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The need for companies to adopt a quality management strategy has significantly increased in recent times as a result of global competition and more demanding customers. It is important to integrate quality throughout the product lifecycle, which includes the design phase. The purpose of the paper is to develop a quality assurance framework for the local production of chemical-coated sand used in the Voxeljet VX1000 printing process. The framework could be used as a basic structure to develop the necessary processes, procedures, and work instructions to ensure the quality of local chemical-coated sand. Die behoefte van maatskappye om 'n gehaltebestuur strategie aan te neem het onlangs noemenswaardig toegeneem as gevolg van globale mededinging en meer veeleisende kliënte. Dit is belangrik om gehalte deurgaans met die produk lewensiklus te integreer, insluitend tydens die ontwerpfase. Die doel van hierdie artikel is die ontwikkeling van 'n gehalteversekeringsraamwerk vir die plaaslike produksie van chemies-bedekte sand wat in die Voxeljet VX1000 drukproses gebruik word. Die raamwerk kan gebruik word as die basiese struktuur om die noodsaaklike prosesse, prosedures en instruksies te ontwikkel om die gehalte van die plaaslik vervaardigde sand te verseker.

Existing techniques to manufacture conventional tool steel inserts for the plastic injection moulding process are expensive and time-consuming. Complex mould inserts, difficult to manufacture with conventional processes, can be produced using Direct Metal Laser Sintering (DMLS) with Maraging tool steel (MS1). MS1 is an additive manufacturing (AM) material made available by Electro Optical Systems (EOS) GmbH. Contrary to material removal processes, DMLS can produce MS1 tool steel inserts directly from Computer-Aided Design (CAD) files suitable for high volume plastic injection moulding. Through DMLS it is possible to create conformal cooling channels inside the MS1 inserts that have advantages in reducing heat rapidly and evenly. This can result in a reduction of cycle times, cost per product as well as improving part quality by eliminating defects such as warpage and heat sinks. This paper will present a comparison between Finite Element Analysis (FEA) simulations of the injection mould inserts with actual mould trails of AM and conventional manufactured inserts. It also includes the design and manufacturing of conventional and DMLS inserts and compares the manufacturing costs and lead times. Using FEA simulations, the design of conformal cooling channels is optimised by comparing the mould temperature of different cooling channel layouts Bestaande vervaardigingstegniek van matryse vir die plastiek - inspuit giet tegniek is duur en tydrowend. Ingewikkelde matrysinsetsels, wat moeilik is om met konvensionele pros esse te vervaardig, kan met direkte lasermetaalsintering (DMLS) met Maraging - staal (MS1) vervaardig word. MS1 is ʼn toevoegings - vervaardiging materiaal wat deur Electro Optical Systems (EOS) GmbH verskaf word. In teenstelling met materiaal verwyderings - pros esse (masji nering ), kan DMLS MS1 staal matryse of insetsels wat direk vanaf rekenaar gesteunde ontwerp prosesse vervaardig word. Dit maak dit geskik vir hoë volume produksie. Deur DMLS kan daar ook vir vorm getroue verkoelings kanale in matryse voorsiening ge maak word , wat tot die vinnige en eweredige verspreiding van hitte lei. Dit behoort tot ’n aansienlike verlaging in produksie - siklus tye en - koste te lei saam met ’n verbetering in die gehalte van die vervaardigde parte a s g evolg v an die voorkoming van defekte soos kromtrekking en hitte - putte. Hierdie artikel vergelyk ʼn eindige element analise van die insetsels wat met DMLS tegnieke en konvensionele tegnieke vervaardig is. Dit sluit ook die ontwerp en vervaardiging van konvensionele e n DMLS insetsels in en vergelyk vervaardigingskostes en leitye. Die ontwerp van vormgetroue verkoelingskanale word deur middel van eindige element analise optimeer deur die gietvorm temperatuur met verskillende verkoelingskanaaluitlegte te vergelyk

