Adjusting Tension During Slot Exchange
The ability to swiftly adjust tension during a slot exchange is a critical component of keeping a web machine running at improved performance and efficiency levels. Tension control is an especially important factor when dealing with media self-adhesive materials, which require a tension that is high enough to keep it effectively adhered to a support.
In general, tension adjustment involves two distinct events: before the start of production and during roll changes. Most web running machines are equipped with a tension control device (TCD) for adjusting the tension during a slot exchange. This device can be used to adjust the tension before the web material is rolled onto the machine and during ongoing web production.
Adjusting tension before production starts
Prior to production, the web should be under tension, a component of tension setting known as pre-setting. Pre-setting allows for tension control, ensuring that the tension does not change as the webbing moves from one position to another on the machine or from one roller or core to another. The position of a TCD setting affects the pre-setting tension and usually involves the number of force measurements taken and the distance between them, known as the distance between pads. Pre-setting values must be within a certain range, depending on the web material, the width of the web, the speed of rewinding, and other variables.
Adjusting tension during roll change
The tension level should also be adjusted during a slot exchange, as the webbing will be going through a process of compression, stretching, and release that can cause the tension level to fluctuate. The tension setting should be adjusted based on the specific characteristics and needs of the web being processed, such as the size, thickness, or type of media.
To adjust the tension during a slot exchange, the TCD setting must first be adjusted. The TCD setting is usually done with a tension adjustment knob, which requires the operator to turn the knob until the correct tension is achieved. The ideal tension point should be somewhere in the middle of the range of possible tension settings.
Conclusion
Adjusting tension during a slot exchange is an important process that can help ensure the smooth and successful running of a web machine. The pre-setting and TCD setting both play an important role in making sure the web operates under the right tension parameters. When done correctly, it can help maintain quality and reduce wastage. In addition, it can also help reduce machine downtime, which can save time and money.
