There are many important components within a die assembly — one being a punch stripper. Below, we’ll discuss what a punch stripper is and why it’s important, as well as some different styles to choose from.
What Is a Punch Stripper?
A punch stripper is a part of a die assembly that holds a workpiece in place. It’s typically placed over a punch and attached to the retainer. However, each die assembly is designed differently.
A punch stripper’s function is to generate enough holding pressure to hold the workpiece in place while the punch retracts from it. There are two objectives here:
- To create a clean, defined punch or shape in the workpiece.
- To cleanly retract the punch from the workpiece after stamping.
To achieve these objectives, it’s critical to choose the type of punch stripper that suits your application best. We’ll help you understand and narrow down your choice below.
Mechanical vs. Urethane Punch Strippers: Which Is Best for Your Application?
There are two main types of punch strippers on the market: mechanical and urethane. Below we’ll describe each of them, along with their respective advantages and disadvantages.
Mechanical Punch Strippers: Pros & Cons
Mechanical punch strippers are an assembly of a tool steel body, a bronze stripper, and a mechanical die spring.
Mechanical strippers are known for their high strength and extended lifespan. Below is a closer look into their top benefits:
- High strength — Mechanical strippers offer stronger and more consistent stripping forces than urethane strippers, increasing strength and ensuring top performance even in advanced stamping applications.
- Long service life — Mechanical strippers offer longer service and punch life than their urethane counterparts, largely thanks to their pre-loaded springs. Mechanical strippers are also rebuildable, unlike urethane strippers.
- Load versatility — Mechanical strippers offer multiple spring options, which enables versatility with desired stripping force..
- Sustainability — Due to their material makeup and increased service life, mechanical strippers are a more sustainable and cost-effective stripping option in the long term.
The most common complaint about mechanical strippers is that they can cost more than other stripping solutions. However, their upfront cost does pay off for many customers in the long term, leaving them happy with their purchase.
Urethane Punch Strippers: Pros & Cons
Urethane punch strippers have rubber-like bodies with vertical tunnels. They generally look like this:
Urethane strippers are known for their simplicity and affordability. The most common benefits of using them are:
- Affordable — Urethane strippers are often cheaper than mechanical strippers.
Urethane strippers’ convenience and affordability come at a cost, however. Common customer complaints regarding urethane stripping solutions include:
- Short service life — Urethane strippers are highly perishable and require more regular replacement.
- Limited pressure — Urethane strippers have limited stripping pressure options and do not have as much load-bearing versatility.
- Higher damage risk — Urethane strippers can fall into the die and cause damage or breakage.
- Low sustainability & cost-effectiveness — Due to their urethane composition and frequent replacement requirements, urethane strippers aren’t as sustainable or cost-effective in the long term.
Moeller’s Industry-Leading Mechanical Stripper Solution: True Strip™
In most cases, mechanical punch strippers are the best choice. Their improved strength and increased lifespan make them a powerful and cost-effective solution for various metal stamping applications, and Moeller has created the best of them all: True Strip™.
True Strip™ is the industry’s strongest and most accurate off-the-shelf mechanical stripper. Built with pre-hardened steel and finished with black oxide for corrosion resistance, it’s built to perform and built to last — even in the most extreme applications. Our customers needed a better solution that made assembly, disassembly, and replacement easier, so we developed it.
Other key features and benefits of True Strip™ include:
- Dual gliding condition to guarantee stability
- No special tools required, unlike imitation products
- Pre-loaded spring that’s threaded to a positive stop
- Eliminates the need for custom stripper plates
- Special multi-hole True Strip™ designs available upon request
True Strip™ is an exclusive, patented product from Moeller. While other industry manufacturers have tried to replicate our design, none have successfully come close. Rival mechanical stripping solutions just don’t perform as well or outlast the True Strip™.
Discover the Benefits of True Strip™ For Yourself
If you’re searching for a durable, high-quality mechanical stripper solution, look no further than Moeller’s True Strip™. Get in touch with one of our representatives to learn more about its unique features and benefits.