3-dimensional fibreglass reinforcements, NidaFusion STO complexes are composed of a sheet of closed-cells foam covered with a reinforcing fibre layer on each side. These three elements are linked together by fiberglass bridging strands, which go through them obliquely, forming triangulations Truss Network.
Cost: NidaFusion uses glass fibers for mechanical properties, the same as the principal reinforcement of the blades because glass fiber provides the highest performance to cost ratio of all composite materials. We use closed cell foams to support the fiber geometry and displace resin during molding which are themselves produced as large volume commodity products typically for either insulation or packaging material. Our patented process is relatively simple, does not require significant space, energy, or capital, and can prospectively be located in close proximity to major users. This combination makes NidaFusion the most cost effective core material on the basis ratio of performance to cost.
Weight: NidaFusion is an engineered product with several performance variables at our control notably including the frequency, size, and orientations of the fiber truss network. Working from the base point of the displacement foam typically of ~35 Kg/m3, the FRP triangulations add a weight density from as low as 30 Kg/m3 to over 100 Kg/m3 dependent upon the configuration chosen.
Manufacturability: The process is analogous to a textile machine. Foam and fiber reinforcement surface layers are combined on a conveyor and transported through a patented machine that inserts glass fiber rovings of continuous tows through the layers of material in a method commonly referred to as “Tufting.” This product has been in production for over ten years, and is presently produced in Europe and the US.
Structure Types: The most common structure established by the fiber triangulations is of parallel rows (type STO & STF). On some occasions this has been produced as a bidirectional structure with orthogonal rows to provide quasi-isotropic properties. Our newest patent pending product version is based upon three rows oriented to create a structure of truncated three sided pyramids (type SXO & SXF). This structure achieves isotropy at lower cost and density than the biaxial version, and is the basis of the product certifications pursued to date. Typically these products are used in large panels subjected to bending, so the triangulations are most commonly specified at +/- 45 degrees to maximize shear capacity. However, for other applications we change the angle to as great as +/- 75 degrees to increase compression capacity at the expense of shear.
Base Core Material: The displacement foam is selected from many alternatives including low index Polyurethane, high index Polyisocyanurate, Phenolic, Polystyrene, Polyethylene, Polypropylene. The selection falls to one of two classes according to the process of the client:
Rigid Foam: Used with single sided tooling vacuum infusion as they must resist compression under one atmosphere. Most common PU.
Flexible Foam: Used with closed cavity molding to permit complex shapes and thickness variations. Most common PE.
Size: Standard machine width is 1.22m, based upon standard foam and reinforcement material width. Length is most commonly dictated as well by standard length of foam supply, PU at 2.44m and PE at 2.75m long. Custom configurations are frequently accommodated. Presently, the isotropic versions are limited to square dimensions of 1.22m x 1.22m. In addition we are presently working to make the PE version available in continuous lengths up to 70m dependent upon thickness, and ultimately the isotropic version will also be available in long and continuous length.
Thickness: Flexible foams may be processed as low as 5mm thick, and rigid foams typically start at 10mm. At present the maximum thickness offered is 50mm.
Glass Type: The rovings used for the triangulations are the same type commonly used by fabric suppliers for textile processing either multiaxial or weaving, and use sizings designated as multicompatible (UP, VE, EP). Other fiber types have been evaluated, but are rarely specified. The reinforcement materials supplied on the surface of the foam are intended to trap the loop ends of the triangulation fibers between this first layer and the laminate of the client. This reinforcement layer is commonly specified as either glass mat (chopped or continuous) or woven. Other products and fiber types may be used with few restrictions and mayalso include resin infusion flow media.
For a very competitive price, NidaFusion STO complexes allow you to build sandwich constructions offering :
Very good flexural strength,
Excellent fatigue and delaminating resistance,
Good high temperature and fire resistance,
Shaped structures with thickness variations,
Excellent thermal insulation
NidaFusion STO is patented and is offered in 2 variations :
NidaFusion STO complexes made of rigid foam and used for the production of planar structures without thickness variation,
NidaFusion STF complexes made of flexible foam and used for shaped structures with thickness variation..
NidaFusion STO complexes can be tailored exactly to your needs (Foam, choice and weight of reinforcements, orientation and spacing of the triangulations), and are made to order.