Glossary of die-cutting and tooling terminology

Suppliers are welcome to submit further terms so that these can be added to the listings below in subsequent publications.

AN ALPHABETICAL GLOSSARY

Abrasiveness – The tendency of some papers, surface coatings, treatments or inks to abrade or wear away die edges, slitter wheels, printing surfaces, etc., by friction.

Air eject cylinder – Developed as an alternative to the more expensive male and female cutting systems for long runs and the solid rotary die-cutter with rubber inserts and without any waste control. The system is making use of so-called air forks, to blow air (6 – 8 bar) into air channels. These air channels, are linked to bores in the cavities. Die-cutting of the holes and blowing out of the waste into a stainless steel vacuum box is done simultaneously.

Anvil position – The cutting cylinders (rotary die, flexible die, etc.) is placed in the bottom position of the cutting unit, whereas the anvil roller is placed in the top position of the cutting unit.

Anvil roller – Hardened steel roller upon which the bearers of a rotary die, magnetic cylinder, perforation cylinder, etc., run. Normally, this cylinder is placed in the bottom position of a die station. However, for certain jobs it is necessary to place the anvil roller in top and the cutting cylinder in bottom position. In case of a support roller the anvil roller would be in the middle position.

Anti-stick coatings – Coatings, engineered to reduce the ability of other materials to stick to them. For certain applications such as hot-melt adhesives, multi-layered labels and labels with high application of adhesive, tooling suppliers will offer the possibility to coat the dies. These coatings should prevent adhesive and ink adhering to the cutting edge and adhesive bridging taking place between the label and the waste matrix.

Axial – Consider a cylinder. The top of the cylinder is a circle. A radius is a line drawn from the centre of the circle to the border or circumference of the circle.

Movement parallel to a radius is called 'radial movement'. The axle of a metal cylinder with shafts on each end may have movement parallel to the axle, that is, from one shaft to the other. This is called 'axial movement'.

Axis – Axis of revolution of the gear; center line of the shaft.

Backlash – Is the striking back of connected wheels in a piece of mechanism when pressure is applied. Another source defines it as the maximum distance through which one part of something can be moved without moving a connected part. In the context of gears backlash, sometimes called lash or play, is clearance between mating components, or the amount of lost motion due to clearance or slackness when movement is reversed and contact is re-established.

For example, in a pair of gears backlash is the amount of clearance between mated gear teeth.

Bearings – The hard rings, often including balls or rollers, which provide a smooth rotary movement to cutters and printing cylinders that come into contact with each other during printing and die-cutting.

Bearing block – A block with internal bearings that holds the cylinders (magnetic cylinder, rotary die, anvil roller, etc.) in position in a die-cutting station.

Butt cut labels – Rectangular labels in a continuous web, which are separated by a single knife cut through the label and/or liner across the web. No matrix is removed between the labels, as is the case with die-cut labels. Separated individual labels on a backing liner are applied by hand or to its application to a container, product or surface.

Back slit – A cut in the release liner or backing, usually along the web, but can be on the back of sheeted pressure-sensitive laminate to allow the face stock to be easily peeled away by hand when die-cutting has not be used.

Case hardening – Case hardening or surface hardening is the process of hardening the surface of a metal object while allowing the metal underneath to remain soft, thus forming a thin layer of harder metal (called ‘the case’) at the surface.

Cavity – Any enclosed shapes on a rotary/flexible die.

Cold-foiling – A more recent development of hot-foil blocking, the cold foil process makes use of a print unit to print a special adhesive on the label web where a metallic effect is required. When the metallic foil is brought into contact with the adhesive it adheres to it to produce the printed foil design on the label.

Converting process – in package or label production, converting covers any process performed to manufacture a complete package or label from a raw material or an unfinished material. The process of transforming rolls of self-adhesive material into labels on a release liner (carrier) presented in rolls or sheets, so as to enable end users to apply them to products, packages or surfaces. This process includes slitting, die-cutting and matrix stripping operations, sheeting, and may also include printing.

Cross cutting – Cutting across the web.

Cross perforations – Perforations across the width of a continuous web for easy separation of individual sheets and/or fan folding of continuous labels. Also any perforation applied at right angles to a label or page, depending on its printed format.

Crush cut – A cut made using a rotary blade in contact with an anvil or base roll.

