Thermoplastic prepreg and semipreg

Continuous fibre-reinforced thermoplastics are already indispensable in numerous applications due to their outstanding properties. They are the ideal choice for the manufacturing of components that require an optimal stiffness-to-weight or strength-to-weight ratio. A wide selection of thermoplastics as matrix materials offers solutions for many applications. At Ensinger, we have been demonstrating our expertise in thermoplastics for over 50 years. In doing so, we are continuously developing our products, materials and offerings, including fibre-reinforced composites.

The Ensinger portfolio of composite materials includes thermoplastic composites in the form of prepregs, semi-pregs and organosheets.

  •  Semipregs are fabrics onto which the selected thermoplastic matrix material is applied as polymer powder and melted on.
  •  Prepregs are the next processing stage. Here, the semipreg is fully impregnated and consolidated under temperature using a double belt press. 
  • Organosheets are manufactured at Ensinger from prepreg or semi-preg material or using a film stacking process. They are fully consolidated and impregnated multi-layer sheets. You can find out more about our organosheets here.

Our prepreg and Semipreg composite portfolio

With our thermoplastic semipreg and prepreg materials, we offer high-quality fibre-reinforced thermoplastics. They are available made of carbon and glass fibre fabrics as well as synthetic fibres such as aramid, basalt fibres or natural fibres, which are resinated with thermoplastic materials as a matrix. The materials used range from technical polymers such as polycarbonate and polyamides to high-performance plastics such as PEI, PPS and PEEK.

Thanks to Ensinger's own compounding, special blends and compounds for semipreg and prepreg materials can also be produced. This means that even unusual customer requirements can be met.

The different delivery forms result from the nomenclature of the TECATEC material:

  • TECATEC-CP = Semipreg
  • TECATEC-IP =Prepreg
  • TECATEC-OS =Organosheet


At Ensinger, we cover the entire process chain in-house - from raw material to finished component. Our portfolio ranges from powders, semipregs, prepregs, organosheets, compression moulded composite plates and finished parts to customer development projects that are realised with a wide variety of material combinations. With Ensinger TECATEC composite materials:

  • Every process step, from grinding and powdering to further processing of the semipregs into prepregs, organosheets or the end product, can be carried out by Ensinger.
  • Special mixtures and compounds for composite materials can be produced thanks to in-house compounding.
  • The use of customer-specific materials, matrix and fibre combinations or fibre architectures is possible in order to create a solution tailored precisely to your application.
  • Fast response & delivery times are possible.
  • There is no minimum order quantity for standard materials.

Thermoplastic prepreg and semipreg materials offer many advantages

  • High impact strength and significantly higher damage tolerance than thermosets
  • High chemical resistance
  • High temperature resistance
  • Tough, non-brittle fracture behaviour due to high elongation at break of the thermoplastics
  • Intrinsic vibration damping of the matrix
  • High stiffness with low weight
  • Extremely low coefficients of thermal expansion (CTE) in a range of about 5x10-6 K-1
  • Automatable production
  • Short process times
  • Thermoformability & weldability
  • Transportability and storability at room temperature
  • Recyclability

Production of semi- and prepreg material

The process of composite manufacturing begins with the grinding of the plastic granulate. The spectrum of thermoplastic polymers that can be ground into powders in-house ranges from engineering plastics such as PP, PA6 and PC to high-performance plastics such as PPS, PEI and PEEK. With their tight tolerances, the powdered materials meet the high demands placed on the application of modern composites.

The powder is then applied to textile semi-finished products, for example carbon or glass fibre fabrics, in the prepreg plant and subsequently melted and pressed. The resulting semi-finished product is called semipreg.  

If the semipreg is then consolidated and impregnated by a double belt or step press, it is referred to as a prepreg. An organosheet is a multi-layer composition of prepregs that are consolidated.

Further processing of the semipreg materials into prepregs and organosheets takes place on Ensinger's own double belt press. With a working width of up to 1800 mm, the double belt press processes not only Ensinger's own thermoplastic semipregs but also unidirectional (UD) materials, UD cross-ply materials, laminates and sandwich laminates with various core materials such as foam or honeycomb. Various combinations of textiles and polymer matrix materials can be realised, including carbon, glass, aramid and natural fibres. Thermoplastic composites can thus be produced in high quantities on the double belt press. 

We support them in the further processing of our materials. With over 15 years of experience in component and process development in the field of thermoplastic composites, we can offer you a customised solution for your application.