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A window on the future

News International-French

26 Jul 2011

A chance encounter at the JEC Composites Show in 2002 between two players who otherwise might never have met has now led to the production of a multifunctionnal pultruded composite profile bringing new levels of airtightness and watertightness to windows of all dimensions.

(Published on May 2005 – JEC Magazine #17)


Reynaers Aluminium France, a subsidiary of the Belgian group of the same name and specialised in aluminium products, and GDP, the French manufacturer of composite profiles produced by the pultrusion process, have joined forces to produce a highly innovative profile intergrating several functions, including watertightness and airtightness.


The profile is aimed at a potentially very wide market, being used as it is to hold vertical window panes in place and to guarantee that the aluminium and glass frontages of buildings in the service sector are perfectly air and watertight. The profile is made from an isophtalic resin and glass fibres arranged flat and unidirectionally; the latter account for about 65% of the profile's weight.




“The innovation in Reynaers’ product resides in the replacing of an extruded aluminium profile by a pultruded composite profile with added functions.


For the first time in the aluminium frontage market - Reynaers have applied for a patent - we have been successful in bringing together traditional materials and the advantages of a composite.


This “smart” profile, used to hold in place vertical panels of glass and to ensure watertightness and airtightness in the case of glass frontgages, has solved the problem of the “industrial” insertion of the compression joints required for such functions.


The pultruded composite profile is produced from an isophtalic resin over a structure based on glass fibres textured and arranged flat and unidirectionally. The glass fibre represents 65% (+/- 5%) of the weight. The co-extruded compression joints are made from Santoprene thermoplastic rubber in special shapes to correspond to their functions. The creation of the product is the result of a chance encounter at the JEC Composites Show in Paris in April 2002, between Reynaers, the designers, and GDP, the manufacturer, both of whom operate in different markets. For several years now, GDP have been successfully applying the double techniques of pultrusion and extrusion, processes which they have patented. Thanks to close techno-financial collaboration, the high development costs were kept under tight control in order to meet the demand from future users.”




“Within the framework of my job, I am always on the look-out for innovations. When visiting the JEC Composites Show in 2002, I discovered the pultrusion process and its advantages when I happened to come across GDP. At that time, I had a particular application in mind, so we got together and I was then able to develop my brainchild. Then GDP made us an offer which developped over time - technical details and data on the product’s feasibility - and this led to the product as it is today.


We’ve now reached the stage of having the product fully evaluated by an official body and it should be coming on-stream in France in September of this year, but already we’re considering marketing it worldwide.


The use of composite solutions also seems attractive to us for the development of other products because, generally speaking, the demands for energy savings are going to push us in the direction of closer partnerships with the actors in the composite industry.


As I see it, composite solutions seem to be promised a fine future in the building industry basically because of the regulations on heating which will become more and more drastic and will force us to use this type of material.”




The profile’s plus factors

The different functions of the composite profile are comparable to those of an aluminium profile: mechanical resistance, dilatation coefficient, machining, extrusion length, etc.
- the co-extrusion of Santoprene compression joints means that the user (the window manufacturer) does not have to insert the joints into the profile, hence a significant gain in productivity
- this gain makes up for the difference in cost of the basic products
- the composite’s thermal conductivity, lower than that of aluminium, makes for a 23% gain in the Ufi coefficient of the glass frontgages produced
- this enhanced performance makes it possible to respond to practically all RT 2000 (Thermal Regulation in France) demands.


At present, it is aluminium profiles which are used most widely in window frames. The new profile is optimised via the addition of a composite solution to which is added the co-extrusion of compression joints, specially shaped for maximum airtightness and watertightness.


One of the main advantages of the profile lies in the time savings it allows on site as the compression joints are already integrated. Besides, quality also enters the equation, compared with conventional joints which have to be inserted manually - a time-consuming and less satisfactory operation.


Moreover, the composite profile guarantees better insulation - in the order of +23% in the Ufi coefficient for glass frontgages. When such enhanced performance is taken into account, the profile responds ramarkably well to the demands of the new thermal regulations in France (RT 2000).


Aesthetics have not been forgotten either for the profile is clad in aluminium in order to secure an elegant finish.


The two companies spent more than two years developing the so-called “smart” profile, from the feasibility studies, via the essential tests to production. The profile is expected to be on the French market early in the fourth quarter of 2005 and will later be launched worldwide.