I kind of used the word “slit” a bit excessively there, but oh well – at least people interested in slitters would easily find their way to this article.
So slitting, huh?
I’m a veteran at writing about slitter rewinders but really, it gives me a light chuckle every time. This is probably due to watching too many horror movies, but saying the word “slitting” repeatedly on the back of my mind kind of has a gory ring to it. Don’t you think?
Anyway, moving on to our agenda for today, I would be talking about different slitting techniques that slitter rewinders use. But first, let’s give our newcomers a brief overview of what slitter rewinders are.
What Are Slitter Rewinders?
Slitter rewinders is a machine used for torture – nah, just kidding (Sorry, I just couldn’t help myself).
This is the real deal now.
Slitter rewinders are industrial machines used to cut, sever, and separate large rolls of materials into commercially sized products like tissue rolls, adhesives, Velcro, foil, paper etc. As you have guessed, slitter rewinders work mostly for circular, rolled items.
The machine’s name basically tells us how it is used. “Slitter” because the first function of the machine is to split the material into thinner sections. Then “Rewinder” because it rewinds the severed material into the tubular handle creating the convenient rolls we know and love.
Slitter rewinders was a groundbreaking invention that helped many industries increase their productions. The first one ever was a creation of Mr. John R. Pulsifer in 1901 (see this article if you wish to read more about the history of slitter rewinders). For more than 100 years, this slitting technology has been refined and reinvented repeatedly until it became the slitter rewinders we know of today – safer, faster, and more efficient.
Also, throughout the years slitter rewinders have evolved from being a one-type-fits-all kind of machine to a diverse set of purposive machines. Simply put, different materials require slitter rewinders that apply different slitting techniques. This allows the machine to cut the material more appropriately.
3 Slitting Techniques You Ought To Know Of
The Razor Cut
Razor cuts are divided into two kinds: In Air and In Grooved Roll. The difference between the two razor cuts mainly have to do with the surface the material is cut against but overall the method is the same.
The razor cut is the simplest slitting technique in the history of slitting techniques. There’s a razor, the razor touches the surface of the material (in air or in grooved roll) and slit. That’s it.
A thing to note about the razor technique though is that it works best with thin and light materials like tissue, thin papers, or baking sheets.
The Score Cut
Also popularly referred to as the crush cut. Why? Because it “crushes” the material with a dull blade in order to divide it into sections. This technique actually dates back way before your granddaddy’s prime and was also the technique used for slitter machines back in the olden days.
But you might be wondering, why build a slitter rewinder that can’t cut very well – doesn’t that defeat the purpose?
The score cut technique is mainly targeted at semi-adhesive and adhesive rolls. What the score cut lack in sharpness, it compensates with pressure. Using sharp blades, adhesive material would be problematic because the sides or edge of the rolls it produces will still be sticky. Using the score cut technique however, the dull blade and slight pressure it applies on the material’s surface make the edges lose its stickiness. This makes the roll neater and more comfortable to handle with bare hands.
The Shear Cut
Shears look very similar to scissors. The shear cut technique, unsurprisingly uses the cutting method that scissors and shears share. With two blades, the shear cut technique cuts by pressing the upper and lower blade against the material simultaneously as it slowly passes through the blades’ junction. However, the only difference is the automation of the process. Normal shears or scissors cut through paper by manually making the two blades meet together. In a slitter rewinder machine, the shear cut method is made possible by two lateral rotating blades. This continuous rotation is necessary because the shear cut method is used for heavier and thicker materials.
