Continuous Filament Winding

The manufacturing of a continuous pipe or a sleeve blank is carried out by applying the glass fiber laminate on a rotating mandrel, calibrated according to the nominal diameter of the pipe under production.
VEM uses two different mandrel technologies, namely steel band mandrel and lamellar mandrel, to produce:

•         GRP/GRE pipe production
•         Diameters from ND 100 – 4000 mm;
•         Production speeds up to 40 m per hour;
•         Nominal Pressure up to 32 bar with hoop winding;
•         Biaxial strength with UD Tape and Cross Filament Winding technology;
•         Premixing System for  Inorganic Filler and Resin
•         Stiffness from 2500 to 10.000 N/m2;
•         Variable pipe lengths;
•         Joints: sleeve, with rubber seal, bonded, lock joint.
 
The innovative Lamellar Mandrel is formed by a shaft with supporting spacer discs calibrated according to the nominal diameter of pipe under production. The disk grooves house the lamellas, positioned parallel to the shaft axis and to each other in order to form the mandrel. The movement of the lamellas on the shaft is carried out through a cam system, which results in a forward and backward displacement that pushes the pipe over the mandrel.
 
The glass fiber laminate is applied onto the moving mandrel according to the following procedure: firstly a release film, e.g. polyester film, is wound on the mandrel, followed by a c-veil, both of them supported by proper winders. Glass roving, together with chopped glass, sand aggregate and polyester resin, is applied simultaneously in predetermined positions, according to design specifications. Finally, a layer of surfacing veil is applied. According to the process philosophy, the inner layer provides the required chemical resistance, while the material applied over the liner layer represents the mechanical resistant outer layer. The pipe’s layers can easily be made in compliance with the appropriate design by controlling the quantity and sequence of various materials applied.

Discontinuous Filament Winding

This traditional type of the filament winding equipment allows the manufacture of GRP or GRE pipes with integral bell and spigot joints, complying with A.S.T.M. code D 2996 Standard Specification for Filament Wound Reinforced thermosetting resin pipes) type 1, grade 2, class E.

The winding of the filaments is performed on a fixed length, rotating mandrel. The raw materials are distributed by a carriage moving horizontally alongside the mandrel. After the construction of the required pipe thickness, the pipes are subject to curing and then extracted from the mandrel. The pipe properties also depend on the raw material ratio, which can include silica sand, and on the winding angle of the fiberglass, ranging from 35° to 90°.

CNG

VEM has developed its own numerical controlled multiple axis, discontinuous, filament winding machines and testing equipment for the production of high pressure, composite reinforced pressure vessels, destined for the storage of compressed gasses together with the associated know-how and technology for a turnkey production plant project.