Selection of a rewinder or a slitter rewinder depends on the following factors:

1- Material to be slit or rewound,

2- Parent roll diameter, width and weight,

3- Finished roll diameter, width, weight and quality.

There are several types of slitter rewinders:

1- Center winder: Center winders are mainly used at the end of a production line. In plastic film production, the melt blown film is wound into finished rolls at the end of the line. Nonwoven lines also use center winders. The center winder is designed to run at slow speeds. Finished roll quality is not the greatest, but it serves it's purpose. The finished roll is wound on a driven rewind shaft. Center winders can be single roll winders, duplex winders, triple winders, four rolls or more - depending on the application. A problem with center winders is speed. As the roll gets bigger, the line speed changes. If allowances are not made to regulate or maintain a constant line speed, the quality of the finished product suffers. Examples: Delta, Doven, Dusenbery 635, Hobbs, Padane

 

2- Center surface winder: In this process the rewind shaft is driven by a bed roll. Line speed is easily maintained at the desired level. Essentially, center surface winder can be used in place of a center winder. These units can either be used for single winding or duplex winding. Examples: Brampton, Cameron, Yashi

 

3- Turret winders: A turret winder has a common "turret". There can be two, three, four or more rewind stations on a turret winder. Basically, these operate like center winders. When one roll is finished, the turret automatically indexes over to the next rewind position. The operator takes off the finished roll while the next roll is being rewound. Examples: Batten Glouster, Hydromatic

 

4- Dual drum surface winder: This machine is the work horse of the paper industry. The rewind shaft is placed on two bed rollers. The rider roller comes down and holds the core in a three point configuration. This allows for full "density" control. The finished roll quality can easily be controlled by applying pressure to the rider roller. This machine can run faster than any other kind of winder; i.e. a Dusenbery 614 can produce 30,000 adding machine rolls in one shift.  Examples: Cameron, Goebel, Parkinson

There are three basic slitting methods that are utilized to cut the material being wound into smaller finished rolls:

1- Score cutting: This is also called crush cutting. A rotary blade cuts against a hardened anvil roller. Material passes through and is cut. A lot of dust can be generated using this method of slitting. Some slitter rewinders have vacuum dust removal systems to take care of this problem.  This is the simplest way of slitting ... very fast set up times.

 

2- Shear slitting: This is essentially a scissor action with a male and female rotary blade system. Material passes between the male and female blades and is sliced. This method of slitting generates very little dust, but it's not totally dust free. Costwise, it is the most expensive method. Setting knives is tedious, labor intensive, expensive and consumes a lot of time. One tiny mistake and all the knives have to be reset again. There are fully computerized versions available that automatically set knives at the touch of a button ... an option that may end up costing a great deal of money.

 

3- Razor slitting: As the name implies, material passes under a razor blade and is slit as it is being wound ... simple, and very cost effective. However, razor slitting cannot be used on thick gauge materials.

 

4- There are also specialized slitting systems available; i.e. hot knife cutting, waterjet cutting, bias cutting, etc. that provide unique slitting options for special winding processes.

Choice of what type of slitting to use is dependent on the material being run on the winder and the type of winder being used.

Knife Holders: These vary in configuration and mounting methods.
Knife Actuation: Pneumatic, mechanical, hydraulic or computer controlled.

We have several different types of slitter knives. Please send us details of what you need. We may have them in inventory.

For additional information, please contact me at .....Email or 920-725-6543