A leading British seal and bearing manufacturer has recently installed a combination of a Guyson Multiblast® RSBblast machine and Guyson Orbit 600 rotary basket washer to blast etch and then wash clean and rust preserve a series of mild steel seal rings.

The company turned to Guyson, the industrial finishing equipment manufacturer, for a solution as it was looking to improve throughput on a time consuming manual blasting operation, which was acting as a bottle neck in its production routine. Blast etching the seal ring surface, to improve surface friction, was already being undertaken on-site using a suction fed manual blast cabinet. But production could take an entire eight hour shift to blast etch a roughened surface on to the inner face of around 150 of the 400mm diameter seal rings.

Dramatic productivity improvements have been gained since the introduction of the automated Guyson finishing equipment. Now one operator can blast etch the same quantity, wash them clean with a rust inhibitor solution and stack them ready to be bonded, in just three hours. All this with the added benefits of improvements in surface roughness consistency without constant manual labour attention. The operator now solely has to load and unload ten of the rings at a time into both machines and press the start button, the rest is automated.

Process trials on the mild steel sealing rings were undertaken at Guyson’s development workshop at Skipton and the automated Multiblast® RSB (Rotating Spindle Blast) system, was selected as the most appropriate replacement blast machine and a modified Orbit 600 rotary basket washer was selected as the perfect partner for undertaking the spray washing.

Blast Etching
Internally the Multiblast blast machine is fitted with a driven turntable and two vertically traversing Guyson Model 400 suction fed blast guns which can now undertake the blast etching process in a fraction of the time per unit, compared to the manual blasting, and to a more consistent, uniform standard with 10 components processed simultaneously.

The 400mm diameter sealing rings are manually stacked horizontally into a component holder on the turntable located in the centre of the rubber-lined blast chamber. The door is closed and the blast process begun. The turntable starts to rotate, at a controlled but adjustable speed, and the two blast nozzles vertically traverse up and down the components, at a pre-positioned angle and stand off distance, to achieve optimum coverage of the inner sealing ring surface, whilst the components rotate under a constant stream of Guyson aluminium oxide blast abrasive.

Once the blast cycle is finished, integral air jet nozzles blow of the residual dust from the seal rings and they are unloaded into the Orbit spray washer. A new set of ten seals rings are then loaded into the Multiblast machine to undergo blast processing.

This Multiblast system in common with most automated shot blast systems manufactured by Guyson is fitted with a PLC/HMI. This gives full operational control over virtually all machine variables and enables through a simple menu system for a ‘recipe’ to be set-up with differing process requirements such as traverse, oscillation and airwash speed, start and finish gun positions etc. These ‘recipes’ can be recalled and used to speedily set-up the machine so as to enable a range of varied components to be processed in a repeatable fashion.

Completing the blast system is a Cyclone Separator and Dust Collector. The cyclone separator maintains a consistent grit size with the media stream to achieve consistent roughness level and is coupled to the cabinet via hard wearing rigid Polyurethane pipework. The cyclone separator creates a vortex of air that carries the heavier re-usable particles to the outside of the rotating air stream which collect in a storage hopper ready to be re-used, whilst the lighter remaining dust, fines and undersize media are separated and collected in the Guyson C800 twin cartridge Dust Collector.

Aqueous Washing
After blast etching, the mild steel seal rings are stacked horizontally into a purposely designed fixture inside a modified Orbit 600 spray wash cabinet for cleaning. A central vertical spray bar is fixed to the roof of the ‘clam opening’ cabinet and lowers down inside the circular seal rings when the lid is closed, matching up with a similar vertical spray bar on the outside of the circle of rings. These both deliver a high impact cleaning curtain of hot aqueous wash solution to remove any traces of blast abrasives. The spray washing takes only a matter of minutes and is undertaken using 5 percent wash solution of Guyson Formula 10 Plus, with a built in rust inhibitor so the parts can be safely shelved after processing for later usage.

Prospective user of Guyson blast or wash systems are encouraged to submit sample components for free feasibility testing to the company's extensive development workshop at Skipton, England.