The Crush Cut Slitting Method: Why Choose It?
So you have a lot of flexible substrates on hand, all in roll form—and you need to break them down into smaller rolls. Or, perhaps convert them otherwise. What are you going to do? We suggest the crush cut slitting method.
Slitting has been among the more popular converting techniques in the manufacturing industry for quite some time. But if you’re just beginning to navigate the process, it’s easy to become overwhelmed. Don’t worry—consider Conversion Technologies International your resource. We’re walking you through the different types of roll slitting, with a special spotlight on crush slitting. Once you’re sure about which one is right for your company’s purposes, you can rest easy and make plans for the future.
What is crush cut slitting?
Let’s get one thing out of the way first: what is slitting, in general, and why do we use it? An important manufacturing method, slitting falls into the converting industry. Although there are different techniques utilized, in general slitting involves slicing a large roll into smaller, thinner strips. We use the slitting methods to convert different types of substrates. Over time, the industry has started to apply it to a variety of different need and substrate materials. These substrate materials usually serve the following categories: packaging, pharmaceuticals, fashion, food and beverage, and beyond.
What types of products do we use slitting processes for? Think thin plastics, nonwovens, foils, cutting paper, vinyl, and other materials. Usually, those materials will be soft and flexible. Although you’ll find some degree of variation depending on the type of slitting, equipment always involves a slitter machine. Each machine unwinds the roll and slices it, rewinding the final product into smaller, slimmer rolls.
As you explore different slitting processes, you’ll find subtle—or sometimes glaring—variations. A popular type of slitting process is crush slitting or crush cut slitting (another term we use is score cutting or score slitting). With this process, we take a moving substrate and pass it between solid rotating anvil and a circular rotating knife or set of rotating knives. The knife or knives (sometimes referred to as score blades) make up the “crush slitter”.
If you need a cheat sheet, just remember: this type of slitting tends to be the most commonly used out of all the available options. We’ll get into why that is a little later.
What do we use crush slitting for?
There’s a reason why this type of slitting is so popular compared to its alternatives. As previously mentioned, all types of slitting generally apply to more pliable materials. The final products we apply them to therefore tend to involve packaging; when flexibility is the need, slitting is the process that splits the materials you’re working with.
One differentiator in favor of crush slitting is its cost efficiency. Although some markets can use different types of slitting, cost-conscious companies often prefer crush slitting because its components are less expensive than the alternatives. Additionally, this method tends to be easier. You don’t have to worry about complicated setup issues. Holders, mounted squarely against the main surface, are the extent of the issues. Plus, the knives we use in this process don’t need to be super sharp—that means less maintenance.
In short: we can apply crush slitting to a lot of different products. We tend to prioritize it over other methods because it’s easier to apply and maintain, and—yep! Less expensive as well. It’s no wonder that the industry tends to favor this process over others. But if you need alternatives…
What are the different types of slitting methods?
We’ve spent a lot of time covering crush slitting already. So, what about the other options on the table? Let’s cover them.
Shear slitting. Perhaps the main rival to crush slitting, shear slitting differentiates itself with a somewhat softer technique. The “crush” in crush slitting refers to the heavier force of the process. Shear slitting, on the other hand, relies on a top and bottom knife, both of which have defined designs. This creates a shear force, similar to that of everyday scissors. This means the slitting occurs at the exact cut point, creating a clean-cut edge.
Because this method requires a careful positioning of the top and bottom knife, it’s a bit more complicated than crush slitting. Operators must position the blades in opposition to each other, double-checking the distance before the cutting begins. Additionally, the shear slitting process requires regular blade resharpening.
Even though it’s a bit more complex, shear slitting can produce a more uniform, cleaner edge. It also produces less dust than crush cutting. So, yes: while crush slitting is cheaper and easier, shear slitting may be preferable if you need more precise results.
Custom razor slitting. With this method, we feed material into razor blades at a precise angle. We can execute this with or without support, placing a grooved razor below the material. Typically, this method suits jobs wherein we require a higher speed. The cuts are smoother and more accurate, but it takes more time to set up than crush slitting.
Conclusion:
Although there isn’t a perfect slitting method, you can certainly get close with the right technique. We recommend researching each method carefully before making a final decision—and from there? You may want to start talking to the experts.
CTI is ready to guide you through the selection process—we have the tips you need. Give us a call at 419-924-5566 or connect with us here. We’re ready to help!