The aluminium extrusion industry has long been seeking a high performance
roller which can be used to support extrusions from the press and down the run
out without rapid deformation from pressure or degradation from heat.
After many years of continuous development we succeeded in producing a roller sleeve with better performance characteristics than the previous styles which have been used to transport profiles at 500ºC.
We have enhanced our woven roller performance by the application of a high
pressure impregnation of specially formulated resins which are compressed to
further increase density after curing. After external grinding, the outside
surface of the roller has a smooth texture which will not mark hot profiles
leaving the press. The resins are red in colour and the roller has become known
as the Red Roller.
Most of our competitors produce roller sleeves from felt with a wall thickness of 10mm to allow plenty of wear to take place before replacement is necessary. This philosophy is flawed by the fact that an uneven run out soon develops as the central area of the roller sleeve quickly wears to a reduced diameter. Multiple extrusions then have a tendency to fall to the lowest part of the support roller and marking can occur.
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The problems of reduced diameter can be clearly seen on this competitor's roller which is 90% worn. |
Driven roller systems which have their speed regulated by programmable logic controllers can only be accurate when roller diameters are reasonably consistent. Allowing roller sleeves to reduce by almost 20% in diameter, which happens with felt sleeves, seriously affects synchronisation between the roller peripheral speed and the extrusion speed. This causes unnecessary wear and increases the possibility of marking the profiles.
The concept of the Red Roller is to keep the wall thickness down to less than 5mm to allow a better opportunity to maintain a level run out and to assist heat transfer through the sleeve to the metal parts of the roller assembly. The advanced materials used to produce the Red Roller give a better working life from 5mm thickness than would normally be expected from the 10mm thick felt types.
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This Red Roller also 90% worn will maintain a level run out. |
The increasing complexity of section shapes within the industry further necessitates the need for a level surface down the run out path.
A simple, unique locking spade system is used to lock the Red Roller sleeve to
the metal tube. We recommend four spades at each end to ensure a good
concentric grip. The locking spades can be re-used on subsequent roller
sleeves.
If the sleeve is clamped between end caps on the roller then the locking spades are not required.
The standard sizes which we currently manufacture are listed in the table but the range will be expanded according to customer demands. We normally recommend the use of 76.2mm (3 inches) inside diameter sleeves for new installations of free rotating rollers.
| INSIDE DIAMETERS | NOMINAL OUTSIDE DIAMETERS | ||
| mm | inches | mm | inches |
| 60.3 | 2.37 | 70 | 2.75 |
| 76.2 | 3.00 | 85 | 3.35 |
| 80.0 | 3.15 | 90 | 3.54 |
| 88.9 | 3.50 | 98 | 3.86 |
| 101.6 | 4.00 | 111 | 4.37 |
| 114.3 | 4.50 | 124 | 4.88 |
| 127.0 | 5.00 | 135 | 5.32 |
A lower cost alternative to the Red Roller is our new Green
Roller which has been developed for less arduous positions along the run out.
The position of changeover from Red to Green can be determined by experience at
individual plants according to press size, profile weight, use of cooling air,
water quench etc. The general concept is illustrated here.
The material used to make the Red Roller sleeve is also
ideally suitable for run out conveyor slates, liftover arms, side guides, die
exit separators etc. It is not recommended for fixed slats in the initial lead
out area unless used with a water spray method.
We offer the full range of steel roller assemblies to carry out standard roller sleeves. Hexagonal bearings are incorporated to allow easy interchange of rollers from different positions on the run out. The two types of cast iron support brackets illustrated are carried in stock and dimensional drawings of each type are available. "R" clips are used for simple location of shaft and roller.
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| Type 1 | Type 2 |
Our range of specialised products for the aluminium extrusion industry extends beyond the run out and over to the cooling table. We produce a complete range of high temperature transfer belts, transfer arm and walking beam covers to suit systems produced by any of the World's handling system manufacturers.
The aluminium extrusion industry, like most industries, is becoming increasingly sophisticated and competitive as customer expectations rise inexorably higher. The relentless quest for technical and commercial perfection coupled with global competition drives the industry ever forward.
Don't be left behind in the race to reduce scrap, improve quality and increase profitability. Invest in the Red Roller, the benchmark of success.
