Slitting

Training on the fundamentals of web processing can be as fun as attending the Kentucky Derby! This year, attendees came to Louisville this year to sharpen their knowledge on web alignment, slitting, winding/unwinding and of course tension control. Each day offered an in-depth look at the principles of one aspect of web handling.

Select the individual courses to improve your specific operational needs or attend all sessions! Industry experts from Fife, MAGPOWR, Tidland, and more will teach you how to make the most of what you've got, or help you to determine what improvements you actually need.

In shear slitting, blade profile is one of the most frequently asked questions. While slit-edge quality is the result of many factors, blade profile is one of the factors most frequently changed in an attempt to improve slit quality. Often, a profile change does not yield the expected results because the shearing mechanism itself is not well understood.

Score slitting, often referred to as “crush” slitting in international markets, is a common method of separating the web. Basically, a hardened steel disk is pressed against a rotating, hardened steel cylinder, creating a crushing nip into which the material is directed. The resultant nip force exceeds the ultimate yield of the material, and the material is severed along the nip line.

The three most common methods of slitting flexible web materials are shear, crush (score), and razor. Of these three, razor has the lowest installed cost, being the simplest and cheapest method. It can be easily adapted to almost any machine, in almost any location. It is potentially the cleanest method of slitting, assuming the appropriate materials are being slit.

Peter Wood starts the day off with an engaging demonstration of fracture mechanics. Attendees then put the theory to practice, taking a break from the books to interact with a hands-on slitting demonstration.

There are several methods of slitting aluminum foil, including shear, razor and crush (score) slitting. This discussion focuses on the shear slitting method, since it is capable of slitting under a far wider range of calipers, tempers, and speeds than razor or crush methods.

Typical Problems

Lecture topics include the following subjects:

Fracture Mechanics: Learn the science of how things come apart at a molecular level. This topic covers the mechanics of web separations using different slitting technology. You’ll also explore the characteristics and properties of the different materials you may be slitting.

Gone are the days when a shear-slitting knifeholder was a primitive, cast-iron contraption that required a pocketful of wrenches every time a pattern change was made. It had to have the durability of an anvil because repositioning involved a lot of pounding with a hammer. Lost time, lost product and accidents were a fact of life. This, of course, is no longer acceptable.