INDUSTRIAL SHREDDERS, GRINDERS and SHREDDER SYSTEMS
Consideration of Shredders & Grinders for Recycling and Other Benefits
Industrial shredders for waste products play a key role in waste management and recycling in today’s manufacturing and disposal industries. They may also be practical for other businesses or business communities, after careful consideration of security, waste management costs and the importance of lowering environmental impact. It’s also important to know what type of shredder is most suitable and cost effective for a given application.
The advantages of using mega-shredders in large-scale waste disposal systems, such as municipal landfill / recycling centers, are fairly obvious. Plastics, wood, rubber, asphalt and similar materials can be immediately reduced to a mere fraction of their original size and many can be sold or given directly back to the public for distribution as useful products. Bio-degradable products will decompose faster after shredding. Shredding also allows those materials that will end up buried forever in landfills to be compacted into a much smaller space with fewer voids, resulting in a more stable base for future development.
Applications for other businesses may not be quite so obvious and the advantages may not be immediately apparent. This guide will attempt to shed some light on possible applications for business and industry, the potential advantages, the types of machines available and how to determine what type of shredder or grinder is right for your application.
Shredder Applications – an Overview
The following list is a brief overview of some possible applications for industrial shredders and grinders in business. Some may be familiar and others may not have occurred to you. Profit-savvy company executives are finding new and profitable ways to employ these units every day. Facts and figures will be covered later in the guide.
Prototype and model destruction
In the manufacturing and engineering industries, espionage is a very real threat. If you create scale models or mockups of projects in your business, those need to be disposed of securely when they’ve outlived their usefulness. In some cases, even full working prototypes may need to be rendered unrecognizable. Industrial shredders may provide the means to do so practically.
In-house waste management
Ecologically sound business practices are moving more toward the forefront in today’s society. Businesses are being called upon to reduce waste and to handle waste products responsibly. Managing at least some of the refuse an industry or complex produces is one way to reduce your carbon footprint.
Lowering the environmental impact of a business is certainly important, but there may be other advantages to this strategy as well. State, Federal and even some Municipal governments now offer several incentives for employing responsible recycling practices. These may come in the form of tax write-offs, licensing discounts, or other inducements.
Other fiscal advantages may be possible, too. Industries may be able to recycle shredded or ground waste directly as raw materials for the same processes. Or, perhaps the shredded materials may be useful in other areas, as in the way some small businesses are shredding cardboard containers for use as free packing material. It may also be possible to create new revenue streams for some businesses through direct sales of shredded or ground refuse products.
Micro-Community waste management
As developers learn to manage an ever-increasing population and “green” building practices become the standard, new buildings and whole complexes are springing up as micro-communities. These hubs for modern living incorporate living, working and shopping environments in the same building or complex of buildings within walking distance of each other. Management companies for these cooperative communities may find the same advantages as businesses and more in managing recycling programs for the entire community. With the proper grinding/shredding equipment, substantial revenues may be built throughout the community and incentives can be offered to clientele within the building or complex.
Just as in private operations, waste management for micro-communities has the potential to provide secondary income streams for development or management companies. Shredded waste products can be marketed directly to other enterprises or recycled within the community as insulation or other building materials.
Direct Industrial Applications
While the advantages are often the same as those of in-house and community management systems, several industries are based on or supported by shredder or grinder operations. Most applications are based on recycling cast-off materials, often creating a viable product in the process. One well-known example is used tire recycling, in which a potential environmental hazard is prepared for reuse in a wide range of areas, from asphalt to playground surfaces.
Other industries that rely on shredding or grinding processes for their operations include the creation of engineered wood products created from reconstituted materials, as well as composite building materials of plastic and wood fiber, and more. Fabrics of recycled plastic and insulation made from various materials also use industrial shredders in their manufacturing processes.
Types of Shredders
Industrial shredders vary in many ways, according to the function they perform. The internal mechanical processes may include cutting, grinding, hammering and compression. Many shredders also incorporate shaking/sorting mechanisms. Internal machinery may travel in rotary, lateral or vertical directions. Speeds of the internal processes also vary widely, to suit the materials the machines will be handling. Shredders can be partially categorized by the type of process or processes they employ.
