Tools made by Theysohn

PVC Profile - Tools

Turn-key solutions and components for

theysohn-various-pvc-profilesrigid and foam profiles in single and multiple strand production for

  • window profiles and sills
  • door and cover panelsrain gutters
  • foam profiles
  • cable ducts
  • skirting profiles
  • curtain rails
  • sheets
  • WPC profiles
  • technical profiles
  • Siding
  • co-extrusion solutions
  • system engineering


Window profiles

theysohn-conch-halleProfile tooling is a highly engineered piece of equipment giving the inner and outer shape to the profile. Theysohn offers tools for different types of profiles and different ways of production.

Theysohn offers tooling and downstream solutions to realize production concepts based on our experience and the preference given by the customer.

The cost savings resulting from the inline production of soft PVC gaskets that are injected into profiles is a big success. This post-co-extrusion process has since become an industry standard.

The main profiles are extruded in single or double strands. On glass beads there are also 4-strand-solutions available for maximum output. A logical extension is to produce window sills as well as panels. Whilst window sills are made from web-based or foamed boards, panels are typically web-based structures. Both types of products can be produced on window lines but are also available on highly specialized extrusion lines.

Cable ducts and gutters

Electrical installation ducts in simple or highly structured designs are a speciality where Theysohn with no doubt, is one of the worldwide leading companies offering turn-key extrusion lines. Ducts are produced from PVC in many colours and constructions, from easy-fitted profiles to highly engineered large channels. Special tooling concepts have been developed to reach safe technical standards.

For rain gutters, the system of profiles range from pipes and half-pipes to rectangular shaped solutions. Co-extrusion with UV-resistant polymers like ASA allows special surface appearances that are well accepted by Theysohn‘s customers worldwide.

Foam profiles

There are many applications ranging from flat sheet to more sophisticated geometries. In order to save material expanded PVC (foam) has been developed especially for cover profiles and pipes. Originally confronted with sceptisism, today the technology of extruding expanded PVC to form foam profiles has worked successfully.

WPC extrusion

theysohn-WPC-extrusionTheysohn has managed to transfer their know-how from window profile tooling and plant engineering to this modern material.

WPC stands for wood polymer composite and is a mixture of 50 - 85 % fibre (e.g. wood, paper, ...), 15 - 50 % polymer (PVC, PP, PE) and 2 - 8 % additives (e.g. coupling agents, lubricants).

The Theysohn group has developed a WPC extruder series with optimised screw and barrel design. Today the product range varies from flat profiles at single and multiple strand extrusion to complex geometries up to 500 mm width.

Areas of Application of Theysohn Profile Tools

  • hollow and solid profiles for decking, siding and fencing systems
  • applications for WPC materials wood/PVC 50/50, wood/PP 70/30 or other customer-specific formulations
  • profile-specific extrusion of up to 6 m/min pull-off speeds or 600 kg/h output
  • Turn-key solutions and components for decking profiles, fencing, skirting profiles, siding profiles, solid & coextrusion 


Siding - the new "face" of buildings

theysohn-pvc-siding-1-blauPVC Siding can be used for cladding of new constructions, remodelling and refurbishing of buildings, offices and villas. Because of an embossing roll which presses a relief effect into the hot sheet, it can look like wood. An optional foil application unit provides a constant application of coloured films with various different styles and colours available, making siding a perfect match to PVC window and door systems. 62 % of all US homes are using Vinyl Siding because of 3 big advantages: zero maintenance, easy to handle and easy to apply.

Other advantages are a lower overall investment compared to wood, aluminium, brick or concrete. Simple to install, smoothing out uneven walls, repelling insects, impact resistance and lightweight. PVC Siding is Typhoon proof (with special designs of up to 300 km/h).

Vinyl Siding Specialties
Vertical siding or soffit is used for covering the bottom side of a roof bulge coming in a solid or vented version. Other possibilites for the use of vertical siding are skirting boards or in the construction of agricultural stables.

