Slitting is an essential process in material converting. The process creates narrower strips from a larger roll of material like paper, plastics, vinyl, foil, nonwovens, and other pliable, soft materials. A slitting machine provides superior results by cutting precise strips from heavy rolls. Also called a slitter or slitter rewinder, slitting machines can unwind the larger roll, cut it into the desired widths, and tightly rewind the smaller rolls.
Many sectors rely on slitting for material converting, including the fashion, pharmaceutical, food and beverage, and packaging industries. We will discuss the main types of slitting machines to help you determine the ideal solution for your application.
Types of Slitting
There are three primary types of slitting processes, each categorized by its cutting technique or device:
- Shear slitting
- Score slitting (also called crush slitting)
- Razor blade slitting
The ideal slitting machine process for your application depends on the type of material you intend to cut.
Shear slitting is one of the most prevalent slitting methods employed in the converting industry. The process uses a male knife to make contact with a grooved female knife, cutting with a mechanism similar to a pair of scissors. Shear slitting machines can cut in various widths depending on the spacing of the female knives or several gang knives. The female knives have a specific spacing on their shaft to cut a specific width.
Shear slitting machines can quickly and precisely cut thin materials with high-quality edges. A standard shear cut male knife holder can reach a maximum speed of 3,500 feet per minute, and a high-speed holder can reach speeds of 10,000 feet per minute.
At Jennerjahn, we offer a variety of shear slitting machines. On our JLS machines, the female knife shaft is typically set up with gang knives for any slit width with 1/2” increments across the width of the machine. On JJF, JJM, JJS, and DJJF machines, the female knife shaft is typically set up with 3/8” wide female knives with spacers to give a specific slit width across the width of the machine. The two most common JJ machine set ups are 3-1/8” and 2-1/4” slit widths.
Also known as crush slitting, score slitting machines use a knife with a rounded edge to force the material into a surface-hardened female knife shaft (called an anvil shaft) or hardened sleeves on a female knife shaft. This action crushes the material by thinning it under the knife, which slits and separates the material. This method is ideal for materials of varying rigidity and thickness.
Crush slitting can be unreliable at higher speeds, so the maximum speeds of our crush slitting machines are lower. A standard score cut male knife holder has a maximum rate of 950 feet per minute, and a high-speed holder can reach 2,000 feet per minute. Crush slitting machines have adjustable slit widths that can accommodate nearly infinite possibilities.
Score slitting is more common on our JLS machines than our JTS or JJ style machines.
Razor Blade Slitting
Razor blade slitting relies on a thin sharp blade in a stationary position to slit material as it passes through the blade. This is preferred as an economical and straightforward slitting method, especially for thin foils and films. Razor slitting relies on lower speeds than the standard 2,300 feet per minute and offers near infinite variability and width adjustment.
Slitter Rewinder Machines at Jennerjahn Machine
Slitting machines can quickly and precisely cut large rolls of material into smaller rolls for convenient transport, storage, and use in converting applications. Razor blade slitting, score or crush slitting, and shear slitting are the three primary slitting machine types, capable of a range of cutting speeds and slitting widths.
Jennerjahn Machine was founded in 1979 and has become one of the world’s most renowned slitter rewinder machine manufacturers. We deliver innovative solutions to our clients through our commitment to customer service, and we have partnered with converters in 24 countries worldwide.