Tumbling-Media

Mass Finishing Renders High Quality Parts

Parts that are manufactured usually need removing of jagged edges, cleaning and polishing before they are fit to satisfy their functionality (the function for which they are being built). This is achieved by means of a process called finishing. Mass finishing is several parts being finished all together. It is typically carried out in finishing machines or systems like tumbling machines, vibratory machines, blasters, centrifugal machines etc. Parts are fed into these machines along with finishing media, finishing compounds and water. The parts and the finishing media scrub against each other, with the compounds aiding in removing the debris and keeping it from re-depositing on the parts. Due to this scrubbing action, mass finishing takes place - edges are smoothed, surfaces get polished, nooks get cleaned and parts get broken from runners.

Finishing media are materials that aid in the mass finishing process. There are many types of media like synthetic pre formed plastic media, ceramic media and natural media like corn cob and walnut shell media. Finishing compounds could be dry or wet and depending on the action required, their composition varies. This determines their abrasive action, alkalinity etc. Mass finishing process can take place as a batch process, as a series of steps or as continuous process. In a batch process, parts are loaded as a batch and after finishing, the batch is unloaded. The next batch now goes in and so on. In the step by step process, the parts are taken through a sequence of processes, one by one. After every step, the parts will have some degree of finishing done on them and after the final step, they will be fully ready. In a continuous process, the loading and unloading of parts happens continuously, while the finishing process is carried out.

Walnut shell media are made from treated and crushed walnuts. As they are natural, they are bio degradable and safe for the environment. They are dry finishing media whose grain size is determined by the weight and composition of the parts being finished. They are very good cleaners too apart from being good polishers. They are suited for use with tumble machines and useful in finishing of parts made from soft metals like brass, aluminium and bronze. Mixed with paints, they act as anti skid agents and are typically used in paints used around swimming pools and pathways. Oil well drilling is another area where they are used, to prevent the oil from stagnating.

Walnut shells have the properties of hardness and fibre. They are also naturally angular and multi faceted, which makes the walnut shell media ideal for deburring. They last long and can be reused many times over. Used in tumbling and in some vibrating systems, they help to reduce cycle times. They can be used on delicate surfaces because they do not have a rough abrasive action. So, they do not damage micro finishes. There are companies who have been in the finishing business for a long time; they can find finishing solutions for any needs. To learn more visit http://gravcollc.com/

Finishing Parts Becomes Easy With Tumbling Media And Compounds

Tumbling media are materials that are used in the finishing process. They are loaded with parts to be finished into finishing machines, with or without tumbling compounds. They help in cleaning, smoothing and deburring of parts. Tumbling media can be man made or natural. Man made media include plastic media, synthetic media and ceramic media which come in preformed shapes. Natural media include walnut shell media and corn cob media. Tumbling media are used in finishing machines like tumbling barrels, vibratory machines and centrifugal machines.

Plastic media are otherwise known as tumbling stones. They come in shapes like cones, pyramids and triangles and have varying abrasive properties. They create smooth but dull finishes on surfaces and because of their light weight are suited for use on parts that might get damaged easily. They are safe on threaded parts and can be used on parts as a pre cursor to anodizing. The cone shaped plastic media act well on parts with holes and triangle shape acts well on edges and flat surfaces. Multiple shapes can be used on parts with complex designs.

Ceramic tumbling media are made of silica, minerals and abrasives mixed in different proportions and processed at high temperatures to produce hardened shapes. They are good for aggressive finishing needs and work well with hard metal parts. They suit usage with heavy loads that cannot be handled by plastics; they also come in smaller sizes and hence are suited for smaller parts. Synthetic tumbling media also come in different shapes; they weigh lesser compared to ceramic media. They are cost effective and are good to provide ultra smooth finishes. Compared to plastic media, they take more wear and tear and residue left from processing is lesser. They are ideal for use in high energy machines like centrifugal barrels.

Tumbling compounds are chemicals used to increase the effectiveness of media by ensuring that glaze is not formed on the parts during the finishing process. They act as abrasive agents and help in maintaining a nice color to the metal parts. They impart anti rust and anti corrosion properties to the parts when the right agents are added to them; they are effective cleaning agents and help in deburring by suspending debris and preventing them from getting re-deposited on the parts. The compounds are either alkaline or acidic in nature depending on the media they are used with.

