Composite Technologies

Powder Towpreg

Adherent Technologies, Inc. (ATI) has developed a powder impregnation and fusing process for the high-speed production of high-quality, low-cost towpreg (“powder towpreg”) for filament winding, braiding, tow placement, and other processes that benefit from using a pre-impregnated tow. Because of the high operating speed of this process (15 to 40 m/min), conversion costs of standard systems are low, leading to lower final part costs. Although the production line (see figure below) serves as a demonstration facility, it has the ability to operate on very small quantities (as low as 2 kg) of experimental powders, a valuable benefit when using expensive materials.

Overview of towpreg line

Overview of towpreg line, machine direction is right to left: (1) tow payout, (2) tow spreading, with machine vision system to monitor tow width and gaps in the spread tow, (3) powder deposition (4) IR ovens for fusing polymer onto the tow, (5) cFP-2020 embedded processor with peripheral devices and pneumatic controls, (6) gamma ray backscatter gauge for monitoring polymer loading, and (7) windup

This technology is extremely flexible in regard to the wide range of materials that can be applied to the fibers. Examples include conventional thermoplastics and thermosets, including specialized aerospace resins such as BMI and polyimide. ,

Features of the ATI powder towpreg and powder towpreg process include:

  • 100% solids product, no solvent removal, therefore no VOCs (e.g. preimidized), reduced toxicity
  • Very fast overall cure cycles for polyimide (4 hours vs. 32 hours for standard slit-tape in complex wound parts)
  • Out-of-autoclave curing for imidized resins used in high-temperature polymer matrix materials
  • Extremely long shelf life (no refrigeration needed)
  • Ability to handle otherwise intractable materials
  • Ability to handle high-melt viscosity materials
  • Ability to incorporate fillers (including nanomaterials) within the tow without introducing filtering effects
  • Compatibility with all current filament winding, fiber placement, braiding, weaving, and pultrusion operations

These features, depending on the specific application, have the potential to yield tremendous production cost savings as well as greatly enhancing the operating characteristics for manufacturing final products.