Slitter Glossary
Winding machine shafts that use air-bladders to secure rolls both axially and radially during winding.
The bottom part of a shear knife pair.
Bi-Oriented (or biaxely) PolyPropylene (BOPP) film is packaging film used in the food and drink industry. BOPP is also used to carry security features on anti-counterfeiting and cigarette carton packaging.
A bowed roller is typically situated before the slitting section and is used to remove wrinkles from the web material.
A braked unwind describes a system whereby the shaft (or shaftless system) of a Slitter Rewinder that houses the master / jumbo roll is controlled using a brake. A braked unwind is the standard unwind type used on most slitter and salvage winders.
Peel off bar in a slitter, winder or lamination system designed to assist with the stripping of the paper carrier, usually as a part of a lamination process.
The use of load cells on a slitter / winding machine to measure the actual tension of materials being wound, so the control system can make very accurate adjustments to ensure precise tension is maintained throughout the winding / slitting process. Closed loop tension control is particularly useful when winding tension sensitive materials / substrates.
Constant geometry layon rollers are mounted on linear (horizontal rather than pivoting) support arms. These do not vary their force as of the geometry change unlike conventional pivoting systems.
When empty cores are placed on the rewind shaft of a slitter they need to be aligned to ensure that the rolls are wound correctly. Lasers are accurate because they show the machine operator exactly where to place the core using a line projected by the laser unit, the position of the line itself is controlled using a system integrated with the slitter control system, or (often in the case of upgrades to third party slitters) with a separate control system.
Core size ‘ID’ refers to the internal diameter of cores.
Crush cutting is a method of cutting that uses circular knives held by knife holders.
Differential chucks (also known as ‘slip chucks’ or ‘ball chucks’) are fitted to the rewind shafts of slitter rewinders to eliminate tension variances that can develop due to (sometimes very minor) material thickness variations across the parent roll.
Differences in the overall material thickness of rolls being slit can result in each slit roll being different diameters and therefore requiring to run at different relative speeds.
When rewinding rolls that are shaft-driven if each have a different diameter some of the rolls will be wound loose, tight, or may even cause the web to break. The slipping effect of differential chucks on a rewind shaft helps achieve an even tension profile across all rewound rolls. The chucks are held in place by an air-bladder within the rewind shaft.
A driven unwind describes a system whereby the shaft (or shaftless system) of a Slitter Rewinder that houses the master / jumbo roll is driven by a motor. A driven unwind is often used when a material is tension sensitive, when an unwinding roll is driven it minimises inertia of the parent.
A slitting / winding machine with two rewind shafts, allowing rolls to be alternately wound on each shaft.
A slitting rewinding machine with a total of four shafts. Two sets of shafts are used for winding while the remaining two sets are used for offloading.
Term used to describe film materials.
The finish roll diameter is a measurement of the diameter of the roll on the rewind of a slitter.
FLT handling is a term used to denote ‘Fork Lift Truck’ handing of materials, usually rolls. In many circumstances the use of a fork lift truck to load rolls of material onto the unwind of a slitter / winder is undesirable due to the potential damage to the materials and the winding machine.
FLT Handling during roll loading can be minimised (and sometimes eliminated) by the use of facilities like shaftless unwinds, or for smaller slitters roll handling trolleys can be used. For roll unloading off-load pushers and hydraulic roll handlers can be used to protect the product and minimise risk to the operator and machine.
Rollers on a winding machine that are not driven by the machine, and are therefore ‘idle’ and are free to be driven by the web.
Meaning the unwind mechanism is mounted as a part of the cutting/rewind part of the winder. Using an integrated unwind minimises the machine footprint and reduced the risk of material contamination found with machines with separate unwinds.
Although the cost of an integral machine is higher due to the greater rigidity required, it is easy to move the machine without the necessity to rewire and re-align the machine each time it is moved. Using an integrated unwind also minimises the web path length.
Interleaving is the term used to describe the problems caused when the edge profiles of two rolls on a rewind shaft become intertwined. Interleaving is to be avoided!
Interleaving is sometimes referred to as ‘interweaving’. Interleaving is a problem particularly related to simplex slitters.
The unwind roll diameter is a measurement of the diameter of your master/jumbo roll.
The unwind width measurement refers to the width of your master/jumbo roll.
Arm-mounted rollers that apply precise amounts of pressure in order to eliminate air from fast-wound webs, ensuring perfectly wound finished rolls.
Lay-on arms are often used when running filmic substrates at speed.
Low density polyethyline (LDPE) is a petroleum based film used for a variety of packaging including the rings that hold together multipacks of canned beverages and as a coating on some board based food and drinks containers.
