Abrasive blast systems are used for cleaning, surface preparation, and light deburring. Blasting is not the best if you are looking for heavy duty deburring equipment but in areas where you just need a little work done it can be done while you do your surface preparation.
The most common type of blasting system is sandblasting. Technically sandblasting uses sand (of course) but the term sandblasting is also used as a more general term for all abrasive blasting. Sand is a good choice for cleaning, paint removal, and removing scale from a surface. One of the gentle abrasives it will not do a lot for smoothing or roughing a surface but the surfaces will be protected while being prepared. Since sand is such an easy to come by media it is one of the cheaper ways to strip or clean a surface.
An uncommon gentle abrasive is corn cob media. Corn cobs are biodegradable and come in a variety of sizes. It is frequently used for the wood of log cabins. Corn cob is of course the tough woody center of an ear of corn; the cob can be broken down to media of a variety of grades and is tough enough to be reused. Because cob media is organic the cleanup is of a non hazardous method and if some of it is left behind it will not be a big deal.
One of the most abrasive of blasting media is steel. Steel media is generally used for roughing a surface to ensure proper adhesion for whatever type of finish that is being put on the surface. Steel media is very durable and can be reused many times in the blasting process (or tumbling or vibratory deburring) before having to be replaced.
Enclosed blasting systems aka blasting cabinets are used for smaller more manageable parts that need cleaning. Using an enclosed blasting system will keep the dust down and the surrounding area clean and safe.
Monday, April 5, 2010
Thursday, April 1, 2010
Thermal Deburring
The process of deburring using heat is called thermal deburring yet another option when it comes to deburring equipment available. The material being finished is placed into a chamber and the oxygen and fuel in the chamber is ignited which deburrs or deflashes the material within. This deburring system is one of the gentlest methods around. The defects in the object are removed with no damage to the product at all. Tumbling machines can occasionally leave burrs behind or if you are working with extremely delicate parts can leave scratches or defects behind.
This method of deburring is used with most, but not all, metals. It does not take much time for this process to be completed and it is safe for the metal to be oxidized in this way.
One of the best reasons to use heat deburring is that all parts of the material being worked on is finished at one time. The heat is not only on the surface but gets to all the small and difficult to reach areas. As technology advances and parts become smaller and more intricate in order to achieve the smoothest product thermal deburring is often the best way to go.
When the oxygen and other flammable gases fill the chamber they are then ignited which sets off a wave of heat which will clean most metal objects of burrs because they are normally very small and thin they are oxidized before the object on which they are on is damaged. The temperature of the item that is going through the process goes up some but very little in comparison to the temperature of the thermal chamber.
The temperature of the chamber gets upwards to 7000 degrees and in 30 to 35 seconds the part is finished and burr-free.
There are many other methods available, such as tumble or vibratory deburring, but few if any of these can actually get into the tight internal spaces that are sometimes required. Other systems work great if you are dealing with a lot of flat surfaces but they can leave burrs in slots and cuts of the part being worked on.
A nice little acidic cleaning and your part will then be ready to go.
Thermal deburring has an expensive start up cost if you are interested in having an in house system but the improvement in quality and the speed at which parts can be completed will help to recover those costs. If the volume done does not lead to purchasing the equipment there are many shops that do finishing and they can be located easily.
This method of deburring is used with most, but not all, metals. It does not take much time for this process to be completed and it is safe for the metal to be oxidized in this way.
One of the best reasons to use heat deburring is that all parts of the material being worked on is finished at one time. The heat is not only on the surface but gets to all the small and difficult to reach areas. As technology advances and parts become smaller and more intricate in order to achieve the smoothest product thermal deburring is often the best way to go.
When the oxygen and other flammable gases fill the chamber they are then ignited which sets off a wave of heat which will clean most metal objects of burrs because they are normally very small and thin they are oxidized before the object on which they are on is damaged. The temperature of the item that is going through the process goes up some but very little in comparison to the temperature of the thermal chamber.
The temperature of the chamber gets upwards to 7000 degrees and in 30 to 35 seconds the part is finished and burr-free.
There are many other methods available, such as tumble or vibratory deburring, but few if any of these can actually get into the tight internal spaces that are sometimes required. Other systems work great if you are dealing with a lot of flat surfaces but they can leave burrs in slots and cuts of the part being worked on.
A nice little acidic cleaning and your part will then be ready to go.
Thermal deburring has an expensive start up cost if you are interested in having an in house system but the improvement in quality and the speed at which parts can be completed will help to recover those costs. If the volume done does not lead to purchasing the equipment there are many shops that do finishing and they can be located easily.
Monday, March 29, 2010
Vibratory Deburring
The vibratory deburring process is a fairly simple and uniform procedure of removing burrs, finishing, and polishing. A variety of media can be used, both naturally occurring and manmade, in the deburring machine depending on the type of material being finished.
A coarse media can be used first for deburring followed by finer media for finishing and polishing. Bowls and troughs are some of the more common chambers used. A tumbler or barrel is frequently used prior to the vibratory machine but is not required.
The media and the item being deburred are placed in the chamber which vibrates to send the media evenly around the item to completely and uniformly finish an item so that it will be smooth and have no burrs (unnecessary lumps and bumps) on it.
Using a softer media such as walnut shells or corn cob pellets will finish and polish a more delicate material and as they are organic and reusable the disposal process of the media is easy and there are fewer local, state, and national waste rules to follow.
A tumbling barrel can be used for the primary deburring stage. A large barrel will rotate and the media will move against the item which over time will complete the finishing of the item in question. The barrels are large hollow (frequently) rubber lined cylinders which slowly turn and grind off the burrs while smoothing edges and surfaces.