Grinders use abrasion, often combined with compression to pulverize materials, usually to produce granular products. Wheels, drums and plates may be used in the processes. These may be either high or low speed machines, according to the type of material they are intended for.
Chippers normally use high speed rotary knives to reduce materials to flakes or chips. They can be manually or automatically fed, and may be single or multiple stage machines. They may also employ single or multiple drums or wheels with single or multiple knives.
Granulators are employed mostly for plastic recycling from production processes like injection molding. These units use knives, rather than abrasive surfaces to reduce parts or trimmings, etc. to fine particles that can them be reused easily in the production lines. Some granulators are equipped with thermoforming units that form the output into easily handled scrap or production parts. Granulators vary widely in size and mechanics according to the type of industry, types of materials handled, and the location in which they will be used.
Hammermills are used to shatter or pulverize materials. The most common configuration is a chamber containing a rotary drum with swiveling hammers of hardened bar or chain. The chamber is typically gravity-fed, and output screens control the size of particle produced. Hammer material, configuration and distribution, and rotation speed are a few of the factors that determine the type of material that can be processed.
Shear Shredders employ rotary cutters or guillotine-style knives to cut materials rather than pulverizing, chipping or grinding. Shears can be found in many different configurations for different industries. Feed types, speeds and type and number of knives differ according to the applications.
Specialty Shredders that are designed for a particular type of material may utilize combinations of the above processes or unique devices developed especially for that material. Tire shredders, for instance, typically use one or more rotary shafts or screws, with interlocking lugs, cams, teeth or blades. The feed is configured to force the tires between the shafts or the shaft and machine surfaces, where the lugs, etc. forcefully tear the tire into small pieces. The shafts are generally rotated at low speeds, under very high torque.
Other special purpose applications present challenges that require unique design features in shredding equipment. Shredders for safe disposal of medical refuse require extremely close tolerances, to render sharps, tape and other small waste products into particles too small to be recognized. Medical waste shredders usually employ rotary grinders to ensure this. Since medical waste is usually sterilized before destruction, these machines often need to incorporate a method for dealing with liquids.
Secure, high technology applications often require the destruction of waste within a clean room. This requires special filtering and dust traps to maintain the dust-free environment.
Fibrous waste and thin sheet goods such as plastic films may present problems for conventional shredders. Specialized shredders are available for reconstitution and recycling of both these types of material.
'All Purpose' Shredders are the heart of major demolition operations and many municipal recycling programs. The machinery usually consists of large, very low speed, high-torque shafts or drums with carbide cams or studs, sometimes equipped with hydraulic rams to assist with the feed. Many of these shredders are capable of reducing entire refrigerators, cars, or other oversized equipment to small pieces in a single pass. They are most often combined with external systems that remove hazardous liquids, gases or solids, sort metals from other materials and otherwise prepare the shredded material for disposal and/or reuse.
As mentioned briefly above, there may be great advantages to using shredders within your business operations or community. While some advantages will be readily apparent, others may require some explanation. Industrial shredders are helping companies and communities address issues from economics to protecting the environment on many fronts.
In today’s economic climate, businesses and communities are pressed to find new ways to cut costs and increase revenues. Shredders may provide new strategic options to help relieve financial pressures and may offer the opportunity to produce new income streams. Let’s look at some examples:
Production waste recovery
Any manufacturing process produces a finite amount of waste. While most companies adopt practices or modifications that minimize this waste, the small amount of raw material that’s lost in processes like molding, punching, casting or trimming is often considered to be a necessary loss. Modern shredder technologies, however, may provide a way to recover most of that loss.
For instance, in an injection molding process, if only 2% of the injected plastic is trimmed in cleaning up the product and a production line uses 2lbs. of styrene for each product, that translates to 0.64oz. of plastic per product. At first glance, this may seem to be an acceptable loss. However, in an operation that produces 3,000 products per day:
.64 X 3,000 = 1,920oz. / 16 = 120lbs. of raw material lost per day
120 / 2lbs. per product = 60 products lost per day
While this example may not be accurate for a given business, it nevertheless provides a basis for examining the feasibility of recovering lost material. Multiply the number of lost products per day by the net profit per product and it may be easy to justify a means to recover the waste.
