Laser remote cutting of plastics for personal protective equipment

The laser as a tool facilitates the fast and precise material processing such as metals, organic materials and plastics. In combination with modern system engineering, laser technology can be used to respond highly efficiently to current challenges in industry and society. The healthcare sector in particular is currently demanding fast and efficient solutions to compensate for existing supply bottlenecks in personal protective equipment. High priority is given to the protection of special occupational and personal groups. Face shields made of transparent foil, which simultaneously fulfil the central requirement of high wearing comfort, may provide a remedy. The shields, laser-cut according to the state of the art, serve as an efficient example of an industrial solution.

Face shields made of transparent foil, which are cut by means of remote laser technology, can significantly reduce the risk of droplet infection via the mucous membranes of the eyes, nose and mouth. The Fraunhofer IWS's multi-remote system "MuReA" is used to manufacture these shields for which medical certification can be applied for. Here, a well-focused laser beam is high-dynamically projected via fast tilting mirror deflection systems along the contours to be cut onto thin and sensitive materials. The process can be performed quasi-simultaneously in a working field of up to one square meter.

A major advantage of this process is the high processing speed which is up to one meter per second. Through the interaction of the two-kilowatt laser spot with the component, the material is chemically decomposed or vaporized. A special air flow continuously ensures reliable removal of the waste products generated. Complex contours and high precision pose no problem for laser remote cutting. The laser-cut edges are characterized by high quality.

Laser remote technology can also be used to process transparent foils made of polyethylene terephthalate (PET), such as commercially used for face shields. Parallel to the development of the remote laser cutting process, a face shield design was developed exclusively from foil cuts. The design meets the requirements of high wearing comfort, simple and fast production and sustainable material selection. The shield allows the adjustment of the forehead fixation to different head sizes and ensures sufficient distance to mouth and nose to prevent fogging.

The developed prototype, "IWShield" (Intense Wearable Shield), consists of five individual plastic parts fabricated in one process step using a remote cutting process. Depending on the head shape and the application purpose, these can be completed in just a few steps. A hook and loop strap connects the ends between head and forehead ribbon. Due to the multiple use of easily disinfectable and additionally recyclable PET in a mono-material design, production is sustainable and minimizes the need for material resources. The solution is currently not yet approved as a certified medical device.

The advantages of the "IWShield" at a glance:

• Quick and easy assembly of the individual parts
• Flexible adaptation to the head shape and the application purpose
• Additional head ribbon for a high wearing comfort
• Adjustable distance to prevent fogging with breathing air
• Low weight of 50 to 100 grams depending on material thickness
• Use of the easily recyclable material PET and similar plastics
• Easy cleaning and disinfection of the material

Application possibilities of the "IWShield" arise wherever an additional protection of the face against droplet infection via the mucous membranes of the eyes, nose and mouth is necessary. From the health sector to the retail trade, the face shield can be used in many different ways.

Possible areas of application are:

• Hospitals, smaller medical practices and dentists
• Care facilities such as hospices and residential care homes
• Schools, day-care centers, children's and youth homes
• Physiotherapists, hairdressers, beauticians
• Points of sale, shopping markets
• Social and charitable institutions