Crush cutting – Commonly used for adhesives and some papers. The score is a circular blade cutting against a hardened steel anvil. The circular knife then ´crushes´ the web against the anvil. Generally, slit edges are not of the highest quality, but crush cutting makes up for it in quick and easy set-up procedures.

Cutter bevels – In die-cutting, the angle of the material supporting the peak of the cutter. The smoothness of the bevel sides directly affects the amount of pressure that is required to penetrate the laminate surface – see cutting angle.

Cut & Tie – The term used when describing a perforation. The cut penetrates through whilst the tie remains to hold the material together.

Cutting station/unit – The part of a label press that contains the equipment to cut a shape or pattern into a given material. A cutting unit includes an anvil roller and/or support roller rotatable on a machine frame about an axis of rotation. The anvil roller has an anvil surface. A cutting tool is mounted on the machine frame for rotation about an axis of rotation, with a cutter interacting with the anvil surface and with supporting rings which are held on the cutting tool and support it relative to the anvil roller with their supporting ring surfaces and/or vice versa.

Cut-to-shape – Is originally a philatelic term referring to a postage stamp or postal stationery (printed stamp image) that has been cut to the shape of the design, such as an octagon, circle or oval, instead of simply cut into a square or rectangular shape.

Die-cutting – The process of cutting a label shape with a die. Most self-adhesive labels and some wet-glue and in-mould labels have to be die-cut to shape as part of their manufacturing and finishing procedure. Depending on the type of label and the printing and/or die-cutting requirement, the operation may be performed using high or hollow dies, flat dies, rotary dies, flexible dies or most recently with digital die-cutting (laser cutting).

Dial gauge – A dial gauge is a precision measurement commonly used to measure machined parts for production tolerances (run out). Dial gauges are capable of producing extremely fine measurement values. Plunger instruments are generally used in conjunction with a clamp or stand which holds the gauge in a fixed position in relation to the work piece. The work piece is then rotated or moved to take the measurements.

Die life – Meterage expected from a new die or that expected following a re-sharpening of a die. Estimates of die life depend on machine setting, type of label-stock, type of adhesive and on operator handling. Estimates of meterage from a die may vary considerably from company to company, machine to machine or job to job.

Die line – A blueprint. Drawing or computer-generated layout of the cutting shape or shapes of a die. Maybe supplied with artwork as an overlay, as a blue line on the base artwork or supplied as computer-generated data on disk, CD or transmitted electronically.

Die strike – The impression left on a backing liner after being converted by a cutting die.

Die wipe – A test to check the evenness of a rotary or flexible die cutting pattern on a backing liner. A solvent pen/marker or fine colored powder is wiped over the silicone surface where a die impression is evident. Where the die has penetrated the silicone coating, the ink or powder stains the backing highlighting unevenness in the cutting depth which can cause the waste stripping matrix to break (see FINAT test method 23 + 23b).

Distortion – A change in the dimensions of an object to compensate for change in length when a flexible die is wrapped around a magnetic cylinder (to be calculated by your tooling supplier.

Dual height – Two different cutting heights combined in 1 tool, possible in both solid cutting tools and flexible dies. In a die drawing, it should be clearly indicated which cutting lines are cutting the different layers of material.

EDM dies – Rotary cutting dies produced using electronic discharge machining (EDM) by eroding the cutting lines. The hardening process takes place before the EDM process thereby eliminating possible distortion of the cutting lines/image. Consequently, these type of rotary dies generally will have a higher accuracy than milled dies.

Ejection rubber – A variety of materials used for facilitating the flatbed and rotary cutting process. These materials used vary in thickness, structure and hardness (shore). It is important to use ejection rubber that is slightly higher than the actual height of the cutting line. This will cause compression (sufficient energy and ejection force) on the rubber thus ensuring complete ejection of the cut out part.

Face cut label – Any pressure-sensitive label in which the face material has been cut to the liner. A die-cut label product from the waste matrix around the labels has not been removed.

Flex – The deflection of rollers or cylinders in a printing press. Also describes the bending qualities or characteristics of any material, including printing plates. See deflection.