In this example, the manufacturing company may benefit from the installation of a granulator or granulators within the molding shop. Modern granulators can be installed in-line or centrally, to facilitate the best solution for a given location. Recovered material can then be fed directly back into the process or used to provide the raw material for other processes, such as thermoformed parts.
Saving recycling costs
Environmental impact is a major concern, so much so that many states have instituted laws that make recycling of many waste products mandatory for homes and businesses alike. Unfortunately, while most business owners are environmentally conscious and happy to comply with these regulations, the cost of recycling can often be a burden. Commercial recycling costs are rising at an astounding rate. With an estimated cost of $50 to over $150 per ton to commercially recycle most materials, cost effectiveness of an outside service may be hard to calculate.
Many companies are realizing cost savings by implementing their own recycling programs. In general, businesses create considerable amounts or recyclable waste in their operations, and the support of operations. From containers for raw materials to break room beverage containers, to packing materials, pallets and more, recyclables creep into the workplace from several directions. By installing proper shredders for the types of material that pass through your business, the cost of disposal can be greatly reduced and perhaps eliminated. In many cases, recycling can offset operating costs through the re-use or sale of the shredded waste. This brings us to the next category:
Generating new income streams
Industrial shredders may bring new revenue to business operations by the generation of new products or raw materials. These products or materials can be used within the processes of the business, used to create new product lines or marketed directly.
The lumber and building materials industry has come to make wide use of this concept. Culled pieces of wood that are unacceptable in board stock are chipped, combined with resins and pressed into wafer board, used extensively for sheathing, decking and floor underlayment in building construction. Even sawdust is collected and processed similarly to create particle board, a dense, relatively inexpensive sheet goods product with hundreds of building industry uses.
Composite materials of recycled granulated plastic and wood fibers are being engineered with advantages over traditional lumber such as light weight, higher strength and mold/mildew resistance. Chipped, shredded or ground bark dust can be resold for landscaping. Chips not reused are resold to paper mills. Fine chips or sawdust are processed into pellets for wood stoves.
Not every industry will enjoy this many options for using waste materials, but these examples may provide the spark necessary to see how putting industrial shredders, chippers or grinders to work in your own operations might generate substantial extra income for your business.
Reduction of community development costs
Today’s real estate developers and architectural companies make use of shredding equipment on building sites to provide many of the advantages we’ve mentioned above. The results are immediate savings in disposal of recyclable products, reuse of building materials as landscaping and fill products, and even the use of packing materials as efficient, low-cost insulation. For those waste products that still need to be recycled commercially, many recyclers offer substantial discounts for prepared scrap and some will purchase and collect processed scrap.
Many contractors and developers own portable shredding equipment and large, micro-community projects often allow builders to make use of permanently installed shredders.
As with any investment for your business, purchasing shredding equipment deserves careful consideration. Costs for industrial shredding equipment can be substantial and careful analysis of cost versus benefits needs to be performed. In many cases, the financial rewards can offset or outweigh the costs, if the equipment is used to its full potential.
In today’s world, being “green” is ever-increasingly more important. Our impact on the environment individually, corporately and as a community weighs heavily on how we’re perceived by our clients, our friends and associates and the general public. Consumers in today’s market are more likely to deal with businesses that demonstrate environmental responsibility. New standards for cleaner community living have created new concerns for developers and municipalities. Federal, state and local governments offer incentive programs for energy efficiency and waste reduction. Industrial shredders play an important role in helping meet the challenges of becoming environmentally friendly.
Fewer, cleaner landfills
Shredding provides easier handling of recyclable waste, thereby encouraging more consistent recycling. In many cases, shredded materials can be reused directly within the operations or communities that disposed of them, resulting in less overall waste output. By combining shredding equipment with hazardous waste disposal and recycling, the introduction of heavy metals, toxins and other hazardous materials into landfills is greatly reduced.
