Glossary of Terms
Not sure what ACLS stands for? How about the definition of 'Rag Rope'? Well, to help make these and other size reduction terms easier to understand, we've put together this online glossary as a reference tool for you. Click on any letter below to view a list of shredding and size reduction terms in the glossary beginning with that letter.
Abbreviation for SSI’s patented "Advanced Cutter Locking System" that uses a pre-load hub assembly to tighten or lock the cutter stack.
Advanced Disposal Fee
In the U.S., “appliances” or “white goods” can refer to household refrigerators, washing machines, dryers, ovens and stoves. Household materials such as hot water heaters can also be included in this waste stream.
Residue resulting from incineration or burning process.
Type of conveyor, cylindrical in shape with spiralled flights (corkscrew), which moves or elevates the enclosed material.
SSI feature which uses control panel timers to trigger intentional, timed reversals. In effect this reprocesses material and reduces particle size. It can also be used to control system capacity which in turn improves material metering to secondary equipment.
A hammermill-type shredder large enough to shred whole cars into fist-sized chunks in less than a minute.
Automotive Shredder Residue
The material left over after an automobile has been shredded and the ferrous metal removed(nonferrous metals plus nonmetallic material).
SSI shredder with a specialized cutter stack to facilitate opening or breaking up large bales without much shredding.
Large bound (and sometimes wrapped) packages of material. Bales are often rectangular in shape and bound with metal wires or banding material. When confirming size, please provide full dimensions (L x W x H) and weight.
A thin strip of flexible material (typically metal or plastic) used to bind material into bundles or bales.
Batch Feed (Fed)
Material which is fed in a “batch” environment is deposited in a single mass - often the contents of a bin, or the load of a grapple. The opposite material feed process is meter fed.
Thick round metal cord that circles inner tire edges. SSI shredders often process tires with bead wire. However, some processors remove beads prior to shredding (using a debeader) to facilitate processing, minimize metal separation or contamination, and extend cutter life.
SSI technology feature: bearing and seal protection
Wheel loader (small type of heavy equipment) with bucket device used for loading or lifting.
Structural steel bracket mounted beneath the cutting chamber and is parallel & center to the shafts. Available as an optional feature, it reduces the particle size of certain friable materials such as wood.
The tendency of some materials to span over cutters, making grabbing and shredding more difficult. Materials demonstrating this problem, such as drums or large wooden boxes, can utilize SSI’s hydraulic ram to minimize this potential problem.
Small, highly compressed bales of material,typically rectangular in shape. Since material is compressed, banding is often not required. When confirming size, provide full dimensions (L x W x H) and weight.
Material which is bound together without compression and often with no defined shape. When confirming size, please provide full dimensions (L x W x H) and weight.
The depth at which material is spread on a conveyor belt.
Abbreviation for “British Thermal Unit.” Measurement of heat to define the energy value of different combustible materials. Specifically, the quantity of heat required to raise the temperature of one pound of water one degree Fahrenheit.
C & D waste
Abbreviation for “Construction and Demolition” waste or debris.
Abbreviation for “Computer Aided Design.” Technology for computerized design or drafting that increases the efficiency and accuracy of design work. SSI uses the latest CAD technology.
Construction and Demolition
Flat steel plates attached to the side walls of a shredder's cutting chamber. The semicircular plates extend between the shredder's cutters with notches fitting closely around the spacer to prevent material buildup between the cutters. SSI offers segmented, or 'floating,' cleaning fingers held in place by retaining brackets on each side of the cutting chamber. Shredders lacking the segmented design often use cleaning fingers connected in a solid comblike weldment. These units generally require cleaning finger removal via the bottom of the shredder.
Type of energy generation process: various waste materials mixed with conventional fuels to produce energy.
Controlled Torque Coupling
A device installed between the electric motor and gear reducer to protect drive components by allowing gears to instantaneously slip when the shredder experiences an excessive load.
- Equipment for compressing goods to reduce volume.
- Roller compactors (heavy equipment) drive through landfills to crush and flatten materials.
- Box style compactors receive and compress material into a boxlike container prior to landfill delivery.
- SSI offers a large “pre-load” compactor for scrap metal and municipal waste. It compresses material into a chamber then ejects it into a container. See “pre-load compactor” or contact SSI for more data.
A mixture of organic decaying matter used for soil enrichment. Materials such as yard waste, leaves, organic household waste and sewage sludge are often shredded to reduce particle size and to facilitate material blending and decomposition.
Computer Print Out paper, typically in continuous form.
