Parkinson Technologies

Auto Knife Positioning Systems Part 1 – Types

Improve Productivity with Automation

By Joe Connelly

Product Manager – Winding and Slitting

If you are seeking ways to improve productivity of your  slitting operation, one way is to consider automating your knife positioning process. There are a variety of ways to accomplish this, and each approach differs in its cost and level of complexity. However, when understanding the added benefits of improved knife placement accuracy, faster changeover times, and improved operator safety, the costs are, in most cases, easily justified.

When we refer to knives being positioned automatically we are generally describing systems that use computer guided actuators to place slitting tooling in designated locations without operator intervention. These typically fall into three main categories: male knife positioning only, female knife positioning only, or systems that place both male and female knives together. Male only systems are most commonly used to position either score knife holders or razor blade holders. Female only systems are typically used to locate a female (or bottom knife) ring in a rotary shear system, leaving the male (or top knife) holder to be positioned by the operator. Male and female systems position both male and female knives using either a common actuator, which requires removal of the web prior to initiating the positioning sequence, or are “web in” systems that use two separate actuators to position the knives while the web remains threaded through the machine. The most sophisticated systems have separate actuators on each knife holder to simultaneously position all holders. In all cases, knives can typically be positioned within five thousandths of an inch (or about 0.1 mm) of their intended location. Positioning is usually completed in a few minutes, while simultaneously actuated systems can do so in mere seconds.

In our next article, find out who can benefit from using automatic knife positioning systems.