The Rapid Product Development Association of South Africa (RAPDASA) expressed the need for a national Additive Manufacturing Roadmap. Consequentially, the South African Department of Science and Technology commissioned the development of a South African Additive Manufacturing Technology Roadmap. This was intended to guide role-players in identifying business opportunities, addressing technology gaps, focusing development programmes, and informing investment decisions that would enable local companies and industry sectors to become global leaders in selected areas of additive manufacturing. The challenge remains now for South Africa to decide on an implementation approach that will maximize the impact in the shortest possible time. This article introduces the concept of a national Additive Manufacturing Centre of Competence (AMCoC) as a primary implementation vehicle for the roadmap. The support of the current leading players in additive manufacturing in South Africa for such a centre of competence is shared and their key roles are indicated. A summary of the investments that the leading players have already made in the focus areas of the AMCoC over the past two decades is given as confirmation of their commitment towards the advancement of the additive manufacturing technology. An exposition is given of how the AMCoC could indeed become the primary initiative for achieving the agreed national goals on additive manufacturing. The conclusion is that investment by public and private institutions in an AMCoC would be the next step towards ensuring South Africa's continued progress in the field. Die "Rapid Product Development Association of South Africa" (RAPDASA) het die behoefte aan 'n nasionale toevoegingsvervaardigingpadkaart uitgelig. Gevolglik het die Departement van Wetenskap en Tegnologie opdrag vir die ontwikkel van so 'n padkaart gegee. Hierdie was veronderstel om rolspelers te lei in die identifisering van besigheidsgeleenthede, die aanspreek van tegnologie tekortkominge, die fokus op ontwikkelingsprogramme en om beleggingsbesluite te beïnvloed wat plaaslike maatskappye en industrieë in staat sal stel om wêreldleiers op uitgekose areas van toevoegingsvervaardiging te word. Die uitdaging vir Suid-Afrika is nou op 'n toepassingsbenadering wat die maksimum impak in die kortste moontlike tyd sal verseker. Hierdie artikel stel die konsep van 'n nasionale Toevoegingsvervaardiging Sentrum van Bevoegdheid as 'n primêre toepassing van die padkaart voor. Die ondersteuning deur die hoof rolspelers in Suid-Afrika vir so 'n sentrum word gedeel en hulle onderskeie rolle is aangedui. Die rolspelers se toewyding word gestaaf aan die hand van hul beleggings in die fokus areas van die Sentrum oor die laaste twee dekades. 'n Uiteensetting word verskaf van hoe die Sentrum inderdaad die hoof inisiatief vir die behaal van die ooreengekome nasionale doelstellings kan word. Die gevolgtrekking is dat belegging deur die publieke en privaat instansies in so 'n sentrum die volgende stap tot die versekering van Suid-Afrika se voortgesette vordering in veld is.

South Africa had a late start with rapid prototyping (RP), with the first system being available in 1991. Up to 1994 only three systems were available in SA. Through active research participation from the CSIR and a number of universities, supported by technology transfer programmes and industry awareness workshops, adoption of RP technologies started to grow. Internationally, RP grew to the extent that several country-based member organizations were formed, and an initiation meeting of the Global Alliance of RP Associations (GARPA) took place during the SME Rapid Conference in Dearborn, USA in 1998. South Africa (SA) was invited under the auspices of the Time Compression Technologies Centre (TCTC) launched by the CSIR, and received an invitation to become a member of GARPA through the launch of a national, inclusive organization. The latter gave rise to a RAPDASA planning/launch meeting held at the University of Stellenbosch, which culminated in the first RAPDASA international conference held in November 2000 at the CSIR, and the election of a first RAPDASA management committee, also at the 1st AGM held during the conference. RAPDASA has been a pillar of strength since then, with an annual international conference being presented. As South Africa's RP awareness grew through the RAPDASA and independent activities, so did the availability of RP platforms in SA. SA also became a benchmark for other countries/late adopters to follow, as slowly a position of following became a position of leading through innovative applications. The paper highlights SA's development approach and history, together with the discussion of case studies in various fields. Contribution to the light metals industry will also be discussed.

Rapid prototyping models have often been used to facilitate customer evaluation and approval of design concepts. This paper presents a method known as customer interaction with functional prototypes (CIFP) aimed at enabling customers to make a more creative input into the new product development process. The basic premise is that the solid freeform fabrication (SFF) technologies used for rapid manufacturing also enable more representative prototypes that can be used for full and frequent customer interaction in the design process. This paper reports an extended investigation where CIFP was used successfully within a small company to introduce a new range of innovative motion analysis products.

