Rohacell 31 IG-F PMI Foam Core

ROHACELL® 31 IG-F is a high-performance PMI (polymethacrylimide) Foam, featuring a very fine cell structure which results in very low surface resin consumption. This foam is ideal for performance critical structures such as UAV wing-skins, wind energy and high-performance motorsport / water sport applications.

PMI foam offers several advantages over Closed Cell PVC foam, these include improved mechanical properties (typically 15% higher compressive strength) much lower surface resin consumption and higher processing temperature making it particularly well suited to prepreg processing.

Advantages ROHACELL® 31 IG-F:

• Almost no resin uptake
• Suitable for high temperature cure cycles
• Compatible with all common resin systems
• Good thermal insulation
• Excellent strength to weight ratio)
• Excellent machining and thermoforming properties

Processing

ROHACELL IG-F foam is compatible with all common resin systems including epoxy, vinylester and polyester, it is easily cut and machined using conventional equipment, thinner sheets are easily cut and profiled by hand using a knife. Moderate single curvature and slight compound shapes are usually achieved with conventional vacuum bagging methods, radii down to 2x the material thickness can be moulded using thermoforming at around 180°C where the foam becomes thermoplastic.

The closed cell structure also means that PVC foam can be used in vacuum manufacturing processes it very well suited to RTM, resin infusion and vacuum bagging as well as conventional open lamination. The fine cell structure is an excellent bonding surface compatible with most standard resin systems including epoxy, polyester and vinylester.

Prepreg: PMI foam is particularly well suited to co-curing in a prepreg laminate. The exceptionally low resin uptake allows the core to be included in the prepreg laminate without the need to include a resin or adhesive film as generally the resin 'scavenged' for the surface bond has no significant effect on the prepregs resin/fibre ratio. The Rohacell IG-F can be processed at temperatures up to 130°C and pressure up to 3bar.

Hand laminating: Rohacell foams are commonly used in hand-laminated and vacuum bagged applications, particularly in the construction of ultra-lightweight sandwich skins in UAV's and competition model aircraft.

Resin Infusion: If properly prepared Rohacell can be incorporated into a resin infusion, to do this resin distribution channels and holes would need to be machined into the foam to allow the resin to properly flow using the same principle as our drilled and grooved PVC75.

Thickness

ROHACELL 31 IG-F is available in 2mm, 3mm, 5mm and 10mm thicknesses. The thinner 2mm and 3mm sheets are ideal for ultra-light weight panels such as UAV wing and fuselage skins, at these thicknesses the vacuum bag will easily pull the foam into moderate curvatures. The thicker 5 and 10mm sheets are commonly used for lightweight flat panels such as bulkheads and hatch covers.

Sheet Size

ROHACELL 31 IG-F is available to buy online in 1250mm x 625mm sheets and for smaller projects 625mm x 625mm and 625mmx312mm sheets. Generally, there is no problem butt-jointing multiple sheets of core material in a sandwich structure where larger panels are being produced.

Density

We offer the ROHACELL IG-F in 2 densities, the 31 IG-F with a density of ~32kg/m⊃ and the 71 IG-F with a density ~75kg/m⊃. The 31 is typically paired with thin (<0.5mm) skins used in super-lightweight applications such as UAV and model wing skins and bulkhead panels. The 71 IG-F has approximately 3x the mechanical strength and stiffness of the 31 IG-F and is ideal for heavily loaded panels with thicker skins such as floors, decks, splitters and chassis elements.

Suitable Applications

As a high performance, prepreg co-curable core material ROHACELL IG-F is suitable for a wide range of application including:

• Aero model making
• Recreation equipment such as skis, snowboards, kiteboards and wakeboards
• Motorsport body panels, floors and splitters
• Aircraft interiors, fuselages
• Architectural panels, cladding, enclosures
• Marine hulls, decks, hatches and floors
• Wind energy turbine blades, enclosures