For materials that are committed to landfills, shredding allows for greater compaction of non-bio-degradable components, creating a more stable fill and allowing disposal of more waste in less area. Most organic wastes can be composted and reused after shredding, eliminating thousands of tons of input to landfills per year and providing valuable resources for consumers.
Preservation of natural resources
Shredding waste allows reuse of metals, reducing the need for new ore mining and helping preserve our natural resources as well as our landscapes. Scrap yards, metal fabrication shops and even the auto recycling industry use shredding equipment to provide mills with clean, recyclable metals in a form that’s easy to transport and incorporate into their smelting processes.
Processing of waste lumber for engineered and composite materials saves our forests. Incorporation of granulated plastics helps extend the useful life of composite building materials, reducing the need to produce more lumber. This also contributes to a reduction in the use of sawmill kilns, and the fuel they consume.
Reduction of emissions
Industrial shredding of waste provides opportunities to lower greenhouse gases and toxic emissions on several fronts, some of which may not be immediately obvious.
As an example, in the past, it was a common practice to burn tires at dump sites before burying the leftover sludge and slag in landfills. Burning vulcanized rubber produces acrid, toxic smoke that drifts for miles and carries fallout pollutants that return to the soil and the water supply. With the introduction of tire shredders, used tires can be recycled as useful products without harmful effects.
Landfill methane is among the most common greenhouse gases. U.S. landfills have been estimated to pour as much as 450-650 billion cubic feet of methane per year into the atmosphere. By incorporating recycling programs aided by the use of shredding equipment, we can reduce the amount of organic waste producing those methane levels.
Wood smoke is a major contributor to pollution levels in metropolitan areas around the world. By using shredders to convert waste wood products into pellets and briquettes, cleaner burning, more efficient fuels are created for wood stoves and fireplaces, thus reducing the amount of wood smoke introduced into the atmosphere.
Mining and ore smelting operations are also major contributors to air pollution, through the burning of fossil fuels in their operations and support equipment. By recovering shredded metals for recycling, we lower the emissions produced by mills and mining operations.
One less obvious reduction in emissions is through reduced transportation requirements. As companies adopt in-house recycling programs, many shredded materials are reused in their own processes, sold, or reduced to a much more manageable size for easy packaging or hauling. Eliminating the need to transport some waste and reducing the bulk of hauled waste means less fuel burned by trucks, trains, planes and ships to move those materials. By recycling waste products, fuel consumption in the manufacture and shipping of new products is also reduced.
Reduction of water supply contamination
Landfills gather contaminants, heavy metals and other pollutants that leach out as materials around them decompose. Many of these materials find their way into subterranean reservoirs and rivers that link to municipal water supplies. Even relatively “clean” metals like copper and aluminum break down in landfills and contaminate water supplies. Above-ground sources like wrecking yards and open dump sites also contaminate water supplies as runoff from rains carries leaking fluids and salts into streams and rivers. Even worse, dumping of refuse directly into major rivers has contaminated them with dangerous heavy metals and carcinogens such as PCBs that make their way into drinking water and even our food supply as fish and shellfish find their way to our tables.
By adopting responsible recycling and disposable programs at the business and community levels, we can help lessen the severity of the problem. Shredders help facilitate responsible recycling by providing waste products that are easier to sort, handle, package, transport and reuse.
As briefly mentioned earlier in this guide, industrial shredders may also provide security for some types of business. Although it is worth noting that this guide is not concerned with document shredding, the destruction of documents is certainly an important part of business in the 21st century, (but again this report is about shredders that are designed for other materials).
A great number of industries develop working prototypes and models during the production of a new product or product line. These prototypes may be based on one or more innovative concepts or technologies that would be of great value to competitors. Reverse engineering a product from a prototype or copying a model design is a practice that has been employed on more than one occasion by companies in many industries. Fields that may have a need for the destruction of prototypes or models include:
· Automobile manufacturing
· Military hardware
· Machine shops
· Metal fabrication
· Aircraft manufacturing
· Space exploration
In reality, this list could go on indefinitely. Any industry that manufactures or designs a useful product or even a novelty runs a certain amount of risk from prototype theft.
