Sandwich panels are increasingly recognised as an ideal solution across various industrial sectors due to their distinctive characteristics, such as lightness, high mechanical strength, and excellent insulation performance. However, to fully leverage the potential of these composite materials, it is essential to use appropriate fastening systems that ensure reliability, structural integrity, and long-term durability.
In this guide, we delve into all you need to know about fastening sandwich panels.
What Are Sandwich Panels?
Sandwich panels are structures composed of three layers: two outer surfaces (skins) and an internal core. This configuration allows for materials with excellent rigidity and mechanical strength while maintaining low weight.
Construction Materials
Various materials can be used for the two outer skins and the internal core.
Skins:
- Galvanised Steel: offers high mechanical strength and corrosion protection due to the zinc coating.
- Aluminium: lightweight and corrosion-resistant, ideal for applications requiring weight reduction without compromising durability.
- Composite Materials: such as carbon fibre or Kevlar, provide an excellent strength-to-weight ratio and are often used in high-tech sectors like aerospace.
- Fibreglass: combines good mechanical strength with insulating properties, commonly used in marine and chemical applications.
Core:
- Polyurethane Foams (PU, PIR): offer excellent thermal insulation and lightness; PIR, in particular, has greater fire resistance compared to PU.
- Polystyrene: lightweight material with good insulating capabilities but lower mechanical strength compared to other options.
- Mineral Wool: excellent thermal and acoustic insulation, along with good fire resistance; however, it is heavier than other options.
- Aluminium Honeycomb: provides high mechanical strength and rigidity with minimal weight, ideal for applications requiring lightweight yet robust structures.
The combination of materials varies based on application requirements, directly influencing the choice of fastening system.
Application Sectors
Various and growing application sectors are increasingly utilising sandwich panels for design, structural, cost, or setup and construction timing reasons. Among these:
- Construction: ventilated façades, partition walls, roofing.
- Transport: automotive, railway, naval.
- Aerospace: compartmentalisation, internal components.
- Refrigeration: industrial cold rooms.
- Furniture and Technical Interior Design.
Technical Challenges of Fastening
Fastening sandwich panels presents several technical challenges that, if not properly addressed, can lead to negative consequences:
- Core Deformability During Installation: excessive or uneven force application can compress or damage the core, compromising the structural integrity and insulating properties of the panel.
- Anchoring Difficulty Without Crushing: securely anchoring the panel without causing crushing requires the use of appropriate fastening systems that evenly distribute the load, avoiding stress concentrations.
- Resistance to Tension, Shear, and Vibrations: fastening systems must withstand the mechanical stresses the panel will be subjected to during its lifecycle, including tensile loads, shear forces, and vibrations, to prevent loosening or structural failures.
- Limited Access to the Rear Side: in many applications, access to the back of the panel is restricted or impossible, necessitating the use of fastening systems that can be installed and perform optimally from the front side only.
Addressing these challenges requires careful design and the selection of appropriate fastening systems to ensure the reliability and durability of sandwich panel installations.
Design Challenges for Fastener Manufacturers
Designing fastening systems for sandwich panels requires solutions that:
- Ensure high mechanical strength on lightweight materials.
- Are compatible with various skin/core combinations.
- Simplify assembly and reduce installation times.
- Are customisable based on panel thickness.
Read also: Composite Materials And Fastening Systems: Challenges For Manufacturers
Specialinsert® Solutions
To meet the diverse fastening needs of sandwich panels, Specialinsert offers a range of technologically advanced products:
- MASTER-PLATE®: a fastening system using adhesives, applicable to any material. Also available with screws, rolling or co-moulding. Plate in galvanised steel or AISI 316L, customisable with threaded or plain attachments.
- DEFORM-NUT® TC/SC/1: extra-short knurled threaded rivet for sandwich panels. The stainless steel system includes an internal adjustable blind screw for secure holding even on reduced thicknesses.
- FAST-CON®: patented stainless steel snap-on metal fastening system, ideal for panelling and cladding. Invisible, corrosion-resistant, and fireproof, it allows for quick and durable fastening.
Conclusion
Proper fastening of sandwich panels is essential to ensure their safety, durability, and performance over time. Thanks to its experience and custom design approach, Specialinsert® offers reliable and certified solutions for every type of application.
Discover more about our range of fastening systems for sandwich panels on our official website or contact our technical team for personalised advice.