The flow rate of the tumbling compounds should be matched with the volume of media being used for a good finish. Tumbling compounds are known to help in degreasing, descaling and removing grime. They help in lubrication of parts to protect them. They help in grinding, polishing and brightening of surfaces. They help to finish delicate parts by providing a cushioning effect and preventing damage to the parts. Acidic tumbling compounds enhance cutting speeds and bleaching efficiency. When used in proper combination with finishing media, tumbling compounds help to reduce cycle times substantially. To learn about the advantages of tumbling media and tumbling compounds, go to http://gravcollc.com/

Finishing Parts Using Vibratory Systems

Mass finishing can be best described as processes in which a number of parts are simultaneously finished. The finishing involves burnishing, deburring, cleaning, removing rust, polishing etc of the parts. The two main types of mass finishing are tumble or barrel finishing and vibratory finishing. In both types, a cyclical action is used to create a grinding action between the various surfaces. Some times, the parts are finished by rubbing against each other. But more often than not, some media is used to achieve finishing. The finishing process can be wet or dry. For a wet finishing, a liquid is used as a cleaner or abrasive. For a dry process plastic, ceramic or dry compounds are used as media. Finishing times vary with the composition of parts. For non ferrous materials, it could be just 10 minutes and for hardened steel, it could take more than 2 hours.

Mass finishing is an art while being a science because the processes involve random action. The mass finishing process could be organized as batch processes, continuous processes or sequential processes. In batch process, a batch of parts are input, worked on and pulled out; the next batch is now input and so on. In a continuous process, the parts are fed and pulled out continuously. In a sequential process, the parts are put through a sequence of processes one after the other. Normally, after every sequence, the part is in a better finished state.

Media are used in mass finishing to accomplish one of four things - cut, luster, parts separation and scrubbing of surfaces. The media could be aluminium media, preformed ceramic media, preformed resin bonded media, preformed shapes in steel, synthetic random shaped media, natural media in random shapes like rocks, cob meal, walnut shells etc. Compounds are used in mass finishing to aid in deburring, cutting, burnishing and so on.

Vibratory finishing machines are used in the vibratory finishing process. The process involves using components like water, finishing media and finishing compounds. Vibratory finishing machines are designed to produce highly smooth surfaces and can act inside deep cavities like tubes. It can be used on varied parts - for delicate parts or large surfaces, which may not be possible in a tumbling process. Loading and unloading vibratory finishing machines is easy. They also have the advantage of lesser cycle times, better cleaning and better color maintenance. These machines are easier to maintain as compared to tumblers. They can mass finish more parts and have less wear on media. Automating or semi automating them is easier compared to tumblers.

Vibrators typically do not have speed control; however, a few of them do. The usual speed is 1700 vibrations per second; for lesser speeds, the parts may sink to the bottom making the finishing process less effective. Vibratory finishing machines work at optimum level when they are between 75% and 90% full. Three parts media to every part metal can be used for delicate parts. For more aggressive finishing, parts can be used without media. http://gravcollc.com/ will provide further details.

Using Walnut Shells For A Bright Finish

Finishing media is a term used to describe material or materials that alters the appearance of a part by cutting off rough edges or deburring them. Finishing media is also used in cleaning, burnishing and polishing of parts and their surfaces. Further, they are used in anti rusting and coloring also. There are many types of finishing media like plastic finishing media, ceramic finishing media, Dry finishing media and wet and dry finishing compounds. There are machines like vibratory system, tumblers and spinning systems in which the finishing is carried out – by putting the finishing media and the parts together. The media rubs against the parts, effectively deburring them. The degree of finish can be manipulated by increasing or decreasing the speed of these machines. It can also be controlled by the type, size and shape of the media being used.

Walnut shells come under the category of dry finishing media; they are nothing but treated walnut shells. The shells are grounded to grit of varying dimensions to suit different needs (depending on the nature and weight of the part being finished). The walnut shell media can be used in cleaning and finishing applications. They are ideal for tumble finishing of metals like brass, bronze and aluminium. Walnut shell grit finds use in oil well drilling, to keep the circulation going. It is also mixed with abrasive paints used typically around swimming pools, in walkways etc where they act as anti skid agents.

Walnut shell media is made by crushing the walnut – it is hard and fibrous in nature. They are long lasting, angular and have many faces. They are mildly abrasive. The main advantage of walnut shell media is bio degradability. It is there fore environment friendly and non toxic. It can be reused many times over. It suits both tumbling and vibratory systems and reduces finishing operations time substantially. Because it is only mildly abrasive, it retains micro finishes; while removing the top layer of paints, it protects the base coating of paints.

Deburring can be defined as a finishing method typically used in manufacturing and industrial units. Metals are made into parts of different shapes and sizes by welding, molding or casting etc. The resulting pieces have jagged edges called burrs. The process of removing the burrs is called deburring. It is essential to make high quality parts that are smooth and functional while being aesthetically appealing too. Abrasive materials are normally used as deburring media. The process of deburring is applied in the wood industry, for wood pieces too. Deburring media varies in composition, shape and size depending on the part being deburred. Ceramic deburring media is used for heavy metals, synthetic or plastic media is most suited for less aggressive needs, precision media that come as small pins and spheres are used on surfaces and parts that need precise and delicate handling, natural media like corn cob and walnut shells for non abrasive deburring and finishing compounds for deburring with a good polishing effect. For further details, log on to http://gravcollc.com/