Haenssler Group Using Kimya ABS-ESD Filament with Ultimaker Open Filament System

In the summer of 2020, the Haenssler Group, a German company that develops and produces unique sealing solutions and complex parts made of high-quality plastics and elastomers, began designing and producing a special part for one of its customers. This customer was looking for a sealant with anti-static properties to provide thermal protection to two components of a car.

This part was to be made up of two separate components that could be easily removed and reassembled during the car’s life cycle. To make the challenge even more difficult, the customer requested 300 of these parts to be integrated into an existing production line. Production had to take place twice a year, in small batches of 150, respecting a precise delivery schedule.

With this in mind, and because its filaments are compatible with Haenssler Group’s Ultimaker S5 3D printer, Haenssler Group has partnered with 3D printing materials manufacturer Kimya.

This is where Kimya ABS-ESD filament comes in

Kimya’s ABS-ESD filament has proven to meet the required requirements while being workable on the Ultimaker S5.

The ABS matrix on which the filament is based provides adequate resistance to impact (Charpy, 10.9 KJ/m²) and heat (up to 90°C), in combination with the tensile modulus and strength value typical of ABS (see Table 1).

Kimya’s patented ABS-ESD fill materials and blending technology allow ESD performance to stabilize around the nominal 10^6 ohm/sp for 11 months following blending. Additionally, to ensure the same ESD performance is maintained in the 106-109 ohm/m² range for each production batch, the surface resistivity (ASTM 527 standard on the 3D printed sample) is evaluated before each batch is sold.

Interestingly, the diameter of the filament also has a notable effect on the reproducibility of the ESD behavior. Kimya ABS-ESD’s narrow dispersion of 2.84mm ± 0.0062mm (99.999936%) in filament diameter allows for flawless extrusion volumes and stacking layer height, prior to melt solidification.

Therefore, control over filament diameter is of even greater importance when processing ESD-based materials, since irregular surface topology and underextrusion effects can hardly achieve efficient and homogeneous charge transport across the entire surface of the 3D printed part.

A personalized profile

The Haenssler group decided that Kimya’s ABS-ESD filament also met two essential criteria: anti-electrostatic resistance (ESD) and temperature resistance up to 90°C. Another advantage was the weight of the filament. At just 2.2kg per drum, Haenssler Group was able to transport and handle material more efficiently, saving time and money.

With the right material, Haenssler Group began the design phase of the component, optimizing its insulating properties by incorporating an internal void. However, during printing, Haenssler Group noticed several imperfections due to delamination marks and flow defects, which sometimes occur when printing large format parts with complex geometries. The Haenssler Group notified Kimya, requesting analysis of the problem, as well as a proposed solution, which came in the form of a custom print profile.

“When we encountered printing defects, Kimya reacted quickly to establish a printing profile that could provide the required level of quality. Therefore, we were able to produce the parts on time,” said Dirk Olbert, 3D engineer at Haenssler Group.

Using the material print profile has allowed the Haenssler Group to more quickly validate the properties of the final part – an overall advantage that allows the company to easily adapt to ever-changing market demands.

ESD safety performance is strongly influenced by the presence of surface defects, which would inevitably alter charge dissipation. This meant that Haenssler Group parts had to be reproducible both in terms of ESD behavior and dimensional accuracy, as well as meeting visual and integrity requirements.

Of the 300 units produced annually by the Haenssler Group, a group of 10 specimens printed on multiple Ultimaker S5 3D printers were selected to undergo manual dimensional analysis, using a caliper, of the most representative characteristics. The results show minimal variation (less than ±0.2 mm) from the target dimensions A, B, C, E, F and a predictable variation of -0.3 mm from the 8 mm target for dimension D. Overall, all samples reported a good level of precision and reproducibility from batch to batch, as demonstrated by the negligible variations of all dimensions tested between different samples.

To fully evaluate the surface quality of the entire printed object, Haenssler Group engineers performed high-resolution 3D scanning analysis on a select number of printed parts using a GOM Atos Core 3D scanner.

This allowed the Haenssler Group to create an optimized ABS-ESD print profile that, in combination with a properly calibrated Ultimaker S5, produced parts with acceptable tolerance limits and small dimensional variations from batch to batch.

According to topography and dimensional analysis, the processability of Kimya ABS-ESD on an Ultimaker S5 printer, combined with its controlled ESD behavior, allowed the Haenssler Group to validate 3D printing as a manufacturing technique for producing medium-volume batches of insulating components. Together, Kimya, Haenssler Group and Ultimaker, through precise 3D printers and the open filament system, were able to develop a customized solution for a very specific customer request. Additionally, the Haenssler Group has seen a 60-80% reduction in material waste in terms of cost per part compared to traditional milling.

The project was also completed in a relatively short period of time, allowing the customer to continue production without interruption.

“Our partnership with Kimya has been extremely beneficial,” said Adrian Heinrich, marketing director of the Haenssler Group. “The Kimya team has demonstrated its reliability and expertise, especially considering the extremely challenging nature of the project. We are sure to continue to collaborate in the future using its 3D filaments for other projects.”