Recently a flexible packaging converter that services the food, beverage, medical, and other specialty markets turned to Double E for help in increasing their capacity. The customer was trying to make a decision on whether to purchase a new slitter rewinder or simply upgrade their older machine. Pains they experienced with their setup included tension control problems, friction style differential rewind shafts that were difficult to maintain, and poor product support.
Tension Control Problems
The existing machine had a motorized unwind with dancer, s-wrap and rewind with ultrasonic sensor that previously had tension control upgrades performed over the years, but it was not working. The operator had to manually adjust the air pressure in the differential rewind shaft and was unable to control the wind quality. This created high scrap rates, bagging web material in some rolls and material that was too tight in others. It also limited the machine speed and caused costly production bottlenecks.
DRS Shafts Difficult to Maintain
The friction ring style differential shafts needed to be constantly oiled and the oil would drip on the food grade material causing scrap. Excess core dust was being generated and contaminated the friction rings, jamming the cam action of the rings which caused the rings to have difficulty gripping the core and ultimately created more dust and lost control. The rings needed to be disassembled and cleaned on a continuous base. Spare parts for replacement rings and other shaft spare parts from an existing shaft supplier proved costly.
Poor Product Support
The original OEM Incotek went out of business and parts were difficult to find and costly if found. The engineering controls company that re-wrote the machine PLC offered poor support. There was no viable solution being offered from other companies to take ownership of the whole system – machine controls and differential rewind shaft.
The Double E Solution
Double E was able to offer a complete solution for a fraction of the cost required to put in a new machine. To alleviate the tension control issues Double E installed a full tension zone retrofit that included pneumatic brakes with T-One tension controller coupled with load cells on the unwind. A new nip roll was installed to replace the s-wrap to set the constant master speed before slitting. A new EP.42 tension control with a T-One controller was used with a US.3 sensor for the rewind. The T-One DRS automatically controls rewind motor drivers and DRS shaft air pressure to achieve proper torque and rewind overspeed all while managing the desired taper tension. This removed all of the “trial and error” guessing for the operators to build high quality rolls, even at light tensions. Now with the automatic control and implementation of a nip, the machine was running at 1350 FPM and making great rolls. Previously it never exceeded 500 FPM.
Now this machine is a versatile part of the production and is used to schedule more demanding jobs and increasing company’s capacity and throughput. Double E engineering measured the machine on site and built a custom bolt-on nip roller. Now material does not slip through nip and the rewind controls are no longer fighting the unwind controls. Re load cells replaced the old dancers. Unwind motor was replaced with CX.250 brake with adjustable torque capacity to control tension on both light materials with small rolls and heavy materials on larger rolls.
DRS-4200 Shafts that are Easy to Maintain
New DRS-4200 shafts only require very minimal lubrication with no more oil dripping from the central shaft. The DRS-4200 rings are manufactured with tighter dimensions and tolerances to keep dust out and cam action working properly. Now with minimal oil and dust contamination, the shaft running time is increased and maintenance time has decreased.
Complete Product Support
With the exception of the main line speed signal and start/stop signals, Double E control system operates completely independent of existing PLC. Full support is now offered from one company. Both Double E and RE are long established companies that offer worldwide support on all product lines, old and new for years to come.
The new completed upgrade to the customer’s machine provided a low cost solution to increase productivity by offering a more efficient tension control solution coupled with a cleaner, easier to maintain and more efficient differential rewind shaft. Now the customer is able to run at higher speeds at a longer period of time with no material waste.
Upgraded Slitter Rewinder