POST SHUT-DOWN START UP
The ongoing COVID-19 pandemic forced many tanneries to shut down or reduce operations by up to 70% for an unknown period of time. These long periods of inactivity can wreak havoc on fleshing and shaving machines if certain steps are not taken in properly starting up the equipment once the shutdown is over.
We strongly recommend to carry out a physical/visual inspection of the machine condition in general and especially the cylinder, before starting up the machines. This is extremely important to consider if the machines have had blades mounted on the cylinder during all these months with the machine, not in operation.
General machine checks
- Check for oil leaks on the grinding chariot lubrication system
- Re-grease the cylinders bearing housings
- Presence of rust on the blades in general (check for cutting edges, cylinder`s surface etc)
- Rebalance and re-level the grinding wheel with a diamond stone – outside of the machines
Since the cylinder has had the blades fitted for a long period, the cylinder body bending force could be very strong (particularly so on longer cylinders) therefore at the machine`s start-up best practice would be to allow the cylinder to spin for an extended period of time.
Perform a regrinding and re-sharpening of the blades would be also recommended: this will help you identify any vibrations in the machine (a major cause of chatter/ribbing marks seen in shaved leather), clean the cutting surface of any potential rust, reactivate the blade`s cutting capabilities, and count with an even cutting level. But DO NOT over grind! Short spark streams and light grinding sounds are the aim here, not deep grinding, large spark streams as this will negatively affect the blade condition, performance, and life.
Importance of care and regrinding
If the period of activity of fleshing or shaving extends over time, and your areas have cylinders with blades mounted already, we suggest following the steps mentioned below to help extend the lifespan of the knives:
- Clean the cylinders with compressed air, making sure that no leather remains on both the blades and the cylinders
- Apply a very light layer of industrial machine grader oil using an airgun on the cylinders, without excess.
- Cover the cylinders in their entirety with industrial paper impregnated in oil, in such a way that the potential humidity does not concentrate on the cylinder. Do not cover or wrap them with polyethylene or plastic film as these materials concentrate humidity.
- When returning to activities, it is essential to restart the cylinder by making it spin for a very long period in order to check any vibrations. If there were no vibrations, you may continue with the level/grinding (as if it was a new cylinder) and the subsequent sharpening.
- To remove the oil, a discard hide can be used, making several passes to clean the cutting edge.
- If in doubt, don’t use rusty or painted blades, which may damage the valuable material surface.
Now for the Good News!
If, after inspection, you find the blades need changing; Hardy UK has a full stock of popular fleshing and shaving sizes ready and waiting for dispatch. Order now via firstname.lastname@example.org
Also carried in stock…
- Paper impregnated in oil
- Industrial machine grader oil
- Copper caulking
- Grinding wheels