Guide to Slitter Knives for Packaging Equipment

vacuum slitter knives

Slitter knives offer a high-precision continuous cutting edge for side vacuum packing or shrink wrapping of food perishables, pharmaceuticals, and electronics. Food packaging specialists know only the highest quality slitter blades provide the versatility and performance they need to keep quality rolling off the line, day after day.

Let’s take a look at how slitter knives work, how they are made, and what to look for in a well-made slitter blade.

What Is a Slitter Knife?

Slitter knives, also known as circular blades or saws, are rotating steel disks with a beveled edge designed to provide continuous cutting action.

Slitter knives are versatile tools, capable of high-speed, high-volume cutting of various materials. Within the packaging industry, they are widely used in side vacuum packaging applications designed to protect food and drugs and extend the life of a wide range of perishables.

How Are Slitter Knives Used?

Slitter blades are used in three common ways to process packaging material:

  • Razor Cutting: A single spinning circular blade is used to slice the packaging material it comes into contact with.
  • Shear Slitting: Two slitter knives are used in combination to deliver continuous sharp, clean cuts in any given packaging material. Shear cutting is used to cut the far thicker grades of material typically used in side vacuum packaging.
  • Crush Cutting: A rotating slitter blade is used in combination with a hardened rubber or metal anvil to slice or severe packaging material. This allows thicker grades of material to be cut, but the results are generally not as clean as razor or shear slitting.

TGW International crafts our slitter knives to exact OEM specifications to perform optimally using any of these three cutting techniques.

What Are Slitter Knives Made From?

Slitter knives need to be fabricated from materials that offer both sharpness and durability during continuous operation. TGW uses 420 or 440-grade stainless steel for most slitter blade designs because of its excellent edge retention properties, durability, and resistance to rust relative to its price.

TGW also supplies slitter knives in M2 high-speed steel for high volume applications and in D2 high carbon steel where additional hardness is required, although knives made with these materials do come at a higher cost.

How Are Slitter Knives Made?

TGW manufactures high-quality slitting knives by laser cutting blanks from standard sheets of stainless or carbon steel. Single or double-beveled blades are then laser etched onto the edges, along with punches, notches, and piercing blades, where required. The knife is then deburred and carefully inspected.

Our slitter knives can also be plated or treated with a range of coatings to enhance durability, protect against corrosion and minimize static and adhesions. Common coatings include:

  • TiN (titanium nitride)
  • PTFE (Teflon), and
  • DLC (diamond-like carbon coating).

What Qualities Should You Look for in a Slitter Knife?

Good slitter knives should offer both performance and durability. TGW aims to provide slitter knives that deliver:

  • Excellent sharpness and edge-holding
  • Good durability
  • Excellent corrosion resistance, and
  • Consistent cutting performance.

At TGW we are always willing to listen to our customer’s concerns and work with them to find a solution. For example, if a customer finds blades are corroding, we can suggest an upgrade to a higher grade of stainless steel or an alternative low-carbon product.

How Does TGW Ensure Quality?

As a leading supplier of industrial blades, TGW takes pride in the quality of our slitter knives and other packaging blades. As part of our commitment to ensuring we supply you with the best quality knife for your application, we work closely with our customers to identify the best product for their specific needs and deliver customized solutions when necessary.

We also insist on a rigorous two-step inspection process of all the cutoff knives we manufacture. This includes:

  • A pre-delivery inspection, including supporting documentation, at the factory and
  • A final inspection of all parts once they arrive in our shipping center.

This is to ensure the customer gets not just the right part, but the right part in the right material with the correct coating and finish.

The Right Knife for the Job

TGW International has decades of experience matching industrial blade technology to our customer’s needs, and our range of slitter knives are no exception. We bring a legacy of more than 100 years of blade-making know-how to our work, and all of our knives are carefully crafted using OEM specifications.

Most of our knives are available in stock to ensure we can meet your needs with the quickest turnaround times, while our quality materials mean TGW blades cut cleaner for longer.

TGW delivers nothing but the highest quality knives. Click below to learn more about our full range of packaging blades and knives, or get in touch to find out how we can serve your individual packaging needs.


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