Knowde Enhanced TDS
Identification & Functionality
- Reinforcement Form
- Reinforcement Material
- Composite Materials Functions
- Technologies
- Product Families
- Mechanical composite properties
Due to the discontinuous 3D structure, the mechanical properties of the powerRibs cannot be described in a generic way. The mechanical properties of power Ribs applied to a base layer can be represented by an equivalent homogeneous layer added to the laminate. The equivalent layer represents the "smeared” effect of the powerRibs over the part's surface.
Note that the equivalent modulus is not identical in both in-plane directions. This is due to the ribs being bonded flat to the base in one direction. However, in the other direction the ribs have to "travel" over the flat ribs at each of their intersections (see modeling FE & 3D guide for illustration).
Due to its grid structure with big tough yarns, powerRibs provides a very high damage tolerance to the part, also ensuring that it stays in one part even when crashed.- Important facts
PowerRibs are well compatible with epoxy and polyester. Sensitive to humidity: dry fabric before use (example: 105*C, 15 minutes). The key factor to optimize the effect of the powerRibs is to create a good rib structure. Therefore, a very flexible vacuum bag or bladder has to be used, such that the flexible film optimally adapts to the contours of the yarns of the ribs. The ribs are normally used as last layer on the surface. However, it is possible to put another fabric layer on top of it. It creates a composite material similar to a sandwich just with higher stiffness properties. However, is is quite challenging to achieve a good compaction.
Near-zero CTE, hence the fabric has good processing compatibility with carbon fibers.
Features & Benefits
- Materials Features
- Features
Fabric construction
Fiber type: Flax (EU)
Construction: 0°/90°
Fiber tex: 3000 TEX
Fabric weight: 215 gsm +/- 5%
Architecture: Grid-like fabric
with 28 mm mesh size
Measurements
Standard width: 1150 mm
Standard roll length: 50 m
Applications & Uses
- Compatible Polymers & Resins
- Composites Processing Methods
- Processing guidelines
The principle of powerRibs is to create a rib structure on the surface of the composite part. Therefore it only works with an open mold process, i.e. with the mold on one face and a flexible membrane on the other. For this reason, different processes are recommended:
Manufacturing with wet lay-up:
Laminate your fabrics in the mold as usual Be sure that there is a little excess resin quantity on the fabrics ("200- 250g/m2)
Place dry powerRibs on the top of impregnated fabrics
Place vacuum bag (very flexible, self-releasing) directly on the fabrics, without peel-ply or flow media.
Pull vacuum: at first the ribs act as air circulation media. Later they get impregnated with excess resin (usage of low viscosity resin is highly recommended).
Manufacturing with prepreg:
Place your prepreg fabrics in the mold as usual
Be sure that there is excess resin quantity in the prepregs (-150-200g/m2), otherwise place a resin film on top of it
Place dry powerRibs on top of the prepreg fabrics
Place vacuum bag (very flexible, self-releasing) directly on the fabrics, without peel-ply or flow media.
Pull vacuum: the ribs act first as air circulation media and then getimpregnated by excess resin from the prepreg.
It is also possible to pre-impregnate ribs before placing them on the fabric.
Check the video "How to make parts with powerRibs prepreg" on our website.Manufacturing with vacuum infusion:
Place your fabrics in the mold as usual
Place the powerRibs fabric as last layer on the top of other fabrics
Place vacuum bag (very flexible, self-releasing) directly on the fabrics, without peel-ply or flow media.
Infuse the fabrics with the resin.
Check the video "How to use the powerRibs" on our website.
Manufacturing with bladder inflation molding:
Place dry or pre-impregnated ribs over the bladder (elastic bladder)
Place other fabrics over the ribs. If the ribs are placed dry, use excess resin in the fabrics)
Place bladder and fabrics in the mold
Inflate the bladder and cure the resin. If the ribs were placed dry, the excess
resin in the fabric impregnates them.
Thermoplastic manufacturing by compression molding:
PowerRibs preimpregnated with PP as well as preforms with powerRibs and a base material of your choice already bonded together are available. Contact
the Bcomp team for further information. To compression mold parts with powerRibs while still conserving the 3D rib effect, a silicon insert is placed on the power Ribs side of the mold. Therefore your tool will need a larger gap size to accommodate the silicon stamp. A 3-4 mm silicon with Shore A hardness between 20 and 30 is recommended. See the video "How to make thermoplastic parts with powerRibs" for more details.
Properties
- Physical Form
- Mechanical Properties
| Value | Units | Test Method / Conditions | |
| Young's modulus in the wavy ribs direction | 1.92 | GPa | — |
| Young's modulus in the flat ribs direction | 1.89 | GPa | — |
| Shear modulus | 280.0 | MPa | — |
| Poisson's ratio | 0.04 | — | — |
| Density | 265.1 | kg/m3 | — |
| Thickness | 1.66 | mm | — |