Easy Molding and Mechanical Processing

ROHACELL^® polymethacrylimide rigid foam is distinguished by its excellent weight-specific mechanical properties. It can be

• milled,
• drilled,
• punched,
• turned, and so forth,

using conventional tools and can be thermoformed at low cost.

For one, ROHACELL^® can be used as

• a production tool in braiding, winding, and preform technology as well as
• a draping aid for producing profile-reinforced shells, and on the other as
• load-bearing structural cores in sandwich construction.

Extremely robust material composites

ROHACELL^® forms extremely robust and durable material composites with all common duroplastic and thermoplastic polymers, whether by bonding or by application of heat and pressure. The high heat distortion temperature of the foam and its exceptional creep compression strength allow very good consolidation of the fiber-polymer composite facings during processing, as well as very short production cycle times. The high-performance foam can be processed at temperatures up to 235°C and pressures up to 0.7 MPa over several hours.

All the common processing methods such as

• liquid impregnation (RTM, VAP, MVI, SLI, Quickstep^®, etc.),
• prepreg autoclave techniques, 
  winding,
• tape laying, and
• molding technology

can be used.

Bonding of the core and curing of the facings in a single step

ROHACELL^® has a 100-percent-closed cell structure in which only the cut pores at the surface are filled with resin. This saves unnecessary weight caused by permeating resin and also ensures adequate bonding to the facings. ROHACELL^® is available in various grades such as WF, RIST, and RIMA, which differ mainly in pore size and therefore in resin uptake. The use of ROHACELL^® allows a co-curing process in which the facings are cured and bonded to the core material in a single work step. Moreover, edges and loaded areas need not be separately smoothed. And, thanks to the high homogeneity of the pores, the contour of the core structure does not appear when very thin facings are used, thus eliminating the need for filling the sandwich structure prior to coating it. All this reduces work steps, cycle times and co-curing costs.