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Article

Alasdair Soja, Jun Li, Seamus Tredinnick and Tim Woodfield

Additive manufacturing (AM) has the potential to revolutionise the fabrication of complex surgical instruments. However, AM parts typically have a higher surface roughness…

Abstract

Purpose

Additive manufacturing (AM) has the potential to revolutionise the fabrication of complex surgical instruments. However, AM parts typically have a higher surface roughness compared to machined or fine cast parts. High surface roughness has important implications for surgical instruments, particularly in terms of cleanliness and aesthetic considerations. In this study, bulk surface finishing methods are described to produce end-use selective laser melting parts.

Design/methodology/approach

The aim was to achieve a surface finish as close as possible to machined parts (Ra = 0.9 µm, Wa = 0.2 µm, Pv = 7.3 µm). A sample coupon was designed to systematically evaluate different finishing techniques. Processes included bulk finishing, blasting and centrifugal finishing methods on individual parts, as well as heat treatment before and after surface finishing.

Findings

Abrasive blasting or centrifugal finishing alone was not adequate to achieve an end-use surface finish. White oxide vapour blasting at high water pressure was the most effective of the abrasive blasting processes. For centrifugal finishing, a 4 h runtime resulted in an acceptable reduction in surface roughness (Ra = 2.9 µm, Wa = 2.0 µm, Pv = 34.6 µm: inclined surface [30°]) while not significantly increasing part radii. The combination of finishing methods resulting in the smoothest surfaces was white oxide blasting followed by 4 h of centrifugal finishing and a final glass bead blast (Ra = 0.6 µm, Wa = 0.9 µm, Pv = 6.9 µm: inclined surface [30°]). The order of these methods was important because white oxide blasting was significantly less effective when applied after the centrifugal finishing.

Originality/value

Collectively, these results describe the development of a practical bulk finishing method for stainless steel surgical instruments produced by AM.

Details

Rapid Prototyping Journal, vol. 27 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

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Article

Jasgurpreet Singh Chohan, Rupinder Singh and Kamaljit Singh Boparai

This paper aims to focus on the changes in thermal and surface characteristics of acrylonitrile butadiene styrene (ABS) material when exposed to chemical vapours for…

Abstract

Purpose

This paper aims to focus on the changes in thermal and surface characteristics of acrylonitrile butadiene styrene (ABS) material when exposed to chemical vapours for surface finishing. The poor surface finish and the dimensional accuracy of the fused deposition modelling parts (of ABS material) because of the stair-stepping hinder their use for rapid tooling applications, which can be improved by vapour finishing process. The differential scanning calorimetry (DSC) tests are performed to investigate the thermal behaviour of ABS thermoplastic after vapour finishing.

Design/methodology/approach

The hip prosthesis replica has been used to highlight the efficacy of chemical finishing process for intricate and complex geometries. The replicas are treated with chemical vapours for different durations. The DSC tests are performed along with surface roughness, surface hardness and dimensional measurements of exposed replicas and compared with unexposed replica.

Findings

The longer finishing time, i.e. 20 s, manifested higher melting peak temperature, higher melting enthalpy and higher heat capacity along with smoother and harder surface as compared with unexposed replica. The finishing process enhanced the bonding strength and the heat-bearing capacity of ABS material. The vapour finishing process enhanced the thermal stability of the material which may extend its sustainability at higher temperatures.

Practical implications

The improved thermal stability of ABS thermoplastic after chemical vapour finishing has been demonstrated. This advancement allows the use of ABS in functional tooling suitable for small production runs with higher flexibility and lead time savings.

Originality/value

The heat effects associated with phase transitions as a function of temperature are studied in case of replicas finished with chemical vapours. The relationship between melting enthalpy and surface characteristics has been ascertained.