Flexible dies – A thin, flexible steel die-cutting ‘foil’ or plate for use on magnetic cylinders, magnetic base or other special die-cutting systems. Flexible cutting dies are etched from specially formulated steel ranging from 0.5 – 1.5 mm in thickness. Flexible dies are lower in cost than solid dies and the economics of use become more attractive as the complexity of the label shape increases. The life is much the same as for a solid die, providing cleanliness, setting, anvil condition, adhesive and label design are properly controlled. Flexible dies are available today with a wide range of surface treatments and provide good results with a wide variety of materials.

Friction – is the force resisting the relative motion of solid surfaces and is usually proportional to the amount of contact force which presses the surfaces together as well as the roughness or the texture of the surfaces.

Hardness – Hardness is a very important property of tool steel that is developed during the heat treating process. It is not one of the inherent properties of tool steel. Hardness is developed through the addition of carbon.

Heat resistance – The ability of tooling steel to resist softening when exposed to heat while in operation. This is a very important property in high-speed steel tools. Excessive heat in a turning or milling operation can lead to the softening of the tool. This softening allows the tool to dull or chip causing premature failure.

Hole punching (pinfeed) is normally used for making EDP holes but other shapes are also possible. The holes are cut by using either a male / female system or using a shaft with movable EDP rings. The latter is used in anvil position to cut onto the face material and the waste is being removed by the waste matrix when stripping the face.

Hot foil unit – The part of a label press that contains the equipment to hot foil self-adhesive material.

Induction hardening – A form of heat treatment in which a metal part is heated by induction heating and then quenched. The quenched metal undergoes a martensitic transformation, increasing the hardness and brittleness of the part.

Journal – The shaft on the operator and gear side of a cylinder that is supported by a bearing.

Key – In mechanical engineering, a key is a machine element used to connect a rotating machine element to a shaft. Through this connection the key prevents relative rotation between the two parts and allows torque to be transmitted through. For a key to function the shaft and rotating machine element must have a keyway, which is a slot or pocket for the key to fit in. The whole system is called a keyed point. A keyed point still allows relative axial movement between the parts.

Kiss cut – A die-cutting operation in which self-adhesive face material is cut through to the release liner backing, but the liner itself is not cut.

Laser hardening – Used as an alternative to the more common surface treatments, some suppliers of flexible dies also offer laser hardened dies. Laser hardening is not offering any reduction in the friction coefficient, but does offer a partial increase in hardness at the tip of the cutting edge. The increase in hardness depends on the carbon content in the steel and not on the energy put in by the laser.

Magnetic cylinder – A stainless steel-based cylinder having a series of permanent magnets glued around its periphery and used in die-cutting to hold flexible dies in place. Magnetic cylinders will fit on to any press that takes rotary dies, and there are no size limitations outside of those relating to the press dimensions. They are installed in exactly the same way that conventional rotary dies are installed.

Matrix waste – The skeleton of face material and adhesive waste surrounding self-adhesive labels after die-cutting. The matrix waste is normally removed on the press converting line by stripping it from the web of die-cut labels and re-winding it on matrix re-wind roller. Waste may also be removed by shredding into small pieces and/or by extraction systems that convey the waste away for bagging or baling. Also known as the waste skeleton.

Micro perforation – Very small perforations or minute pinholes in paper that enable a section or part of the paper to be easily separated. Micro perforation leaves a smooth edge without the normal more jagged edge found with standard methods of perforation.

Operating temperature – An operating temperature is the temperature at which a label press operates. The press will operate effectively within a specified temperature range which varies based on the device function and application context, and ranges from the minimum operating temperature to the maximum operating temperature (or peak operating temperature.

Oxidation – result of a reaction between tool face and oxygen exposure. In order to prevent tooling to rust (oxidation) please clean and oil the tool carefully before storage. Oxidation can have a detrimental effect on the cutting results of both rotary dies and well as flexible dies.

Perforation – A line or row of cuts or tiny holes that enable a paper or web of labels to be folded, torn off or separated easily. Perforation may be horizontal or vertical with standard or micro perforations (cut versus tie).

Razor slitting – Mostly used for slitting thin plastic films – these type of systems are very simple, quickly and easy to set. Although razor blades are a low cost product, they need to be frequently changed to ensure a good quality slit edge.

