News

November 25, 2024

Maintain the proper geometry!

Bowed rollers can be a very effective and aggressive web spreading device. However, to get the most from your bowed rollers it is extremely important to maintain proper geometry. Here are some rules of thumb when applying bowed rollers:

• Almost all of the spreading takes place in the entry span to the roller. The longer your lead-in distance (unsupported web distance leading into the bowed roller) the more spreading you will get. The lead-in distance should be roughly double the lead out distance (unsupported web distance leading out of the bowed roller).

Perfect for Even Slit Separation

• Keep your lead out distance to a minimum. The smaller this distance, the less chance you will have of wrinkles returning to your web.

• Keep wrap angles to a minimum. Often times when I am in the field and see bowed rollers that are not operating properly or they are causing more trouble than they helping, it is because wrap angles are too great. My opinion is (and I have had many people argue with me about this) that wrap angles around bowed rollers should NEVER exceed 30 degrees.

View our video on YouTube here

One last word about bowed rollers; when applied properly they will effectively remove wrinkles. But the question is, what are you doing to your web by utilizing a bowed roller? The potential problems with bowed rollers are not that they do not take wrinkles out, they do. The problem is that the web tension profile as the web travels over the bowed roller is not even. Due to the raised center of the bowed roller, you will deliver added tension to your web in its center. How will that affect your material? Will your material be distorted by your bowed roller? That is the question to ask when using bowed rollers to remove wrinkles.