At Frontier Technology Corporation (FTC), one of our core specialties is neutron shielding. We offer cutting-edge protective shipping containers for radioactive materials and other essential technologies for handling hazardous neutron sources such as californium-252 (Cf-252). 

Water Extended Polyester (WEP) resin encases materials and creates a strong, effective barrier around the material to protect anyone nearby and the surrounding environment from the hazards of neutron source exposure. Since this resin is capable of successfully enclosing neutrons, it performs well as a shield when transporting Cf-252. In this blog, we will talk a bit more about WEP resin, including its key features and advantages.

What Is Water Extended Polyester (WEP) Resin Material?

WEP beads are a solid polyester resin material and are emulsified with water to enhance their physical properties. After the emulsion process, fillers are added to reduce shrinkage and adjust appearance before a catalyst is used to cure the material.

Extending the resin with water absorbs heat, making it easier to cast parts without exotherm issues while keeping productions costs low. Since the resin mixture has low viscosity, it can properly form to the exact shape of complex and intricate designs with minimal risk of error. It also cures quickly, allowing for quick mold turnover. 

What Are the Advantages of Water Extended Polyester Resin Material?

Choosing the right material for every part of neutron source containment equipment is crucial. WEP resin boasts excellent protective performance when used as shielding for neutron sources, as well as for personnel safety equipment, shielding walls, and pass-through ports. Along with excellent performance as a neutron-containing material, it offers these key advantages:

Frontier Custom Neutron Shielding Wall
Frontier Custom Neutron Shielding Wall


Because WEP resin is mixed with a substantial amount of water to achieve its beneficial properties, this results in a lower cost relative to other materials. WEP resin’s ability to cure quickly and completely fill complex molds also cuts costs by reducing production times and eliminating the risk of incomplete or poorly made finished products.

Track-Free Curing 

Resin-based products cure in the air without needing any heat or specialized curing processes, resulting in track-free cure.

Beneficial Qualities

WEP resin has a variety of desirable qualities, including:

  • Resistance to wear and weathering
  • Temperature resistance in relatively low-heat environments of up to 176°F (80°C).
  • Low shrinkage, which can be augmented with the presence of proper fillers
  • Resistance to water and other chemicals

Water Extended Polyester (WEP) Resin at Frontier Technology Corporation

At FTC, our team excels at creating the radioactive protection that industries need to ensure safe handling and disposal of these materials. Our shielding solutions are trusted throughout the mining, nuclear, and military industries, among many more. 

To learn more about our WEP material, neutron shielding, or to get started on your shielding solution, click here for our main neutron shielding resource or contact us today.