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How to process 12mm or ½” wire free granule mix to a fiber free crumb.


How to process 12mm or ½” wire free granule mix to a fiber free crumb.

wire free tire rubber from an Eidal rasper

The above picture above shows the result of taking a whole tire through an Eidal shredding process and then through an Eidal rasper process.

The shredding process has taken a whole tire to a 50mm fuel chip stage and the Rasper process has taken the 50mm fuel chip to a wire free 12mm minus granule stage

The next process is to take the 12mm minus granule to a crumb stage.

crumb rubber from granulation line

This outline follows our first two data sheets on tire recycling for chip making and granule making

We have outlined in prior documents the first stage of a recycling system, that being the shredding stage

Tire Derived Fuel, or TDF

This is what a 2″ or 50mm fuel chip looks like. It takes three to four cuts in a shredder or shredding system to take a whole tire down in size to a 2″ fuel chip. This is important to remember in understanding the process of cutting tires to smaller pieces. You are shredding in three dimensions and the fuel stage is a slice and dice operation that needs at least 2 cuts to make the proper size chip. And in reality the process takes 4 cuts.

We have also outlined in prior documents the second stage of a recycling system, that being the Rasper stage. Now we will proceed to further our discussions about the third stage in a tire recycling system, that being the granulator Rasper stage.

As outlined earlier, the shredder or shredding stage of a tire recycling plant is designed to process whole tires into a 50mm, or 2 inch fuel chip, commonly referred to as a TDF chip (Tire Derived Fuel chip).

Baled tires for transportation

The picture above shows baled tires being received for recycling at a tire plant.

As we have noted, for many years tire recycling involved basic shredding of tires for legal disposal of the waste material into a landfill or for energy via burning.

tire recycling equipment

Over the last 45 years tire recycling has evolved from basic disposal through a fuel preparation stage to a full recycling stage today.

Today, there are even more changes, as the value of the steel or metal contained in a tire has turned into a major income stream of significant bottom line value for tire recycling.

baled tire wire for re-sale

This is a significant change in the industry turning a scrap tire into a commodity item, steel and rubber.

The steel today is a 1070 alloy steel that when clean of tramp rubber can command the attention of worldwide buyers. However, the process to take a whole tire to a wire free form and to clean the wire after this process involves a significant investment of at least 1 million dollars or more.

Due to this high entry cost tire recycling is still at the beginning stages of development, which means that there are great opportunities in this field for investment and expansion. One important factor to also understand is that a tire recycling system can process other waste materials and that also increases the business opportunity for investment.

industrial tire shredder, the 7272

You can start with a single shredder system or you can move into a multiple shredder system to take whole tires to a fuel or aggregate form. The entry level for tire recycling is one shredder. One shredder is needed to cut the tires into a form that can be used as daily cover at landfills or as a civil engineering chip for erosion control and fill type of projects.

The important factor to understand is that there are a lot of tires in the world and that they are a very special area of recycling, one that we understand and know…since 1966.

four industrial shredders for massive production

This picture above is for a fuel system the design of which can be made to process 5, 10, 15, 20 or more tons of tires per hour into a fuel chip form.

We can design any system that you need and with our Eidal industrial shredder brand, we design what we build, we build what we design, since 1966.

This is important, as there are now 500 companies around the world, most now from china that copy shredder designs to sell around the world. We would like you to buy our shredder but if you buy from another group, you will eventually call our group to help you solve your problems.

Our consultancy is available for a fee and we welcome helping others fix their problems and issues in regard to their shredders purchased from groups other than our company.

CM tire Recycling, broken shredder

This is a broken CM shredder (made by Columbus McKinnon) that we repair and fix for clients.

