Technology Reglass

Carbon composite is a material consisting in 60% volume ratio carbon fibre and 40% resin. Carbon is a high resistance and rigid filament with a diameter of nearly 7 microns.

There are several kinds of carbon fibres that can be divided into 3 main classes: high resistance (HR), high module (HM) and ultra high module (HHM). They are different in price and performance. The first one, usually the cheapest, emphasizes the resistance, the second and the third let predominate the stiffness features. The latter, with same rigidity, weighs up to 5 times less than metal.

Carbon composite rollers can be manufactured using very different technologies.

All technologies use resin matrixes that guarantee the best compactness of the material. Air bubbles and resin surplus low drastically the total quality of the product. Therefore, they have to be monitored carefully.

The two most used technologies are: Filament Winding and Wrapping

The first consists in applying contemporaneously resin and fibres on the mould; with this process the resin distribution on the piece can result less homogenous.

Reglass uses Wrapping technology (mainly used in aerospace field and in F1) which guarantees the best quality because the indirect process can be controlled better.

First of all the fibre is impregnated with the most suitable resin matrix and this produces a sort of sheet of material, known as prepreg.

During the process, the resin percentage and the microscopical fibre-resin homogeneity are continuously monitored by control instruments to preserve the required standards. In a following phase, the pre-impregnated product is applied onto the matrix.
Reglass with its own patented molding process assures the best mechanical features. (+20% compared with the competitors).

Reglass uses unidirectional carbon fibres prepreg sheets for the roller production. Specialized personnel apply these sheets by hand on the mould. The layers are oriented in controlled angle directions determined by the roller structural project

The structure of a typical cylinder is composed by at least three layers: the inside and outside layers consist in fibres that are predominantly transversal to the roller axis and contain like a shell the central layers, whose fibres are directed predominantly longitudinal.

Some types of rollers consist of nearly a hundred layers

The use of unidirectional prepreg products guarantees a better result (up to 20%) in comparison with fabric prepreg, because the carbon filament disposition is perfectly rectilinear and not corrugated, just like in the texture warp/weft structure.

The fabric is used by Reglass on the outside of the roller to protect the layers below.

After the polymerization, the carbon tube is machined, the steel or aluminum heads installed; at last honed following the requested tolerances. For each roller the company information system guarantees the traceability of the materials and process.

Moreover Reglass can provide metal, ceramic or elastomeric surface coatings for any need e.g. surface hardness, wear and tear resistance, friction reduction or other requirements for the process where the roller is used.

The technological advantages in using Reglass carbon fibre rollers are many:

lower weight
The weight of a carbon fibre roller, compared to a steel roller with the same performance, can be from 4 to 20 times lower depending on the type of performance required.

Low inertia
Thanks to the lower mass involved, the moments of inertia have extremely low values. This allows to work with very thin films (even with a thickness lower than one thousandth of a millimeter) achieving a great precision on the load cells. Fast accelerations and decelerations are possible. This reduces the power needed for the motorization of the lines..

High stiffness
The roller stiffness in various directions can be chosen and pre determined. The use of different types of fibres results in values between those of aluminum and more than twice those of steel but with dramatically less weight.

High critical speed
The high stiffness and low inertia make these rollers ideal while working at high speed. They can in fact operate at unreachable rotation speed for any other kind of material or they can bear a diameter that is much lower than metal rollers.

Mechanical efficiency
The anisotropic features of composite allow to design for the type of performance needed by the client, optimizing weight, diameter and physical-mechanical qualities. The reduction of the installed power that derives from it allows to maintain moderate machinery costs for the constructor and reduced energy consumption for the user. In many cases the roller motorization is no more necessary increasing this way cost saving and simplifying the machine building.

Thanks to these features carbon rollers are chosen because in many cases these are the only solution to increase the performance of a machine and make it economically more convenient.
The higher carbon roller cost, as Reglass is able to prove, returns in a very short time.

Very important is also the resin, epoxy matrix which bonds the fibres: the quality of the resinous formulation and of the fibre-resin microscopical bonds guarantees the compactness of the structure and an optimum stress transfer to the fibre.