Here is everything on the internet that you need to know about industrial shredders.
You will learn:
- What is an Industrial Shredder?
- The Different Designs of Industrial Shredders
- How Industrial Shredders Work
- Types of Materials that are Shredded
- And much more…
Chapter One – What is an Industrial Shredder?
An industrial shredder is a piece of heavy duty equipment designed to shred dense and light materials to prepare them for recycling or for the destruction of unusable products. They are an environmentally sound device that takes otherwise useless materials and transforms them into raw forms for remanufacturing or waste management.
Industrial shredders vary from office equipment designed to destroy sensitive documents to huge commercial industrial shredders that prepare materials for disposal or recycling. In recent years, shredders have become an essential part of manufacturing and production as an assist to helping reduce the amount of waste dumped into landfills.
Chapter Two – Different Industrial Shredder Designs
There is a type of shredder designed for any type of material: from ones that shred paper and cardboard to large industrial shredders that can shred mattresses and sheet metal. Shredder designs are divided by their type and can be driven by electric or hydraulic motors. There are a wide variety of structural factors that include single shaft, double shaft, and four shaft, to name a few.
Industrial Shredder Designs
Single Shaft Shredder –
Single shaft shredders are used for waste recycling and have one shaft with rotary blades, a hydraulic pusher plate, and a screen underneath to filter materials to conform to the proper size. The single shaft rotates at a low RPM rate and shreds materials to one or two inches. They are used when a consistent particle size is required and are ideal for shredding plastic materials.
Double Shaft Shredder –
For double or dual shaft shearing shredders, shearing blades are mounted on two shafts that rotate into each other at slow speeds to quietly shred large high volume feed stock into small pieces of one to five inches. The low speed prevents the creation of dust during shredder operation. The main purpose of double shaft shredders is to handle large quantities of bulk volumes of materials. The video below, from SSI Shredding Systems, explains the benefits of a dual shaft shredder.
Three Shaft Shredder –
The three blades of a three shaft shredder rotate at different speeds to provide a continuous flow of feedstock. The size selection for shredded materials is determined by the screen that the material has to pass through when leaving the shredding chamber. If the material is not small enough, it is recirculated through the machine until it is the proper size to pass through the screen.
Four Shaft Shredder –
A four shaft shredder has four shearing rollers with four sets of shearing knife rollers with different cutting shapes. The process of a four shaft shredder allows for pre-shredding and secondary shredding to happen simultaneously, which improves production efficiency. Quad or four shaft shredders are used to shred materials that need separation with uniform sized particles. The video below, from SSI Shredding Systems, gives a complete explanation of the benefits of a quad or four shaft shredder.
Horizontal and Vertical Hammermill Shredder –
Horizontal and vertical hammermill shredders work by crushing fed materials with a series of repeated blows by small hammers. A steel drum, that has hammers mounted on a shaft, rotates rapidly striking the fed material beating it into small particles. The five key styles of hammermills are gravity discharge, pneumatic discharge, full circle screen, horizontal in feed, and lump breakers. Regardless of the style, how the hammermill operates is essentially the same.
Grinders shave, chip, and grind small pieces from large objects using abrasives or compression that flattens the material. Grinders break materials down to fragments that are a half inch or less. Two styles of grinders are tub and horizontal. Tub grinders are top loading and are designed to grind wide materials. Horizontal grinders have a conveyor belt and do a smooth consistent grinding. Grinders are similar to dual shaft shredders with two rows of sharp steel cutters that slowly rotate to breakdown material.
Granulators turn materials into flakes or granules, which can be sold as raw material for remanufacturing. They have an electric motor that turns a rotor that has cutting blades attached and enclosed in a chamber. They come in a wide variety of sizes and shapes. In the chamber, the blades on the rotor shred the material into reusable granules.
Chapter Three – How Industrial Shredders Work
Though the basic concept behind shredders is relatively simple, there are a variety of complex engineering methods that are employed in their design and manufacture. The common shredder, that can be found in a home office, is one of the simpler types of shredders with one, two, or more blades. They are normally straight line where material is fed through a slot in the top of the shredder and deposited in a basket or receptacle.
Shredders designed for industrial use are more complex and have to be engineered specifically for the material that they will disassemble. A main concern for industrial shredders is the size and shape of the final material, which can be a few inches to granules.
