DRS-4200 (ball type). Differential Rewind Shaft

For multiple slit differential rewinding applications.

Works in low or high tension applications.

Allows narrow and/or varying slit widths and yields uniformly wound rolls.

Slipping occurs inside the shaft so no core dust is crated – contamination is minimized.

 

The DRS-4200 works like a "Shaft within a shaft". Winding cores are mechanically locked onto one or multiple friction rings, depending on core width. When the outer race is rotated against the inner race of the friction ring the expanding balls ride up cam ramps to center and grip the core. These friction rings then consistently slip like a clutch around a central shaft which is runs at an over speed RPM. Similar to a strip shaft, this central shaft contains air bladders and friction strips running along the shaft. Winding torque to the friction rings (and consequently the cores and rolls) is controlled by adjusting the air pressure to the bladders pressing out on the friction strip which exert force on the inner surface of the friction rings. In general, more winding torque is required as the rolls build and bladder air pressure increases. Because separate rolls require separate winding torques, some will slip more than others. Through this differential slipping, proper winding tension is maintained for each roll.

 

 

• Any core size can be accommodated from 1" up to 12."

• Ring width standard range: 1/4", 1/2", 1", 2" (any width can be engineered from 1/4" up to 6" wide).

• 3" and 6" friction rings using the same central shaft.

• Outer rings are machined so balls are completely captured and cannot wear out the ring over time causing the balls to drop out of shaft.

• • Lightweight materials – friction rings are made of hard anodized AL and in some cases use glass balls to keep weight down versus other friction ring style shafts.

                  

Available options:

• "TWIST" Technology" - Spring loaded rings that lock the core in place in the default position. Guarantee every friction ring under a larger width core is engaged when loading. Also allows for use of automatic core loaders since each ring does not need a separate twist operation to "cam lock" it into place. Load with shaft rotating slowly and as soon as the rotation stops, the rings will lock.

• BD "Bi-directional" Friction Rings - Load a core for either over-winding or under-winding without removing the rings and turning them around, saving job setup times.

• Control de tensión EP42-DRS - If your slitter rewinder currently uses a "lock core winding" type, it is not recommended to just replace the standardstrip shaft with a differential type shaft. For properly wound rolls, a special tension control system is needed that will separately control the shaft overspeed and differential air pressure. The Double E / RE EP.42 DRS tension control system will take care of this upgrade for you without needing to hire a separate controls integrator or consultant to re-program you machine's drives or PLC. Please contact your Double E territory manager for more details!

 

 

The Differential Rewind Problem:

All rolls of material have differences in material thickness and/or coating thickness across the width of the web. These thickness variations are present in each wrap of the roll. When a master unwind roll is slit and then re-wound, these thickness variations cause a different rewind torque requirement for each separate roll across the rewind shaft.

A "lock core" shaft can only transmit a single winding torque to all rolls, so some rolls may wind too loose and some too tight. This can cause many quality problems. Some are immediately noticeable rejects such as broken webs, roll telescoping, weaving, starring, and crushed wraps or even crushed cores. Other problems related to roll hardness are not as easily discovered when a wind is completed and can be passed along to subsequent unwind processes for other departments or even customers to discover.

Datasheet Differential Rewind Shafts