DO IT IN COMPOSITE
COMPOSITE MATERIALS : DEFINITION AND CHARACTERISTICS
KEY MECHANICAL CHARACTERISTICS
The process / Our materials
The process consists in winding up resin-soaked fibers (glass or carbon fibers…) on a mandrel, and then in polymerizing the structure (heat-induced polymerization in a sterilizer). The winding machines are digitally controlled and guarantee a perfect reproductibility of the fabrications. As a result, what we get are materials with very good mechanical characteristics (high fiber rate : 60 to 75 % by mass) and with the possibility to place the fibers optimally in the direction of the stress to support.
There are 2 kinds of winding, which can be combined during the tube’s fabrication process :
- Hoop Winding : (90-to-85-degree angle in relation to the mandrel’s axis) (”parallel winding”)
- Helical Winding : (80-to-30-degree angle in relation to the mandrel’s axis) (”crossed winding”)
Playing with the number of ”hoop” and ”helix” in the structure of a tube as well as with the given ”crossed” angle, it is possible to optimize the structure according to the stress supported by the part. After polymerization, the finished part is separated from the mandrel during the ”demandrelling” operation.
Here are the different qualities according to the nature of the parts :
- Carbon tubes : low density, good specific mechanical characteristics. High continuous use temperature (130°C).
- Hybrid tubes : glass/carbon combination (delamination properties under impact – shielding). These solutions make it possible to combine technical nature and design. Advanced material.
- Glass tubes (E-Glass fiber) : Glass-fiber tubes are used for applications requiring insulating tubes, which are able to resist internal pressures and high-temperature working environments (130°C max).
Our materials (for standard production such as shipbuilding) :
- Covers : E-Glass roving – 1200 Tex or high-resistance carbon fiber.
- Matrix : Epoxide resin (bisphenol A type) and hardener (amine type) mixing.
(These values are given honestly and with reservations, they don’t engage our company’s responsibility).
Density = 2 to 2,1 kg/dm3
Tensile strength, longitudinal direction = 12 dN/mm²
Tensile strength, circumferential direction = 70 dN/mm²
Bending tensile strength = 10 dN/mm²
Elastic modulus, circumferential direction = 3500 daN/mm²
Bending elastic modulus = 1500 dN/mm²
Use temperature (C°)
– 50°C to 120°C
KEY CHARACTERISTICS OF OUR COMPOSITE PARTS
Tools for the epoxy resin fabrication (glass or carbon fiber)
Minimum thickness 0,8 mm (standard) 0,03 mm (machined – on demand).
Tools for the polyester / vinylester fabrication (glass or carbon fiber)
Wide range of mandrels for a low economical launch price.
DIMENSIONAL TOLERANCES AND SURFACE FINISHES
on internal diameter…
Internal diameter tolerances : H11
Rectitude : 0,1 mm/m
Ovalization : 0,05 mm max.
Internal roughness : AR between 0,5 and 1,5 μm
Explanation : the fiber is wound-up around a mandrel whose surface finish is extremely smooth, the internal roughness of the tube makes it possible to seal directly on this surface (*).
(*: depending on the selected mandrel and its surface finish. Please consult us for high-pressure sealing).