PhD (Development and Management Engineering), North-West University, Potchefstroom Campus Additive Manufacturing (AM) which is also known as 3D printing technology; is a process by which digital 3-dimensional data is used to build up components or parts layer upon layer by depositing material. Additive manufacturing has been identified as a $21^{\text { st }}$ century emerging technology and is becoming popular within the academia and several industries globally. At present, Additive manufacturing has a wide variety of potential application areas such as automotive, aerospace, healthcare, electronics, manufacturing, education, tooling, food, construction, etc. In this era of Fourth Industrial Revolution, FIR, also known as 'Industry 4.0', additive manufacturing has been recognised as one of the nine technologies of industry 4.0 (i.e. Internet of Things, Big Data and Analytics, Cybersecurity, Cloud Computing, Simulation, Augmented Reality, Autonomous Robots, Additive Manufacturing and Horizontal and Vertical System Integration) that is expected to revolutionize different sectors and bring about a significant transformation in industrial production and manufacturing industries. South Africa is one of the active countries on the African continent promoting additive manufacturing technology, education and research both in the academia and industry. The South African government through the Department of Science and Technology has invested significantly towards research activities and growth of AM technology. As additive manufacturing technology is growing in South Africa, there is a need for more educated personnel and industry professionals in the field. In 2013, during a stakeholder workshops in South Africa, education was highlighted as one of the main priorities to ensure a successful adoption of AM technology in South Africa. The stakeholders include people from industry, government, higher education institutions, 3D printing service providers and R&D institutes. Additive manufacturing technologies are still at an infant stage and to reap the full potential of this technology, its inclusion in the educational curriculum is crucial. To achieve this, an effective framework for additive manufacturing education must be developed. Through a comprehensive literature survey, it was identified that there is no specific framework for additive manufacturing education at the universities worldwide; including South African universities as well. As part of South African Additive Manufacturing Strategy which is to ensure AM education at different educational levels; the development of a short, medium and long-term educational framework for AM was identified as one of the essential measures to achieve this. The research problem for this study is that "as several manufacturing and industrial sectors are adopting AM technologies in South Africa, there is a need for more university graduates, most especially in science and engineering with fundamental or in-depth knowledge of AM technology to work with the emerging AM sectors or 3D printing service bureau in South Africa. It is very important to develop an effective framework for AM education for South African universities that will further promote AM education among students, academia and industry's professionals". Therefore, this study focuses on "Additive Manufacturing Education" and aimed to investigate the impacts of AM technology at selected South African universities and thereafter, to propose a framework for effective additive manufacturing education using South African universities as the case study. The South African universities were selected because of the active presence of AM research group, AM/3D printing lab and well-equipped state-of-the-art AM in-house facilities for use of the students and academics. This study is expected to answer one main research question and four sub-research questions as rightly formulated and stated in the first chapter of the thesis. This study has been conducted using a case study research approach with the main data collected through a comprehensive structured questionnaire and followed by open-ended questions distributed among university students and academics. The questionnaire was carefully designed based on literature reviews. The factors/variables used were identified through a literature survey and were considered suitable in the development of a framework for additive manufacturing education and these factors includes - additive manufacturing technology, technology transfer, educational curriculum, in-house facilities and research and development (R&D). The first phase involved a pilot survey circulated among academics, AM experts and 3D printing service bureaus with the aim to complete the questionnaire and to provide significant feedback as relating to the closed-ended and open-ended questions in the questionnaire, hence, it assisted the researcher to improve the quality of the measuring instrument. The second phase involved the main data collection; and the questionnaires were circulated among students and academics across selected South African universities and appropriate hypotheses were also formulated. The third phase involved the statistical analysis, discussion and interpretation of the data. Finally, the framework for AM education was developed. The main contribution of this study towards the existing body of knowledge in additive manufacturing technology was in the form of a proposed framework for additive manufacturing education at the universities. The framework explains the main activities or factors that would ensure a successful AM education framework/implementation at the universities. The proposed framework would allow the government sectors/department/bodies and key players in AM in South Africa and abroad to see the need to invest significant towards the advancement of AM technology, education and research activities at the universities. Doctoral

