EconCore honeycomb structures are produced from a single continuous thermoplastic sheet using the company’s patented ThermHex technology. This involves a sequence of thermoforming, folding and bonding operations. Cell size, density and thickness of the honeycombs can be altered with simple hardware and/or process parameter adjustments. The process allows for inline bonding of solid skins to one or both sides of the honeycomb, to create an extremely cost-effective finished composite panel.
|Flexible extruder for honeycomb production can handle a wide range of thermoplastics from polyolefins to engineering thermoplastics.|
Prior to the installation of the new purpose-built extruder, EconCore was carrying out its honeycomb developments using sheet unwound from a roll. “Now that we can produce our own sheet in-line, we have more flexibility in our operations and it is obviously much easier to make changes to the material formulations,” says Wouter Winant, the company’s Technical Manager.
At the heart of the upgraded line is a purpose-built 50-mm extruder, built by MEAF Machines B.V. (Yerseke, The Netherlands) and equipped with a special 500-mm sheet die built by flat-die specialist EMO Extrusion Molding (Micheldorf, Austria). EconCore and MEAF collaborated closely on the design of the laboratory extruder, which is equally capable of processing polyolefins, bioplastics and high-performance thermoplastics such as polycarbonates, polyamides, and polyphenylene sulfide.
“This is a non-typical set-up, but it is very important for our development work,” says Winant. “EconCore already has licensees around the world producing continuous honeycombs and honeycomb-cored laminates in polyolefins – predominantly polypropylene – and we intend to continue refining the process technology for these materials. The new line is partly intended for this purpose.
“At the same time though, we are extending the potential of ThermHex technology by enabling it to be used with thermoplastics with superior mechanical and thermal performance – what we call HPTs [high performance thermoplastics]. Normally this would require the use of a second extruder, since the processing characteristics of polyolefins are quite different from those of HPTs. But with this purpose-designed extruder, we have so far managed to obtain excellent results on around 10 different kinds of polymers.”
The MEAF extruder has a 50-mm barrel holding a screw with an L:D of 34:1, which is typical for polyolefins. However, it also has a superior heating capability, with each of its five zones rated at 5.8 kW. Despite this high power rating, the extruder is highly energy-efficient, in line with MEAF’s philosophy of creating extrusion systems with low carbon footprints. A 600-L dryer for hygroscopic materials is fully integrated into the production system. Maximum output from the extruder is around 150 kg/h.
“We have been cooperating with MEAF for several years now, on various projects, and the results have always been very encouraging,” says Tomasz Czarnecki, Chief Operating Officer at EconCore. “Both our companies are small/medium-sized, with a flexible approach to getting things done, and a strong thirst for success, so we work together well.”
“Licensees of our ThermHex process have no obligation to use MEAF extruders, but it quite often happens that they decide to choose this option, as they are encouraged seeing the results that this equipment delivers.” – Czarnecki adds – “The call for innovative, light-weighting material solutions is very loud while the cost-efficient processing within the integrated production process combined with cost savings linked to the product’s weight reduction and production energy-efficiency is at high demand. This generates the fuel for our developments. After successful commercial evolutions within the current, globally distributed network of our licensees in the sectors of industrial packaging, building, automotive as well as wider transportation and others, and with the new, exciting license projects in the pipeline, we intend to continue our cooperation to take ThermHex technology to the next level, amongst others with HPTs.”
Meet the EconCore team at IAA, the International Trade Fair for Mobility, Transportation and Logistics in Hannover, Germany, at Booth E35 in Hall 24 September 20–27, 2018, and at FachPack, in Nuremberg, Germany, at Booth 9 – 136 from 25–27, 2018.