Details

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

Keywords

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Article

P. Mamalis, A. Andreopoulos and N. Spyrellis

Some of the basic mechanical characteristics such as tensile, bending, shear, compression, and surface properties of cotton knitted fabrics after a durable flame‐retardant…

Abstract

Some of the basic mechanical characteristics such as tensile, bending, shear, compression, and surface properties of cotton knitted fabrics after a durable flame‐retardant finishing, were studied by the objective‐evaluation method developed by Kawabata and Niva using the KES‐F system. In addition, properties such as bursting strength, drape and sewability were studied in order to further explore the influence of this treatment on the fabrics. All treated fabrics were flame‐retardant but their mechanical properties showed changes as a result of the above finishing. More specifically, a significant reduction in the bending and shear properties was recorded, which suggests that the flame‐retardant finishing primarily affects the above characteristics.

Details

International Journal of Clothing Science and Technology, vol. 13 no. 2
Type: Research Article
ISSN: 0955-6222

Keywords

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Article

Robert Bogue

The purpose of this paper is to provide a review of finishing robot technology and its applications.

Abstract

Purpose

The purpose of this paper is to provide a review of finishing robot technology and its applications.

Design/methodology/approach

The paper initially considers the development of automated finishing technologies and then discusses robotic systems. The uses of robotic finishing are illustrated through reference to a range of applications and case histories and a final section summarises the key benefits of the technology.

Findings

The paper shows that robotic finishing is being adopted by a range of industries including the aerospace, automotive, medical and household goods sectors. The technology has been shown to yield significant benefits, notably improved productivity, cost reductions, more consistent quality and reduced reject levels.

Originality/value

The paper provides a useful insight into robotic finishing and illustrates the key applications and benefits of the technology.

Details

Industrial Robot: An International Journal, vol. 36 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

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Article

Priyanka Gupta, Manas Datta Roy and Subrata Ghosh

This paper aims to assess the relationships amongst the tearing strength of fabrics after each chemical processing stage and after finishing of plain-woven cotton fabric…

Abstract

Purpose

This paper aims to assess the relationships amongst the tearing strength of fabrics after each chemical processing stage and after finishing of plain-woven cotton fabric. An effort has been made to study the effect of different finishing chemicals (tear improver) and their different concentrations on the high-density fabric tear strength and its sub-component with respect to the co-efficient of friction value of yarns for all the fabric samples. It also aims to establish a statistical model for prediction of tear strength with identified parameters as yarn–yarn friction co-efficient, yarn pullout force and single yarn strength.

Design/methodology/approach

In case of woven fabrics, it cannot be assumed that only yarn friction plays the role in deciding fabric-tearing strength. Whether the static or kinetic frictions need to be considered or the linear or capstan frictions have to be analyzed, to incorporate the results of friction analysis in the tearing behavior, need to be assessed. In the present work through a fabrication of yarn–yarn friction measurement, under a synchronized slow speed as that of actual fabric tearing (50 mm/min), has been carried out. After each wet processing stage, surface characteristics of yarns have been changed. Surface of yarns becomes smoother after finishing and rough after dyeing, which affects the co-efficient of friction of yarns, accordingly.

Findings

After each wet processing stage, the surface characteristics of yarns are changed. Surface structure of yarns becomes smooth after finishing and rough after dyeing, which affects the co-efficient of friction of yarns. For all the fabrics, the weft-way tearing strength is always higher than warp-way tearing strength. It is also observed that yarn pullout force is not the only responsible factor for tearing strength of such fabric. It is because of the combined action of yarn–yarn friction, yarn pullout force and single yarn strength for a given structure.

Research limitations/implications

A more extensive investigation with respect to concentration as well as further variety of chemicals requires to be identified for the optimum concentration level for each chemical. A mathematical model based on the three parameters as yarn–yarn co-efficient of friction, yarn pullout force and yarn strength for all woven fabric structure to achieve optimum strength level has been established which could be further extended for each fabric structures.

Practical implications

The problem has been identified from the day-to-day exercise of the commercial textile industry. The whole of the sample preparations have been done in the industry by using commercial machines under standard industrial conditions. The findings have been discussed and suitably introduced in the industry.

Originality/value

The whole of this paper has been unique in idea origination, sample preparation and execution of tests. The findings are very important for the researchers as well as for textile industry.