The type of shredding equipment employed for prototype destruction depends, of course, on the materials involved in the manufacturing process. Demolition and recycling companies may be able to perform this service, and may be sufficient for your purposes. Individual business owners should consider the security risks and the frequency of the need for product destruction as well as the cost of shredding equipment before deciding which methods to use.
Every business stores sensitive information on several levels. Accounting records, client information, account usernames and passwords, bank account information, and even addresses, phone numbers and birthdays need to be protected in today’s society. With very few exceptions, that information is committed to magnetic media, in other words, computer hard drives, backup tapes, CDs, removable disks and external storage devices from USB flash drives to wireless network drives.
System upgrades, expansions, mergers, downsizing and equipment replacement all leave records on magnetic media that needs to be eliminated. As you know, formatting, erasure, and traditional software “wiping” methods don’t ensure that the data can’t be read. Even mechanical failure of a drive doesn’t prevent retrieval of the files by non-conventional means.
Complete destruction of drives, discs, tapes, memory sticks and other data storage is yet another job for industrial shredders. The most common configuration for data shredders is the all-purpose, rotating shaft type, due to the wide range of materials involved in the manufacture of data storage devices. Storage device shells, electronics and media are reduced to bits in a few seconds, rendering the data unusable.
Secure data destruction services can be hired and may be an inexpensive alternative to purchasing your own shredding equipment. Some important considerations are the type of destruction method used and the reputation of the business providing the service. It is also important to weigh the value of the data to other parties. In-house data destruction is imperative for some businesses.
Selecting the Right Shredding Equipment
Even before you make the decision to invest in industrial shredding equipment, it’s important to choose the correct equipment. While it may seem enough to simply know what operations your equipment will need to perform and the materials it will be handling, the decision should involve more. There are many points to be considered and these may affect the feasibility of the equipment for your applications. Let’s examine those points:
Type of material
The type of material is, of course, among the most important factors in choosing a shredder and will have a great deal to do with the type of shredder you’ll need. For instance, if you operate a tree service, sawmill or cabinet shop your shredder will most likely be handling wood and wood products. A high-speed chipper will likely be the best choice for your business. Tire centers will require machines that can handle steel wire and cable along with rubber and nylon. These applications will be better served by low-speed, multiple shaft machines with interlocking cutters or cams and very high torque.
Plastics have low melting points and will generally need to be shredded at relatively low speeds, or cut, to avoid clogging machinery. Granulators and similar machinery will be the most likely choice for companies that manufacture plastics or for plastic operations in recycling centers.
Construction and demolition companies, business and municipal recycling centers and some manufacturing industries may need to handle the disposal of many different materials. Depending on how the shredded materials are to be used or disposed of, individual units may be used to process each material, or an all-purpose solution may be the more cost effective choice.
Simply stated, the type or types of material to be shredded will determine the type of shredding action required. Fortunately, most modern shredders are designed and manufactured for particular groups of materials, so the guesswork has been mostly eliminated.
Output requirements for your shredded waste will also help determine the type of equipment to install. Tire recycling centers, for instance, may simply ship their shredded output to other facilities for separation, re-shredding and grinding. If so, a single-pass shredder or shredders will probably suit their needs and will probably cost less. If the center intends to create marketable products from their processes, their shredders will need to be equipped to separate metals from studs and belts from the output, and to re-shred and/or grind the output to produce the final product.
In mixed scrap recycling applications, some operations will simply want to reduce the size of the waste to facilitate easier transportation to a recycling facility. Optionally, a business or community may want to handle all processing of recyclables within their own operations. This will require the addition of sorting and separating stages. Depending on the intended use of separated outputs, baling or compaction equipment may be required.
As previously mentioned, it may also be possible to directly reuse shredder output within your own processes or to create a marketable product. Cabinet shops, for instance, may be able to process their waste to create wood pellets or briquettes for use in wood stoves.
Capacity will be determined by the physical size and amount of material to be handled. Capacity may be limited by more than hopper size. For instance, a tire shredder with a hopper large enough to accept a heavy equipment tire may not have a drum or cutters of sufficient size to accept the tire. Check rated capacities carefully.