MEng (Development and Management Engineering), North-West University, Potchefstroom Campus This study aims to determine the properties of polymer powders for laser sintering (LS) which are most desirable from a customer perspective. With multiple options of imported material being available, it is possible to directly compare different materials to each other. Historical usage data is available for two sintering materials, ie. PA2200 and PA2221. This data shows the demand for the different powders over time. Questioners will be used to further analyse the requirements of the VUT’s clients. The information gathered will be used to create a foundation for qualifying new and possible locally sourced materials for additive manufacturing operations in South Africa. Schmid, M. and Wegener, K. (2016) noted that AM is becoming a viable production technique, however there is a significant limitation on applicable materials. They also showed that only 1/200 000th of the quantity of polymer material sold globally is produced as LS powder. The possibility of localising this material has obvious financial and business model implications for South Africa, and will likely increase market penetration in the country by lowering the cost of AM parts. Producing polymer powders for export will also be a possibility if local testing is successful. Masters

PhD (Environmental Sciences), North-West University, Potchefstroom Campus Bone tissue engineering scaffolds fabricated by additive manufacturing can offer an alternative treatment option to currently used bone graft methodologies. Chitosan, a biocompatible and biodegradable naturally derived polymer, offers great promise as a biomaterial for tissue engineering applications. Chitosan scaffolds have previously been fabricated using additive manufacturing techniques, however, the use of crosslinkers, weak mechanical stability and structural resolution of fabricated scaffolds remain problematic. Therefore, in this study the researchers aimed to develop a biopolymer blend that can be used to fabricate scaffolds using a thermal printing technique that is suitable for bone tissue engineering applications. Additionally, the potential of this biopolymer blend as an antibacterial coating for titanium implants was investigated. In the present study chitosan was prepared using ascorbic acid blended with poly(vinyl acetate), a biocompatible synthetic polymer, to aid the printing process. Formulation optimisation was performed to establish optimal component (chitosan, poly(vinyl acetate) and ascorbic acid) ratios. Based on stability, chitosan with concentrations of 2%, 3% and 4%, prepared using 1% ascorbic acid and 1% poly(vinyl acetate) was selected (PVAc composite 2% CS, PVAc composite 3% CS and PVAc composite 4% CS). Surface morphology showed that PVAc composite 2% CS was non-porous, while the 3% and 4% chitosan counterparts were porous. All three PVAc composite films were biodegradable and showed sufficient swelling properties. Biocompatibility was evaluated by means of an indirect cytocompatibility assay, using two different cell lines: human gingival fibroblast and human foetal osteoblast cells. Cell viability for all PVAc composite films exceeded 90%, surpassing the ISO 10993 standard of 70% cell viability for a biomedical device to be considered safe. The biocompatibility of PVAc composite films was also confirmed through cell morphology and cell attachment studies. AM simulation demonstrated the printability of PVAc composite 3% CS and PVAc composite 4% CS hydrogels. These hydrogels were directly printed using a moderate temperature (± 95°C), well below the decomposition temperature of chitosan. Layered scaffolds were fabricated, and ultrastructural surface morphology showed porous scaffolds. PVAc composite hydrogels showed antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, the two bacterial strains most commonly associated with implant-related infections, as wells as gram-negative Escherichia coli. These antibacterial properties present in the hydrogels may prove to be beneficial when used as a coating agent for titanium implants or as a scaffold to prevent bacterial growth. As a proof of concept, PVAc composite hydrogels were used to coat porous titanium discs using dip-coating method. Results indicated that the hydrogels successfully coated the titanium discs with varying surface coverage and thickness. Although coating was not optimal for these titanium discs, the obtained results showed the potential of these hydrogels as antibacterial coatings for medical implants. The present study set the foundation for future work in developing a patient-specific scaffold that can be used as a biomedical implant to overcome the limitations and disadvantages accompanying bone grafting treatments. Doctoral