How Industrial Shredders Work
The operation of a shredder may seem rather simple since you place material in them that is cut by single or multiple blades into fragments for reprocessing or waste management. The engineering principles behind the operation of a shredder are more complex than their simple function. The basic elements of a shredder include a rotor, a counter blade or counter blades, housing, motor, feeding, power system, and a control system and can include grabbing.
- Rotor – The rotor on a shredder has saw teeth cutters that mesh with knives to shred scrap and waste.
- Blades – Blades are at the heart of a shredder but must be chosen carefully to fit the material to be shredded since not all blades can be used on all materials. They are made of hardened alloyed steel and may be coated to add to their useful life.
- Housing – The housing contains all of the components of the shredder and is made of heavy duty metal.
- Motor – The motor on a shredder operates at a slow speed to lessen its stress. The slow rotating speed and high torque allows the shredder to shred a variety of materials.
- Power Systems – The two types of shredders are hydraulic and electric. Electric systems are preferred since they take up less space and can process most materials. Hydraulic power is better for heavy duty processing and can handle overloads from batch feeding.
- Feeding – Batch and meter feeding are the most common feeding methods, where batch feeding is designed to shred large quantities of material. Metered feeding is placing materials in the shredder at an even flow and normally employs some form of conveyor.
- Grabbing – This is the process whereby the shredder takes the material and pulls it down into the cutting blades. Its function is determined by the size and shape of the cutter hook as well as the texture and weight of the material.
- Control Systems – With the advancement of technology, modern shredders for industrial use have touch panel control systems that allow for in process adjustments to shredding eliminating the need to access the mechanism to make changes and adjustments.
The Shredding Process
Material to be shredded is fed into the shredder. This can be accomplished with a hopper, where material is dropped in from the top or on a conveyor.
With a common paper shredder, the paper is grabbed by the blades and pulled through the knives or cutters. The process for industrial shredders is slightly more complicated since they are capable of shredding a car with a great deal of force. In either case, the cutting mechanism grabs the material and pulls it through the rotating blades changing large whole materials into small pieces.
As the material passes through the shredder, it is cut into shapes of various sizes depending on the material being shredded and the design of the shredder. For some materials, a secondary or granulator may be used to further reduce the size of particles.
Sizing Screen –
Sizing or discharge screens are found on bulk shredders to screen materials and send oversized pieces back through the shredding blades to ensure that it reaches a specific size. Screens are designed to fit the type of material and come in a wide variety of sizes. Shredder screens align with the rotating cutter such that there is an interaction between the cutter and screen.
During the screening process, contaminants such as sand, stones, glass, ceramics, and various metals are removed by the screen, and air, ballistic, over belt magnetics, and eddy current separators capture them
The process of collecting the shredded materials falls into several categories with a different method for each type of shredding device, shredded material, and ultimate use of the particulates. Some systems have a conveyor system that collects the material to be used as raw material for repurposing. Unlike the common paper shredder that has a trash can type container for shredded material to fall into, industrial shredding requires other steps to prepare material for recycling.
In some systems, the shredded material passes through a granulator to convert it into smaller particles, pellets, or other types of raw material. Other processes may dump the material into a large bin or bale it. The purpose of the shredding process is to avoid dumping reusable material into a landfill and preparing it for remanufacturing.
Chapter Four – Materials that are Shredded
There is no limitation to the types of materials that can be shredded, which can include computers, disk drives, cars, aluminum cans, and outdated and unusable equipment. For each type of material, there is a special shredder design that can precisely crush solid materials and prepare it for repurposing, reutilization, or waste management.
Materials that can be Shredded
Plastic production benefits the most from shredders and combines the shredding process with granulating to prepare shredded plastic materials for reprocessing. Plastic industrial shredders shred large plastic materials like car bumpers, pipes, and storage drums to reduce them for granulation. The shredders, moving at slow speed, break the large objects into smaller pieces that are collected, washed, treated, and then granulated for recycling.
Tire shredders prepare used tires for disposal or recycling. In order for tires to be repurposed or sent to waste management, they must meet the size requirements of the state or region where they are being processed. A primary tire shredder converts tires into two to six inch shreds and have a single or dual shaft design. The secondary shredder, grater, refines the larger pieces down to one inch or smaller fragments and filters out any wire pieces.