Feed type breaks down to two basic types: manual and automatic. Hopper-fed, multi-purpose shredders most often are manually fed, as the feed for these units tends to come intermittently, from fork lifts, trucks, bins, or by hand. Horizontal shredders, such as some wood chippers or plastic extrusion granulators, may be available with automatic feed options. For operations with a constant supply of material for the infeed, automatic feed will probably result in less clogging and less wear to cutting or grinding surfaces. Manually fed shredders may provide a less expensive alternative. Again, it’s important to examine the needs of the operation carefully.
Portability is often a factor in selecting a shredder. While conventional recycling centers don’t normally need to be mobile, demolition companies, construction firms, landscapers and other enterprises may realize the most benefit from the ability to use their shredding equipment on-site. Shredded materials can be transported from the job site more easily, and in many cases may be reusable directly on the job. For example, pulverized concrete can be used as aggregate in new concrete, or as fill material. Likewise, shredded wood can be immediately used as mulch for landscaping.
Portable shredders range greatly in size and care should be taken to determine the size that best suits your needs. It’s also essential to consider power or fuel requirements for a unit that will be moved from site to site.
Process location options
Process Location Options can be a major factor in selecting shredding equipment. Referring back to the earlier example of an injection molding process, granulator units are available in under-process models that can accept trimmings directly from production lines, or as larger, central units that require the excess material to be brought to the shredder by conveyor or other means. Either of these options may be more viable and cost effective for a given application.
Similar options may be available in many applications and may make a considerable difference in the cost of purchasing and operating the equipment. There are a number of factors that coincide with these basic choices, for instance the cost of retrofitting existing equipment for in-line installations.
Health and safety concerns
Health and safety concerns are often overlooked in the selection of shredding equipment. Many shredding operations create large amounts of dust and airborne particles. Shredding or grinding equipment may need to include dust containment and removal systems to protect employees and/or operations. This becomes particularly important for equipment that will be operated indoors and in crowded locations.
Noise is another critical consideration that’s often forgotten. Shredding and grinding processes can produce noise levels far above safe hearing ranges. While hearing protection is always a good idea and often required by OSHA, it is important to note that the community where your equipment is located may have legal noise limitations that might determine the type of shredding equipment you can use in your location.
Even low-speed shredders can produce flying fragments. Brittle metals and plastics can break apart violently under pressure and this can result in various projectiles with the potential to do great harm to employees and surrounding structures or equipment. While most manufacturers make sure that shredder housings can withstand the impact of these objects and keep them contained, openings like hoppers and feed doors may need additional guards to avoid mishaps.
Maintenance and repair
Maintenance and repair are a necessary part of operating any kind of industrial equipment and shredders are no exception. In fact, considering the stresses these machines endure, even the best-built shredders may be considered high maintenance. Most notably, knives, cams, cutters, hammers, etc. will wear under normal use and will need sharpening or adjusting. Breakage of these parts is also possible, from accidental feed of materials the machine isn’t designed for, such as a spike in a wood chipper or a titanium rod in a general-purpose shredder.
The hours of downtime required for maintenance or repair of equipment may help determine the feasibility of using that equipment. Consider the options carefully. Does a shredder have replaceable blades, or is it necessary to replace a shaft? Which takes more time? How difficult is it to set blade tolerances? Does it require a tear-down of the machine? How readily available are replacement parts? What parts need lubrication? How often? These questions and more are worth the time it takes to ask them.
There are other choices to be made and many other considerations before deciding to purchase industrial shredding equipment. Throughput speeds, physical size, power requirements (and associated operating costs), weather resistance, and many other factors will all have some bearing on what kind of equipment to buy, and whether it’s practical to buy the equipment in the first place.
This guide is intended as a general overview of industrial shredders, their use and the potential advantages of operating them, as well as some important considerations in selecting equipment. It’s our hope that readers will be able to use this information to help decide whether shredders are a good investment for their purposes, and if so, what equipment is best suited to their requirements.
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