CARBON square tubes pultruded (DPP™ / R&G)

Pultruded CFRP round tubes made from high-strength carbon fibers and epoxy resin are ideally suited for lightweight, high-load structural applications with loads acting primarily in the longitudinal direction. They are manufactured using a continuous pultrusion process with 3K high-tensile carbon fibers (e.g. Torayca® T300/T700 or equivalent) embedded in a thermosetting epoxy resin matrix.

Due to the pultrusion manufacturing process, the fibers are aligned unidirectionally along the rod axis. This results in profiles with exceptionally high tensile strength and stiffness in fiber direction, a high fiber volume content and very low void content.

The CFRP round tubes are available in two quality grades, differing in dimensional accuracy, surface finish, manufacturing precision and price.

DPP™ (Premium Grade)

The premium-grade “DPP™” round tubes are manufactured in the Netherlands and feature outstanding dimensional accuracy, very tight tolerances and excellent straightness. A high fibre volume content of approx. 62 % combined with an extremely low void content provides optimized mechanical properties.

DPP™ round tubes are particularly suitable for small diameters and highly precise or tolerance-critical applications. Due to the manufacturing process, the surface is slightly rougher.

Standard (R&G)

The “R&G” version is an economical alternative for general technical applications. It offers good to very good industrial tolerances, a smoother surface finish and a high fibre content of approx. 67 % with approx. 33 % epoxy resin content.

This version is especially suitable for applications with lower requirements regarding tight tolerances and maximum precision.

Typical Technical Properties

(depending on grade)

• Fiber type: HT carbon fiber (Torayca® T300/T700 or equivalent)
• Fiber orientation: unidirectional
• Matrix system: epoxy resin
• Density: approx. 1.78 g/cm³
• Heat distortion temperature: approx. 120 °C
• Tensile strength: > 3 GPa
• Tensile modulus: > 200 GPa
• Interlaminar shear strength (ILSS): approx. 100 MPa
• Very high strength and stiffness in fiber direction

Tolerances

DPP™ round tubes feature particularly tight tolerances and excellent straightness. The standard version offers good industrial tolerances with slightly larger deviations.

Straightness deviation is typically limited to a maximum of 1 mm/m.

Processing Instructions

These round tubes are especially suitable for structural applications with loads acting in the longitudinal direction.

Internal release agents used during the pultrusion process may migrate to the surface. For optimum bonding performance, careful surface preparation is therefore recommended:

• Sand bonding surfaces using 220 grit abrasive paper
• Thoroughly remove sanding dust before bonding

Recommended adhesives:

• Epoxy resin adhesives
• Cyanoacrylate adhesives (instant adhesives)

Identification

The respective quality grade can be identified by the suffix in the product designation:

• “DPP™” R&G is the official German distribution partner for premium DPP™ CFRP profiles manufactured by Van Dijk Pultrusion Products.
• “R&G”