FibreTuff for Micro Molding and Extrusion

Micro molding Accumold part

FibreTuff Micro Molding

 FibreTuff compounds are a novel solution for creating radiopacity in micro molding and extruded medical devices and implants. The traditional fillers used for radiopacity / radiopaque in polymers are barium sulfate, bismuth and tungsten. FibreTuff can replace these traditional fillers in nylons, polypropylenes and PEBAX. Furthermore, these traditional fillers are 4 times heavier and more costly. Plus, these traditional fillers will compromise part performance, or make the part brittle with less elongation and lower strengths.

Consider using FibreTuff when the following requirements are needed:

  • Devices needing radiopacity and absorbable qualities.
  • Not degradable in the human body.
  • Drug delivery
  • Devices requiring Standard Sterilization methods.
  • Sensitive tooling constraints - long production runs.
  • Gates sizes are more than 0.003"

Cost Benefits using FibreTuff 

  • Specific Gravity is 20 to 30% less than other biomaterials.
  • Doesn’t require specialized packaging.
  • Not very hygroscopic at 10-30% cellulose
  • No Extensive drying - at 20% cellulose with high heat polymer .21% Test method ISO 62 24 hr. immersion.

Micro Molding Customers

Process validation

• Sodick injection system is good for FiberTuff material evaluation per Kohei Shinohara.

• Sodick utilizes a proprietary two-stage V-LINE method for plasticizing and injection


• Both 14mm screw and 18mm screw were used to mold. The feeding is better on the

18mm screw but both small screw treat the raw material of FiberTuff biopolymers.

• The process was very stable and the parameters were consistent.

FibreTuff Specifications for Micro Molding

Tensile Str. @ Yield ISO 527  41 Mpa

Tens. Elong. @ Yield ISO 527  3.2%

Flexural Strength ISO 178  60 Mpa

Flexural Modulus ISO 178   2,540 Mpa

Izod Impact Strength ISO 180 kj/m2      3.69

Specific Gravity ISO 1183    1.0190

Gardner Impact D54    20 ft.lbs.

Heat Deflection ISO 75  85.70 C

Color Visual - Radiopaque

Flow Rate * D1238 gr / 10 minutes 5.7

Moisture D6980   0.07%

Medical Tubing extrusion with FibreTuff

FibreTuff can be added as a master batch / salt and pepper mix to increase radiopacity of certain types of medical tubing - PEBAX, Nylon and Polypropylene. The traditional fillers used to increase radiopacity - barium sulfate, bismuth and tungsten is used at 40 to 50% loadings which sacrifice the elasticity of tubing and will increase brittleness.