HP takes printing expertise into the third dimension

Hewlett-Packard is an old hand at printing. One of the pioneers of the personal computing market, the company has many decades experience of two-dimensional printing, and has seen revolutions in the technology of printing heads in both its consumer and industrial markets. Now, it is leveraging that expertise into the 3D printing and additive manufacturing worlds, and has a novel approach to keeping costs down.

“In general, in the additive world you buy your machine from the OEM and you have to source material through the same OEM or their sales network,” explained Paul Gately, business manager for 3D printing on HP’s stand in the dedicated 3D printing zone (Hall 6, stand 740). “At HP, we sell a printing solution; we don’t want to develop their own materials, so we work directly with plastics manufacturers to certify their materials to work on our machines. That makes it more open source, and it gets the parts cost – in this case, the materials you are printing – down. Parts cost, along with throughput – that is, the time taken to reduce the part – are the two major factors for customers to decide whether additive manufacturing is cost-effective for them.

Like many in the sector, Gately is keen to stress the advantages of additive over traditional manufacturing techniques. “If you’re machining, you waste a good deal of material as swarf,” he said, “and for injection moulding, you need specialist tooling. In both cases, if you need to change the part, you repeat all your costs. In 3D printing, all your design is in CAD, so it’s easy and cheap to change. If you’re printing a gear wheel, for example, you can make 1800 units in 24 hours, or you can just produce a few. We are seeing quite a lot of traditional manufacturers embracing additive for its potential to make short production runs cost-effective.”

The plastics manufacturers working with HP include BASF and Henkel, and they did not need convincing, Gately said. One particular plastic is even finding its way as a direct replacement for metal. PA 12, a grade of nylon, has similar properties to aluminium when printed, and a Spanish train manufacturer is using it to produce brackets that were previously made from metal. “That’s not a replacement we are driving, it’s coming from the customers,” Gately said. “Although in fact we are going to move into metal printing, and an announcement can be expected later in the year."

The technology HP uses comes directly from its 2D printing business, Gately explained. “We use the same printing head as we use on our platform the print onto latex. The only difference is, rather than using ink we print a fusing agent. When we deposit powder onto that it builds into air and watertight parts, and with the ability to print 3 million droplets per second we can get superb resolution.”

One innovation being shown off at MACH is a new range of colour printers. Although colour can be used for decorative purposes, Gately is keen to stress its engineering application. “If again you take a gear wheel as an example, you can produce it so that as material wears off  in use the part changes colour and indicates that it needs changing. You can also make colour-coded jigs and fixtures, and produce identifying QR codes directly as part of the production process.”

The ability of additive manufacturing to customise parts is also in evidence. One customer, Leeds-based Crispin Ordontics, produces fracture braces that replace cumbersome and heavy plaster casts to help broken bones heal. A patient’s brace can be designed directly from x-rays and produced to fit precisely and provide the exact support needed in the same time the traditional cast would be applied in the hospital’s plaster room. Dental alignment is another example of customisation. Where traditionally, a dentist would fit wire braces to the teeth and just them periodically to shift the teeth into the correct alignment, now a set of 12 customised transparent plastic braces are provided with a new one to be inserted each month. “HP supplies the machines to make the vacuum forms for the braces – because of biocompatibility issues it’s better to vacuum form than to directly print the brace itself.”

HP launched its 3D printing business in 2016, and only two years later 3 million parts are produced using its technology every year, including parts for its own machines. “50% of parts on the 4200 series are printed on our technology,” Gately said.