Sandwich panels are manufactured by bonding two thin, strong face skins to a lightweight core material, creating a composite structure that is far stiffer and stronger than any of its individual layers. The core separates the skins and transfers load between them, which is what gives the panel its structural efficiency. The sections below answer the most common questions about how that process works, what materials are involved, and where the finished panels are used.
What materials are used to make sandwich panels?
Sandwich panels are made from three main components: two face skins and a core material. The skins carry tensile and compressive loads, while the core resists shear forces and keeps the skins separated at a fixed distance. The choice of skin and core materials determines the panel’s weight, strength, stiffness, and suitability for a given application.
In thermoplastic composite panels, the skins are typically glass-fibre or carbon-fibre reinforced polypropylene (PP) or polyethylene terephthalate (PET) laminates. The fibre content and orientation are engineered to match the load demands of the application. For example, a cross-ply laminate with fibres oriented at 0° and 90° in alternating layers distributes mechanical properties evenly in both directions, making the panel equally strong regardless of installation orientation. A unidirectional or multi-ply layup concentrates strength along a specific axis, which suits floor panels or scaffolding boards where the dominant load direction is predictable.
Core materials vary widely across the broader market and include PP foam, PP honeycomb, PET foam, balsa wood, aluminium honeycomb, and mineral wool, among others. Each core type offers a different balance of density, compressive strength, thermal performance, and cost. PP honeycomb cores, for instance, deliver high compressive strength at low weight, making them well suited to floor panels that must carry concentrated point loads. PP foam cores offer more flexibility in density specification and are commonly used in wall cladding panels where bending stiffness rather than point load resistance is the primary requirement.
How does the sandwich panel manufacturing process work?
Sandwich panel manufacturing is a continuous or batch lamination process in which face skins and a core are bonded together under heat and pressure to form a single, integrated structure. The exact process depends on whether the panel uses thermoplastic or thermoset materials, but the fundamental sequence is the same: prepare the skins, position the core, apply heat and pressure, and then cool and consolidate the panel.
In a continuous thermoplastic production line, raw skin materials are fed from rolls and pre-heated to bring the thermoplastic matrix above its melting point. The core material is introduced between the two skin layers, and the assembled stack passes through a heated press or double-belt laminator that applies controlled pressure across the full panel width. The heat activates the thermoplastic matrix in the skins, which flows into and bonds with the core surface. As the panel exits the heated zone, it enters a cooling section where the matrix solidifies and the bond consolidates. The result is a fully integrated panel with no adhesive layer required, since the thermoplastic matrix itself forms the bond.
This continuous process allows for high production volumes and consistent panel quality across long runs. It also enables very large panel formats. Production lines capable of producing panels up to 13,500 mm in length and 2,950 mm in width can supply truck body builders, trailer manufacturers, and other large-format users without the need for field joints or on-site splicing.
What’s the difference between thermoplastic and thermoset sandwich panels?
The core difference between thermoplastic and thermoset sandwich panels lies in how the matrix material in the face skins behaves under heat. Thermoplastic matrices melt when heated and solidify when cooled, making them reprocessable. Thermoset matrices cure irreversibly through a chemical reaction and cannot be remelted once set. This distinction affects manufacturing speed, recyclability, and end-of-life options.
Thermoplastic sandwich panels
Thermoplastic panels use matrix materials such as polypropylene (PP) or PET. Because the matrix can be remelted, thermoplastic panels can be thermoformed into curved shapes after initial production, and the material is recyclable at end of life. For European OEMs subject to the EU End-of-Life Vehicles (ELV) Directive, recyclability is a compliance requirement, not just a preference. Thermoplastic panels also tend to have shorter cycle times in production, since cooling rather than curing determines the process speed.
Thermoset sandwich panels
Thermoset panels use matrix materials such as epoxy, polyester, or vinyl ester resin. Once cured, they cannot be reshaped or recycled through conventional material recovery routes. They are common in aerospace and marine applications where high temperature resistance or specific chemical resistance is needed. However, for commercial vehicle and scaffolding applications in Europe, the recyclability limitations of thermoset panels increasingly work against them as sustainability reporting requirements under the CSRD tighten.
How are sandwich panels cut and finished to size?
Sandwich panels are cut to size using CNC routing, circular saw cutting, or water-jet cutting, depending on the panel material and the precision required. For thermoplastic composite panels, CNC routing is the standard method for custom dimensions, delivering clean edges and tight tolerances without delaminating the skin-to-core bond.
