SKY ENGINEERING

For more than 50 years WEBER have been successfully engaged in the development and building of extrusion plants, in particular for profiles and pipes. WEBER's roots lie in over 70 years of tradition in developing and building gearboxes, especially for extrusion to transmit high torques. Numerous patents granted for the gearboxes as well as for relevant processing equipments are now extrusion standard in many cases and document the innovative strength of WEBER.

The in-house manufacture of screws and barrels represents a main expertise of the company. Thanks to the long-standing, comprehensive know-how in the field of process technology, which is expressed in a wide variety of screw geometries, an optimum extrusion solution for each application for each application is guaranteed.

Its capacity for in-house production enables WEBER to realise tailor-made solutions for the customer. Processing requirements for each specific application are fulfilled consequently same as other requirements like adjustment to floor space availabilities. WEBER is able to quickly respond to customer requirements and to offer as well the highest quality standards which are expected by our customers. A large stock of spare parts is also guarenteed.

Extrusion Technology

Window Profile Extrusion

• WEBER is the market leader for extruders in the field of window profile extrusion.
• WEBER extruders ensure all qualifications for a high product quality regarding surface finish, colour homogeneity, dimensional accuracy, shrinkage, distortion, and impact resistance and enable e safe and economic production.
• WEBER extruders with a processing unit length 22 D are in particular characterised by a high flexibility and meet the increasing profile variety.
• WEBER has designed especially for window profile extrusion the completely new extruder DS 12.28 enabling high production speeds also for multi-chamber profiles. Its maximum capacity when processing PVC-window profile formulation is an output of 600 kg/h.
• WEBER offers space-saving designs for co-extruded profiles, such as different colour profile surfaces, probably made of PMMA or use of recycled material for non-visible surfaces. Conical twin screw extruders or single screw extruders used as co-extruders are mounted to the main extruder in a floor space saving way. Normally they are fixed to the basic frame of the main extruder on columns and can be adjusted in their position and incline to the location of the terminal point of the co-extrusion tool by means of hinges.
• WEBER has found the optimum solution for increasing the installation area with its DUO system, namely to put 2 extruders with confined centre-lines onto one installation area. Each strand can be extruded as mono strand and thus the output of the production line compared to a mono strand line can be doubled.
• Combining this DUO system with co-extrusion leads to compact quadruple extrusion plants complying with the requirements of state-of-the-art window profile production in an optimum way. All four extruders can be controlled by one main operation station or alternatively by separate control stations for the right and left-hand strand.

Extrusion of Technical Profiles

• Technical profiles, e.g. from the construction and furniture industry, the automotive and kitchen appliance industry, are mainly co-extruded. There are also profiles with metallic reinforcement.
• WEBER offers profound processing know-how, the appropriate automation and control technology as well as the most suitable and floor space saving arrangement.
• Concept and most solid design consider economy, ease of maintenance and wide processing parameters.

Extrusion of WPC

• WEBER had and still has an important share in the development of the extrusion of fibre material, a mixture of natural fibres - preferabl wood - and thermoplastics.
• Two different procedures have proved to be suitable:
  • In direct extrusion process the required material components (wood fibres and PVC, PP, or PE) are added to the extruder by means of volumetric dosing, in the extruder materal is mixed, homogenized and plastified.
  • The WPC (Wood-Polymer-Composite)-process uses pre-mixed pellets.
    Standard extruders are used, the same as for the processing of PVC.
    Special machines are not required. Due to their higher productivity
    extruders with processing lengths of 22 D and more are preferred.
• Manufacture of compounds to be extruded is done by three different methods:
  • Plast agglomerator: A mixture is produced consisting of spherical grains of different sizes.
  • Heating/cooling mixer combination: An agglomerate is produced having the shape of uneven grains of different sizes.
  • Pelletizing extruder: Direct extrusion process is creating WPC pellets having even grain sizes as they are known as plastic pellets.
• WEBER offers special solutions to customer requirements for the different material specifications. We can develop in our modern technical laboratory the most suitable solution together with our customers. Continuous engineering with our customers ensures ongoing development and is immediately considered in the series manufacture of our products.
• WEBER offers a special range of machinery for the WPC extrusion covering the whole and wide field of different technologies and applications.
• Firm material content in the formulations as well as the content of abrasive and corrosive materials require a special wear protection for the extruder. For this application WEBER treats the screw fligths in the total length of the screws with a hard metal alloy and provides the barrel surfaces with a hard metal surface having a thickness of several millimetres. According to the latest experience an optimum service life is achieved.

