German family-run company igus is a worldwide manufacturer of energy chain systems and bearings made from plastic. The range of products is enormous: around 100,000 variants are available ex stock. Each year, the company develops 150 to 250 innovations. igus uses the freeformer to produce functional parts and prototypes from standard granulates, mainly the company’s own lubricant-free, abrasion-resistant materials.
“We develop iglidur brand tribo-plastics, which have gliding properties despite the fact that they contain no external lubricants. We use these materials to produce corrosionand wear-resistant bearings, for example,” explains Tom Krause, who works as a product manager at igus, promoting additive manufacturing. “We offer next-day delivery, even in batches as small as one item if necessary worldwide.”
The company operates around 350 injection moulding machines and has been collaborating with ARBURG in this area for many years. The wide range of products, customer-specific special solutions in small volumes and short life cycles are the perfect way to introduce additive manufacturing to a company as a complement to injection moulding.
APF successfully introduced in 2015
igus uses several processes, including ARBURG Plastic Freeforming (APF) since February 2015. “We see it as a major advantage of the freeformer that we can use our own high-performance plastics for prototypes and functional parts,” emphasises Tom Krause. “This means we are now able to combine freedom in design with the wear-resistant properties of our tribological materials.”
Of the more than 40 special materials that igus uses, three are specially designed for additive manufacturing. More are to follow. With the freeformer it is possible in principle to process the same plastics as in injection moulding.
The materials first have to be qualified to ensure that this can work “smoothly”. Qualification includes, for example, the precise adaptation of parameters such as temperature, droplet discharge or layer thickness to the specific properties of the material.
Additively manufactured bearings as wear-resistant as moulded parts
“The freeformer currently mainly processes ‘iglidur I180’, which is suitable for industrial applications and uses this to produce parts such as bearings, grippers and gearwheels in an additive manufacturing process,” explains Tom Krause. “Our tests showed that this material is around fifty times more resistant to wear than conventional ABS for 3D printing. In the test laboratory, a bearing made from the injection moulding material ‘iglidur J260’ in an additive manufacturing process was found to be just as wear-resistant as an injection-moulded part made from the same material.”
In general, additive manufacturing offers significantly more freedom in geometric design than injection moulding. When it comes to the development of new products directly from 3D CAD data, changes in design can be implemented immediately, so that the next generation of the prototype or design sample, or an ongoing product can be quickly produced without requiring a mould.
igus provides a 3D printing service
This is the ideal way to test a new product in practice before it is moulded in large quantities. The additive manufacturing process is also an ideal way to produce replacement parts. Since spring 2015, igus has taken things one step further and
now offers its own 3D printing service. “The customer simply uploads his 3D CAD data to our website. We check whether his requirements are feasible, produce a quote and ‘print’ the required part from our iglidur material after we receive the order,” explains Tom Krause. “The freeformer also allows us to process two different components. Thus, for example, we can use support material to create complex geometries or to produce a component mainly from conventional ABS, reserving our wear-resistant high-performance plastic for the sliding surfaces only.” igus is planning to make more injection moulding materials “printable” in a step-by-step approach. Tom Krause believes that the iglidur standard materials will be of particular interest for the future, alongside specialist materials such as conductive products and materials that are approved for use in the food industry.