Exclusive-use processing machines that reduce tire chips to crumb rubber using two compression rolls to fracture material.
Type of shredder often used in office environments for security shredding purposes. Crosscut shredders can deliver a very small and consistent particle. However, they typically can't accept boxed or bagged material, or large amounts at one time. Similarly they cannot generally process materials contaminated with metal (such as fasteners or binder rings). Slow-speed shredders are more appropriate for such applications.
Rubber processed into a small granule, typically measured in “mesh” units. Most scrap tire applications request end products ranging from 6-40 mesh.
Method using super cool liquids or gases (such as liquid nitrogen) to freeze materials. Once deeply frozen, material is easily fractured to a smaller size.
Also called instant-trip relay. An electrical sensing device that monitors the circuit amperage in the shredder motor. If motor amperage exceeds the relay setting, an internal switch opens to signal the PLC (Programmable Logic Controller).
A thick metal disk with one or more hooks on the outer edge and a hole in the center. The center hole allows the disk to be mounted on a shaft to form a cutter stack. SSI center cutter holes are either keyed or hexagonal in design.
Cutter to Cutter Clearance
The gap between overlapping cutters in the cutting chamber. Width of gap is set to obtain most effective shearing.
Environment in which paper is shredded for security purposes. Goal: to “destroy” data.
Machinery to remove the bead in a tire. Although the process is not typically required before shredding on an appropriately sized shredder, debeading facilitates the metal separation process and improves cutter life.
A type of granulator or high-speed knife mill, which can reduce material to a fine powder. It is typically used in highly classified military or government applications.
See “data destruction.”
Although not common, some recycled material (especially paper) processors encounter “double bales.” A small bale is water soaked then reprocessed into a larger bale to create the double bale. This dishonestly increases the weight and resulting value of material.
Separation of material after it has been shredded. Usually material leaves the actual shredder on a conveyor belt and then is sent through magnets, eddy current separators, trommels, and other downstream separation equipment.
Device used to compact drums, typically in the vertical position, into a round compressed block with accordion or fanlike pleats.
Material not easily fractured. Examples include cardboard, paper, cloth, soft plastics, steel drums and tires. When shredded, ductile material is typically shred into strips of varying lengths - unlike friable material, such as wood, impact plastics and cast aluminum, which fractures into smaller pieces.
Eddy Current Separator
A device for separating non-ferrous metals from non-metallic material that works by creating a mechanically driven rotating or alternating magnetic field and moving a non-magnetic metallic particle into this field. An eddy current is created in the particle, producing a magnetic field with a like polarity, and ejecting it from the fixed field generator.
Product generated by forcing material under pressure into a formed shape. In shredding applications, typical materials are formed plastic and aluminum extrusions such as aluminum door and window frames.
Material which is (or includes) steel or iron.
The process of breaking apart fibers (e.g., crumb rubber processing environments). Shredded tires are processed into a granule then subjected to a screening and separation process (typically using air systems) to remove fiber.
Material which fractures or crumbles easily. Examples include wood, stone, hard impact type plastics, some cast metals and glass. When shredded, friable material breaks into irregular pieces - unlike ductile materials (such as paper) which often generates strips of varying lengths.
Articulated wheel loader (heavy equipment) with bucket device for loading or lifting.
- A device for measuring, registering or testing.
- A unit of measurement to describe material thickness - such as steel drums.
A rectangular-shaped box that is part of the shredder's frame. The box contains two large, straight-cut gears attached to cutter shafts.
A cylindrical-shaped housing located between the drive motor and shredder gearbox that contains planetary gears for reducing the input drive speed to the shredder.
A type of high-speed processing equipment typically using fast turning knives (with a mounted screen) to cut material into small, consistent particles. Granulators and other high-speed units can be integrated with slow speed shredders.
Although designs vary, guillotines typically use large, heavy rectangular blades to chop bulky materials.
The term refers to a variety of high-speed mills which use fast-turning “hammers” to crush or pulverize material into small, consistent particles. Mills can be integrated with slow-speed shredders for an integrated system.
Individuals or firms which collect and transport materials. In our industry, the term refers to waste haulers who take materials to landfills or waste transfer stations.
Although specific definitions vary by state or country, hazardous materials typically are harmful to life (i.e., poisonous, explosive, caustic or flammable) and require special handling or disposal.
Abbreviation for “High Density Polyethylene.” A type of plastic used in milk, juice and water bottles. (Known as “PEAD” in Mexico.) See SSI Plastics Application Training Sheet for additional data.
