Senior Flexonics Pathway manufactures a variety of composite belt configurations to meet the varied needs of all our customers. Shown for illustration purposes is one of the premium grade belt constructions for each rated continuous operating temperatures.

 

Fluorinated Elastoplastics

Fluoroelastoplastics combine the corrosion resistance of a fluoroplastic with the flexibility of a fluoroelastomer through the addition of FKM to the PTFE compound. Fluoroelastoplastic materials have been used successfully in over 10,000 expansion joints worldwide, providing exceptional performance even in the severe chemical environments found in flue gas desulfurization plants (FGD), pulp and paper (recovery boilers), refuse derived fuels (RDF) and smelters.

DARLYN® Product Line

Senior Flexonics Pathway is an authorized fabricator of expansion joints utilizing Chemfab Corporation's DARLYN fabrics. These products were first introduced in 1983. The DARLYN line of materials are fluorinatedelastoplastic alloys. Because of their thermal and chemical capabilities, fluoroelastoplastic fiberglass reinforced, PTFE-coated and laminated belting materials are being used extensively in expansion joint designs for all types of systems.

Perfluoroplastic, due to its crystalline nature, is inherently stiff which reduces the long term flex endurance and life of PTFE fabric expansion joints. To overcome this shortcoming, fluoroelastomer (Viton®/Fluorel®) is blended into a patented alloy which bathes the coated fiberglass matrix significantly increasing the flexibility, tear resistance, tensile and shear strength of DARLYN fabricated belts. This means longer in-service life.

DARLYN can be easily identified by its lack of stiffness. The uniformly distributed alloy coating is more compliant than PTFE, filling the voids and impregnating the woven structure. This pliable matrix maintains consistent physical and chemical properties over a wide range of temperatures and corrosive conditions experienced in flue gas ductwork.

Consistent Coating Process

The DARLYN series of products are coated and cured over a dozen times in the patented process. The multilayer alloy coating of PTFE and FKM completely surrounds the fiberglass foundation, and then is multi-coated with PTFE. This unique procedure is a characteristic of the detailed quality and consistency which guarantees the longevity of the DARLYN products.

DARLYN material is manufactured with 100% defect free, continuous, twisted multiple filament fiberglass. This means that for the entire length of your DARLYN belting material the strands are uncut, homogeneous and guaranteed the strongest fiberglass fibers possible. Numerous strands are than grouped and twisted together maximizing the flex, tensile, shear and tear characteristics of thousands of filaments. These glass yarns are then bathed with a protectant PTFE coating to resist self-abrasion and friction during flexing, and chemical attack preventing acid from wicking in service, which destroys conventional woven glass.

DARLYN 1100 CB & ULTRACHEM

CB or Chemical Barrier was developed for superior corrosion resistance. A multilayer PTFE cast film is thermally and chemically welded to DARLYN 1100 and ULTRACHEM assuring an even greater protection from corrosion due to exposure in the most extreme conditions. This isotropic film (identical physical properties in all directions) is built up through multiple operations assuring a uniform thickness, nonporous, chemically inert barrier. Further, when combined with the DARLYN and ULTRACHEM isotropic fabric, the result is a uniform membrane which can flex without stress concentrations, distributing the load equally throughout the belt.

High Temperature Applications

  • Superior strength retention, even after repeated flexing.
  • Fast, easy field splicing
  • Outstanding corrosion resistance
  • Less than 1/4 the weight of 100% fluoroelastomer fabrics, resulting in lower installed costs

FLEXON-700

A composite belt designed to provide continuous reliable service at 700°F (371°C). A tightly woven fiberglass insulation is thermally bonded to the FLEXON material. This composite design provides insulating properties at elevated temperatures and prevents separation of the insulation.

FLEXON-1000

A composite belt designed to provide continuous reliable service at 1000°F (538°C). A non-woven fiberglass needle-mat insulation is bonded to the ULTRACHEM material and encased in aluminized coated fiberglass cloth.

FLEXON-1200

A composite belt designed to provide continuous service at 1200°F (649°C), by the addition of a 1/2" (13 mm) of ceramic mat insulation to the FLEXON 1000. Inconel® wire inserted silica cloth is used as the encasement to replace fiberglass in applications above 1000°F (538°C).

FLEXON-1500

A composite belt designed to provide continuous service at elevated continuous temperatures to 1500°F (816°C).

Note: Designs are available to 2000°F (1090°C).

Ultraflex EV4® Fluoroelastomer and Elastomer Design Data

Belt Construction

  • Fluoroelastomer terpolymer material, ASTM FKM (Viton® B with a C Cure or Fluorel® FT2350) per FSA-DSJ-401-94, Para. 3.1 (virgin FKM 68% by weight Flourine / 70% by weight FKM, balance 30% by weight thermal type carbon black with calcium hydroxide. Magnesium oxide and less than 5% by weight process aids).
  • Aramid / fiberglass reinforcing material treated to ensure a minimum 24 lbs. / lineal inch Adhesion per ASTM D-413
  • Heavier FKM ply on gas slide providing optimum "unbalanced ply" design
  • Computer controlled belt press that guarantees optimum uniform pressure and heat distribution over the entire material surface