The Science of “Elastic Memory”: How Radiation Revolutionized Wire Protection

In 1957, in a small building in Redwood City, Raychem pioneers changed the world of materials science forever [12, 13]. By applying the new science of radiation chemistry to polymers, they created a phenomenon known as “Elastic Memory”—the foundation of every DR-25 tube we manufacture today [14-16].

Covalent Bonds: The Molecular Magic

Standard plastics melt when heated. However, when we expose polymers to high-energy electron beam radiation, we create covalent bonds between polymer chains—a process called cross-linking [17-19]. These bonds act like a molecular web, tying the molecules together so the material becomes non-melting and incredibly tough [15, 18].

The Two-Stage Process of Heat Shrink

1. Expansion: The cross-linked material is heated just enough to melt its crystals, stretched under pressure, and cooled while deformed [15].
2. Recovery: When the end-user applies heat (minimum 175°C for full recovery), the crystals melt again, and the cross-linked “memory” pulls the material back to its original, smaller shape [20-22].

Why Our 20-Year Heritage Matters

Managing the radiation dose is critical; too little and the material won’t shrink properly; too much and it becomes brittle [19]. With 20 years of precision manufacturing, we control this process to ensure every inch of our DR-25 offers optimum high-temperature fluid resistance and abrasion protection [17, 23].

Learn More About Our Radiation Process