Details

Research Journal of Textile and Apparel, vol. 24 no. 3
Type: Research Article
ISSN: 1560-6074

Keywords

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Article

Wenlong Zhou, Yinqiao Bao and Maosong Li

Naturally colored cotton (NCC) based wovens are finished with 1,2,3,4-butanetetracarboxylic acid (BTCA), which is an environmentally friendly durable press (DP) finish

Abstract

Naturally colored cotton (NCC) based wovens are finished with 1,2,3,4-butanetetracarboxylic acid (BTCA), which is an environmentally friendly durable press (DP) finish. The colors of the NCC wovens before and after DP finishing are examined. The color fastnesses to home laundering and light irradiation are compared and evaluated. The DP finishing of BTCA has a negative effect on the color of NCC based fabrics. About 1/3 of the shade depth of the NCCs are decreased after a BTCA finishing. For both the fabrics with and without a DP finishing, home laundering results in evident color changes with decrease of shade depth. However, for probable crosslinking to pigments, a DP finishing could significantly improve the home laundering color fastness of NCCs. The performance of the color fastness to light after a BTCA finishing depends on the cotton breed. The BTCA finishing of the green NCC minimally improves the light fastness, while for the brown NCC, the color fastness to light decreases after the BTCA finishing.

Details

Research Journal of Textile and Apparel, vol. 13 no. 4
Type: Research Article
ISSN: 1560-6074

Keywords

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Article

Harlal S. Mali, Bhargav Prajwal, Divyanshu Gupta and Jai Kishan

The purpose of this paper is to study the integration between fused deposition modeling (FDM) technology and abrasive flow machining process to improve the surface quality…

Abstract

Purpose

The purpose of this paper is to study the integration between fused deposition modeling (FDM) technology and abrasive flow machining process to improve the surface quality of FDM printed parts. FDM process has some limitations in terms of accuracy and surface finish. Hence, post-processing operations are essential to increase the quality of the part.

Design/methodology/approach

Initially, a sustainable polymer abrasive gel-based media (SPAGM) using natural polymer and natural additives (waste vegetable oil) was prepared using different combinations of (abrasive mesh size, percentage of abrasives and percentage of liquid synthesizer); then the characterization of media was done to check various properties. As media is an essential part in the process which helps in increase the surface finish, it needs to have some desired characteristics such as the following: the developed SPAG needs to hold the abrasives; its viscosity has to be medium so that it can easily flow through the machine; and its thermal stability caused by the increase in the temperature during various cycles of operation. For that, it is characterized rheologically as well as thermally to find its various properties.

Findings

Experiments were performed on FDM-printed parts using an L9 orthogonal array with different parameters to find their effect on the workpiece. Scanning electron microscope images of SGAPM showed sharp edges of abrasive particles and bonding pattern between polymer chain molecules. Good surface finish and material removal rate (MRR) was observed at high pressure and long finishing time with 50 per cent abrasive concentration.

Originality/value

The authors confirm that this work is original and has neither been published elsewhere nor is it currently under consideration for publication elsewhere.

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Article

Iwona Frydrych and Małgorzata Matusiak

The purpose of this paper is to investigate the relationship between the formability of cotton and cotton/polyester woven fabrics and their selected properties: weft…

Abstract

Purpose

The purpose of this paper is to investigate the relationship between the formability of cotton and cotton/polyester woven fabrics and their selected properties: weft density, weave and a way of finishing. It shows how the mentioned properties influence fabric formability and analyze a statistical significance of investigated relationships.

Design/methodology/approach

In paper two groups of cotton and cotton/polyester woven fabrics of different structure and a way of finishing have been measured in the range of their basic structural properties as well as bending rigidity and initial Young’s modulus. Formability of investigated fabrics has been calculated on the basis of bending rigidity and initial Young’s modulus. Next, ANOVA has been performed in order to analyze the relationships between the weft density, weave and a way of finishing of woven fabrics and their formability.

Findings

The paper shows that all selected properties of woven fabrics significantly influence their formability as well as that there is statistically significant interaction between mentioned independent factors. It provides empirical results confirming that the influence of raw material composition of investigated cotton and cotton/polyester woven fabrics on the formability of fabrics is statistically insignificant.