Definition may vary by industry. However, we refer to size reduction technology which operates from 100 rpm to 900 rpm (or higher). It is the opposite of slow-speed technology which typically operates at 20 to 30 rpm.
Mills using a high-speed principle of inertia (low-torque) as opposed to slow-speed (high torque).
A type of high-speed mill, often equipped with fast turning rotors to process materials including wood and MSW.
A type of blending equipment used primarily for waste paper pulping in a recycling operation. Although hydropulpers can accept whole bales of waste paper, breaking bales apart using SSI’s bale breaker unit can increase the efficiency of this process.
Hydraulic Power Unit (HPU)
A set of components consisting of the hydraulic pump, motor, control valves, fluid reservoir, filter and hoses assembled to power the ram cylinder.
See 'Current Relay'.
Type of SSI hopper designed for installations processing material which may bridge or requires additional material feeding control. Hydraulically operated lifting fingers reposition material to minimize bridging--or lift material off cutters to slow processing. This device can be used where an SSI infeed ram is not desired.
A type of high-speed mill, similar to a granulator, using fast turning knives, or blades to process material.
Site created for depositing or disposing of waste material.
Process to extract waste material from older landfills. Benefits: land recovery for more lucrative purposes, recovery of valuable recyclable materials, and extension of the landfill life.
Abbreviation for “Low Density Polyethylene.” A type of plastic used primarily for producing garbage bags. (Known as “PEBD” in Mexico.) See SSI Plastics Application Sheet for more data.
Wheel loader (small type of heavy equipment) with bucket device for loading or lifting.
loose (materials) Materials not bagged, boxed, baled or bound in any way.
The material on the conveyor belt that needs to be sorted.
A round drum with multiple replaceable cutter inserts which cut against a fixed bed knife. Used for reducing materials such as plastics, electronic scrap, wood waste and nonferrous metals.
Measurement unit for fine, granular materials. The term refers to the open spaces of a wire, fiber or thread network (series of horizontal and vertical lines). If granules fit within a space occupying 1/40 square inch (in either direction) they are “40 mesh.”
Method to feed materials on a controlled basis into a shredder or compactor. It is the opposite
of material which is “batch” fed.
Type of equipment readily moved from site to site. Mobile equipment is trailer-mounted with
an independent power source. Mobile equipment is different than “portable” equipment which can be moved, but may not be trailer mounted.
Abbreviation for “Materials Recovery Facility,” a site to sort waste materials and to “recover” or collect recyclables.
Abbreviation for “Municipal Solid Waste,” often a mixture of residential and commercial waste.
Non-iron based metals such as aluminum and copper.
Material that the shredder does not have the power to shred due to its size, material or hardness. It typically triggers reversals in the effort to shred. Following a reversal, a shredder attempts to reprocess the material. If it is “nonshreddable” the shredder eventually shuts down to allow the operator to remove the materials. SSI’s shock load protection feature typically protects the shredder from damage if non-shreddables are fed into the unit.
Abbreviation for “Oversized Bulky Waste.” Term often applies to a mixture of furniture, appliances, mixed wood waste, etc.
Abbreviation for “Old Corrugated Cardboard.” Material is typically baled prior to recycling by pulp and paper mills.
Abbreviation for “old magazines.” Material is typically baled prior to recycling by pulp and paper mills. The recycling process can benefit from using an SSI bale breaker unit.
Abbreviation for “old newspaper.” Material is typically baled prior to recycling by pulp and paper mills. The recycling process can benefit from using an SSI bale breaker unit.
Abbreviation for “Off The Road.” Term describes types of tires, often oversize, used on “off the road” equipment such as large mining vehicles.
Abbreviation for "Old Telephone Directories."
Abbreviation for “Old Waste Paper.” Material typically includes mixed office paper, often baled for recycling by pulp and paper mills.
Material measurement designation following the shredding process. Any discussion shouldinclude length and width dimensions.
Type of tire typically used in passenger automobiles. In the U.S., an average passenger tire is about 20 lbs.
Abbreviation for “Poly-Ethylene Terephthalate.” A type of plastic used to produce bottles for soft drinks and edible oils. Also see SSI Plastics Application Sheet.
Type of equipment with an independent power source that can be moved, but not on its own wheels. It differs from “mobile” equipment which is trailer-mounted.
Abbreviation for “Poly-Propylene.” A type of plastic used to produce caps and lids for bottles and containers. Also see SSI Plastics Application Sheet.
