A Technical Guide to Industrial Converting Blades and Applications

Manufacturing often involves processing raw materials to make them usable for end products. Industrial converting blades consist of slitter blades, razor blades, and other types that break large sheets of material into smaller, usable pieces. 

Converting blades process materials such as plastic packaging, paper, film, textiles, and rubber. Because this processing requires precise, uniform results, converting machines often have tight blade tolerances. 

To maintain accurate cuts over time, you need a blade customized to the material. Using a blade that is too soft can cause excessive wear and heat, potentially breaking your machine. Packaging blades are also vulnerable to dust and other debris generated by often abrasive materials. 

Use this guide to understand how blade design and geometry impact performance and learn to choose the right one each time. 

Main Blade Types Used in Converting Operations

Industrial machinery typically converts films, foils, labels, nonwovens, and paper or cardboard using the following types of blades: 

• Razor Blades: Industrial razor blades cut thin films, foils, and other packaging materials into smaller slits. Razor blades produce narrow cuts with less waste, but they aren’t as effective on thicker materials. 
• Circular/Rotary Blades: Unlike razor blades, circular knives and blades rotate while cutting. These blades cut large sheets of material into smaller pieces and score, trim, and perforate materials. 
• Straight Blades: Like razor blades, straight blades are useful when you need a stationary blade to make your cut. Straight blades are better for precise, consistent cuts with clean lines. 

Slitter blades can refer to any of the industrial blades loaded into a converting machine. They can be straight or circular, depending on the preferred cutting method. 

Orient straight blades to the material to trim, score, or cut at a precise angle. These blades often feature single- or double-bevel edges and are very sharp for added precision. Mounting in specific locations on a machine keeps them in one place. 

Rounded blades mount to a central hole on a rotating shaft for continuous cutting motions. They may have teeth, depending on their use. For example, a converting process that starts with a rough cut you'll trim down later, use a rounded blade with fewer teeth. Some machines also have components to reduce vibration during cutting. 

How Materials and Hardness Influence Blade Life and Cut Quality

Industrial conversion blades need to be sharp and durable. Working with abrasive materials such as plastic and rubber requires a blade with high hardness and wear resistance. Packaging industry knives are often made of:

• High-Grade Steel: Stainless steel and other high-grade steel resist corrosion. They are also tough enough to resist chipping. High-grade steel is good for razor cutting and other low-pressure applications. 
• High-Carbon Stainless Steel: High-carbon is harder and more abrasion-resistant than stainless. Use these blades to cut plastics and other abrasive materials. 
• Tool Steel: High-performance carbon and alloy steel can withstand the heat generated by frequent cutting. Tool steel blades are also tougher and cut faster than other options.

When it comes to industrial packaging machine blades, hardness refers to how well a blade withstands wear, dulling, and scratching. Harder blades resist abrasion and stay sharper longer. They are also better for precision edges. 

Toughness is the ability of a blade to withstand impact without chipping or breaking. Tough blades can withstand high-impact cutting, ideal when working with an unforgiving material such as wood or rubber. They also perform better at high speeds. These blades don’t offer the same level of precision, however. If you need clean, uniform cuts, go with a harder blade. 

Blade Geometry Essentials: Bevels, Edge Profiles, and Tolerance Control

Blade geometry is another factor influencing how your converting machine blades will perform. Most converting blades either have single bevels or double bevels. 

A single bevel cutting edge is at an angle other than 90 degrees on one side of the blade. Think of a razor. Single-beveled edges are extremely sharp and precise. 

Double bevels are symmetrical, with both sides cut to an angle. They generally make a “V” shape. This geometry is thicker and more durable but doesn’t provide the same precision as a single bevel. 

Edge thickness refers to the cutting edge, measured in fractions of an inch or millimeters. Thinner edges are sharper and create smoother cuts with less dust. 

The surface finish is the texture of your cutting edge. Smoother edges produce less drag and pristine cuts. 

Sharpening your blades changes the edge surface. Precision grinding is crucial when processing materials such as a thin film or coated paper that need clean, uniform cuts. If your blade's edge is too rough, you could end up with frayed edges on slits. 

Packaging industry knives often require a balance between durability and control. Converting technology has made it easier to overcome common cutting challenges.

Using Industrial Converting Blades Across Different Materials

A single converting blade won’t work for all applications. Some materials produce more friction and heat. Your blade should have the appropriate metal composition and modern blade coatings to withstand heat, friction, and adhesion. However, using the wrong blade for a material can generate more dust and even cause the blade coating to peel.

Select industrial custom blades suited for the materials your machinery processes: 

• Films: Industrial razor blades with a single edge cut through thin films with precise, uniform cuts. Choose one that is durable but not too tough. 
• Foils: Industrial razor slitting blades and straight knives provide greater control. Choose one made of high-grade material with a coating to reduce friction. Otherwise, the heat generated during cutting could damage your blade. 
• Labels: Because labels can cause adhesives to stick to the blade, choose a durable, heavy-duty blade with a nonstick coating. 
• Nonwovens: Nonwovens require hard, heat-resistant blades. Choose a high-performance steel or tool-grade steel. 
• Paper/Board: Straight slitter blades produce more uniform cuts. Round blades work better with laminated boards and abrasive papers. 

Precision Converting Blades: Choose the Right Partner

Experience matters when finding a partner for custom converting blades. Hyde brings 150 years of U.S.-based manufacturing experience. We know metallurgy and have the verified capabilities to fabricate blades that can withstand industrial use. 

Reach out to us today for a consultation and get optimized converting blades that last.