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Tabletop 3D printers have become more common in homes, schools and libraries as their prices have come down and they have become easily available. According to the study by the Finnish Institute of Occupational Health, Aalto University and the University of Helsinki, nanoparticles are emitted into the air when printers are used.  Printing every once in a while is not very harmful, but we should recognise the exposure and attempt to reduce it in places where people are exposed to printing daily.

‘Exposure can be reduced by acquiring an encased printer that has been designed with emission management in mind, by avoiding staying in the same room with a printer for longer periods of time or, most reliably, by directing the emissions out of the indoor air,’ says Specialist Research Scientist Anna-Kaisa Viitanen from the Finnish Institute of Occupational Health.

Raising the temperature will increase particle emissions

Researchers from the Finnish Institute of Occupational Health measured the emissions produced by a tabletop FDM printer, i.e. an extruder, when using ABS and PLA, the two most common plastic mixtures.

‘Printing ABS plastic using a tabletop printer caused nanoparticle emissions whose spread into the indoor air should be restricted,’ Anna-Kaisa Viitanen summarises.

‘The printer should be placed in a space in which people do not stay constantly. Ventilation in the space must be as efficient as possible and the emissions should be directed as close to the outgoing air channels as possible,’ estimates Professor Kaarle Hämeri from the University of Helsinki.

Both ABS and PLA are thermoplastics, i.e. plastics that have to be heated for extrusion.

‘The oil-based ABS requires heating to about 230–250°C and the biodegradable PLA to about 180–210°C,’ say Research Director Jukka Tuomi and Researcher Kirsi Kukko from Aalto University.

‘Raising the temperature increased the emissions significantly in the measurements, also with PLA, so we have to ensure we choose the right printing temperature,’ they stress.

‘We also need to be careful with the printing materials and only use the plastics that have been designed for the particular purpose,’ the researchers point out.

‘A mug is printed using food grade plastic and jewellery using plastic that is known to be safe in contact with the skin,’ Kukko summarises.

‘The plastic ribbons used in tabletop printers are about 20 times more expensive than the bulk material used in industry. Ordering the cheaper material online is therefore an attractive idea, but it is worth keeping in mind that there is no guarantee about what it contains,’ stresses Jukka Tuomi, who is also the President of the Finnish Rapid Prototyping Association.

More research results and instructions on industrial 3D printing also due

The Finnish Institute of Occupational Health, Aalto University and the University of Helsinki studied the emission of particles and gases in the use of 3D printers intended for small scale printing, e.g. in schools and libraries, as part of a wider project that focused on 3D printing in work environments. The guidelines for printing for employees will be completed next autumn at the latest. The project as a whole will be completed by the end of 2016.

The range of printers and materials is larger in industrial printing so the variation of emissions is wider. Treating the printed objects with chemicals is an integral part of 3D printing and is typically used in printing on an industrial scale.

‘When chemicals are used in post-processing, it is important to perform a risk analysis of these chemicals and people must use the correct protective equipment,’ Viitanen points out.

The Finnish Institute of Occupational Health is responsible for the measurements in the research project and the University of Helsinki for the modelling of the emissions. Aalto University's contribution will be its practical expertise in 3D printing and knowledge about what kind of 3D printing is carried out in Finland.

The study has been funded by the Finnish Work Environment Fund (Työsuojelurahasto).

More information:

Specialist Research Scientist Anna-Kaisa Viitanen
Finnish Institute of Occupational Health
tel. +358 43 825 0672
anna-kaisa.viitanen@ttl.fi
www.ttl.fi

Researcher Kirsi Kukko
Aalto University
tel. +358 50 344 7248
kirsi.kukko@aalto.fi

Professor Kaarle Hämeri
University of Helsinki
tel. +358 9 19150 850
kaarle.hameri@helsinki.fi

The results are presented in the organised in Nordic3DExpo.

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