TIP OF THE WEEK: Slitting Methods

A closer look at the three main types of slitting; Razor, Shear, and Score.

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Understanding Different Slitting Methods

There are three principal slitting methods for slitter rewinders, and recognizing the optimal method for your material mix is crucial. Below is an examination of these methods, their advantages, and the suited products.

Razor Slitting

Razor Slitting involves using razor blades set at an angle either in individual holders or multiple configurations in cassettes to slit the moving web. There are two variations: Razor-in-Air and Razor-in-Groove. Razor-in-Air offers simplicity without extra support, making it suitable for slower speeds. Razor-in-Groove, on the other hand, employs a roll with grooves to support slitting at higher speeds. This method is economically favorable with low tooling costs and is ideal for thin films and lightweight foils.

Shear Slitting

Shear Slitting employs a male and female circular knife creating a rotating 'scissor' effect on the incoming web. The female knives are shaft-mounted while male knives can be individually held or shaft-mounted. This method yields excellent slit quality at high speeds with minimal dust creation and extended knife life. Applicable to various materials like films, paper, laminates, tapes, textiles, and foils.

Score Slitting or Crush Cutting

Score Slitting or Crush Cutting is a widely utilized slitting technique, especially for older slitter rewinders. It uses a rotating knife pressed against a hardened roller, also known as an anvil roll. The simplicity in adjustment allows easy width changes. Crush slitting works efficiently on diverse materials including tapes, self-wound adhesives, textiles, non-wovens, foams, and rubber.

All three slitting methods have demonstrated their efficacy in the industry. Depending on your material mix, using multiple methods in a single machine can be advantageous. Elite Cameron often provides machines integrating two methods, typically razor and shear, or razor and score. However, we have also engineered solutions encompassing all three methods.

Detailed Overview of Slitting Types

In the converting industry, slitting is an essential process during production. Large rolls of soft, flexible materials such as film, foil, plastics, technical textiles, and paper are converted into narrower strips for further processing. Slitting machines create precise cuts to accomplish this. Given the challenge of accurately slitting soft materials, selecting the right slitting method and blades is vital. Konetool, a seasoned supplier of tungsten carbide slitting blades, shares practical experiences and insights into slitting types and blades.

What is slitting in converting?

In the converting sector, slitting is a well-known process. Flexible materials are initially produced into large rolls for easy transportation and storage, known as parent or master rolls. These need to be sliced into smaller widths for production needs, making slitting an essential method. Through slitting, master rolls are transformed into narrower strips suitable for various applications.

Slitting is versatile and can handle materials like paper, films, foils, fabrics, textiles, leathers, vinyl, plastics, tapes, and more, widely used in industries such as packaging, automotive, food processing, medical, and recycling.

Types of slitting

There are two main slitting types: log slitting and rewind slitting. Log slitting involves cutting the parent roll directly, while rewind slitting unwinds the master rolls, cuts the long sheets, and rewinds them into narrower segments.

1. Log Slitting

In log slitting, a large roll of flexible material is loaded onto a log slitter, resembling a large tree trunk. A circular blade slits the roll into required widths as the roll spins on a mandrel. Log slitting is effective for materials like tapes, PVC, paper, foams, tissues, films, and foils.

2. Rewind Slitting

Rewind slitting includes razor slitting, shear slitting, and crush cutting.

A. Razor Slitting

Razor slitting utilizes sharp blades to cut material, held stationary in a slitting machine. This method is economical, clean, and easy to set up but unsuitable for heavy, abrasive materials and generates more heat.

B. Shear Slitting

Shear slitting operates like scissors with a top-mounted male knife and a bottom-mounted female knife. This method provides accurate, high-speed cuts with less heat and dust but is more expensive and challenging to set up.

C. Crush Cutting

Crush cutting or score slitting uses a rotating knife against a hardened roller to cut materials of varying thickness. It is economical and easily adjustable but produces lower quality cuts with more dust.

Factors to consider when selecting slitting methods

Consider the material being cut. For thin substrates, use razor slitting; for thicker, pressure-sensitive materials, crush cutting is effective. Also, consider if professional converters will be involved. Shear slitting, though challenging to set up, offers precise, smoother cuts and is optimal for long runtimes due to less heat and dust generation. Budget constraints are also significant; shear slitting typically incurs higher costs.

Slitting blades

Selecting the right slitting blade enhances efficiency. Konetool offers superior tungsten carbide slitting blades like industrial razor blades, Zund blades, and dished knives. Request a quote today for more information!

Interested in learning more about Slitting Machine Manufacturer? Eastsign provides more details.

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