The purpose of a metal shredder is to squeeze large pieces of metal that are too large for waste management or transport and tear them into more usable pieces. Metal shredders come in various styles depending on the metals that they process. Large models can have 10,000 horsepower motors and be capable of shredding trucks and automobiles. Metal shredding is a rapidly growing business due to the world’s demand for recycled metals.
Industrial wood shredders or chippers reduce pieces of wood to smaller refined chips, fragments, or sawdust as part of the process of recycling. The design of the blades of the shredder determines the size of wood that the shredder is capable of processing. Three typical types of wood shredders are high torque roller, drum, or disc. High torque shredders operate at lower speeds using an electric motor, while drum shredders are similar to large material shredders where wood is fed in and grabbed by shafts. Disc shredders have a spinning disc that shreds materials.
Biomass is a source of renewable power and has become an important source for many countries since it contains large amounts of stored chemical energy. The purpose of a biomass shredder is to reduce the size of feedstock for use by biomass boilers at power plants. Biomass shredders transform feedstock from farm and forestry products into proper particulate form. All biomass has different character traits requiring biomass shredders to be specifically designed for each type.
The unique construction of textile fibers presents a challenge for their shredding since they can be synthetic, artificial, or naturally woven as well as contain zippers, fasteners, buttons, and rubber. The textile shredding process separates the various materials removing and detaching them. Clothing, textiles, and other fabrics are shredded into filaments, square short single fibers, or debris in the form of flakes or powder. The shredded materials from a textile shredder are reused for insulation and padding.
Medical Waste –
Medical waste shredders are designed for processing of sterilized medical waste that may be toxic, unsafe, or hazardous. Empty glucose bottles, hose syringes, blood bags, scalpels, needles, gloves, and other medical equipment cannot be disposed of by burning since they emit toxic gases. Medical waste shredding cuts medical equipment into unrecognizable pieces and makes it safe for proper disposal.
The mechanism of a medical waste shredder involves the use of a fixed cutter with multiple shearing discs to destroy and reduce medical materials into fragments. A major factor in the rise of medical waste shredders are the regulations as stipulated in the Health Insurance Portability and Accountability Act (HIPAA) that requires proper destruction and disposal of patient information.
Much like plastic shredding, aluminum shredding has become an important recycling industry. The process involves shredding aluminum items down to forms that are easier to handle for further processing. Prior to being shredded, aluminum goes through a process designed to remove dust and other materials. It is then sent through a set of magnetic separators to remove any ferrous metals. Once cleaned and separated, it is emptied into the shredder. Once it is shredded, it is melted and cast into aluminum blocks.
Glass Bottles –
Glass crushers are used to change glass bottles and products into a powder to be cleaned and molded into new products or hollow blocks. They can crush bottles of various sizes to significantly reduce the amount of waste for landfills. There are several benefits to crushing or shredding bottles into powder or reusable sizes. The process saves on waste, storage space, and provides material that can be remelted into new products.
Paper shredders have been used for over 110 years and have become a staple of business practices to ensure the security of sensitive documents. The use of shredders has grown to the point that they are commonplace in small businesses and homes. Industrial shredders are able to destroy large volumes of confidential materials in bulk and shred over 500 sheets at once. They run continuously to feed a compactor that turns the shredded paper into bales. Unlike a home shredder, an industrial shredder needs a means of removing paper dust from the 1000’s of sheets it destroys every day. In some instances, where there are books, large catalogs, or manuals, before the material can be shredded, it has to be pre-shredded due to the volume rate that an industrial paper shredder processes feedstock.
Automobile shredders have become an essential part of the harvesting of scrap metal. The process for shredding a car begins with crushing it to reduce its volume. The common feeding method for automobile shredding is a hopper that is located above the shredding blades and cutting tools. To ensure that the shredder does not receive too much material at one time, a feeding device controls the movement of the car into the shredding blades. The result of the process is high density, uniform scrap that is later separated by plastic, rubber, carpet, and glass to be reprocessed.
Cardboard shredders operate much like a paper shredder and transform uncontaminated cardboard into small sized pieces for further processing. Unlike paper shredders, certain cardboard shredders perforate cardboard for use as packing material, as can be seen in the image below.
Mattresses are the bulkiest and most difficult trash item for waste companies to dispose of and have become a major recycling problem. Their size as well as the difficulty of storing and handling them is a tremendous challenge. Though we may define a mattress as a single component, they have multiple materials hidden inside, which increases the difficulty of their disposal.