Before installing siding to the house wall, a proper insulation in combination with moisture barrier should be installed. To further improve thermo insulation of walls, the back side of siding can be equipped with pre-manufactured foam sheets.

Extrusion process

A main extruder and a coextruder plastificate PVC dryblend with a dual manifold die forming a 2-layer flat sheet. An embossing roll presses a relief effect into the hot sheet followed by a calender with 2-4 chill rolls. Optionally, a foil application unit can be used. Exchangeable post forming calibrators produce different profile shapes. A combination of slotters and punches are used for nail slots and ventilation holes. A belt puller and a special cut-off-press are used to attain an extrusion speed up to 55 m/min. 


PVC/C-PVC Pipe heads

Turn-key solutions and components for

solid, co-extrusion and foam pipes in single and double strand production for

  • compact pipes 16-710 mm
  • dual strand compact pipes 16 - 250 mm
  • 3-layer foam-core pipes 32-710 mm
  • C-PVC hot water pipes 10-400 mm
  • cable protection pipes 10-400 mm
  • co-extruded rain gutter pipes 32-160 mm
  • pressure, irrigation pipes and drainage systems 



theysohn-streamTheysohn developed the “RK Streamliner” pipe head with the following advantages for our customers production.

  • higher melt pressure after the torpedo and therefore a much better welding effect
  • based on the higher melt pressure after the torpedo, high melt pressure in the die set is no longer necessary for achieving optimum pipe quality
  • shorter die sets
  • wider pipe diameter range for each pipe head
  • modular system: use of die set of the nearest smaller pipe head
  • fast mandrel exchange to adjust wall thickness of end product
  • 30 – 35 % less volume of head reduces resistance time of material resulting in a reduction of stabiliser

The new pipe heads “RK STREAMLINER” can be used for single and double strand extrusion. The PVC pipe head RK is still available.

PVC Compact pipes

theysohn-V-Block theysohn-compact-pipe Compact pipes are the backbone of a pipe production. They consume the highest volume of PVC and are produced with the highest output of more than 2500 kg/h for twin-extruder applications in the industry too! Compact pipes are typically produced in accordance to local or international standards, as there are ISO-Standards in Europe and ASTM Standards in America. Middle East and Asian standards are mainly ASTM oriented whilst China’s national standard is following the recommendations of the ISO standard. More than 300 local pipe standards are known so far. Typical applications are sewerage pipes (100 - 710mm diameter) and pressure pipes (32 - 500mm) as well as venting installations or cable protection pipes.

Theysohn is offering a wide range of extruders with output from 50 - 2500kg/h using conical and parallel twin screw extruder technology and pipe heads from 16 to 710 mm diameter, operating 6 different types of pipe heads in single and twin-strand operations.

Theysohn is consistently working on improvements in their technology. Current priority has a further reduction of overweight production to minimize material cost and a new pipe head layout to control longitudinal waves.


C-PVC pipes

theysohn-cpvc_pipe theysohn-rohrkopfMore than 30 years C-PVC pipes are known to the market. Theysohn is one of the market leaders. Special developments on screw geometries, new pipe head systems and die sets with extensive multi-layer chromium plating were necessary. C-PVC (chlorine loaded PVC) enhances the chemical resistance of the final product but therefore requires intensive protection against corrosion of the parts of extruder, screw and pipe head being in direct contact with the melt.

High output lines with a speed of 2 x 14 m/min. are possible based on new pipe head and calibration technology. Typically a premixed dry blend will be used. Mixing plant options are available, but are rarely seen. Reason is that the typical application in the chemical and food industry requires severe tests and homogenisation provided by the suppliers of dry-blend to be used by the extrusion companies.

Shortage on raw material availability in general leads to supply contracts between extrusion company and the ten leading material suppliers. Theysohn with its excellent connections to the dry blend suppliers will always assist to make contact to the decision makers.

Typical dimensions are 16 – 63 mm with wall thickness of 2 – 5 mm.