We can fix or repair, any shredder brand from around the world. We don’t care if it was made by the Germans, the Italians, the Canadians, the Americans, the Indians or the Chinese. We can fix or upgrade any shredder.

dual rasper line for massive tire recycling projects

This picture above shows a dual Rasper system for taking a 50mm fuel chip to a wire free granule form. Because of the new and growing demand to remove the steel from the tire, to meet recycling demands and to increase the bottom line revenue for a tire recycling plant we have taken the standard Rasper and turned it into a super Rasper..

Basically this Eidal super Rasper removes the steel from the rubber and this steel removal stage is called the Rasper stage and always involves a Rasper type of system

The overall result of a Rasper system when removing the steel from the rubber produces two fractions, a steel fraction and a rubber fraction.

industrial shredder rasper

Taking a 2″ tire chip to a 12mm wire free granule requires 64 cuts per chip. Which means that the Rasper stage is working very hard as compared with the shredder stage.

Normally it takes 500 hp to process 10 tons of whole tires per hour into a fuel chip. That’s 50 hp per ton to make a 2″ fuel chip.

Normally it takes 400 hp to process 4 tons of fuel chips to a wire free 12mm granule. That’s 100 hp per ton to make a 12mm wire free chip from a 2″ fuel chip.

64 times more cutting, and only twice the horsepower.

The Rasper is a very efficient machine

industrial shredder rasper rotor

You can’t remove the wire or metal from a tire unless you process the tire in an Industrial Shredder/Rasper design system.

As outlined above the tire is prepared for the proper size so that it can enter into the Rasper stage.

As outlined in prior data, you have to size a tire properly into a TDF form (tire chip) using a “slice and dice” shredding process.

By shredding a whole tire, three or four times, in different directions, you make the tire derived fuel feedstock for a Rasper, or for the Rasper system.

The Eidal Rasper system design uses our special rotor, which is bi-directional for reduced wear. We have a patent on this bi-directional rotation for reducing downtime from wear.

Rasper rotor pulled out for maintenance

There are several designs of this Rasper concept.

There are also several names for these types of machines.

The most common name is “the Rasper” but there are also other derivations used in the industry, correct or not, such as a “grizzly”, “granulator”, or “knife hog”.

There are also machines that are being sold as Raspers, which are not Raspers, one such mis-application are hammermills and granulators.

They are not the right machine for the job. We make granulators and we make hammermills, so we can be objective.

All buyers need to understand that many groups in this industry make only one type of shredder or grinder. We make 450 different shredders and grinders, so we can always offer the proper machine.

If a company only makes one type of machine they must offer you that machine, or suffer going out of business.

What’s more important: We are the lowest cost provider in the world and our prices are half the prices of any other shredder in the western world

We are also the same price of any Chinese or Indian shredder.

Enough said? have we made our point?

Buy from the right shredder group and there are very few of us in the world that are the right shredder group.

We are one of them.

Saturn is one of them: we invented it.

SSI is one of them: we invented it

Shred Tech is one of them: we invented it.


industrial rasper single line

Our “bi-directional Eidal Rasper”  is designed to process a rough tire shred, or if possible, and more desirable, a 50mm tire chip.

This machine physically rip and tears the steel out of the rubber chip, by a mechanical rip and tear design of the rotor or cutting head, its not unique, its standard to the industry.

No magic here, its just old fashioned rip and tear technology

When the Eidal Rasper is done with its task what exits the machine is a mix of 12mm minus wire free rubber granules, and basically “rubber free” clean tire wire.

In the industry, “clean tire wire” normally means 98% rubber free.

However, depending on the design of the system and the needs of the customer or end users of the rubber and steel, you can change the design of the Rasper system to allow for different grades of rubber sizes and different grades of clean steel.

One such change is to use a primary Rasper and a secondary Rasper in the Rasper system design.

Rasper bombay screen

One other change common in the Rasper system is to change the screen opening, or screen size, or screen design in the Rasper.

Shredder rasper screen for tire recycling

The larger the screen size in the Rasper, the less wear encountered by the Rasper.

