Guide to Straight Cut-Off Knives for Packaging Equipment

straight cut-off knives

Straight cut-off knives turn the continuous form packaging on your assembly line into the discrete products your customers recognize on the shelf. Clean-cutting, high-performance packaging knives are essential to efficient line operation and the final quality of your product.

Let’s take a look at what straight cut-off blades do and how choosing the right industrial blade supplier can give your company a sharp edge.

What Are Straight Cut-Off Blades?

Cut-off blades are used to slice continuous plastic film feeds in manufacturing. They are employed towards the end of the packaging process to separate individual packages once they have been filled and sealed.

Cut-off blades are particularly important in food packaging, where they are used in standard processes including:

  • Vertical form fill sealing, where bags are formed, filled vertically with a liquid or a loosely packed solid product then sealed and separated.
  • Horizontal form fill sealing, where preformed bags are filled and separated with the finished product on a moving line.
  • Vacuum packaging, where a perishable product such as prepared meat is vacuum sealed before separation.

Straight cut-off blades are used to provide a clean separation between packages when more complex package edging, such as a zig-zag pattern, is not required.

Why Is Tooth Profile Important?

Blade manufacturers like TGW International offer straight cut-off knives with a variety of tooth profiles for different applications and film thicknesses. Common profiles include:

  • Toothed: Small v-shaped teeth along the length of the blade to perforate and slice thinner plastics.
  • Scalloped: A series of half-moon-shaped bevels provide a combination of perforation and shearing for thicker films.
  • Straight bevel: A straight, single-bevel blade, often used where two blades work together to scissor-cut packaging for horizontal form fill seal packaging.
  • Easy Open: A customized straight blade with an offset tooth to cut a tear notch so it’s easier for customers to open packaging, often used with a thicker vacuum pack or vertical form fill seal materials.

How Are Straight Cut-Off Blades Made?

Depending on the hardness or durability required by the application they are being used in, TGW straight cut-off blades are made from materials including:

  • D2 high carbon high chrome steel,
  • M2 high-speed steel, or
  • 420 or 440 stainless steel.

While the hardness of high carbon steel is preferred for demanding cutting applications, stainless steels offer greater durability to blunting and breakage and greater corrosion resistance. High-speed steels provide better cutting performance at speeds where heat build-up is an issue.

TGW blades can 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).

TGW International offers decades of experience in matching blade materials to specific applications in order to ensure both hardness and strength. Our team can tailor cut-off knives to your specific needs, ensuring that your machines keep running and your cut quality remains constant.

What Qualities Should You Look for in a Straight Cut-Off Knife?

You should expect both durability and performance in a cut-off knife. TGW strives to provide straight cut-off knives that deliver:

  • The right cut profile for your package
  • The right look for your product
  • Easy-open notches and other add-on features, and
  • Long life and consistent cut quality.

Choosing a high-quality knife will also save money on maintenance and replacement parts as well as reduce wear and tear on your line machinery.

How Does TGW International Ensure Quality?

As a leading supplier of industrial blades, TGW takes pride in the quality of our packaging knives. 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 to deliver customized solutions when necessary.

We also insist on a rigorous two-step inspection process of all the cut-off 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 not only that we are supplying our customer with the right parts, but that every blade we ship meets the correct material and hardness requirements for that customer.

Trust TGW to Help You Make the Cut

If you are an OEM or end user in plastic packaging then clean, efficient material cutting is central to everything you do. Trust TGW International to help you deliver the quality and consistency your customers expected with our superior quality cut-off knives.

At TGW, we bring a knife-making legacy of more than 100 years to the business of delivering today’s most advanced industrial blades. Click below to learn more about how our cut-off knives and other packaging products can give you the edge you need.

PACKAGING BLADES & KNIVES