Creating materials on the fly with multi-jet 3D printers

Multi-jet 3D printing is one of the available rapid prototyping technologies. Objet’s technology lets you print multiple photopolymer materials simultaneously, including ones created “on the fly.” With this technology, you can simulate the appearance, touch, and the function of your design.

By Zehavit B. Reisin, Head of Consumables Line of Business, Objet and Sam Green, author, Objet blog

Connex illustration_re_opt
After selecting the material you want from a computer menu, the software commands material from the two cartridges mounted in a Connex 3D printer to dispense from the 798 nozzles of the print head. The print head deposits the materials, a drop at a time, fabricating on the fly a digital material, to create the part. So, for example, by jetting both a rigid and rubber-like material together you can produce a range of different materials with variable Shore A values, or varying color shades.

When Objet introduced its first inkjet-based 3D printing system in early 2000, it made it practical for medium and small-size companies to quickly and efficiently produce complex, high quality 3D models and prototypes. But that of course, was just the beginning.

Back in 2000, Objet’s original Quadra Tempo delivered just one material, known in its time as M510. Fast forward to December 2007 when Objet introduced its Connex multi-material 3D printing capability. Unlike other 3D printers, and unique to inkjet-based technology, the Objet Connex jets two materials at the same time and even mixes and composes them to produce up to 14 different and unique material characteristics in one 3D printed part.

Alongside the technological developments in 3D printers are the major improvements in the variety and function of the materials that go into producing the actual 3D models and prototypes: Whereas in 2000 Objet offered the single M510 material, today it has nearly 70 different 3D printing materials.

Some of these materials are new in their own right. These include a family of rigid opaque materials in blue, black, white and gray; two rigid transparent materials, a family of rubber-like materials ranging from translucent to gray and black with varying Shore A values, a polypropylene-like material, and various dental and medical materials including a transparent bio-compatible material suitable for prolonged skin contact and mucosal membrane contact of up to 24 hours.

So how do you reach nearly 70 materials? The Connex multi-material system is able to mix and compose two base materials together to create a range of composite materials, known as Digital Materials.

3D printed skateboard deck

It begins with the two cartridges you mount into the Connex. There are 17 modeling material base cartridges, from which you install two into the 3D printer. Then, you select from a computer menu the material you want to use for your prototype, such as VeroBlack, TangoPlus, and so on. The Objet software determines which material from the cartridges goes into each of the 798 nozzles of the print head. The print head then deposits the materials, a drop at a time, fabricating on the fly, a digital material to create the part. So, for example, by jetting both a rigid and rubber-like material together you can produce a range of different materials with variable Shore A values, or varying color shades.

Some combinations of two cartridges can develop up to 14 specific Digital Materials in a single part. So far, Objet has developed the chemistry for 70 materials. This process provides a unique level of prototyping flexibility enabling designers and engineers to precisely match their prototypes to suit the look, feel and in some cases function of their intended end products.

With this ability to both mix and compose materials and of course, print separate different material elements within the same model, you can accurately simulate complex assembled products. For example, it’s possible to print a pair of transparent eyeglasses with rubber over-molded nose and ear supports—all in a single print job—or a car wheel with a rigid hub and rubber-like tire, or a hair brush with a rigid white body and black rubber-like bristles—all seamlessly grown together within the Connex 3D printer.

Until now, all of these material developments have occurred within the realms of standard plastics simulation. Digital Materials allow you to also create hybrid composites that feature the best properties of two base materials so you can create engineered plastics.

Objet260 Connex Open2_opt
The Objet260 Connex is the third multi-material 3D printer.

In 2011 for example, Objet introduced an ABS-like Digital Material—its first composite material able to simulate strength, toughness, and temperature resistance. The ability to use acrylic-based photopolymer materials to 3D print functional prototypes combining high toughness and temperature resistance has traditionally been a challenge. However, with the Connex multi-material 3D printer, you can combine two different cartridges, one for toughness and one for temperature resistance, to create an ABS like material that is both tough and temperature resistant for a functional prototype.

This means that designers and engineers are no longer limited to prototypes that look and feel like the end product—now they can even function like the end product. The ABS-like Digital Material can be used to create a range of functioning parts such as a skateboard deck that can support a full-grown man, or a foldable stool able to support more than 100 kg.

The ABS-like Digital Material is also suitable to simulate snap-fit parts such as clips and buckles or springs that undergo repeated flex during usage.

This year Objet also introduced a clear transparent material and a high-temperature resistant material, important additions for inkjet-based 3D printing and functional prototyping. And of course, like almost every other Objet material, any new addition to their range becomes another component for a whole range of new Digital Materials. Each Digital material is tested and examined by Objet according to ASTM standards. Data sheets detailing a material’s characteristics are available on the company’s website.

In effect then, Objet’s range of materials is exponentially increasing with every new material they develop. Twelve years ago there was one. Today there are nearly 70. And in a few years’ time? Probably hundreds.

The rapid advance in 3D printing capabilities opened up by the multi-material Connex technology and Digital Materials means that the future for product design and development is bright. Objet is at the first generation of inkjet-based engineering plastics simulation. Now that the threshold has been crossed, expect materials with even higher toughness and temperature resistance in the coming years.

This means that designers will be able to simulate nearly any 3D design they imagine—and do so to the last detail, whether it’s how they appear to the eye, how they feel in the hand and how they perform in real functional tests. It also means that 3D printing will continue to become an even more important component to design companies and offices in every industry and application.

3D printed architectural model in Objet Rigid White Material. Courtesy of Rietveld Architects.

In an economic environment where the loss of manufacturing efficiency is increasingly felt, 3D printing is now being recognized as a primary tool for reducing costs, time-to-market and stimulating the production of more effective end-products—which is, of course, the goal of every designer, manufacturer and entrepreneur. MPF

Objet Ltd.
www.Objet.com