Extrusion is a type of continuous extrusion process strands from plastic materials or preliminary products (eg. granules). Hard from the beginning extruded mass through heating, thickening and shearing turns into uniform melt sa as extruded mass is plasticized.

To begin the process of extrusion, trucks must provide the necessary raw materials. After passing inspection of goods entering various components (PVC, chalk and titanium dioxide) is enriched in the mixing of certain additives according to a special recipe GEALAN. In two separately controlled mixing line performs an automatic weighing of raw materials, adding an internal recycle material, and transporting, dispensing, mixing, drying and cooling of the material. Ready mixed material is transported to the silo daily and is already prepared for the proper extrusion process.

First extruded window profile from GEALAN left the factory in 1968. Since then there is continuous development and improvement of the extrusion process, of which evidence can be eg. coextruded window profiles.

Apparatus for extrusion – apart from the extruder and tools – includes equipment extrusion lines where there is a calibration of the extrudate, cooling, pulling, cutting to length and deposition. All extrusion line equipment must be technically suited to the capacity of the extruder. For example, hot and unstable profile – after leaving the tool – must be cooled down during the calibration process, and there get the final shape. In the calibration zone vacuum is generated, resulting in pressing the outer surfaces of the profile to the wall of zone calibration. After passing a bath filled with water-cooling mechanism and the draw-off, the inside and the outside of the profile is applied to the protective film before it is cut into six-meter pieces in the cutting device. Then the device automatically sorting packing profiles to the container. After packing the container profiles are stored in the logistics center or send immediately to the customer by truck .

In the case of co-extrusion core of the profile, consisting of a liquid melt of white PVC, is connected inseparably with a colored liquid acrylic. Process takes place in the vo-extrusion tool, which, in addition to the main extruder there is connected a second extruder, feeding the tool with the acrylic melt. Colored acrylic melt is exactly applied to the surface od the profile, which will be exposed to the weather condition,  sunlight, rain and snow in the finished window. Acrylcolor profile leaving the nozzle od co-extruder is two-color now. Thanks to the combination of different materials (PVC and acrylic) we get product in which the required functional characteristics represent a higher quality. Co-extrusion process provides unparalleled color durability. With the gradual replacement of window units in one and the same block of the building visual differences remain almost unnoticeable, even after many years.

Coextrusion is used in GEALAN since 1980. The confirmation of the undeniable achievements in this field are RAL acrylcolor quality signs and mark of the South German Plastics Centre.

An interesting way to reduce Uf factor is filling foam profiles. The new technology of static dry glazing – STV? creates in this field a completely new perspective. The large surface area bonding glass and sash special tape STV? makes the steel reinforcement in the wing is no longer necessary. The resulting empty main compartment in the wing can be used to improve thermal insulation. The main objective of the connection technology, STV and IKD? was to achieve a Uw factor of less than 0.80 W / (m? ? K) – so the standard required for passive houses.

To achieve the accepted goals it was necessary to create a filling that will be possible to be weld. In addition GEALAN engineers have developed a method of production, which at the stage of extrusion profile allows profiles to be filled with foam. This means that the manufacturer of the windows does not bear any costs associated to the investment in additional equipment, because he receives the profiles factory filled with foam. The next stages of the production of windows, such as trimming or welding take place completely normally.