Find out more – http://en.wikipedia.org/wiki/Low-density_polyethylene
The unwind roll diameter is a measurement of the diameter of your master/jumbo roll.
The unwind width measurement refers to the width of your master/jumbo roll.
The minimum slit width on a slitter specification refers to the smallest width of finish roll that is required.
Spreader roller with static elimination properties.
Utilised to offload slit rolls from the rewind shafts. The offloading tree can also provide support for the rewind shafts on cantilevered machines.
The term ‘overwind’ refers to the position on the roll where the web meets the roll and winds onto it – the roll winds from the top of the roll.
When unwinding some low-tack and adhesive rolls the material being unwound can remain stuck to the parent roll longer than is helpful to the overall process. This can lead to a running web either gaining too much tension or temporarily losing tension.
This problem is solved by including a peel-off roller near the unwind/master roll, which will hold the unwinding web of material at a constant and acute angle to ensure that correct tension is maintained.
A peel-off roller sometimes works in conjunction with a nip roller, which is used to isolate tension between two points on a web path.
Polyethylene terephthalate (PET) is a polymer resin widely used in food and drink packaging. The name is confusing because this product does not contain polyethylene.
Razors used for cutting, normally held in place by a razor comb or razor blade holders. Useful for slitting some thin filmic substrate.
The controls on slitters are designed to be very simple to operate yet the system has extensive diagnostics should they be required. We also provide a port on the system for secure Internet access to allow our engineers to monitor the performance of the machine remotely.
To utilise the remote diagnostic system, we require the customer to provide a static IP address with port forwarding.
Reversible running enables salvage/doctor rewinders to run in two directions, allowing print direction to be corrected without the need to unload and re-load the roll.
The shaft onto which a roll is wound.
Term used to describe when the unwind part of a winder is not built into the same sideframes as the rewinding part of the machine.
A separate unwind is sometimes utilized when additional processing machine (like laser perforation) is placed in the web path.
On a machine with a shafted unwind the master/parent roll is supported by a shaft running through the core of the roll.
When talking about shaftless roll handing we are usually referring to the unwind/master roll part of a winding machine. When rolls or cores are held in place without shafts the system might be referred to as ‘shaftless’.
The parent/master roll will be held in place by two chucks, one each side of the roll, the two chucks are moved into place and handle the roll by motors. Shaftless systems are sometimes used to pick master/parent rolls up from the floor or a pallet.
Circular knives that rotate together as a male and female pair acting much like a pair of scissors, generally used for heavier gauge films and papers.
A slitting/winding machine with a single rewind shaft.
Some of the slitters in our machine range (the Universal X6 for example) feature an additional operator controllable tension zone. The tension through the slitting knives can be set independently of the unwind and rewind tensions, ensuring the optimum tension through the slitting knives
Generic term referring to a machine that is used to cut (slit) rolls of material while they are being re-wound.
For example, our machine the Universal X6 is a slitter, but it might also be called a slitter rewinder or a slitting machine.
A splice table, with web clamps or vacuum systems, is a device mounted on a winding machine to assist the operator to neatly join two webs.
Roller used to spread the web material. A spreader roller can also be used to prevent interleaving of finish/rewind rolls on a simplex slitter.
Some materials and winding methods can generate huge amounts of static electricity that can be dangerous to operators and damaging to materials.
There are several designs of static elimination systems. and on slitters they are often installed after the unwind and before the two rewind shafts.
Term used to describe materials being fed through a machine as a web.
Idle roll on a driven shaft, thereby using the stiction of the bearings to drive the roll. Tendency driven rollers can be used to reduce the energy required from the web to drive the idle roll from rest.
Sometimes used on slitters and salvage winders to reduce the chance of path rollers damaging materials as they pass through the machine.
A touchscreen is used in control systems to facilitate fast and very user friendly controls.
Motorised winders used for the removal of excess material.
The term ‘underwind’ refers to the position on the roll where the web meets the roll and winds onto it – the roll winds from underneath.
The shaft or shaftless system onto which the parent/master roll is loaded.
Unwind Diameter on a SlitterThe unwind roll diameter is a measurement of the diameter of your master/jumbo roll.
The unwind width measurement refers to the width of your master/jumbo roll.
The term ‘web’ is a generic term used to describe material as it passes through a slitter/winding machine.
Web guiding is used on winding machines to correct unevenly wound rolls. A sensor reads either the edge or a printed line and using an extremely fast actuator motor moves the parent/master roll from side to side to correct the web position laterally.
