Impulse Heat Seal Knife Cut/Seal and Cut Capability

Heat Sealing with a Cutting Operation

Some heat sealing applications may benefit from a cutting operation incorporated into the process. There are two approaches to cutting film with the first being a physical blade contacting film to produce the cut. A second method is to melt through the film using a specially profiled heat seal band, heated cut wire, or cold cut wire.

Knife cut

A knife cut operation is made possible by a blade physically contacting the film to be cut. Some PackworldUSA heat sealers such as the PW5500 series machines offer a knife cutting option which places the blade behind the heat-sealing jaw bar. While in cycle, the blade traverses and produces the cut film. Because the heat seal and knife cut operation are in physically different locations of the machine, the cut produced leaves a portion of unsealed film beyond the heat seal.

Seal and Cut

Seal and cut operations are another way to trim film. This process melts through the film instead of cutting it with a blade. Melting is made possible by a special heat-sealing element configuration and there are a wide variety of options.  LEARN MORE: TOSS Band Profiles

Finding the best seal and cut configuration involves trial and analysis of various options. Beaded bands and T-profile bands are shaped with a cutting feature formed into the heat seal band material. A Custom Seal-Cut Band (CSC Band) is manufactured by attaching a cut wire to a flat or tapered profile heat seal band. CSC bands offer a higher degree of configurability because there are many cut wire diameters and different heat seal bands widths offered which create numerous options but are more costly than a formed band due to added labor costs.

All three of these heat seal band types provide a cut while also providing a more substantial seal width. If a minimal seal width is desired, another option is a heated cut wire which is a round wire that produces a much narrower seal path. Some materials respond well to a cold cut wire. This involves mounting a non-energized cut wire on the opposing jaw bar. A cold cut wire can be mounted in different locations to adjust the seal width produced.