Very critical for a successful production is an optimal tuning of the screw to ideally work with the formulation of the raw material. A major advantage of Theysohn is the active core thermoregulation system for the screw allowing a wide production window to cope with fluctuations in the process or material. This technology allows to actively control the melt temperature, another vital factor in the process.

Typical applications are C-PVC hot water pipes (outside mat, inside highly glossy) used to avoid corrosion and chalk residue block the flow. Solar heating systems use these pipes to transport hot water at up to 95° C from the heat collectors to the heat exchanger. Other applications are to transport hot or chemically corrosive media in the food- and chemical industry to replace highly expensive metal pipes or PP pipes showing much less resistance to heat and chemical substances.

Another big advantage is the utilization of glue-based connection systems instead of welding or mechanical fittings.

Roof-drainage downfall pipes

theysohn-regenrinne theysohn-RohrDrainage systems to guide rain from roofs into the canal systems are one of the major application of smaller co-extruded (2-layer) or compact pipes. For the inner side of the product often a certain amount of recycling material is used, the outside is PVC highly loaded with pigments and/or ASA for higher weathering and especially UV resistance. Theysohn has developed special solutions using ring-channel-dies to form the outer skin. This is an excellent example for combining the competences of Topf tooling on rain gutter profiles with its high requirement for gloss with the vast Theysohn experience in pipes leading to a close match on optical appearance factors, as there are colours and gloss, for systems utilizing gutter systems made from downfall pipes as well as half-shell profiles.


Co-extrusion tools

Co-extrusion pipe head TW 250 direct / TW 400 direct

The TW 250/400 direct co-extrusion pipe head has been specially developed for the production of 3-layer sandwich structured pipes. Foamed or low cost formulations containing regrind or lower levels of expensive pigments and stabilizers for the middle layer reduce costs while maintaining the necessary ring stiffness of the pipe.

  • complete line: conical or parallel twin-screw extruders from Theysohn, co-extrusion pipe head, die sets and downstream equipment
  • co-extrusion block design similar to pipe head design
  • can be used in combination with 2 or 3 extruders
  • easy control of wall thickness distribution through exchangeable parts
  • with the TW direct pipes with following OD can be produced:  TW 250 direct 90 - 250 mm, TW 400 direct 200 - 400 mm
  • with a foamed middle layer, weight savings  up to 30 % compared to compact pipes can be achieved
  • up to 80 % of the wall thickness can be made of regrind  material, with minimum inner and outer pipe layers of 0.5 mm
  • special formulations and customer assistance available
  • co-extrusion die design for stripes on outside of pipe


Co-Extrusion Block TW 4-10

theysohn-schaumrohr theysohn-TW43-layer sandwich structured pipes are produced with the co-extrusion block TW 4-10 and save up to 30 % material costs. Foamed or low cost formulations containing regrind or lower levels of expensive pigments and stabilizers for the middle layer reduce costs while maintaining the necessary ring stiffness of the pipe. Up to 80 % of the wall thickness can be made of regrind material with minimum inner and outer pipe layers of 0,4 mm. With more than 150 TW 4-10 co-extrusion Systems sold, Theysohn is able to guarantee  highest levels of experience and assistance incl. special formulations.

Using virgin or recycling material has been the major advantage of this technology. Standard fitting systems, as known for compact pipes, can be used. The output ranges from 200 to 2000 kg/h using a combination of two or three extruders in a production setting. Highest capacity sold is 20 m/min. Smaller dimensions are using double-strand technology. Another big advantage of Theysohn is the low-cost formulation recommended.

Pipes are usually produced to national standards. The main standards are EN 1401-1 and EN 13476 as well as US F 891. Wall thickness is determined in a way that ring stiffness classes of 2, 4, 6 and 8 kN can be achieved. Highest classes already done are 16 kN. A typical application is sewerage pipes reaching a market share of 85 % on comparable applications in Europe, which have totally erased compact pipes for this application.

Development priorities are higher filling of foam core and skin, 3-extruder settings with colouring of the outside skin only and extended use of recycling material in the middle layer.