Thermoplastics are replacing traditional thermosetting resins as matrices in composite
materials in many applications due to their enhanced properties. Thermoplastics exhibit better
toughness, durability and damping properties and provide the options of continuous processing,
reshaping, and reparability, as well as more favourable recycling and processing routes that do
not involve chemical reactions [1]. However, their high melt viscosity makes it difficult to
impregnate continuous fibres, which restricts commercial applications.
Recently developed dry coating techniques allow the production of long fibre
thermoplastic matrix towpregs without most of the previous impregnation problems [2, 3]. In this
work, a new coating line was developed to produce long fibre dry coated thermoplastic matrix
towpregs at rates compatible with industrial production. The polymer deposition rate was
considerably increased to allow processing towpregs at greater speeds (approx. 10 m/min) than
current equipment. A new coating chamber was used to allow improved control of the fibre and
polymer contents and the towpreg impregnation quality. Other general improvements were also
made in the equipment to allow better monitoring of the towpreg processing.
Glass or carbon fibres with polypropylene towpregs (GF/PP and CF/PP, respectively)
were produced on the new coating line which were then submitted to extensive tests to verify
their polymer content and impregnation quality.
This paper presents the results of the tests and discusses the optimization of the new dry
coating line. The results show that the new deposition chamber allows production of economical
thermoplastic matrix towpregs with improved efficiency that may be used in the industrial
production of composites for commercial markets.
Local photo-polymer deposition-assisted fabrication of multilayer paper-based devices
