Large-Format Printer Opens Up New Range of Medical Applications for 3D Printing

Thanks to its exceptional flexibility, 3D printing has proven itself in a variety of medical areas. This groundbreaking technology is used to manufacture patient-specific implants and small prostheses, as well as detailed models of organs for training purposes. However, due to the small size of conventional printers, products can only be made up to a certain size. 

Against this background, the DeltaTower was developed to allow greater freedom in terms of size and design. In Germany, this revolutionary piece of 3D printing equipment is available exclusively from PICCO’s 3D World. The printer’s frame is designed in a special way that makes the manufacturing space significantly higher than before, meaning objects 110 cm high and 55 cm wide can be produced. Long orthoses and prosthetics of homogenous design are now a possibility. Many different materials – including biocompatible polyactides (PLA) – can be deployed, depending on application. This new technology is used (among other companies) by medi, a manufacturer of medical products.

“During the development phase of new products, we always need individual components that, due to reasons of cost, cannot be manufactured using traditional methods. That’s why we are leveraging 3D printing technology in our company in a variety of areas” states Patrick Bauer, who works in medi’s R&D division. This company offers a wide range of medical devices for phlebology, orthopaedics and prosthetics – and many other areas. Bauer continues; “Because we are requiring metre-high components with increasing regularity, the DeltaTower is ideal for us.”

Conventional 3D printers work using a rail system moving along the X, Y, and Z axes. In contrast, the DeltaTower features three high-precision linear guides and six holding arms that move the hotend, the printer head with a hot nozzle. The arms are controlled with belt drives, and move the printing unit in three dimensions – the workpiece stays still on the printing bed throughout the entire process.

“This technique means there are no vibrations of the kind typically caused by moving print beds – and as a result, it is possible to print taller objects,” explains Joachim Schmidt, CEO of PICCO’s 3D World, who sell, and provide maintenance services for, the DeltaTower in Germany.

The L and L Dual models can be used to manufacture objects with a height of up to 110 cm, and a depth and width of up to 55 cm. The latest model in the line, which will be presented at this year’s Euromold trade fair, can even manufacture products with a depth and width of 65 cm. Furthermore, the printer head’s unique mounting mechanism means the printer remains extremely quiet throughout the printing process.

Simple installation and operation

To achieve the very highest levels of precision and longest possible lifespan, the printer is constructed using precisely machined aluminium components. These are individually scrutinised by hand, and tested to make sure they function properly. A heated bed, with constantly adjustable temperature, is installed on top of the base plate. The bed holds the printed object stably on the surface without damaging it. This is necessary to make sure the object does not slide during the printing process. The device is comparatively straightforward to use, as a sensor automatically calibrates the base surface and adjusts it to make it even. The operator must only manually calibrate the Z-axis. For optimal results, when the printer is first set up, the integrated screw-in feet should be adjusted to ensure it is perfectly horizontal.

3D printers work using object models. These are normally created with CAD software and exported in the standard STL format. The data is mapped as a set of individual coordinates that the printer later has to interpret and use. The file to be used for printing can be transmitted from a computer to the printer via USB or TCP/IP 10/100. A storage device is all that is needed, because the DeltaTower features an integrated LCD panel and a turn-and-click wheel. The display shows the operator all the important parameters – and the system also allows the operator to adjust temperatures at all times.

Cheap manufacturing with a range of materials

Objects are printed using the fused deposition modelling (FDM) method. In FDM, a filament of the desired material is heated up to 295 °C, making it melt. The molten material is applied layer-by-layer by a nozzle, thus forming an object. The nozzles used in the single and dual DeltaTower models have diameters of 0.35 mm to 0.9 mm. There is also a unit with 7 x 0.40 mm nozzles arranged in a ‘shower head’ formation for rapid printing. There are also nozzles with other diameters that can be easily swapped in. Many materials can be used for printing, including common plastics such as PA, ABS and PETG – as well as materials particularly relevant to the medical industry, such as ceramics and PLA, a biocompatible and biodegradable plastic.

“The durability of the printed components is – depending on material and construction – good to very good,” Bauer explains.

The thickness of the layers can be defined in line with the specific needs of the application – from 0.05 mm for fine details, to 0.5 mm for high stability or rapid production. The duration of the printing process depends on how thickly the material is applied, the size of the product, and the material.

“You’ve got to make a few attempts and get a bit of experience before you start getting good results. However, overall, the design and development phase for new products is much faster. Furthermore, FDM is the cheapest method of its kind, which is what swayed us towards 3D printing” Bauer summarises.

This simple method – which enables manufacturing specific, individual designs without the need for any subsequent work or creating much waste – makes manufacturing small product batches, prototypes, and pilot batches cost-efficient. This means that patient-specific medical devices can be made.

Image: PICCO’s 3D World

Image: PICCO’s 3D World

Image: PICCO’s 3D World