MSc (Occupational Hygiene), North-West University, Potchefstroom Campus Background: In the additive manufacturing (AM) industry there is very little information available regarding the area emission of and personal exposure to HCSs [particulates, metals and volatile organic compounds (VOCs)] during selective laser sintering (SLS), utilising nylon and alumide. It is possible that HCSs are emitted into the air during the pre-processing, processing and post-processing activities, which could lead to respiratory exposure, followed by the development of adverse health effects. Aims: To determine the physical and chemical composition of both virgin (new) and used nylon and alumide. In addition, the aim was also to determine the area emission of and personal respiratory exposure to HCSs that take place during SLS utilising nylon and alumide powder. Methodology: The physical and chemical composition of virgin and used nylon [nylon-12 (PA2200)] and alumide was determined with particle size distribution (PSD), scanning electron microscopy (SEM) and X-ray fluorescence (XRF) analysis. Area emission of particle size fractions 0.01 μm to > 1μm was determined with a TSI Model 3007 Condensation Particle Counter (CPC) (TSI Inc., Shoreview, Minnesota, USA), while the area emission concentration with a particle size range of 0.3 – 10 μm was determined with a TSI AeroTrakTM Airborne Particle Counter (APC) (TSI Inc., Shoreview, Minnesota, USA). National Institute for Occupational Safety and Health (NIOSH) Methods 0500 and 7300 were used to determine the area emission of and personal exposure to inhalable and respirable sized nylon and alumide dust. A Gillian Gilair Plus sampling pump (Sensidyne, Clearwater, Florida, USA) was calibrated to a flow of 2 L/min and connected to an Institute of Occupational Medicine (IOM) sampler to determine the inhalable and respirable sized nylon and alumide dust. Personal Nanoparticle Respiratory Deposition (NRD) samplers were connected to Gillian Gilair sampling pump calibrated to a flow of 2.5 L/min to determine the personal exposure of AM operators to particles < 300 nm. Traceair VOC badges were used to determine the area emission of and personal exposure to VOCs during all three phases of SLS utilising nylon and alumide. Results: PSD results indicated that all virgin and used nylon and alumide fell into the inhalable particle size range (63.85 - 65.30 μm) and that the measured PSD differed from the particle sizes listed in the Material Data Sheets (56 μm – 60 μm). There were no statistical significant differences (p < 0.05) found between the volume weighted mean particle sizes of virgin (new) and used nylon and alumide powders. The SEM analyses also confirmed that there were no visible differences in the size and shape between virgin and used nylon and alumide. XRF analyses found that virgin powders consisted of 39% of aluminium (Al), while used powders consisted of 51% of Al. An increase in particle number concentration was identified during all three phases of AM, when compared to the corresponding ambient readings. An increase in particle number concentrations were identified for specific activities, such as machine cleaning, powder mixing, machine warm-up, build removal and removal of excess powders from the build. For all APC results, the 0.30 μm particle size fraction indicated the highest concentration compared to 0.5, 1, 3, 5 and 10 μm. During gravimetric area emission sampling of SLS utilising nylon over an entire shift, low concentrations of inhalable and respirable sized dust was detected, while the results for SLS using alumide was below the detection limit. The personal exposure results indicated that the highest concentration of exposure to inhalable sized nylon and alumide dust took place during the post-processing activities (5.52 mg/m3 and 5.32 mg/m3). The personal exposure to respirable sized nylon and alumide dust only took place during post-processing activities (0.18 mg/m3 and 0.59 mg/m3). All personal particulate exposures were below the respective OELs for total inhalable and respirable dust. Small concentrations of particles < 300 nm were also detected during SLS using alumide. Aluminium (Al), iron (Fe), titanium (Ti) and zinc (Zn) were metals found in personal and area samples during SLS with alumide. Acetone, pentane, chloroform, toluene and naphthas were the VOCs detected during area emission and personal exposure during SLS utilising nylon and alumide. All personal exposures to VOCs were well below respective OELs. Conclusions: This study confirmed that HCSs (particulates, metals and VOCs) are emitted into the workplace atmosphere during SLS with nylon and alumide. However, the concentration HCSs emitted were very low according to standards. AM operators experienced personal exposure to these HCSs (particulates, metals, and VOCs) during this process, especially during post-processing. It was recommended that a portable local extraction ventilation (LEV) system should be used, especially for manual handling of powders during pre- and post-processing activities to be able to capture particles before they become airborne. Isolation of machines were also recommended to minimise the concentration of particles emitted. Cleaning protocols and personal hygiene measures are two important administrative control measures which should be revised. Masters

