New honeycomb cores promise high heat performance at low weight

2 mins read

EconCore has developed new honeycomb cores for laminated sandwich panels made with Sabic’s Noryl GTX resin, a polyphenylene ether (PPE) blend, and EconCore’s proprietary technology.

The new honeycomb core is said to offer higher heat performance, better dimensional stability and lower water absorption compared to honeycomb structures made with traditional thermoplastics. These properties enable the new core material to be used in demanding applications such as certain automotive, e-mobility and photovoltaic components.

Furthermore, combining this new honeycomb core with thermoplastic composite skins to produce an all-thermoplastic sandwich panel can facilitate recycling.

Thermoplastic honeycomb structures deliver a high performance-to-weight ratio and efficient energy absorption under impact. The rigidity of honeycomb sandwich panels is known to exceed that of monolithic materials, including solid composites. Also, sandwich structures are an effective means of reducing mass in a wide range of weight-sensitive applications.

In addition to reducing raw material use, the honeycombs support recyclability. Combining the PPE-based core structures with thermoplastic composites skins, such as those based on nylon, can result in a recyclable and sustainable solution.

Furthermore, sandwich panels made exclusively with thermoplastics can be efficiently processed into finished parts with complex geometries using compression moulding processes, which can help reduce cycle times.

Because the honeycomb exhibits high load-bearing capacity even at temperatures up to 180°C, it may be a good candidate for lamination with thermoset prepregs in processing environments where high curing temperatures are typically applied. The honeycomb can also potentially be used for applications where sandwich panels must deliver high performance at elevated temperatures.

EconCore honeycombs are produced from a single continuous thermoplastic sheet using the company’s patented technology. In this unique process, the material is extruded and in-line formed into the honeycomb structure without the need for secondary operations. Specifically, this involves a sequence of extrusion and thermoforming steps to transform the extruded film into a half-hexagonal web that is directly folded into a thermoplastic honeycomb structure.

The high efficiency of this continuous process minimises production costs, making the product very competitive economically. Furthermore, the technology allows for integration of the skin lamination step in-line with the honeycomb core production, providing opportunities for effective, continuous manufacturing of value-added laminated sandwich panels.

Sabic’s Noryl GTX resin provides heat resistance during processing of up to 240°C, with conductive grades that may be used in powder-coated automotive body panels. Compared to nylon, Noryl GTX resin has lower water absorption and a lower density, reducing part weight. The material is said to offer excellent impact performance and stiffness across a wide temperature range. Sabic is also currently developing a new grade with extreme low-temperature impact performance for potential use in honeycomb cores for electric vehicle (EV) battery protection.