Type of compactor which pre-crushes material prior to loading into a transfer container. Unlike a compactor which crushes material directly into the container which transfers it.
SSI offers a special compactor design which compacts and weighs material prior to transmitting it to a transfer trailer.
Preparing material prior to a secondary handling. Material is often “preprocessed” by a shredder, prior to secondary processing by equipment such as high-speed mills.
Abbreviation for "Plastics Recovery Facility."
Shredding material to destroy a product. Materials such as date-expired food products and defective products (often with brand names) are shredded prior to disposal to reduce theft from a landfill and associated liability.
Programmable Logic Controller (PLC)
A solid state electronic device that receives information from sensors and push buttons, processes the information using stored, programmed logic and executes commands to control machine or process operations.
Abbreviation for “Poly-Styrene.” A type of plastic used to produce egg cartons, meat trays and disposable drinking cups. Also see SSI Plastics Application Sheet.
Processing cellulose materials such as wood and paper into a blended mass for making (or remaking) a product.
Term for irregularly shaped plastic formed when plastic molding or extrusion equipment discharges feed stock (when soft) following a color or material run. See also SSI’s Plastic Application sheet.
Abbreviation for “Poly-Vinyl-Chloride.” A type of plastic used to produce pipes and clear food packaging. See also SSI Plastics Application Sheet.
Term for waste material generated by the ragger device in a hydropulper. It is a continuous, rope-like mass of entangled wire, plastic and fiber, often 18" in diameter. Pulp and paper mills sometimes shred this waste material prior to incineration.
Hydropulper component to entangle non-pulp waste material and remove it from the pulping process as “rag rope.”
Abbreviation for "Refuse-Derived Fuel."
Sites to process polyurethane foam scraps for carpet underlay. Scraps are first shredded, then granulated into small chips. Chips are then formed into large blocks or logs that are cut or peeled into final sheets.
Reduced Voltage Start-Up
See 'Wye-Delta' starting
Waste generated by homes or residences. In the U.S. this material typically includes organic waste, mixed paper and plastic.
A high-speed hammermill which uses rings as opposed to hammers.
Abbreviation for "Residential Mixed Paper."
Term which refers to material which is shredded into large pieces (often 4"-6" wide with varying lengths. The primary purpose of “rough shredding” material is to achieve volume reduction, product destruction or preprocessing (prior to a secondary process).
SSI technology feature: bearing and seal protection
Waste paper or cardboard processed by pulp and paper mills is referred to as “secondary fibers”.
The motor on the shredder, which can be configured a number of different ways including electric or hydraulic.
An assembly typically consisting of the shredder frame, endplate, gearbox, cutting chamber and all operating component parts contained within these components.
A broad, flat, often thick piece of material.
Term which refers to material impacting under force. It is often encountered when high-speed equipment (such as granulators or ;hydropulpers) process bulky materials. Shredding such materials (on a slow-speed shredder) prior to high-speed processing can minimize this damaging tendency.
Technology which operates at approximately 10 to 30 rpm. Opposite of high-speed technology which typically operates at speeds of 100 to 900 rpm.
Slow Speed, Shear Type Shredder
A high torque, low speed industrial shear shredder consisting of two or more counter rotating shafts equipped with hooked knives capable of reducing a wide variety of materials such as tires, paper, and baled metals such as aluminum.
A small, non-hooked disk placed between cutters to maintain a precise distance between the cutters.
A velocity sensing device consisting of a proximity switch, target, control module and associated wiring. The switch signals the PLC when the input shaft exceeds or falls below a preset rate.
Abbreviation for SSI’s patented “Severe Shock Protection” controlled torque coupling feature.
Term which refers to equipment operating on an independent basis.
Type of large truck tire typically used on cement or special use vehicles. A super-single is larger than a normal truck tire and often replaces two standard truck tires.
A hammermill-type shredder with a larger capacity than the typical hammermill used for shredding cars.
Abbreviation for “Tire Derived Fuel”. Tires which have been shredded into chips for use as a fuel supplement. Although dimensions differ by market, the most popular dimension in the United States is 2"x2" / 50mm x 50mm.
A shredder used primarily for woody, vegetative debris. A tub grinder consists of a hammermill, the top half of which extends up through the stationary floor of a tub. As the hammers encounter material, they rip and tear large pieces, pulling the material down below the tub floor and ultimately forcing it through openings in a set of grates below the mill. Various sized openings in the removable grates are used to determine the size of the end product.
Materials that a shredder is unable to handle because they are too large or too thick to be shredded.