Most hard materials can be put through a tumbling deburring process which will get it ready for the vibratory deburring stage.
Once the item has finished tumbling it will need to be cleaned of the media (grit) used in the tumbling process in order to prevent contamination of the vibratory media. Some types of grit can be reused and some types cannot.
A session in a vibratory deburring machine and all remaining defects to the finish should be corrected and the item is then ready to be used.
A coarse media can be used first for deburring followed by finer media for finishing and polishing. Bowls and troughs are some of the more common chambers used. A tumbler or barrel is frequently used prior to the vibratory machine but is not required.
The media and the item being deburred are placed in the chamber which vibrates to send the media evenly around the item to completely and uniformly finish an item so that it will be smooth and have no burrs (unnecessary lumps and bumps) on it.
Using a softer media such as walnut shells or corn cob pellets will finish and polish a more delicate material and as they are organic and reusable the disposal process of the media is easy and there are fewer local, state, and national waste rules to follow.
A tumbling barrel can be used for the primary deburring stage. A large barrel will rotate and the media will move against the item which over time will complete the finishing of the item in question. The barrels are large hollow (frequently) rubber lined cylinders which slowly turn and grind off the burrs while smoothing edges and surfaces.
Most hard materials can be put through a tumbling deburring process which will get it ready for the vibratory deburring stage.
Once the item has finished tumbling it will need to be cleaned of the media (grit) used in the tumbling process in order to prevent contamination of the vibratory media. Some types of grit can be reused and some types cannot.
A session in a vibratory deburring machine and all remaining defects to the finish should be corrected and the item is then ready to be used.
Sunday, March 28, 2010
Deburring
Deburring is the process in which cut and shaped materials of all types are rendered smooth and usable in a factory setting. When a material, let’s say metal, is cut before it can be used to actually make something it needs to be safe and functional. There are specific deburring methods used for certain materials.
Blast Deburring is when a media is directed while under pressure to the item needing finishing. Numerous media types are used in blast finishing. Sand, water, and beads are a small sample of the types of media used. The process used to remove burrs also depends on what the final product will be. A fine highly polished item needs more attention and finer and finer types of media used than something that is not to be seen.
The material will need to have smooth edges in areas that are intended to be smooth. Nicks and scratches will be removed as well as any loose material that was not removed in the cutting or molding process. Sometimes a grain is put into the material which will give a uniform scratched appearance, this process is called graining.
The process can include tumbling or vibratory deburring which is often one of the final stages in burr removal. Tumbling and vibratory media will (as with blasting) depend on which type of material is being polished.
There is a wide variety of deburring equipment and tools available for use in both the home and shops that provide the parts to the assembly plant. The necessary equipment includes the finishing media and the device that introduces the media to the rough product.
Home deburring equipment can be as simple as a file or can be more complex such as a deburring wheel. A small example of a deburring wheel that is used at home would be the regular old dremel tool. These are small quick rotating sandpaper covered tools that can be found in most homes. Larger wheels are used in a professional setting but they work on the same principles.
Other types of deburring include thermal (heat), cryogenic (cold), and dry ice. Each method has its place and is preferred by some materials or some people.
Thermal deburring uses heat to remove burrs by oxidation. The burrs themselves have a smaller surface area which means that the burrs will be effectively destroyed while the metal that they are attached to remains unchanged except the burrs are no longer present.
Cryogenic deburring is often used on rubber and plastic. Liquid nitrogen and the media are tumbled together and the result is a smooth burr-free finish.
In dry ice deburring the ice itself is the media and it is blasted to remove burrs and the dry ice then evaporates which leave no media to dispose of after the process is completed.
A very basic definition of deburring but one must start with the basics and work up from there.
Blast Deburring is when a media is directed while under pressure to the item needing finishing. Numerous media types are used in blast finishing. Sand, water, and beads are a small sample of the types of media used. The process used to remove burrs also depends on what the final product will be. A fine highly polished item needs more attention and finer and finer types of media used than something that is not to be seen.
The material will need to have smooth edges in areas that are intended to be smooth. Nicks and scratches will be removed as well as any loose material that was not removed in the cutting or molding process. Sometimes a grain is put into the material which will give a uniform scratched appearance, this process is called graining.
The process can include tumbling or vibratory deburring which is often one of the final stages in burr removal. Tumbling and vibratory media will (as with blasting) depend on which type of material is being polished.
There is a wide variety of deburring equipment and tools available for use in both the home and shops that provide the parts to the assembly plant. The necessary equipment includes the finishing media and the device that introduces the media to the rough product.
Home deburring equipment can be as simple as a file or can be more complex such as a deburring wheel. A small example of a deburring wheel that is used at home would be the regular old dremel tool. These are small quick rotating sandpaper covered tools that can be found in most homes. Larger wheels are used in a professional setting but they work on the same principles.
Other types of deburring include thermal (heat), cryogenic (cold), and dry ice. Each method has its place and is preferred by some materials or some people.
Thermal deburring uses heat to remove burrs by oxidation. The burrs themselves have a smaller surface area which means that the burrs will be effectively destroyed while the metal that they are attached to remains unchanged except the burrs are no longer present.
Cryogenic deburring is often used on rubber and plastic. Liquid nitrogen and the media are tumbled together and the result is a smooth burr-free finish.
In dry ice deburring the ice itself is the media and it is blasted to remove burrs and the dry ice then evaporates which leave no media to dispose of after the process is completed.
A very basic definition of deburring but one must start with the basics and work up from there.
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