Instructions and Terminology
This App calculates the average ideal or theoretical throughput of a simple roll-to-roll converting line such as a printing press or slitter-rewinder. There are several ways that you can use this app to compare the ideal with what the machine is actually doing based on known production numbers. One example would be to estimate the biggest uncertainty in productivity which may be the accumulated irregular down time. You simply move the slider until the predicted and actual outputs match. Then go down on the floor and find out what is going on during the downs or perhaps find out that the machine is slower in other regards.
Terminology
- Length (metres or feet) - is the length in the daughter/finished/shipping rolls - so the length of the Master Roll is Sets*Length
- Accel (m/min/sec or ft/min/sec) - is the average acceleration rate of the machine. The range may be 3-60 in the Metric System or 10-180 in the US system. While this can be timed, productivity is usually not very dependent on this variable in most cases.
- Decel (m/min/sec or ft/min/sec) - is the average deceleration rate of the machine. Again, the range may be 3-60 in the Metric System or 15-180 in the US system. While this can be timed, productivity is usually not very dependent on this variable in most cases.
- Sets/Master - is the number of 'sets' of daughter/finished/shipping rolls per parent/master roll. If your number is greater than 20, simply enter 20. If your run one-for-one, this is set to 1. On a printing press, for example, a 'set' is simply a daughter/finished/shipping roll. On a rewinder, for example, a 'set' might be 1-50 rolls cut across the width, but is not the number entered here. It is always the number of sets cut from the master.
- Master Change - The number of minutes it takes to change a parent/master roll out ABOVE and BEYOND what it takes to change out the set of shipping rolls. If you are running one for one, this is set to 0.
- Speed - actual running speed of the machine which is less than or equal to design speed
- Set Change - The number of minutes it takes to change a 'set' of daughter/finished/shipping rolls.
- DownTIme - The number of minutes on a 24 hour day where the machine is not running ABOVE and BEYOND the time it takes to change out finished and master rolls. This extra downtime is for things like slitter changes, grade changes, maintenance and so on.
Outputs
- SpeedAverage - The average speed or throughput of that roll-to-roll or rewinder line
- Min/Set - The average time it takes to run a 'set' of finished rolls.
- Length/24hrs - is the average productivity in km in a 24 hour day
- Finished Sets/24hrs - is the average number of finished 'sets' per day
- MasterRolls/24hrs - is the average number of master rolls per day
Users can readily convert length into tons and per day into per month or year.
The pie chart shows where most of the time is being spent. If most is in "Run" that means that increasing run speed is important. If most is in "Sets" then reducing the sets/roll or speeding up set change is important, similarly if "Roll" is significant then decreasing roll change time is important.
