Multishot Weakens Reliability — MPS Builds the Future of EHV Insulators

Are your EHV Polymer Insulators Designed for Manufacturing Efficiency or Product Longevity?

It’s easier and cheaper to make an EHV insulator in multiple segments instead of in one shot. This segmented process requires removing all microscopic contaminants on the rod, preheating it, injection-molding over one section of it, and then allowing it to cure and cool. Afterwards, hours or days later, the entire preparation and process will be repeated on each of the subsequent sections.

Protect the Rod, Protect the Life

Over time, moisture and electrical activity will degrade fiberglass, so the insulator’s rubber sheath is there to encapsulate and protect it. Multi-shot injection molding introduces weaknesses that can allow moisture to reach the fiberglass, such as weak rubber to rubber molding joints, rod contamination between molding operations, and crimped end fittings being reheated. Additionally, the injection molding process introduces mold parting lines that provide a convenient shelf for pollution to align down the length of the insulator. This is the most common way suppliers manufacture polymer insulators – is there a better way that removes weaknesses to increase the insulator’s lifespan?

Designed for Longevity

MPS’ manufacturing processes provide a 50-year expected life by engineering out these weaknesses to better protect the rod. We do so by extruding a seamless sheath of our proprietary silicone along the entire prepped rod in one step – up to twenty-feet long. There are no rubber-rubber joints, no mold parting lines, no reheating of crimped fittings, and a non-destructive bonding check is done on every unit. A subsequent step allows MPS to apply a shed pattern chosen by your team that best fits the characteristics of each project.

Click here to learn more about how MPS polymer insulators are designed for longevity in the harshest environments and up to 765kV.