Folded honeycomb from a continuous thermoplastic sheet
Core material and process
The patented ThermHex honeycomb material and technology allows production from a single continuous thermoplastic sheet by successive in-line operations.
The ThermHex core is produced from a single sheet by a thermoforming, a folding and a bonding operation. ThermHex honeycombs have closed skin strips, allowing perfect bonding of skins onto the core.
ThermHex technology enables the cost efficient production of honeycomb cores from a wide range of thermoplastic polymers with a large variation in cell size, density and thickness.
The ThermHex production technology enables the production of themoplastic honeycombs directly from the extruder or from a roll of material.
Inline postprocessing to panels and parts leads to further cost reductions by optimal process integration.
EconCore technologies allow for production of ThermHex honeycomb cores from different thermoplastic polymers via a coil of film or by direct extrusion and enable a direct further processing in-line. The range of polymers include (but is not limited to) PP (Polypropylene), PE (Polyethylene), PS (Polystyrene), PET (Polyethylene terephthalate), PA (Polyamide), PC (Polycarbonate), ABS (Acrylonitrile-butadiene-styrene), PPS (Polyphenylene sulfide), PEI (Polyetherimide).
In combination with different skin materials EconCore honeycombs offer a wide range of application possibilities. Low production costs of EconCore honeycombs enable substitution of other honeycomb cores and homogeneous panel materials. In development projects with our customers and licensees we develop panels and parts for packaging, graphical automotive, transportation, building & construction as well as furniture markets.
ThermHex technologies for packaging & graphical applications
100% polypropylene (PP) ThermHex honeycomb boards are especially applicable to reusable plastic transportation boxes and solutions in the logistics sector, such us for example durable and hygienic plastic pallets. Layer pads, dividers, protection panels are complementary applications.
Same honeycomb panels are used in the applications in advertisement – PP boards are printable.
ThermHex PP honeycomb panels are a proven solution, realized by a number of EconCore’s licensees based all over the world, outperforming conventional corrugated plastic boards and PP cup shaped (bubble) panels. The advantages of ThermHex technology over these traditional solutions are very evident:
- bidirectional performance
- enhanced rigidity, flexural strength and compression strength and this at lower weight,
- cost savings due to lower material and energy use while the process is kept fast and continuous,
- very good thermal insulation.
ThermHex technologies for automotive interior parts
Lightweight sandwich panels may be produced directly in-line with the core production by direct in-line lamination of skins onto the ThermHex honeycomb core. Sandwich panels with thermoplastic skins and a ThermHex honeycomb core enable the very cost efficient forming of complex sandwich parts for automotive interior applications. In short, ThermHex technology is an answer to the critical needs of the industry: high performance combined with low weight and minimal cost!
Sandwich panels with ThermHex honeycomb cores are especially suitable for the following automotive interior components:
- luggage compartment floor and spare wheel covers
- door panels / door inserts
- seat back stiffeners and compartment dividers
- cabin floor and underfloor systems
- overhead systems (enhanced sounds absorption with an open cell honeycomb structure)
ThermHex technologies for applications in transportation
The continuously produced honeycomb sandwich panels offer a unique opportunity in the transportation segment, including applications such as delivery truck boxes, pick-up truck boxes, trailers, cladding panels in trucks and vans but also in the railway sector. Higher temperature resistant thermoplastic materials enable meeting the needs related to exterior applications while FST or fire resistant materials are suited for the use in mass transportation segment. Honeycomb panels with various skin material types (thermoplastics, thermoplastic composites, GRP, aluminium and steel) offer unbeatable performance and unique cost position.
The relevant key features of ThermHex honeycomb technology and sandwich panels:
high mechanical performance due to the honeycomb structure of the sandwich core
- thermo-formability (complex shapes possible in one shot process, including over-molding options)
- thermal insulation (still air in the small honeycomb cells is a perfect insulator)
- enhanced damping performance
- weight reduction due to the honeycomb sandwich design
- cost reduction due to the in-line integrated, efficient production process
ThermHex technologies for building and construction
ThermHex honeycombs with PP, steel or aluminium, CPL or HPL skins may be used for example in façade and inner cladding as well as furniture and visual communication applications. These material combinations enable cost efficient sandwich panels with outstanding weight-specific mechanical properties.
The direct in-line lamination of skins onto the continuously produced ThermHex honeycomb core allows for a very cost efficient production of panels for interior, furniture and cladding. The 100% PP panels can also be used as a temporary fencing and concrete casting panels.
PET nonwovens may be laminated onto the ThermHex core to enable processing with thermoset materials.
EconCore provides technology for cost efficient continuous production of honeycomb cores.
EconCore materials and processes combine aerospace honeycomb technology with efficient packaging production technologies. This enables cost efficient continuous production of paper honeycombs and thermoplastic honeycombs by successive in-line operations for automotive, furniture, building and packaging applications.
The EconCore honeycomb cores provide in these application areas
three key advantages:
- Fast and continuous in-line core production and in-line panel lamination
= Minimal costs
- Excellent mechanical properties, structure similar to aerospace honeycombs
= Minimal weight
- Recycable materials (thermoplastic polymers and natural fibres)
= Minimal environmental impact
The folded honeycomb concept was developed at the K.U.Leuven in Belgium.
Our technology to continuously produce honeycomb cores combines the excellent mechanical properties and the low weight of aerospace honeycomb with the automated production and low production cost of packaging processes. The folded honeycomb core material (ThermHex) and its cost efficient continuous production processes is protected by granted patent families.
Our core materials are most suitable to replace homogeneous materials and foam cores in the thickness range from 4 mm to 16 mm in cost sensitive high volume applications.
Today, the exploitation of the economical advantages of weight reduction has become essential for many industries.
It is well known that the task distribution in sandwich construction enables high stiffness and strength for lightweight panels and parts. Sandwich construction with low cost core materials can not only be more lightweight but also more cost effective, especially because the advancement and automation of production processes results in a reduction of the production cost for lightweight sandwich panels.
The combination of materials to utilize their favorable properties is the basic idea of composites engineering. With a monolithic material, a thickness increase leads to an increase of both weight and material cost of a panel.
Sandwich constructions use the fact that the core of a panel that is loaded in bending does not carry much in-plane stresses and does not represent the surface of the panel. The core can thus be made from a different, more lightweight and/or less expensive material. Sandwich construction takes the different demands on the central layer (core) and surface layers (skins) into account.
The selection and optimisation of the different material layers according to their demands enables to improve the weight and/or cost specific properties of the construction. The potential economic advantage of low cost core materials is as big as the potential weight saving due to low density core materials.
The support of the skins (to prevent relative displacements of the skins out-of-plane and in-plane) is the main task of every sandwich core material, thus a classification should be made based on how this task is fulfilled by the different core materials. Honeycombs are used in aerospace industries since many decades as the preferred core material for very light and strong sandwich panels and structures. From all sandwich core materials honeycombs enable the best mechanical performance per weight, thus they offer the largest potential for material cost savings.
ThermHex cores and production process
ThermHex cores and panels
ThermHex panel production line
ThermHex PP container boxes
Examples of ThermHex panels with different skins for automotive applications
Truck boxes and cladding
Examples of ThermHex sandwich panels for interior and furniture applications
ThermHex core: Thermoplastic folded honeycomb
Principle components in sandwich construction and task distribution between core and skins
Effect of sandwich construction on weight and material cost and the economic advantage of low cost cores
Sandwich core material classification and comparison