Arburg to produce 3,500 high-tech face masks daily

Arburg has launched a project to produce face masks injection moulded from LSR (liquid silicone rubber) and PP (polypropylene) to combat the spread of the COVID-19. About 3,500 of these multifunctional high-tech masks are expected to be produced daily under series production conditions.

The product will initially be used to protect the company's employees worldwide and then be distributed via the district of Freudenstadt to hospitals and care facilities.

The flexible masks do much more than act as a simple fabric mouthguard, according to Arburg. The multifunctional product consists of a soft LSR mask that is put over the nose and mouth and a firm PP shield with eyelets for attaching elastic bands. In the middle there is a standardised connection with a hole (DIN EN ISO 5356-1:2004).

Four LSR masks are produced per cycle and then removed by a six-axis robot.

Backed up by renowned partners

"The LSR component and mould simulation was carried out using the Sigmasoft software from Sigma Engineering. In around five weeks, our partners Polar-Form and Foboha built the corresponding injection moulds for the LSR and PP components," says Gerhard Böhm, Arburg Managing Director Sales, regarding the current situation.

Also, the companies Ewikon and Männer were also involved in the implementation of the mould technology. Other partners were Barth Mechanik and Packmat, as well as the raw material for several 10,000 masks was sponsored by the chemical group Wacker and Borealis.

The opening is sealed with a flow gate to protect against infection in everyday life. This diverts the breathing air downwards and thus significantly reduces the risk of infection. In the next expansion stage, a filter housing can be fitted on the opening.

By using corresponding FFP2 or FFP3 filters, doctors and nurses, for example, can reliably protect themselves from viruses or bacteria when in direct contact with sick people.

The masks are designed for multiple use and can be easily sterilised. "It was also important for us to take advantage of the performance of plastic materials and to create a product that is suitable for long-term use. In this way, resources can be conserved," emphasizes Dr. Thomas Walther, Head of the Application Technology Department at Arburg.

The temper-free LSR material of type Elastosil LR 5040 is suitable for food contact applications according to FDA CFR 21 §177.2600 and BfR XV. "Silicones", and has been tested for biocompatibility. In addition, the LSR has good sealing properties, a high tear resistance and can be easily sterilised.

Two Allrounder electric injection moulding machines being used 

Two electric injection moulding machines are being used. An Allrounder 570 A with a clamping force of 2,000 kN produces the LSR masks at the Arburg Training Center using a 4-cavity mould from Polar-Form, while an Allrounder 470 E Golden Electric with a clamping force of 1,000 kN and a 2-cavity mould from Foboha simultaneously produces the associated PP shields at the Customer Center.

The face mask consists of a soft LSR mask and a firm PP shield with eyelets for fastening the elastic straps.

The larger injection moulding machine operates with a LSR dosing system from Elmet and a six-axis robot from Kuka, which, in a sophisticated demoulding process, removes the flexible masks from the mould and places them on a conveyor belt.

In the second machine, the PP shields are handled more easily by a linear Multilift select robotic system. Finally, the PP shield is manually placed on the silicone mask with interlocking, this is completed with the corresponding elastic bands and packed.

By using a temper-free LSR, this step can be carried out without disruptive production stops caused by the time-consuming and energy-intensive tempering of the component.

"We expect to produce at least 15,000 of these masks per week in two-shift operation. If we were to work around the clock, it would even be possible to double this number," explains Manuel Frick, who as an LSR expert at Arburg designed the product.