Modern and newly developed mattress shredding equipment are able to shred up to 200 mattresses per hour reducing the bulky material to small fragments. The video below, from SSI Shredding Systems, gives a brief view of the process.
Chapter Five – The Benefits to Using an Industrial Shredder
As environmental concerns continue to grow and gain greater focus, more and more industries are seeing the benefits of using shredders as a method of taking useless and out of date materials and converting them to raw materials for remanufacturing. The main quality that attracts companies to shredders is the reduction in the size of waste.
For most people, when they hear the word shredder, they immediately think of a paper shredder since they have become so common and useful. Though the original purpose for shredders was to destroy confidential documents, their use has expanded and become essential in a wide variety of industries.
Benefits of Using Industrial Shredders
One of the main concerns of many companies today is the cutting of costs and increasing revenue. Shredders provide a strategic advantage in those efforts. Even in this time of sustainability and increased efficiency, waste is still a major issue since every manufacturing process produces it. Industrial shredders can take waste from production and convert it into reusable raw material.
Recycling Costs –
Concerns for carbon footprint, environmental impact, and waste management have encouraged governments to institute laws that require companies to follow specific guidelines regarding waste materials. Added to these concerns is the rising cost of recycling that is rising at a rapid rate with costs of $50 to $150 per ton for the use of commercial recycling.
By using shredders, companies are developing their own recycling programs. Every item in an operation is being examined for possible recycling and repurposing from aluminum cans from soda machines to pallets, drums, and product packing material.
New Source of Income –
The main source of new revenue from shredders is the creation of raw materials, which can be reused by the company that produces them or be marketed to other businesses. The major businesses that have taken advantage of the concept are the lumber and construction industries, where shredded materials are combined with resin and formed into wafer or particle boards.
The uses for shredded plastic are endless from granulating it into resin for the manufacture of new plastic products to being used as filler and insulation. With the advancements in industrial shredding equipment, the transformation of plastic into reusable raw materials has become efficient and productive.
Reduced Community Development Costs –
With the strain that is being placed on tax dollars, developers are searching for ways to reduce costs on projects but be able to produce viable and quality construction. Shredders take otherwise useless waste materials and convert it into materials for landscaping, fill products, and lowering of building insulation costs.
If a recycling company is employed to remove waste materials from a development project, the amount they charge is substantially lower when the waste has been processed into scrap. The majority of projects have as a part of their plan a permanently installed, on-site shredder.
Production Waste Recovery –
All manufacturing processes produce waste as a side product. Even with efficiency monitoring, streamlining of processes, and waste management, there is still a considerable amount of material left. This is especially true with molding, punching, casting, and trimming, which is a necessary part of production.
In injection molding, two percent of every item produced is waste as it is removed to make the product conform to its design. Each product uses approximately two pounds of plastic with a waste factor of 0.60 oz. Looking at item by item, this does not appear to be much of a loss. If a company produces 3000 products per day, the amount of waste converts to 120 pounds of raw material lost every day or sixty new products.
By installing a shredder granulator, a company can recover the loss and make use of the waste material.
Environmental Factor –
The word “green” has taken on a whole new meaning in modern culture. The philosophy of the 50s, where items were thrown out the windows of cars and dumped at the side of the road has gone the way of the dinosaur. The main focus of companies today is to reduce their environmental impact and work to develop a world they can pass on to their children. With the financial incentives offered by governmental agencies and the benefits to the environment, companies are looking for solutions to their waste problems. The mechanism of shredders is a practical and convenient means of taking materials that could end up in a landfill and repurposing them.
As every waste management company will tell you, we are rapidly running out of space to dump our garbage. Garbage collection companies to large corporations are looking to shredding technology to reduce the amount of waste that has to be taken to the dump. Shredded materials can be reused, repurposed, and remanufactured to be put to a useful purpose. These methods significantly reduce the number of materials that end up in a landfill.
Saving Natural Resources –
The shredding process takes useless metal products and transforms them into raw materials. Our planet does not have an endless amount of ore and natural resources. By taking the metals that have been fabricated and processed and shredding them into usable pieces, companies can remove the need to use natural minerals for product production.
In the middle of the twentieth century, waste dump operators commonly burned used tires before bulldozing them. This process produced toxic gases that drifted for miles before falling out as pollutants into the soil and water. After this method was outlawed, tires were buried as part of landfill operations. With the introduction of tire shredders, old worn tires can be reused to make new tires and avoid the production of hazardous gases.