MEng (Development and Management), North-West University, Potchefstroom Campus The importance of South Africa's foundry industry cannot be overemphasized as it contributes towards the economic development of the country. It has been reported that the local foundry industry has been under severe pressure in previous years owing to very low economic growth, drought and continuing import leakage. The Vaal University of Technology positioned itself to provide cutting edge services to the foundry industry that are aimed to assist local foundries to become more competitive on a global scale. The services offered include casting simulation and printing of moulds and cores. The moulds and cores are printed with a Voxeljet VX1000 machine that uses a binder jetting process. The local manufacturing of moulds and cores for the foundry industry, using binder jetting additive manufacturing technology, is still considered to be expensive. The high manufacturing cost can be directly linked to expensive printing material, supplied by the OEM. A possible solution to mitigate the printing cost could be to localise the chemical coated sand used in the Voxeljet 3D printing process. However, this poses a risk to the quality of the printed components, as no quality assurance measures, for chemical coated sand, are available. Due to this reason, a quality assurance framework for the chemical coating process had to be examined. This study investigated the evolution and meaning of "quality" and defined quality assurance as processes, procedures and work instructions, which are used to ensure a repeatable product or service that adheres to a desired quality standard. The quality by design methodology was identified as a suitable methodology to aid with the development of the quality assurance framework that could be used to ensure the quality of the chemical coated sand. The methodology consisted of 8 sequential steps that were used to determine the quality target product profile, critical quality attributes, process flow diagram, critical process parameters and material attributes, quality risk assessment, design space, control strategy and continuous improvement strategy of the chemical coating process. These components serve as the QA framework that could be used as a basic structure or guideline for the development of processes, procedures or work instructions. Masters

PhD (Occupational Hygiene), North-West University, Potchefstroom Campus Background: Additive Manufacturing (AM) is the process of joining feedstock materials one layer at a time in order to produce objects from a three dimensional (3D) computer aided design (CAD). Powder bed fusion (PBF) and direct energy deposition (DED) are two widely applied powder based metal AM processes used commercially in the South African AM industry. A number of studies have investigated small desktop polymer material extrusion fused deposition modelling (FDMTM) 3D printers and found that these printers are high emitters of particulate matter and volatile organic compounds. Chamber studies have been of value by contributing to a better understanding of emissions from FDMTM desktop printers. However, despite the numerous studies on particulate matter emissions from desktop FDMTM printers there is an unbridged gap to identify the hazardous chemical substance emissions from and the respiratory exposure of AM operators when utilising metal powders in AM. AM processes takes place in three distinct phases, namely the pre-processing, processing and post-processing phases, and occupational exposure may occur during each of these three phases since most tasks are manually performed by the AM operator. To date only one study has investigated particle emissions from and exposure to metals during PBF while there is no published literature on emissions or exposure from DED. PBF and DED are applied in South Africa and therefore, the investigation of particle emissions from and personal exposure of AM operators to hazardous chemical substances (metals) is needed. Aims and objectives: The general research aim of this thesis was to assess the emissions of and occupational exposure to hazardous chemical substances (particles and metals) associated with two metal powder based AM process categories (powder bed fusion and direct energy deposition) at three South African institutions utilising AM. The specific objectives were: (i) to establish the physico-chemical characteristics (particle size, shape and elemental composition) of virgin and used metal powders, used during powder bed fusion and direct energy deposition, and the relevance thereof to AM operators’ health. (ii) to assess particle emissions and respiratory metal exposure of AM operators when using three titanium powders