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Article
Publication date: 1 June 2004

Abstract

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Assembly Automation, vol. 24 no. 2
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 20 October 2014

Xiang Ren, Qingwei Zhang, Kewei Liu, Ho-lung Li and Jack G. Zhou

The purpose of this paper is establishing a general mathematical model and theoretical design rules for 3D printing of biomaterials. Additive manufacturing of biomaterials…

Abstract

Purpose

The purpose of this paper is establishing a general mathematical model and theoretical design rules for 3D printing of biomaterials. Additive manufacturing of biomaterials provides many opportunities for fabrication of complex tissue structures, which are difficult to fabricate by traditional manufacturing methods. Related problems and research tasks are raised by the study on biomaterials’ 3D printing. Most researchers are interested in the materials studies; however, the corresponded additive manufacturing machine is facing some technical problems in printing user-prepared biomaterials. New biomaterials have uncertainty in physical properties, such as viscosity and surface tension coefficient. Therefore, the 3D printing process requires lots of trials to achieve proper printing parameters, such as printing layer thickness, maximum printing line distance and printing nozzle’s feeding speed; otherwise, the desired computer-aided design (CAD) file will not be printed successfully in 3D printing.

Design/methodology/approach

Most additive manufacturing machine for user-prepared bio-material use pneumatic valve dispensers or extruder as printing nozzle, because the air pressure activated valve can print many different materials, which have a wide range of viscosity. We studied the structure inside the pneumatic valve dispenser in our 3D heterogeneous printing machine, and established mathematical models for 3D printing CAD structure and fluid behaviors inside the dispenser during printing process.

Findings

Based on theoretical modeling, we found that the bio-material’s viscosity, surface tension coefficient and pneumatic valve dispenser’s dispensing step time will affect the final structure directly. We verified our mathematical model by printing of two kinds of self-prepared biomaterials, and the results supported our modeling and theoretical calculation.

Research limitations/implications

For a certain kinds of biomaterials, the mathematical model and design rules will have unique solutions to the functions and equations. Therefore, each biomaterial’s physical data should be collected and input to the model for specified solutions. However, for each user-made 3D printing machine, the core programming code can be modified to adjust the parameters, which follows our mathematical model and the related CAD design rules.

Originality

This study will provide a universal mathematical method to set up design rules for new user-prepared biomaterials in 3D printing of a CAD structure.

Details

Rapid Prototyping Journal, vol. 20 no. 6
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 1 December 1996

Jeff Beals

Points out that emerging designs of modules housing electronic components, such as engine control modules, are putting greater demands on dispensing and robotics…

Abstract

Points out that emerging designs of modules housing electronic components, such as engine control modules, are putting greater demands on dispensing and robotics equipment. Looks at the key issues of decreased gasket diameters, zero‐knit lines and speed of processing which are facing equipment suppliers.

Details

Assembly Automation, vol. 16 no. 4
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 1 February 2000

Steven C. Moore and Timothy J. Kurcz

Describes the rationale, purpose, and design of the Loctite Corporation One‐PassTM (patent pending) robotic flange cleaning system. Also details two complementary LoctiteTM

Abstract

Describes the rationale, purpose, and design of the Loctite Corporation One‐PassTM (patent pending) robotic flange cleaning system. Also details two complementary LoctiteTM formed‐in‐place (FIP) gasket sealant dispensing systems: AccuPump 1000 (a progressive cavity positive displacement pump for silicone and anaerobic FIP technology), and PressPakTM 1000 (patent pending) (a pumpless dispensing system for silicones, anaerobics, and high viscosity abrasive‐filled adhesives or solder pastes). Integrated with a high‐performance Loctite dispensing system, the One‐PassTM creates a highly robust, robotically controlled FIP flange‐sealing assembly process. This technology combination enables worldwide producers of engines, transmissions and axles to replace expensive molded gaskets with higher‐performing FIP adhesives and sealants at a fraction of the cost.

