PSI Kolkata

  If you've spent any time around motors, transformers, or heaters, you've probably heard someone say "just use a mica sheet" without ever explaining why. So let's actually explain it - in plain language, no jargon dump. We've been making mica sheets at PSI for thirty years now, and if there's one thing that hasn't changed in three decades, it's this: most insulation failures don't happen because someone picked the wrong material. They happen because nobody explained what the numbers on the datasheet actually mean for the job at hand. This guide fixes that. What a Mica Sheet Is, in Plain Words Mica is a natural mineral that splits into thin, flat layers - and those layers happen to be excellent at two things: blocking electricity and resisting heat. A mica sheet takes that raw material and turns it into something you can actually use - a flat, workable insulation board or roll that sits inside motors, transformers, switchgear, and heaters to k...

  A lot of attention has gone into 4680 battery cells over the last few years, and honestly, it's easy to see why. They store more energy, reduce the number of cells needed inside a battery pack, and help manufacturers squeeze more performance out of the same space. For EV makers chasing longer range, that's a pretty attractive package. But every battery engineer knows there's another side to the story. The more energy you pack into a cell, the more important it becomes to control what happens when something goes wrong. And that's where thermal propagation enters the picture. If you've ever seen footage of a battery fire, you've probably noticed that it rarely stays confined to a single cell. One cell overheats, the neighboring cell gets hotter, then another follows. Before long, the issue has moved well beyond the original failure point. With larger-format cells like the 4680, that risk becomes harder to ignore. Because each cell stores more energy, a failure e...

When people look at finished mica products, they usually see a clean, uniform sheet or tape and assume the process behind it is straightforward. In reality, the mica industry involves a series of careful steps where even small inconsistencies can affect the final outcome. Over the years, I have come to realize that producing reliable mica insulation is less about machinery and more about control, patience, and understanding the material itself. Mica is a natural mineral, and that itself introduces the first layer of complexity. Unlike synthetic materials, it does not come in perfectly uniform form. Every batch can behave slightly differently. That is where most production challenges begin. Variability in Raw Material One of the most fundamental challenges in mica production is the variability of raw mica. Mica is mined, not manufactured. Its quality depends on geological conditions, mining practices, and processing methods. Even within the same source, the mineral can vary in: Flake si...

Choosing the right mica product is not something I take lightly, especially after seeing how insulation decisions affect real industrial performance. Over the years, I have worked with engineers, plant managers, and procurement teams who often focused only on price or thickness. But in practice, selecting the correct mica material goes much deeper than that. Mica products are used in environment s where heat, voltage, and mechanical stress exist together. If the wrong type is selected, the system may still run initially, but problems start appearing over time. Insulation breakdown, overheating, or unexpected shutdowns are usually the result of poor material selection. Understanding Your Application First Before selecting any mica product, the first step is to clearly understand where and how it will be used. In my experience, these are the questions that matter most: Is the application electrical, thermal, or both? What is the operating temperature range? Is there high voltage involved...

I’ve lost count of how many times someone has asked me this on-site -  “Which one should we go with, muscovite or phlogopite?” It usually comes up when a project is already facing heat-related issues, or when a new installation is being planned and nobody wants surprises later. On paper, both look similar. Both fall under mica insulation materials . Both are used across motors, generators, and cables. But once you start working with them in real conditions, the differences become pretty clear.  Where Muscovite Mica Is Commonly Used In a lot of motor rewinding workshops I’ve visited, muscovite mica is still the go-to material. It’s widely used, easy to source, and works well in standard electrical applications. You’ll often see it in: mica sheets for motors Slot insulation in rotating equipment General-purpose mica tape insulation For moderate temperature ranges, it does its job without issues. From a handling point of view, it’s also easier. Clean splitting,...

 I still remember one inspection we did in a manufacturing unit after a minor fire incident. The damage wasn’t massive, but what stood out was this - a few systems stopped working much earlier than expected. Not because the equipment failed, but because the cables feeding them couldn’t hold up. That’s usually where people start paying attention to fire survival tape . Until then, it’s just another layer inside a cable that nobody really thinks about. Why These Cables Matter More Than People Realize In normal operation, cables just sit there doing their job quietly. Carrying current, nothing dramatic. But during a fire, the expectation changes completely. Now those same cables are expected to keep emergency systems alive - alarms, exit lighting, sometimes even control circuits that help shut things down safely. I’ve seen setups where everything depended on those few circuits staying active for even 20–30 minutes. Without proper electrical insulation materials , that simply d...