and maraging steel during the pre- processing, processing and post-processing phases of AM at three AM facilities utilising PBF. (iii) to assess particle emissions and respiratory metal exposure of AM operators when using two stainless steel powders during DED at an AM facility. Methods: Samples of virgin and used (recycled) titanium and maraging steel as well as used stainless steel powders, along with their respective safety data sheets (SDSs) were collected from three AM facilities in South Africa utilising PBF and DED. Powder samples were characterised in terms of particle size distribution (PSD), particle shape and elemental composition. Real time monitoring devices, namely a Condensation Particle Counter (0.01 to > 1 μm) and an Airborne Particle Counter (0.30 to 10.00 μm) were used to investigate particle emissions [particle number concentrations (p/m3)] during PBF and DED process phases. The concentration of metals in the workplace air was established by means of static area monitoring according to the National Institute for Occupational Safety and Health (NIOSH) 7300 method using a closed-faced cassette (CFC). Personal (AM operator) respiratory exposure to metals used the same NIOSH method. Ethics approval for this study was obtained from the Health Research Ethics Committee of the North-West University (NWU-00004-16-A1). Researchers followed well know occupational hygiene methods, and other state of the art methods nor currently used in occupational hygiene compliance monitoring. Personal exposure to metals < 300 nm in size was assessed by using a nanoparticle respiratory deposition sampler. Results: Only one of the three titanium powers PSD was in accordance with the SDS. From the SEM images, thoracic sized (< 10 μm) and respirable sized (< 4 μm) particles were observed in powders from all three facilities. The elemental composition analysis (XRD analysis) of the investigated powders differed from the composition stated in the respective SDSs. Particles ≤ 1 μm were present in the workplace air. Increases in particle number concentrations were observed during specific pre- and post-processing tasks such as cleaning and powder sieving which led to an increase in particle emissions with the highest particle number concentration of 6.12 x 1010 p/m3 (0.01 to > 1 μm) measured during the post-processing phase of PBF with titanium. Tasks such as unloading of the AM machines led to particle concentrations (0.01 to > 1 μm) as high as 5.98 x 1010 p/m3 during PBF with maraging steel and 5.75 x 1010 p/m3 during DED of stainless steel. Static area monitoring indicated low concentrations of metals in the work place atmosphere during PBF and DED. During both PBF and DED, AM operators were exposed to detectable concentrations of metals including aluminium, chromium, copper, iron, nickel, titanium and vanadium, including metals < 300 nm in size. Full shift metal exposure was calculated for comparisons with occupational exposure limits (OELs) of all detected metals. AM operators’ personal respiratory exposure was < 1.04% of the time weighted average OELs (TWA-OELs) when using titanium powders, and < 3.60% of the respective TWA-OELs and < 9.01% of threshold limit value (TLVs®) during the use of maraging steel. Exposure to Ni, a human carcinogen, was the highest. Conclusion: There is a shortage of studies reporting particle emissions from and AM operators’ respiratory exposure to metals resulting from use of titanium and metals powders used in PBF and DED. Inadequate information in the SDSs may mislead employers and AM operators’ regarding the protection of AM operator health, and therefore, powder characterisation should form an integral part of risk assessments at each facility. During the pre-and post-processing phases of PBF and DED, particles were emitted during phase specific tasks such as cleaning, sieving, and unloading of the AM machine. When particle number concentrations during the processing phase from PBF and DED were compared to FDM™ printers, it was found that particle number concentrations emitted from FDMs™ were approximately five to nine times higher. The maximum particle number concentrations emitted from DED were 3% lower than that of PBF. Low concentrations of metals were present in the workplace atmosphere throughout the use of titanium, maraging steel and stainless steel powders. Although no OELs were exceeded, AM operators were exposed to detectable concentrations of metals, including metals < 300 nm in size. The findings of this study serve as a starting point to create awareness of AM operator exposure associated with metal AM, and to assist industrial AM facilities in identifying hazards and implementing phase and task specific control measures during PBF and DED using titanium powders and metal powders. Eleven recommendations are made for the attention of all role players including AM powder manufacturers/suppliers, employers (AM facilities) and AM operators/employees in an effort to reduce particle emissions from and AM operator’s respiratory exposure to metals. Along with the recommendations, specific limitations experienced during the study were also identified along with recommendations for future studies. Doctoral