Designing with FITS panels

  • The FITS System, part integration, local reinforcements, etc.
    brings a new way of desiging

  • In aircraft interiors in particular, but in the transport in general the weight of the part is increasingly important. With Nomex Honeycomb sandwich panels used in aircraft-, train- and boat interiors, the core density is so low there is not much weight anymore to be reduced. Further weight reduction have to come from a different way of part manufacturing. This is what the FITS System is aiming for. Having a panel weight equal to Nomex/phenolic panels between 6-12 mm, but having all kind of part manufacturing technologies which significantly are reducing the added weight at part level or strengthening the parts by connecting the top with the bottom facing.

    Also part integration and reduction of the weight of i.e.. inserts, and a total different way of designing are reducing the part weight there where Nomex parts do have significantly added weight.

    The bending strength/stiffness of FITS panels with a thickness of < 6mm is superior to Nomex Honeycomb panels, giving the possibility to select facings with a lower weight/m², ft².  
    For example a typical FITS panel for a sidewall application, a 3,1 mm, 0.12 inch, panel has one facing of 2 layers of glass fabric US Style 120 (glass weight 100 gr/m², 0,025 lb/ft² at the impact(inner) side and 1 layer of US style 120 at the outer side giving a weight /m² or ft² of  ± 800 gr/m², 0,164 lb/ft², which is about 250gr/m², 0,051 lb/ft² lower in weight as the nowadays applied Nomex versions. Tg or glass transition temperature of the FITS panels = 210 Celcius, making FITS panels even applicable for steam-ovens.

    Further advantages are: Insulation and only 1,5 % water uptake during lifetime and no fungus.

    These very thin, but very stiff  FITS panels can also be used for ceiling panels, but then in combination with local stiffenings, see pictures, having a panel weight of 800-900 gr/m², resulting in weight savings of at least 350 gr/m² or  0.072 lb/ft².

    We have summarized some Weight and cost savings of the several part applications in the following table:

    Application FITS panel weight Weight savings compared to Nomex panels Manufacturing time Recycable at
    part level
    Side walls 800 gr/m²; 0.164 lb/ft² 250 gr/m²; 0.051 lb/ft² 2 - 4 minutes yes
    Ceilings 800 gr/m²; 0.164 lb/ft² min. 350 gr/m²; 0.072 lb/ft² 4 - 8 minutes yes, no fungus or water uptake
    Luggage bins 1500 gr/m²; 0.31 lb/ft² min. 400 max. 1200 gr/m²
    min. 0.88 max. 2.65 lb/ft²
    max 60 minutes/bin yes
    Galley doors (20) same as Honeycomb A min. of 2 kg weight saving for each door 2 minutes/door yes

    Example of a prototype OSC with U-shape sides connecting with top and bottom panels. Resulting in significant weight-, cost- and lead-time savings.