Research limitations/implications

Results of investigations can be applied for cotton and cotton-like woven fabrics.

Practical implications

The paper includes implications for woven fabric engineering from the point of view of achieving the expected fabric formability.

Social implications

The results enables the choice of appropriate fabric for the given clothing.

Originality/value

This paper fulfills an identified need to study how the formability of woven fabrics can be shaped by an appropriate selection of their structure and a way of finishing.

Details

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

Keywords

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Article

Jasgurpreet Singh Chohan and Rupinder Singh

The purpose of this paper is to review the various pre-processing and post-processing approaches used to ameliorate the surface characteristics of fused deposition…

Abstract

Purpose

The purpose of this paper is to review the various pre-processing and post-processing approaches used to ameliorate the surface characteristics of fused deposition modelling (FDM)-based acrylonitrile butadiene styrene (ABS) prototypes. FDM being simple and versatile additive manufacturing technique has a calibre to comply with present need of tailor-made and cost-effective products with low cycle time. But the poor surface finish and dimensional accuracy are the primary hurdles ahead the implementation of FDM for rapid casting and tooling applications.

Design/methodology/approach

The consequences and scope of FDM pre-processing and post-processing parameters have been studied independently. The comprehensive study includes dominance, limitations, validity and reach of various techniques embraced to improve surface characteristics of ABS parts. The replicas of hip implant are fabricated by maintaining the optimum pre-processing parameters as reviewed, and a case study has been executed to evaluate the capability of vapour smoothing process to enhance surface finish.

Findings

The pre-processing techniques are quite deficient when different geometries are required to be manufactured within limited time and required range of surface finish and accuracy. The post-processing techniques of surface finishing, being effective disturbs the dimensional stability and mechanical strength of parts thus incapacitates them for specific applications. The major challenge for FDM is the development of precise, automatic and controlled mass finishing techniques with low cost and time.

Research limitations/implications

The research assessed the feasibility of vapour smoothing technique for surface finishing which can make consistent castings of customized implants at low cost and shorter lead times.

Originality/value

The extensive research regarding surface finish and dimensional accuracy of FDM parts has been collected, and inferences made by study have been used to fabricate replicas to further examine advanced finishing technique of vapour smoothing.

Details

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

Keywords

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Article

Pedram Parandoush, Palamandadige Fernando, Hao Zhang, Chang Ye, Junfeng Xiao, Meng Zhang and Dong Lin

Additively manufactured objects have layered structures, which means post processing is often required to achieve a desired surface finish. Furthermore, the additive…

Abstract

Purpose

Additively manufactured objects have layered structures, which means post processing is often required to achieve a desired surface finish. Furthermore, the additive nature of the process makes it less accurate than subtractive processes. Hence, additive manufacturing techniques could tremendously benefit from finishing processes to improve their geometric tolerance and surface finish.

Design/methodology/approach

Rotary ultrasonic machining (RUM) was chosen as a finishing operation for drilling additively manufactured carbon fiber reinforced polymer (CFRP) composites. Two distinct additive manufacturing methods of fused deposition modeling (FDM) and laser-assisted laminated object manufacturing (LA-LOM) were used to fabricate CFRP plates with continuous carbon fiber reinforcement. The influence of the feedrate, tool rotation speed and ultrasonic power of the RUM process parameters on the aforementioned quality characteristics revealed the feasibility of RUM process as a finishing operation for additive manufactured CFRP.

Findings

The quality of drilled holes in the CFRP plates fabricated via LA-LOM was supremely superior to the FDM counterparts with less pullout delamination, smoother surface and less burr formation. The strong interfacial bonding in LA-LOM proven to be superior to FDM was able to endure higher cutting force of the RUM process. The cutting force and cutting temperature overwhelmed the FDM parts and induced higher surface damage.

Originality/value

Overall, the present study demonstrates the feasibility of a hybrid additive and subtractive manufacturing method that could potentially reduce cost and waste of the CFRP production for industrial applications.

Details

Rapid Prototyping Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2546

Keywords

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