Slitters and slitting equipment uses fixed or rotary knives to slit or trim webs of paper, film, foil, fabric, tape, or other rollstock to a specified width. For softer materials such as plastic films, both straight and circular blades may be used. These cutting blades are made of metal and can be set to a desired width. Some slitters and slitting equipment have multiple blades or knives so that operators can specify several cutting widths for a single roll. Other slitters have just a single blade or knife.
Features for slitters and slitting equipment include tension control and roll alignment. High-speed and low-tension slitters are available.
In terms of applications, slitters are used widely by the printing, coating, and converting industries as well as by tape and textile manufacturers. Selecting slitters and slitting equipment requires an analysis of product specifications and features.
Basic specifications include rewind roll OD, unwind roll outer OD, maximum web width, and maximum web speed. Typically, the outer diameter (OD) specifications and the maximum web width are measured in inches (in) or centimeters (cm). Maximum web speed is measured in either yards per minute (yd/min) or meters per minute (m/min). Specialized slitters and slitting equipment may carry additional product and performance specifications.
With regard to features, suppliers of slitters and slitting equipment provide information about unwind tension control, web guiding, slitting methods, and rewind tension control. Choices for unwind and rewind tension control include closed loop and open loop. Web guiding methods may include digital edge or line guiding with servo actuation.
There are there choices for slitting method: tangential or rotary shear, razor, and crush-cut. Slitting machines and slitter rewinders range from basic equipment to fully-automatic systems. High-performance slitters and slitting equipment are designed to run at speeds as high as 700 m/min and may provide closed-loop tension control. These trimmers are often equipped with automatic knife positioning, core alignment, and automatic tension setting.
Features may also include differential air shafts and shaft-less unwinds, touch screen controls, and compliance with CE requirements. The European community requires CE marks for all slitters and slitting equipment that will be sold, or put into service for the first time anywhere in Europe.