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.
-A-
ACLS
Abbreviation for SSI’s patented "Advanced Cutter Locking System" that uses a pre-load hub assembly to tighten or lock the cutter stack.
ADF
Advanced Disposal Fee
Appliances
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.
Ash
Residue resulting from incineration or burning process.
Auger
Type of conveyor, cylindrical in shape with spiralled flights (corkscrew), which moves or elevates the enclosed material.
Auto-Chop
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.
Automobile Shredder
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).
-B-
Bale Breaker
SSI shredder with a specialized cutter stack to facilitate opening or breaking up large bales without much shredding.
Bales
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.
Banding
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.
Bead Wire
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.
Bearing Protection
SSI technology feature: bearing and seal protection
Bobcat (loader)
Wheel loader (small type of heavy equipment) with bucket device used for loading or lifting.
Breaker Bar
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.
Bridging
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.
Briquettes
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.
Bundles
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.
Burden Depth
The depth at which material is spread on a conveyor belt.
BTU
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-
C & D waste
Abbreviation for “Construction and Demolition” waste or debris.
CAD
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.
C&D
Construction and Demolition
Cleaning Fingers
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.
Cogeneration
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.
Compactors
- 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.
Compost
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.
CPO Paper
Computer Print Out paper, typically in continuous form.
Cracker Mills
Exclusive-use processing machines that reduce tire chips to crumb rubber using two compression rolls to fracture material.
Crosscut Shredders
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.
Crumb Rubber
Rubber processed into a small granule, typically measured in “mesh” units. Most scrap tire applications request end products ranging from 6-40 mesh.
Cryogenic Systems
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.
Current Relay
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).
Cutter
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.
-D-
Data Destruction
Environment in which paper is shredded for security purposes. Goal: to “destroy” data.
Debeader
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.
Disintegrator
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.
Document Destruction
See “data destruction.”
Double Baled
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.
Downstream Separation
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.
Drum Crusher
Device used to compact drums, typically in the vertical position, into a round compressed block with accordion or fanlike pleats.
Ductile
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.
-E-
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.
Extrusion
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.
-F-
Ferrous
Material which is (or includes) steel or iron.
Fiber Separation
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.
Friable
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.
Front-End Loader
Articulated wheel loader (heavy equipment) with bucket device for loading or lifting.
-G-
Gauge
- A device for measuring, registering or testing.
- A unit of measurement to describe material thickness - such as steel drums.
Gearbox
A rectangular-shaped box that is part of the shredder's frame. The box contains two large, straight-cut gears attached to cutter shafts.
Gear Reducer
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.
Granulators
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.
Guillotine Shears
Although designs vary, guillotines typically use large, heavy rectangular blades to chop bulky materials.
-H-
Hammermills
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.
Haulers
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.
Hazardous
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.
HDPE
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.
High Speed
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.
High-Speed Mills
Mills using a high-speed principle of inertia (low-torque) as opposed to slow-speed (high torque).
Hog
A type of high-speed mill, often equipped with fast turning rotors to process materials including wood and MSW.
Hydropulper
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.
-I-
Instant-Trip Relay
See 'Current Relay'.
-K-
Kick-Up Hopper
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.
Knife Hogs
A type of high-speed mill, similar to a granulator, using fast turning knives, or blades to process material.
-L-
Landfill
Site created for depositing or disposing of waste material.
Landfill Mining
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.
LDPE
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.
Loader
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.
-M-
Material Burden
The material on the conveyor belt that needs to be sorted.
Medium-Speed Shredders
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.
Mesh
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.”
Meter Feed
Method to feed materials on a controlled basis into a shredder or compactor. It is the opposite
of material which is “batch” fed.
Mobile
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.
MRF
Abbreviation for “Materials Recovery Facility,” a site to sort waste materials and to “recover” or collect recyclables.
MSW
Abbreviation for “Municipal Solid Waste,” often a mixture of residential and commercial waste.
-N-
Non-Ferrous
Non-iron based metals such as aluminum and copper.
Non-Shreddable
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.
-O-
OBW
Abbreviation for “Oversized Bulky Waste.” Term often applies to a mixture of furniture, appliances, mixed wood waste, etc.
OCC
Abbreviation for “Old Corrugated Cardboard.” Material is typically baled prior to recycling by pulp and paper mills.
OMG
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.
ONP
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.
OTR
Abbreviation for “Off The Road.” Term describes types of tires, often oversize, used on “off the road” equipment such as large mining vehicles.
OTD
Abbreviation for "Old Telephone Directories."
OWP
Abbreviation for “Old Waste Paper.” Material typically includes mixed office paper, often baled for recycling by pulp and paper mills.
-P-
Particle Size
Material measurement designation following the shredding process. Any discussion shouldinclude length and width dimensions.
Passenger Tire
Type of tire typically used in passenger automobiles. In the U.S., an average passenger tire is about 20 lbs.
PET
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.
Portable
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.
PP
Abbreviation for “Poly-Propylene.” A type of plastic used to produce caps and lids for bottles and containers. Also see SSI Plastics Application Sheet.
Pre-Crusher Compactor
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.
Pre-Load Compactor
SSI offers a special compactor design which compacts and weighs material prior to transmitting it to a transfer trailer.
Preprocessing
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.
PRF
Abbreviation for "Plastics Recovery Facility."
Product Destruction
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.
PS
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.
Pulping
Processing cellulose materials such as wood and paper into a blended mass for making (or remaking) a product.
Purgings
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.
PVC
Abbreviation for “Poly-Vinyl-Chloride.” A type of plastic used to produce pipes and clear food packaging. See also SSI Plastics Application Sheet.
-R-
Rag Rope
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.
Ragger
Hydropulper component to entangle non-pulp waste material and remove it from the pulping process as “rag rope.”
RDF
Abbreviation for "Refuse-Derived Fuel."
Rebonding Facilities
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
Residential Waste
Waste generated by homes or residences. In the U.S. this material typically includes organic waste, mixed paper and plastic.
Ring Mill
A high-speed hammermill which uses rings as opposed to hammers.
RMP
Abbreviation for "Residential Mixed Paper."
Rough Shred
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).
-S-
Seal Protection
SSI technology feature: bearing and seal protection
Secondary Fibers
Waste paper or cardboard processed by pulp and paper mills is referred to as “secondary fibers”.
Shredder Drive
The motor on the shredder, which can be configured a number of different ways including electric or hydraulic.
Shredder Head
An assembly typically consisting of the shredder frame, endplate, gearbox, cutting chamber and all operating component parts contained within these components.
Slab
A broad, flat, often thick piece of material.
Slamming
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.
Slow-Speed
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.
Spacer
A small, non-hooked disk placed between cutters to maintain a precise distance between the cutters.
Speed Switch
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.
SSP
Abbreviation for SSI’s patented “Severe Shock Protection” controlled torque coupling feature.
Stand-Alone
Term which refers to equipment operating on an independent basis.
Super-Singles
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.
Super-Sized Shredder
A hammermill-type shredder with a larger capacity than the typical hammermill used for shredding cars.
-T-
TDF
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.
Tub Grinder
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.
-U-
Unshreddables
Materials that a shredder is unable to handle because they are too large or too thick to be shredded.