Rotary Pressure (RP) cutting – a shear type of cut made by passing two precisely machined cutters by or through one another. The material is actually squeezed or compressed to the point of bursting without the two parts of the tool ever touching. The two cylinders that make up the tool set both rotate at exactly the speed in order to create a perfect match. Not very common in the narrow web industry. Only for cut through applications and (very) long runs.

Rule cutters – Rule cutter are used for flat die-cutting in presses where the web is momentarily halted during the actual cutting process. Consequently, the output speed is somewhat slower than when rotary tooling is used.

In its most simple form, the flat ruled cutter may be produced by working to dimensions, obviating the need for a drawing when the shape is a simple square, rectangle or circle. For more complex cutting shapes a key line can be drawn by hand or created by some form of electronic origination at the same time as the label design is created.

Shear cut – Used to describe the cutting of a continuous web of stock using an action similar to the action of scissors.

Shear slitting – Shear is the most versatile slitting method. Shear slitting can be used for a wide variety of papers, films, laminates and foils. Shear slitting variations can be ‘tangential/kiss’ or ‘wrap’ shear which involves a loaded male blade against a female ring, creating a scissoring effect to slit the web. Shear slitting typically provides the highest quality edge quality.

Sheeting – Converting rolls of printed or unprinted label-stock into individual sheets on a roll-fed press.

Slitter/re-winder – The use of slitter/re-winder technology is one of the principal methods of off-line converting rolls of self-adhesive labels, tapes and flexible packaging film into the correct width rolls ready for shipping to customers. The operation may also be combined with web inspection as part of the final stage in a converter’s quality control program.

Slitting – The action of cutting rolls of label stock to specified widths on a slitting machine. Slitting is undertaken using either stationery or rotary knives or blades in a machine with roll unwind and rewind devices, tension control and web tracking. Slitting of master rolls to narrow-web roll widths is normally undertaken by the label stock manufacturer, whose machinery has lubricated slitting knife cleaning pads on each rotary blade to stop adhesive build up on these slitting tools. These slitting machines also have a special splicing table, before the slitting station, where a diagonal butt splice can be made after removal of pre-marked sub-standard material, plus paper mill and coating machine joins.

Slitting wheels/knives – Dividing a web of label stock in the lengthwise direction by rotating slitting knives so as to produce two or more narrower webs. Slitting may be carried out with shear or crush cutting. Shear cutting produces a good quality edge a high line speeds with little dust; crush cutting can be economical if speed and edge quality are less critical.

Standard air eject dies (through shaft bore) – Air eject cylinder which uses compressed air to blow out of the holes drilled in the various cavities. For these types of cylinders there is little/no control over the waste ejection.

Stepped anvil – An anvil with the bearer area either higher or lower than the main body. Stepped up – bearer is lower than the body, creating a deeper cut.

Stepped down – body is lower than the bearer, creating a more shallow cut.

Stripping – Also called waste stripping. Removal of the face material and adhesive (the matrix waste) from around the die-cut label by taking it around a roller, or over a metal bar, prior to being re-wound. See also Matrix waste.

Thru cut/Through cut/Cut through – The action of die-cutting through all the layers in a pressure-sensitive laminate. This may take place in just one part of the cutter profile, or it may involve the complete profile.

Tolerance – the permissible deviation from a specified value. This applies e.g. to flexible die height, calliper of a backing.

Tool(ing) steel – Tool steel refers to a variety of carbon and alloy steels and that are particularly well-suited to be made into tools. Their suitability comes from their distinctive hardness, resistance to abrasion their ability to hold a cutting edge, and/or their resistance to deformation at elevated temperatures (red-hardness). Tool steel is generally used in a heat-treated state.

Trim – Trim is used to describe the normal edge waste that is removed from a master roll of label stock. On the printing and converting line, trim describes an action on the press, i.e. edge trim, waste trim.

Vacuum die – Rotary dies with removable inserts. Instead of blowing out the waste, the cut out particles are sucked away through the journals by means of vacuum.

Wear resistance – The ability of tooling steel to resist erosion. Wear resistance in tool steel is achieved by the presences of carbides. Chromium, molybdenum, tungsten and vanadium are the four carbide-forming elements commonly found in tool steels.

Web tension control – the amount of pull or tension applied to the web as it passed through the press. Poor tension control will result in registration problems in the printing, embellishing and converting processes.