Pipe Extrusion

PVC Foam Core Pipes

• The heart of the foam core pipe line is the Feedblock. The WEBER-Feedblock FBL enables the production of pipes up to max. 500 mm diameter.
• Up to a pipe diameter of 200 mm, nozzle and mandrel are directly mounted onto the Feedblock.
• For pipe diameters up to 315 mm a special pipe head FRK is flanged to the Feedblock FBL. The FRK with its short body length and lowest possible volume is adjusted specially to the FBL and offers maximum process efficiency. Thanks to low costs in investment an economic pipe extrusion is guaranteed. By using the pipe head FRK the tooling time can be reduced significantly.
• For pipe diameters up to a nominal size of 500 mm a standard pipe head RK is attached to the Feedblock.

Plain Pipes

• Solid wall pipes, also called plain pipes, are representing the classical design and are used for example as pressure mains water pipes and gas pipes. Thickness of the solid pipe wall is decisive for the pressure resistance.
• In the pipe head pipes are extruded from the melt strand. WEBER offers two kinds of head constructions: the classical pipe head for processing PVC, its mandrel is fixed by spiders and the polyolefin pipe head with spiral distributor, distributing the melting strand radiantly outwards and melt is flowing to the ring-shaped nozzle orifice overlapping in spiral flow channels.
• WEBER offers pipe heads up to a nominal diameter of 630 mm.

Corrugated Pipes

• Due to their profile design corrugated pipes have high ring stiffness at a low material use. As single wall pipes they are also flexible. To improve the hydraulic properties they are provided with a smooth inner wall and are called double wall corrugated pipes.
• PVC double wall corrugated pipes are produced on a parallel twin screw extruder, double wall corrugated pipes of polyolefins are co-extruded on at least two single screw extruders (type NE or ES).
• Production lines for corrugated double wall pipes have special requirements. The co-extrusion die head has a fixed position and must not be affected by the length expansion of the barrels during heating up. WEBER has realised this by a special low-friction floating bearing of the extruders.
• For NE extruders pulling the screw to the rear is an advantage and avoids having to remove co-extrusion die head and corrugator for cleaning of inspection purposes.
• Control of the co-extrusion lines including optional colour stripe extruders as well as synchronization of the corrugator can be easily handled by the common extruder control WPS.

PXE Pipe

• PEX pipes are largely pressure, heat and additionally corrosion resistant. Due to these properties they are mostly used in the field of heating and sanitation. They have also found appropriate use in geothermical plants, district heatings, for air-conditioning (area cooling) and for industrial applications.
• Cross-linking of polyethylene achieves a considerable increase of creep strength, resistance to stress cracking and low temperature impact strength. It also results in an increase of long-term presssure resistance, creep and temperature resistance. In addition also wear resistance is improved.
• For cross-linking the molecular chains three methods are used:
  PEX-a is the chemical cross-linking by means of Peroxide
  - Engel process (Ram-extrusion)
  - PAM process (inline-cross-linking in a salt bath)
  - UNIPEX process (inline-cross-linking in an infrared oven)
  PEX-b is the chemical cross-linking by means of Silan in subsequent hot water pressure treatment
  - Sioplas process
  - Monosil process (cable industry)
  - Sphresile process
  PEX-c is the physical cross-linking by following shelling with electron rays (β- resp. γ-rays)
• WEBER supplies pipe extrusion lines for all three methods. For PEX-b and PEX-c the lines are usually standard pipe lines where the cross-linking process is initiated in a subsequent production step with suitable equipments. For the PEX-a process WEBER prefers the UNIPEX process with an infrared oven integrated into the pipe line.