Nip Type Anti-Wrinkle System for Web Converting

Description:

Nip type spreader rollers are normally short face rollers (less than 12” face) and small diameter (less than 3” diameter). These rollers are supplied in a left and right hand set. Each set consists of 2 rollers pre-loaded so each roller face is pressed together; these roller faces must be parallel with each other. Each roller set is very similar in design to other nip rollers used in converting (such as drive nips). One of the rollers in each set must be rubber covered (for traction); sometimes both rollers in the set are rubber covered.

Theory of operation:

The left and right-side nip sets are mounted to the machine frame and each edge of the web is fed through the nip rollers. The left and right side nip roller sets are then angled away from each other, facing in the downstream direction. Because of the web handling principle, that a web will seek to align itself perpendicular to a roller, in its entry span to that roller, each web edge will seek to be perpendicular to each nip roller set. This type of spreader roller is extremely aggressive and will spread more aggressively than most other types of spreader rollers.

This type of spreader roller has no wrap angle. Because the web is not supported across its full width, the material must be fed straight in and out of this spreader roller assembly.

Advantages:

• This type of spreader roller is the most aggressive.
• Simplicity of design makes this type of spreader roller easy to maintain.
• The amount of spreading is easily adjustable, by changing the angle of each nip set independently of each other.
• Works well with woven and non-woven webs.

Disadvantages:

• Because this spreader roller will not support the web across its full width, it will mark, distort and possibly tear most foils.
• This type of spreader roller is specifically designed for woven and non-woven materials. Any other type of materials may have difficulty with this type of spreader roller, because of web distortion.