Details

Industrial Robot: An International Journal, vol. 27 no. 1
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 1 March 1997

Jeffrey Boyt Dalling

Claims that, although the use of adhesives in automated assembly is common, the use of structural adhesives is not so. Indeed, the use of structural adhesives can be…

Abstract

Claims that, although the use of adhesives in automated assembly is common, the use of structural adhesives is not so. Indeed, the use of structural adhesives can be termed a “new technology”. Offers advice on their use and concludes that the benefits outweigh the threat of failure.

Details

Assembly Automation, vol. 17 no. 1
Type: Research Article
ISSN: 0144-5154

Keywords

Content available
Article
Publication date: 3 July 2007

Abstract

Details

Soldering & Surface Mount Technology, vol. 19 no. 3
Type: Research Article
ISSN: 0954-0911

Content available
Article
Publication date: 25 September 2007

Abstract

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Soldering & Surface Mount Technology, vol. 19 no. 4
Type: Research Article
ISSN: 0954-0911

Content available
Article
Publication date: 13 September 2013

Abstract

Details

Soldering & Surface Mount Technology, vol. 25 no. 4
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 1 May 1960

PAUL RICHARDSON

SIMPLIFIED CONTROL OF THE MOTOR CAR has occupied the minds of designers ever since the earliest days of the industry. In the many attempts to make driving a car easier for…

Abstract

SIMPLIFIED CONTROL OF THE MOTOR CAR has occupied the minds of designers ever since the earliest days of the industry. In the many attempts to make driving a car easier for the man‐in‐the‐street, steam was one of the forms of propulsion used until the early ‘thirties’ but when the internal combustion engine finally won the day, efforts were concentrated on finding something better than the friction clutch and manually operated gearbox for use in conjunction with this type of engine. Before World War II several fully automatic transmissions for passenger cars had already been developed, especially in the U.S.A., and it was during this war that these transmissions found application in fighting vehicles. With the return of peace, motor manufacturers turned to fully automatic transmissions in a big way. It is hardly surprising, considering the generally advanced state of mechanisation in that country, that in the volume production of this type of transmission the U.S. again took the lead. Also, the large output of the domestic motor industry offered the best chances for a favourable return on the considerable capital investments inherent to volume production of complex transmission designs.

Details

Industrial Lubrication and Tribology, vol. 12 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 April 2005

Li Geng, Wei Feng, Dietmar W. Hutmacher, Yoke San Wong, Han Tong Loh and Jerry Y.H. Fuh

This paper aims to present a novel rapid prototyping (RP) fabrication methods and preliminary characterization for chitosan scaffolds.

Abstract

Purpose

This paper aims to present a novel rapid prototyping (RP) fabrication methods and preliminary characterization for chitosan scaffolds.

Design

A desktop rapid prototyping robot dispensing (RPBOD) system has been developed to fabricate scaffolds for tissue engineering (TE) applications. The system is a computer‐controlled four‐axis machine with a multiple‐dispenser head. Neutralization of the acetic acid by the sodium hydroxide results in a precipitate to form a gel‐like chitosan strand. The scaffold properties were characterized by scanning electron microscopy, porosity calculation and compression test. An example of fabrication of a freeform hydrogel scaffold is demonstrated. The required geometric data for the freeform scaffold were obtained from CT‐scan images and the dispensing path control data were converted form its volume model. The applications of the scaffolds are discussed based on its potential for TE.

Findings

It is shown that the RPBOD system can be interfaced with imaging techniques and computational modeling to produce scaffolds which can be customized in overall size and shape allowing tissue‐engineered grafts to be tailored to specific applications or even for individual patients.

Research limitations/implications

Important challenges for further research are the incorporation of growth factors, as well as cell seeding into the 3D dispensing plotting materials. Improvements regarding the mechanical properties of the scaffolds are also necessary.

Originality/value

One of the important aspects of TE is the design scaffolds. For customized TE, it is essential to be able to fabricate 3D scaffolds of various geometric shapes, in order to repair tissue defects. RP or solid free‐form fabrication techniques hold great promise for designing 3D customized scaffolds; yet traditional cell‐seeding techniques may not provide enough cell mass for larger constructs. This paper presents a novel attempt to fabricate 3D scaffolds, using hydrogels which in the future can be combined with cells.

Details

Rapid Prototyping Journal, vol. 11 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

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