By reducing the amount of materials that are sent to landfills, the number of methane gases from them is radically reduced. It has been determined that landfills produce as much as 650 billion cubic feet of methane, each year, that escapes into the atmosphere. The use of shredders, to reduce landfill waste, lowers the level of methane gases.
Security and Data Protection –
Every business has sensitive information that is not designed for general consumption. This factor was the main reason for the introduction of the first shredders over a hundred years ago. The concerns of that time are just as relevant today, especially with the rise of electronic communications. All sizes of shredders have become commonplace in offices and businesses. The need for shredding and destruction of sensitive materials has given rise to the shredding industry, which has rapidly developed over the last forty years.
Public Relations –
Proper appearance to the public is a major concern for all industries. Companies that show a desire to protect the environment and preserve our natural resources are held in high regard by consumers. All companies have a portion of their advertising, marketing, and website programs that emphasize their desire to protect the atmosphere and preserve it for future generations. Shredders and their technology are a major part of fulfilling a company’s goal of being properly green and aligned with consumer attitudes.
Chapter Six – Safety Guidelines for Industrial Shredders
Though shredders have become a common piece of equipment that is found in multiple businesses, schools, and industry, they are still a serious piece of equipment that require proper care in order to perform at their best. It is essential that safety guidelines be followed when operating them, regardless of their size.
Shredder Safety Guidelines
Qualified – All sizes shredders should be operated by a person that is experienced with the equipment and aware of its safety procedures.
Safety Features – Prior to operating a shredder, workers should familiarize themselves with the safety features of the machine, which include emergency shut offs and proper clothing.
Loading – Every shredder has a list of the amount of material that it is capable of having fed into it and at what rate. It is important that the person operating the device understand how much they can feed since machines can jam, which makes them dangerous and unpredictable.
Proper Maintenance – Shredders are a piece of industrial equipment that should be on a regular maintenance schedule. They should never be operated when they appear to be in disrepair. When a shredder is being cleaned or repaired, it should be turned off and unplugged. Below is a short list of steps for maintenance of industrial shredders.
System Care – Most shredders are typically off when not in use since they have an automatic off switch. For added care and safety, they should be checked to be sure they are off when not in use.
Cleaning – It is very typical for office and personal shredders to be emptied regularly since they will stop operating when full. For small shredders, it is important to clean the blades on the shredder shafts to avoid them from getting fouled with bits of paper. For industrial shredders that may operate continuously, it is important to plan a regular downtime when the shredding chamber can be cleaned or replacement of the shredding blades.
Fire Prevention – The concern for fires may not be part of the operation of a small portable shredder. In the case of industrial shredders, their operation has the potential being a fire hazard. Modern technical shredders have fire, heat, and spark detectors in their hoppers and conveyors.
Industrial Shredder Maintenance
Industrial shredders are far more complex and technical than portable shredders since they handle large volumes of bulk material and can be in constant operation for hours at a time. There are steps that companies take to ensure that their equipment is always available and operating.
Five Steps to Ensure Proper Industrial Shredder Operation:
- In accordance with manufacturer guidelines, replacement parts should be on hand for emergency repairs.
- Manufacturers of large industrial shredders offer maintenance agreements for regular repairs and assessment of their equipment.
- Shredder liners should be checked to assess their position in relationship to the rotor.
- Material can build up between the shredder disk and wall. This can be prevented by checking and maintaining the rotors.
- Cutters and anvils should be operated in accordance with manufacturer specifications and not in access. If they are overused, they lose their ability to cut and eject shredded materials or drag and damage the machine.
- A shredder is a piece of heavy duty equipment designed to shred dense and light materials to prepare them for recycling or the destruction of useless materials.
- There is a type of shredder designed for any type of material from ones that shred paper and cardboard to large industrial shredders that can shred mattresses and sheet metal.
- There is no limitation to the types of materials that can be shredded, which includes computers, disk drives, cars, aluminum cans, and outdated and unusable equipment.
- Shredders designed for industrial use are more complex and have to be engineered specifically for the material that they will disassemble.
- As environmental concerns continue to grow and have greater focus, more and more industries are seeing the benefits of using shredders as a method of taking useless and out of date materials and converting them to raw materials for remanufacturing.