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Article
Publication date: 30 May 2008

Javier Munguía, Joaquim de Ciurana and Carles Riba

This paper seeks to present the results of a study carried out within rapid manufacturing (RM) service providers and engineering centres in Northern Spain. By disclosing…

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Abstract

Purpose

This paper seeks to present the results of a study carried out within rapid manufacturing (RM) service providers and engineering centres in Northern Spain. By disclosing strategies for their everyday operation, it is intended to show how the internal expertise acquired overtime copes with the lack of standards within this industry.

Design/methodology/approach

The study was deployed by means of a survey including four main issues: RM concepts, process planning, materials and costs. Questions range from general RM perceptions to specific production criteria like: layer thicknesses, laser power, quality assurance methods, etc. A special emphasis is made on cost parameters, since they play a major role when selecting the final manufacturing route.

Findings

The so‐called “de facto standards” were found to be widely used in order to minimize production risks for RM. The study also suggests the need for specific RM standards based on key issues like material recycling, process planning and costs assignment.

Practical implications

The study is mainly focused on additive RM processes used in Spanish centres. Although, some other technologies applied elsewhere might not be considered, it is assumed that most of the technologies mentioned in this study are available worldwide, thus providing valuable information to increase the general RM base of knowledge.

Originality/value

Unlike most of the RM literature based on benchmarking of processes to provide information, this paper shows first hand data from users and service providers, showing RM practices and preferences from a different approach.

Details

Rapid Prototyping Journal, vol. 14 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 2 January 2018

Isabel Bagudanch, María Luisa García-Romeu, Ines Ferrer and Joaquim Ciurana

The purpose of this paper is to demonstrate the feasibility of incremental sheet forming (ISF), using the most common variants, single-point incremental forming (SPIF) and…

Abstract

Purpose

The purpose of this paper is to demonstrate the feasibility of incremental sheet forming (ISF), using the most common variants, single-point incremental forming (SPIF) and two-point incremental forming (TPIF), to produce prototypes of customized cranial implants using a biocompatible polymer (ultrahigh molecular weight polyethylene, UHMWPE), ensuring an appropriate geometric accuracy and cost.

Design/methodology/approach

The cranial implant is designed based on computerized tomographies (CT) of the patient, converting them into a 3D model using the software InVesalius. To generate the toolpath for the forming operation computer-aided manufacturing (CAM) software is used. Once the cranial implant is manufactured, a 3D scanning system is used to determine the geometric deviation between the real part and the initial design.

Findings

The results corroborate that it is possible to successfully manufacture a customized cranial implant using ISF, being able to improve the geometric accuracy using the TPIF variant with a negative die.

Originality/value

This paper is one of the first research works in which a customized cranial implant is successfully manufactured using a flexible technology, ISF and a biocompatible polymer. The use of polymeric implants in cranioplasty is advantageous because of their lightweight, low heat conductivity and mechanical properties similar to bone. Furthermore, the cost of the implant has been calculated considering not only the raw materials and manufacturing time but also the environmental impact, revealing that it is a cheap process with a low lead-time.

Details

Rapid Prototyping Journal, vol. 24 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 14 January 2014

Evila L. Melgoza, Guillem Vallicrosa, Lidia Serenó, Joaquim Ciurana and Ciro A. Rodríguez

This work aims to present the design of a new continuous tool-path strategy for open-source low-cost fused deposition modeling (FDM) machines, such as Fab@Home or RepRap;…

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Abstract

Purpose

This work aims to present the design of a new continuous tool-path strategy for open-source low-cost fused deposition modeling (FDM) machines, such as Fab@Home or RepRap; and the development of an innovative integrated tool to design and fabricate customized tracheal stents with any FDM machine and six patient parameters. Both contributions were validated and implemented by obtaining a customized medical-grade silicone tracheal stent.

Design/methodology/approach

For the design of the new deposition strategy, a Python programming language was used. The new tool-path strategy was proposed as a continuous path to avoid drops and gaps and to improve the accuracy of the final model. Meanwhile, patient parameters were obtained by medical doctors and introduced into the innovative integrated system. On the one hand, one mold generated automatically, and viewed with Matlab® software, was fabricated with a Fab@Home machine, optimized with the continuous tool-path strategy. On the other hand, the same generated mold was viewed in SolidWorks/Excel software and was fabricated using a commercial FDM machine. Finally, the mold was filled with medical grade silicone, and a silicone tracheal stent was obtained.

Findings

Path planning for extrusion technologies is still a major concern, especially for open-source FDM machines. The results obtained in this work show the benefits of applying the newly developed continuous tool-path strategy to optimize the performance and efficiency of these machines. In addition, the proposed innovative integrated system allows the fabrication of customized tracheal stents rapidly and affordably.

Practical implications

The possibility of obtaining customized tracheal stents is a worthy challenge. Medical doctors could play a more active role and interact during the design process, helping to obtain more suitable stents. The method proposed herein would provide the opportunity to obtain real values from the trachea of a patient in the operating room and quickly fabricate a customized stent that would fit the patient's trachea perfectly.

Originality/value

The results obtained in this work are relevant and have future applications in both the medical and the additive manufacturing fields. The optimized tool-path strategy can help to improve and enhance the use of low-cost FDM machines. Moreover, the innovative automatic design approach to fabricate tracheal stents may open new market opportunities in the medical device field.

Details

Rapid Prototyping Journal, vol. 20 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 20 April 2015

Karla Monroy, Jordi Delgado, Lidia Sereno, Joaquim Ciurana and Nicolas J Hendrichs

Therefore, the purpose of this study is to understand the relationships between the processing parameters and the geometric form of the produced single tracks, in order to…

Abstract

Purpose

Therefore, the purpose of this study is to understand the relationships between the processing parameters and the geometric form of the produced single tracks, in order to control dimensional quality in future experimentations. The quality of the deposited single track and layer is of prime importance in the selective laser melting (SLM) process, as it affects the product quality in terms of dimensional precision and product performance.

Design/methodology/approach

In this paper, a vertical milling machining center equipped with an Ytterbium-fiber laser was used in the SLM experimentation to form single cobalt-chromium-molybdenum (CoCrMo) tracks. The different geometric features and the influence of the scanning parameters on these morphologic characteristics were studied statistically by means of ANOVA.

Findings

Evidently, track height (h1) inaccuracy reduced in layer thicknesses between 100 and 200 μm. The re-melt depth (h2) was determined by the energy parameters, with laser power of 325-350 W and scanning speed (SS) of 66.6-83.3 mm/s being the most favorable parameters to obtain the required anchoring. Moreover, a contact angle of 117° was proposed as optimal, as it permitted an adequate overlapping region and a full densification, and, finally, an SS of 50 mm/s and a layer thickness of 250 were suggested for its development.

Originality/value

The comprehension of the phenomena inherent to the process is related to the single track geometrical characteristics, which allow the definition of an optimal value for each factor for a further proposal of processing conditions that can finally derive a higher precision, wetting, density and mechanical properties.

Details

Rapid Prototyping Journal, vol. 21 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

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