The Chinaplas show in Guangzhou marked the Asian debut of Arburg's freeformer additive manufacturing process. Arburg's Helmut Heinson, Managing Director Sales, Arburg headquarters, detailed the technology at a pre-show media event, where he emphasized its applicability to industrial production.
With Arburg Plastic Freeforming, inexpensive conventional plastic granulates are the base material - one of the advantages compared to other additive manufacturing processes that employ filament typically costing considerably more than $10 per kg. Further, a significant advantage of freeforming according to Arburg is that, through using standard resin grades and by nature of the process, the properties of the parts outputted are equivalent to injection-molded parts.
|Arburg's Heinson: Freeforming is a truly industrial process.|
As with injection molding, the granulate is first melted in a plasticising cylinder. A stationary discharge unit with a special nozzle then applies tiny plastic droplets layer-by-layer onto the part carrier using high-frequency piezo technology at a specified duty cycle of 60 to 200 Hz.
Depending on the nozzle used, the diameter of the droplets generated under pressure is between 0.2 and 0.3 millimeters. The moving part carrier is positioned so that each droplet is deposited at the precise point calculated in advance. During cooling, the tiny droplets automatically fuse together.
The desired three-dimensional component is thus created layer by layer. The construction chamber of the freeformer offers space for parts with maximum dimensions of 190 x 135 x 250 millimeters.
The freeformer is equipped with a movable three-axis part carrier and two stationary discharge units. The second discharge unit makes it possible to process two components at the same time. This means, for example, that parts can be produced in different colours, with special tactile qualities, or as a hard/soft combination.
Alternatively, the second discharge unit of the freeformer can be used to build up structures from a special support material. This makes it possible to achieve unusual or very complex part geometries.
A special material is available for the supporting structures that can be removed in a water bath. As an alternative, a supporting structure can be built up in the same material as the part itself. This option is preferred for parts with free-standing structures and clearly defined edges. A thinned out intermediate layer with targeted, predetermined breaking points enables the supporting structure to be simply broken off mechanically at a later stage.
One great advantage of working with the Freeformer according to Arburg is that no dust or emissions are produced and no additional infrastructure is therefore necessary. No extraction units or cooling water are required. The system is therefore also perfectly suitable for use in an office environment.
The 3D CAD data for the parts being manufactured (STL files) is processed offline on a personal computer. Special software generates the necessary manufacturing data through slicing. Once the freeformer controller has received this data - which determines axis movements, etc. - production can begin. Operation is extremely simple, no special programming or processing knowledge is required.
"With the freeformer, we have extended our industrial production offering for plastics processing," Heinson said. "While customers have long been able to rely on the company's injection molding expertise and therefore the efficient mass production of plastic parts, the same now applies to the cost-effective additive manufacturing of one-off parts and small, multiple-variant batches." The potential of the freeformer and of "Arburg Plastic Freeforming" will be demonstrated live in Guangzhou at booth 5.1A41. Additive manufacturing of functional parts for the electronics and cosmetic packaging industries will be demonstrated with two freeformers.
Both freeformer exhibits will produce highly complex parts. The second discharge unit we will use for a special supporting material that can be easily removed in a water bath. Arburg will produce spray caps in two sizes, a mobile housing and a gear card.