Teams from Wits University’s digital incubator at the Tshimologong Precinct, the School of Mechanical, Industrial and Aeronautical Engineering (MIA) along with the Transnet Centre of Systems Engineering (TCSE) and the Transnet MatlafatÅ¡o Centre (TMC) are putting their engineering knowledge to use in tackling a shortage of personal protective equipment (PPE).

The escalating spread of the virus has increased the demand for PPE and medical supplies as more people test positive for Covid-19 daily. Healthcare facilities in the country are seeing a shortage in these supplies for their staff.

Netcare 911, one of the healthcare facilities currently experiencing a massive shortage of protective gear, has called on the 3D printing community to assist with printing head rings for face shields for use by medical staff treating patients with Covid-19.

Recognising that each head ring for the face shields would take approximately 90 minutes to produce, and with limited 3D printing capacity to hand, a team made up of Guy Richards, Letlotlo Phohole, Moses Mogotlane, Palesa Riba and Randall Paton decided on a laser cut solution that would save time.

“Netcare was going to provide the actual shield and clips to put it together,” says Letlotlo Phohole, acting director of TCSE and TMC. “We were not happy with the limitation and wanted to use what is readily available to us, cheap to make, and lightweight. Most of all, we wanted to produce a complete product.

” We also anticipated long printing times with a 3D printer and possible filament shortages given the national drive for face shields and masks.”

After numerous attempts last Monday (30 March) to cut the shield from downloaded files from GitHub and Thingiverse – a software development platform where over 40 million developers collaborate online to host and review code, manage projects, and build software – the Wits team redesigned the original designs, applying rapid prototyping processes, which they then cut using their laser cutter.

The face shields, which are made from polyvinyl chloride (PVC) sheeting, are a flat pack consisting of two pieces that can be rapidly assembled. “The school had stock of the PVC sheeting from another earlier project. The shields are therefore being provided at no cost to the hospitals,” says Paton.

Adhering to best safety practices is crucial in the production of these face shields.

“We ensure that after production they [face shields] are washed, rinsed, and dried to remove any potentially harmful residue from the laser cutting. This is done in a production line fashion and is now the tightest bottleneck in the project, given that we only have one working laser cutter,” Paton adds.

With an average production time of three minutes (including setup time) to cut a set of pieces for each face shield, the team can make 200 to 500 shields a day to help meet the growing demand of protective gear for medical staff.

“We have developed a system that lets us feed the rolled plastic directly into the cutting bed and draw more through when done so speed is climbing,” says Paton. The team has reduced the cutting time to 90 seconds per shield, but the washing and drying still add to that time.

Four days after the call from Netcare 911, the Wits team had produced 140 face shields and distributed 120 to the Wits Donald Gordon Medical Centre and another 20 to the Wits Protection Services staff.

An additional 300 face shields have been produced to date, of which 200 will be donated to Charlotte Maxeke Johannesburg Academic Hospital and 100 to Rahima Moosa Mother and Child Hospital.

The Wits engineers hope to distribute face shields to Helen Joseph and Chris Hani Baragwanath hospitals, which are also Wits teaching hospitals.

Head of MIA, Professor Robert Reid comments that the team is upholding one of the five core values of the school, botho (humanity).

“We strive to nurture and develop the community of which we are part,” he says. “During this time of national crisis, it is imperative that we use our skills and facilities in any way that will serve our community. I am therefore delighted that we are able to help keep safe the healthcare workers on the frontline in their fight against this awful pandemic.”

Paton says the nationwide response to the call had inspired him.

“I think that many South Africans, as a nation of ‘make-a-plan’, are frustrated by not being able to help in a tangible way during the lockdown and this has channelled that energy somewhere. This has been as inspiring to be a part of as watching everyone trying to help Netcare with 3D printing for the face shields. These are extraordinary people in extraordinary times.”

The Faculty of Engineering and the Built Environment has plans to develop other medical equipment, including respirators, devices to prevent people from touching their faces, and medical masks (with filters made out of vacuum cleaner bags and make-up cotton pads designed by students of their own volition). These cross-disciplinary projects involve people from different faculties at Wits and other stakeholder groups.

More than R100 000 has been raised for this initiative from 68 donors.