-chain educators the ability to teach the newsvendor model with pricing…

Abstract

This case is used in Darden’s Supply-Chain Operations elective. The field-based case gives supply-chain educators the ability to teach the newsvendor model with pricing under a capacity constraint using real-life decisions. By 2005, Eastman Chemical Company, based in Tennessee, had created a new specialty plastic, Tritan, which demonstrated heat resistance and durability properties that might allow Eastman to compete in the lucrative polycarbonate plastics market. Development of this product was a major breakthrough for both Eastman and the broader chemical industry. The Eastman specialty plastics team had to contend with numerous challenges, however, before producing Tritan at full scale. First, Eastman had to commercialize a completely new material that only had been produced in the lab; second, the team had to develop a supply chain to manufacture a new component (monomer) and a new product (polymer) simultaneously; and finally, it had to analyze market entrance options given capacity constraints. Thus, the specialty plastics team faced several dilemmas: who should the initial launch partners be, given Eastman’s limited manufacturing capacity, and how aggressively should Eastman price Tritan, given that price would drive demand in the launch markets and in new markets?

Details

Darden Business Publishing Cases, vol. no.
Type: Case Study
ISSN: 2474-7890
Published by: University of Virginia Darden School Foundation

Content available

Abstract

Details

Pigment & Resin Technology, vol. 36 no. 6
Type: Research Article
ISSN: 0369-9420

1 – 10 of 701