What are the main components of fibreglass profiles?

Design and Engineering

  • Can pultruded profiles take any form?

    Top Glass is able to produce profiles having sections inscribed in a rectangle of dimensions 1300 x 330 mm. In the event that the customer has a project involving a large profile, Top Glass is able to adapt its production machines (which have been internally designed and built for more than 50 years).

  • It is possible to produce fibreglass profiles to a specific design?

    Profiles and sections can be defined by the customer within the geometric limits set by pultrusion technology. Our technical department is on hand to guide customers in defining profile shape and geometry. All moulds can be engineered and manufactured on our production site.

  • What is the minimum thickness for pultruded profiles?

    Standard pultruded profiles have a minimum thickness of usually not less than 2mm. Particular projects that require less thickness, can be developed together with the customer. In its 50-year experience, Top Glass has successfully made round profiles of under 1mm in diameter and shaped profiles of 1 to 1.5mm

  • It is possible to produce a profile having a different thickness (non-constant) over its section?

    Yes. In principle, it is possible. Top Glass's technical office is always available to guide customers in the choice of thickness to be used in line with the requirements of end use and technological limitations.


  • What are the main components of fibreglass profiles?

    Pultruded profiles are composed of resin (thermosetting or thermoplastic), reinforcing fibres (glass, carbon or other), catalysts (liquid and powder), mineral fillers, pigments and various additives (flame retardant, UV inhibitors and others).

  • Can fibreglass reinforcements only be used on their own?

    No. It's possible to use them with different types of reinforcements. Further details are available on this page.

  • What types of resin can be used in pultrusion?

    Top Glass uses polyester, vinylester, epoxy and acrylic resins.

Physical and mechanical properties

  • What is the creep behaviour of fibreglass profiles?

    Pultruded profiles with thermosetting matrices have limited creep phenomenon when compared to those with thermoplastic matrices. This makes them highly suitable for engineering applications.

  • What kinds of environments are fibreglass profiles resistant to?

    Pultruded profiles are very resistant to corrosion due chemicals and stray currents. Their resistance to chemicals is specifically determined by the resin used to make them.

  • Are fibreglass profiles compliant with the RoHS 2 directive?

    Yes. Pultruded profiles are compliant with this regulation.

  • Can pultruded profiles be used in contact with drinking water?

    Top Glass has internally developed a specific version, AQVA TRIGLASS, which is certified in accordance with the French ACS (Attestation de Conformité Sanitaire) standard and can therefore, be used in contact with drinking water. It is possible to currently produce these profiles in two colours: yellow and grey.

Processing and assembly

  • Can fibreglass profiles be machined?

    Yes, fibreglass profiles can be machined by: a)     grinding b)    drilling c)     milling d)    cutting

  • What kind of equipment can be used for working fibreglass?

    You can employ traditional woodworking machines with pultruded profiles. The only addition is you need to use tools, such as diamond blades or specialised cutters, made for working on fibreglass and composite products. Extensive machining of composite materials causes dust (not harmful to health in terms of composition and granulometry) that must be removed using a vacuum system

  • Can threaded inserts be integrated into fibreglass profiles?

    Threaded inserts can be applied to pultruded profiles by work done at the end of the production process.

  • Can you use screws on fibreglass profiles?

    Specific threading screws may be used depending on the type of load to be supported and the thickness of the pultruded profile. Top Glass's technical office is always available to guide customers in the choice of thickness to be used in line with the requirements of end use and technological limitations.

  • What technologies are available for assembling fibreglass profiles?

    For assembling fiberglass profiles you can use the following technologies: bonding,  bolting,  riveting

  • Can fibreglass profiles be welded?

    No. Pultruded profiles cannot be welded.

  • Can fibreglass profiles be pasted?

    Pultruded profiles can be glued together or to different materials such as metals. Suitable glue types can be identified depending on the type of joining necessary, climatic conditions and the final mechanical properties to be obtained.

  • Can fibreglass profiles be bolted?

    Pultruded profiles can be mechanically joined using bolts. Top Glass's technical department is always available to its customers to provide guidance about the size of holes, positioning and tightening torque to be used.

  • Can fibreglass profiles be merged?

    Pultruded profiles made of polymeric thermosetting matrix cannot be merged.


  • It is possible to develop prototypes for pultruded profiles?

    3D prints of profiles can be done to verify fittings and projects. But, a pultruded profile can only be prototyped in terms of composition (reinforcement and matrix) and mechanical properties by producing it with a mould.

  • What are the minimum production lots that can be requested?

    It is possible to produce even just a few meters. However, since pultrusion requires complex, time-consuming layout it is more economical to request industrial scale lots. With reference to profiles with standard shapes, this would be lots in the range of from 1,000 to 3,500 metres (The Top Glass sales office is at your disposal for more information).


  • Can fibreglass profiles be recycled?

    ­For over 25 years, Top Glass has been deeply committed to developing options for the recycling of composite materials. Our company has patented (nr. 6623575) a method for manufacturing our products with recycled material without reducing mechanical performance. This patent also integrates the reduction of CO2 emissions and the carbon footprint based on recent indications of the European Composites Industry Association (EUCIA). To meet the requirements of current regulations on energy saving, Top Glass has carried out a LCA (LIFE CYCLE ASSESSMENT) study in cooperation with the Polytechnic of Milan (Politecnico di Milano). This study considered LCA as a synergistic element in materials recycling within our own production. In 2020, the CSI institute issued the “FRP200004” certificate of conformity, declaring part of our waste recyclable and reusable as a new raw material for a different production cycle. TRIGLASS®️ profiles as well as truncated poles from our technology and by our equipment are now considered recycling materials at all levels.

Surface finishing

  • What colours can fibreglass profiles be made in?

    Pultruded profiles are available in any colour. The colouring of profiles is obtained by means of the mass dispersal of RAL colouring paste. This is mixed with the other components of the polymer matrix and reinforcement fibres. As a result, it undergoes a slight colour change in relation to the starting RAL colour.

  • Can fibreglass profiles be transparent?

    Pultruded profiles cannot be transparent because of the presence of reinforcing fibres, mineral fillers and additives dispersed en masse within the matrix. We can achieve various effects of translucency that can be evaluated together with the customer during profile design.

  • Can profiles be fibreglass coated?

    Pultruded profiles can be painted and coated with PVC foil (typical for windows) or with properly shaped metal laminates.

  • Can fibreglass profiles be labelled or marked?

    Traditional labels can be applied to pultruded profiles. If you need to indelibly mark profiles, this can be done during the production process by applying a final surface layer of polyester fabric with the appropriate code and/or customer logo.


  • What are the tolerances for pultruded profiles?

    All tolerances for Top Glass pultruded profiles are available on this page.

  • What are the length limits for pultruded profiles?

    There is no physical limit to the length of a pultruded profile. As it is a continuous production process, the technology theoretically allows infinite length. Normally, length does not exceed 12 metres to avoid logistical problems in lorry transport.


  • Are pultruded profiles always in stock and available for purchase even in small batches?

    Top Glass offers a wide range of shapes which are always available in our stock (subject to prior sale), which is dedicated to customers who need limited quantities. A special section on these products is available through this page.