The Intermediate REDS is a sorting system for rolls of toilet paper and kitchen roll (Roll Exchange Divider System).
The term “intermediate” differentiates this type of machine from the so-called “log-saw REDS”.
The log-saw REDS sorts the product taking advantage of the functioning principle of the log-saw to whose exit it is directly connected: the space that is created between a log of cut product and the successive one (necessaryfor log exchange inside the log-saw itself) is used by the REDS to change the position of a mobile belt and interface it towards one of the available exits.
Two functioning conditions must be satisfied:
• support the exit speed of the product from the log-saw keeping the cut rolls adjacent.
• carry out the position change of the mobile belts more quickly with respectto the time of transit of the empty space between a log and the successive one.
The Intermediate REDS, differently from the Log-saw REDS, is found at a certain distance from the log-saw: the rolls, initially grouped in logs, later spread between the outfeed of the logsaw and the REDS intermediate.
Functioning modes
The following function modes can be individualised:
Sorting system (flow divider or diverter). In this case the flow of product at one entry is deviated into two exits.
Combiner. In this case the flow of product coming from two entries is directed towards an individual exit.
By-pass. In this case the REDS acts as a simple conveyor (example, sorting system with wrapper out of use, or combiner with a log-saw out of use).
Balancer. In the particular case of the Intermediate REDS with two entry levels and two exit levels, it may be necessary to supply the downstream machine with a greater quantity of product from that arriving from an individual log-saw.
Accumulation of the product coming from the log-saw which is then transported downstream in “trains” is managed in every arrival lane – in the most general case these trains reproduce the log in exit from the log-saw.
As well as accumulation, management devices are envisioned on each lane to allow passage of the product according to pre-fixed quantities.
Configuration and types of machine
The Intermediate REDS can be characterised by the following aspects:
Mobile belt movement direction
The mobile conveyor belts, whose movement leads to variations in connections between entries and exits, may take place horizontally and vertically.
Mobile belt movement activation
The mobile belts can be activated by pneumatic cylinders or by movement systems activated by brushless motors.
Product train product formation
Controlled exit of the product (formation of the trains) can be carried out:
• with launching/dosing device units with lateral belts activated by brushlessmotors;
• with pneumatic product singularisation systems (downstream shutdown units eventually assisted by upstream braking units).
The two systems are mainly different due to the greater average transfer speed that can be obtained with the launching units. The product is pressed between two synchronised belts, whose speed profile is set via software, and opportune sensors are able to detect if the product solidly follows the speed profile set on the launching belts. When the pneumatic singularisation units release the product (stop on the moving belt) this does not start immediately.
This delay increases at the increase of the production speed.
Regarding adjustment flexibility, if the pneumatic singularisation is obstacle type (gate), the number of rolls per launch is equal to the number of rolls that are positioned between the gate and the brake – the adjustment range must be prepared at the design stage. If the pneumatic singularisation unit works by friction the number of rolls to release may be modified via software, but the control of the number of transferred rolls is less efficient: if thel layout is critical the system must be avoided.