The larger the screen size used in the Rasper, the less clean the steel will be of attached rubber.

However, in most cases, a Rasper can easily produce a wire free rubber granule, and a wire that is 95% rubber free.

tire wire from rasper production

The picture above shows the various sizes of tire wire that are removed from a tire during the Rasper stage.

The important factor in a Rasper system design is the need for clean wire free rubber and clean rubber free wire.

Clean rubber is made using a 15mm screen in the Rasper

Clean steel is made using a 20 mm screen in the Rasper

General clean rubber and general clean steel is made using a 25mm screen in the Rasper

As you can see in the screen data, there is not a universal screen size that makes clean rubber and clean steel.

Clean rubber free of steel is easy to make.

Clean steel free of rubber is not easy to make.

industrial shredder rasper discharge

There is a compromise in a Rasper system where the design must allow for the production of wire free rubber granules takes a priority over clean steel or tire wire.

Further processing of the steel or tire wire after the Rasper in a wire cleaning system is often necessary to ensure a low wear cost in the Rasper and a high return value in the tire wire.

Baling or briquetting of the tire wire is also a consideration that must be made in the system design to determine the proper required density of the metal for shipment and smelting to maximize the its value for the recycling venture.

tire wire magnetic separator

Very clean tire wire commands up to 50% more value than lower grade tire wire contaminated with rubber. High density baling or briquetting of tire wire also commands up to 50% more value than loose material

Baled tire wire

Therefore, in the Rasper design you often must include a wire cleaning system and a wire baling system

The basic design of a Rasper system includes a magnetic separation and often a screening system

The tire chip is fed into the Rasper, single or dual Rasper line, and the material that is discharged from the machine is a wire free rubber granule mix and steel.

The steel is removed with a simple cross belt magnet

The rubber is normally screened to separate the various size rubber granule and crumb fractions in the discharge material mix

The system for screening can be designed to help clean loose dirt and dust as well as loose fiber from the rubber granules.

tire wire magnetic separator stopped

This picture above shows the discharge magnetic system and screening system attached to the Rasper system

industrial tire recycling system for wire free production

This is another view of a Rasper system with a magnetic removal design and an auger feed system to move the granule mix into a truck for transport

The best design for a Rasper is to take the wire free rubber granule and screen for different sizes

Rasper screening system

This is a typical layout of an Eidal Rasper with a magnetic removal system for the tire wire and a double deck screening system to separate the rubber fraction from the Rasper

The important design features of the Eidal Rasper is the tool steel inserts that reduce the maintenance intervals of the machinery and lower the cost per ton of production

The main rotor assembly is typically driven with a 400 hp drive motor

The main rotor turns at about 100 rpm.

tire recycling system layout

This is a typical Rasper layout for a tire recycling plant or even a wire recycling reclaim plant.

The design is simple and robust and is an addition to typical tire shredding operations that produce only TDF or tire derived fuel

The design of the Eidal Rasper system can also be used for wood pallet grinding where metal is removed from the wood fraction and screened for recycling and mulch.

The design of the Eidal Rasper system can also be used for wire and cable processing to reclaim copper and Aluminum from waste wire and cables.

The design of the Eidal Rasper system can also be used for WEEE or electronic waste recycling and computer recycling to help extract valuable materials from the waste stream.

Exterior shot of tire recycling system for wire free

This picture shows a single Eidal industrial shredder and a single Eidal Rasper design with a simple Infeed conveyor and magnetic removal design.

There are small versions of our Eidal Rasper and large versions of the machine

The smaller version is often called the Eidal nibbler Rasper

Mini systems or entry level system using the Eidal Rasper or the Eidal nibbler Rasper can help many recycling groups enter into a wide range of recycling applications

If will be our pleasure to answer your questions and help you find the most appropriate shredding solution for your business.

We invite you to contact us by using the contact form below, by email or by telephone at +1 (815) 674-5802.

Dan Burda

President & Owner

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