Panels are available in custom dimensions cut to your exact specification. For truck body floor panels, CNC routing delivers the dimensional accuracy needed for flush fitting against frame rails and bulkheads, eliminating the need for on-site trimming and reducing assembly time. For scaffolding boards, cutting to precise plank lengths is important for compliance with EN 12811 load class requirements, since unsupported span length directly affects the load rating of the finished board.
Edge finishing is an important step that is often overlooked. Raw cut edges expose the core material to moisture and UV radiation. Edge sealing and edge bending protect the core from these exposures, which is particularly relevant for scaffolding boards washed down on site and truck floors subjected to regular pressure washing. A properly sealed edge extends the service life of the panel significantly and maintains the structural integrity of the core over time.
What quality checks happen during sandwich panel production?
Quality control in sandwich panel production covers raw material verification, in-process monitoring, and finished panel testing. The goal is to confirm that the bond between skin and core meets specification, that dimensional tolerances are within acceptable limits, and that the mechanical properties of the finished panel match the design requirements.
During production, key process parameters including temperature, pressure, and line speed are monitored continuously. Deviations in any of these variables can affect the quality of the skin-to-core bond or the fibre volume fraction in the skins, both of which influence the panel’s structural performance. Finished panels are tested against relevant European standards: tensile properties are measured to EN ISO 527, flexural performance to ISO 14125, and fire classification to EN 13501-1 where required by the application.
For scaffolding panels, load testing against EN 12811 is the relevant benchmark. A panel that achieves load class 4 under EN 12811 with no support underneath demonstrates a verified structural performance level, not just a claimed one. This kind of documented test result is what allows procurement engineers and safety managers to specify composite scaffolding boards with confidence.
Which industries use manufactured sandwich panels?
Sandwich panels are used across a wide range of industries and composite panel applications wherever a combination of low weight, structural stiffness, and durability is needed. In 2026, the strongest demand growth for thermoplastic composite sandwich panels is concentrated in commercial vehicles and scaffolding, driven by payload regulations, sustainability requirements, and the shift to electric drivetrains.
In the commercial vehicle sector, truck body builders and trailer manufacturers use sandwich panels for floors, side walls, and roof panels. Replacing steel or plywood with a composite panel reduces the structural dead weight of the body, which directly increases the legally permitted payload. In electric trucks and vans, this weight reduction carries an additional benefit: lighter body structures extend battery range per charge. Every kilogram of structural dead weight reduces range, which makes weight reduction a range argument as much as a payload argument. This is a standard procurement question from EV fleet buyers in 2026, and it is changing how truck body builders specify their materials.
In scaffolding, composite panels replace traditional timber or aluminium planks. A thermoplastic composite scaffolding board is lighter to handle, does not absorb water, and does not rot or splinter over time. Thermoplastic composite floors in heavy transport last significantly longer than plywood alternatives. Over a 15-year vehicle life, a composite floor eliminates two to three plywood replacement cycles. Once you factor in panel cost, installation labour, and vehicle downtime, the composite is cheaper per year of service even at a higher unit price.
Other applications include cargo boxes, horse vans, caravans, mobile homes, and façade panels, where the same combination of low weight and durability applies.
How Compoform Supports Your Sandwich Panel Specification
We manufacture thermoplastic sandwich panels using PP honeycomb and PET foam cores, focused on commercial vehicles and scaffolding. Our production line runs up to 13,500 mm × 2,950 mm, so we can supply large-format panels in custom dimensions without field joints or on-site trimming.
When you work with us, we review your design before production starts. That means we look at your assembly process, your load requirements, and your dimensional constraints, and we configure the panel accordingly. Specific things we bring to that conversation:
- Self-supporting floor panels: A 30 mm PP sandwich panel floor is self-supporting, removing the need for an aluminium subframe and eliminating a production step for truck body builders.
- Edge protection as standard: Edge sealing and edge bending are part of our finishing process, protecting the core from moisture and UV in wash-down environments.
- Verified load performance: Our 10.5 mm scaffolding panel achieves EN 12811 load class 4 with no support underneath, based on our own testing.
- Recyclable materials: All panels use thermoplastic matrices, supporting your compliance with the EU ELV Directive and CSRD sustainability reporting requirements.
We do not ship panels to spec and move on. We stay involved through integration, flag issues before they reach the production floor, and support you through iteration as your design evolves. If you are specifying composite panels for a truck body, trailer floor, or scaffolding application and want to work through the configuration with our engineering team, get in touch to start that conversation.