Deburring Centre used the method of thermal deburring to assist a multinational company that had a problem with its manifolds being rejected due to internal burrs.
Entire batches of the company’s manifolds were being rejected by their clients even if only one burr was found The client also happened to be overseas, adding to the complications.
The cost of collection, inspection, rework, further inspection, and redelivery, although significant was exacerbated by the extra admin time, extra processes and extra customer handling that had to be put in place to reassure the client that the incident was contained.
But despite 100 per cent hand deburring (by skilled, conscientious staff) and 100 per cent inspection (at magnification) by the quality department, burrs were still being missed.
Their best efforts reduced the number of burrs but not the number of batches rejected.
While the larger burrs pushed up at cross holes could be readily identified, they often caused damage to bores as they proved reluctant to be removed as they were bent back and forth before finally coming loose.
However, it was the very fine hair-like whisps that proved difficult to locate and almost impossible to completely remove.
Unfortunately, it is these razor-sharp smaller pieces that cause seizure to moving parts and the most damage to seals.
The company’s search for a deburring method tended to find external, or surface focused, deburring methods.
Or internal methods that were unrealistically expensive and still not guaranteed to remove all potential loose burrs.
However, a little-known method called thermal deburring suggested automated, cost-effective, guaranteed internal deburring.
Thermal deburring has been around for some 40 years, but is not widely known.
It works on the ability of material to dissipate heat, or not, as the case may be.
Burrs, with a large surface area and a small mass, are unable to dissipate the blast of heat quick enough to avoid their temperature rising above their oxidising point where they instantly turn to an oxide.
The bulk of the component is able to safely dissipate the heat among its mass – causing no metallurgical change.
The means of deburring, a gas – a mixture of natural gas and oxygen – is non selective and permeates everywhere and surrounds every burr.
There is no hole too small or part too inaccessible for the gas to permeate.
In fact the smaller, harder-to-see, easiest-to-miss, whisker burrs are the first to oxidise.
Using a gas is also non-abrasive to the component’s surfaces and 100 per cent of potential loose burrs and contaminants can be guaranteed removed.
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