Packaging and general film
Eight-piston rings are the standard build for packaging film and general film slitting.
Pneumatic Differential Winding Shaft
Air Differential Friction Shaft
Air slip shafts use pneumatic core locking and controlled differential slip to support stable torque transmission, core holding and multi-roll winding quality in slitting and rewinding applications. Also known as: air slip shaft, pneumatic differential shaft.
Shaft Structure & Winding Function
Pneumatic locking through forward and reverse winding
Suitable for PET film, electronic film, packaging film and lithium battery-related separator, electrode, copper foil or aluminum foil slitting applications where suitable.
- A central air-pressure shaft provides pneumatic locking, pneumatic slip and accurate torque transmission over a wide tension range.
- The roll core stays positioned during forward and reverse rotation, making the design suitable for automatic roll loading and unloading.
- Dual-air-path XC versions separate locking pressure from regulating pressure, enabling continuous control from very low tension to higher winding tension.
- New air-expanding versions with assist wheels or rolling surfaces make large-diameter and heavy-roll rewinding easier to unload.
| Core Size | 3-inch standard core, 76.2 +/- 0.2 mm |
|---|---|
| Ring OD | 75.5 mm body OD, up to 77.9 mm expansion point |
| Ring Widths | 19, 20, 25, 30, 35, 40, 45, 50, 60 mm depending on version |
| Expansion Piece | Metal expansion piece or rubber expansion piece |
| Control Options | Single air path, dual air path, dual-link dual air path and ultra-low-tension versions |
Where piston count changes the air-shaft application
Lithium electrode and separator
Twelve-piston rings are specified for electrode and separator slitting, where torque consistency across many narrow rolls decides the yield.
Power battery foil
Sixteen-piston rings are for copper and aluminum foil on power battery lines, including dual-air-path rings for 12–17 mm foil widths.
Automatic load and unload
Pneumatic locking holds the core through forward and reverse rotation, so the core does not shift or loosen on automatic handling systems.
Slip Ring
Piston count and air-path options
Different slip ring structures can be selected according to core size, ring width, air path, expansion piece and winding tension requirement.
- Slip rings can be configured with metal expansion pieces or rubber expansion pieces.
- The 3-inch standard ring has a body outside diameter of 75.5 mm and expands to 77.9 mm at the highest point.
- Standard core fit is 76.2 +/- 0.2 mm for paper, plastic or composite cores; special core sizes can be customized.
- Available inner diameters include 45, 49 and 50 mm.
- Single-air-path rings are commonly 40 mm wide, with 19, 20, 25, 30, 35, 45 and 50 mm options.
- 8-piston rings are suitable for packaging film and general film slitting; 12-piston rings suit lithium battery electrode and separator slitting; 16-piston rings suit power battery copper and aluminum foil slitting.
- Dual-air-path rings can be as narrow as 20 mm, with 25, 30, 35, 50 and 60 mm options for power battery electrode, copper foil and aluminum foil slitting.
- Ultra-low-tension rings are typically 50 mm wide for extremely low friction tension, including 10 micron PET and electronic film.
Selection Notes
For an air-shaft replacement, separate the core-locking function from the tension-regulating requirement in your description. An XC dual-air-path arrangement is not established merely by measuring the bore: identify the existing air paths and piston layout as well. Include the slit width and material so the 8-, 12- or 16-piston selection can be reviewed in its actual winding context.
Replacement Slip Rings
Replacement air rings matched to pistons and air paths
Availability
Air slip rings can be supplied separately from the complete shaft. A shaft built by another manufacturer can also be considered when the ring dimensions and pneumatic arrangement match. Lead time is confirmed with the quotation after the piston count, air paths and measured sizes have been reviewed.
What to measure / send
Identify the number of pistons on each ring: 8, 12 or 16. State whether the shaft uses a single air path or the dual-air-path XC arrangement, and whether its expansion pieces are metal or rubber. Measure the ring bore against the 45, 49 or 50 mm options and give its width. Include the 3-inch core inner diameter, normally 76.2 mm, the shaft keyslot or air-hole positions, quantity, and clear photographs of both an old ring and the shaft.
What ships
The supply is an air slip ring of the same agreed structure, configured to your ring inner diameter, width and friction material. The quotation identifies the piston and expansion-piece configuration as well as the air-path version, so a replacement request does not become an order for an unspecified general-purpose ring.
Why the existing piston arrangement belongs in the drawing
The eight-piston build is described here for packaging and general film, while twelve pistons are associated with electrode and separator slitting. Sixteen-piston rings are listed for copper and aluminum foil on power battery lines. Those distinctions make the old ring more useful than a request that simply says “3-inch air shaft.” A photograph plus the piston count connects the replacement dimensions to the version already operating on the line. Report any change from the original material or slit layout rather than treating every air ring as equivalent.
Two pressures need an identified XC arrangement
In the dual-air-path XC version, locking pressure and regulating pressure are separated. That is the stated reason this arrangement can cover very low tension through higher winding tension. When an existing shaft uses this arrangement, document both air paths on the shaft drawing and include the ring width; the listed dual-path widths differ from the single-path options. The 50 mm ultra-low-tension ring is another stated version, associated with very low friction tension for 10 micron PET and electronic film, rather than a description of every pneumatic ring.
Technical Reference Data
Key-ring test data: a reference, not an air-ring specification
Air force data below retain the individual test dimensions, materials and pressure conditions; compare those conditions with the ring you need.
Note on this data: the two tables below are measured on key-type slip rings, as published in the manufacturer's technical document. They show how pull force tracks air pressure on a dual-air-path ring and are useful as a reference for that relationship, but they are not a substitute for air-ring figures. Ask us for the pull force data for the specific ring width, piston count and friction material you are considering before you size a shaft.
40 mm Dual-Air-Path Key-Type Slip Ring Pull Force
Test condition: four 8 mm pistons, 40 mm wide dual-air-path key-type slip ring.
| Air Pressure (kg/cm2) | 0.2 | 0.4 | 0.6 | 0.8 | 1 | 1.2 | 1.4 | 1.6 | 1.8 | 2 | 2.2 | 2.4 | 2.6 | 2.8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pull Force (N) | 1.9 | 2.1 | 2.4 | 2.6 | 2.8 | 3.1 | 3.5 | 3.8 | 4.2 | 4.6 | 4.9 | 5.2 | 5.6 | 6.1 |
| Air Pressure (kg/cm2) | 3 | 3.2 | 3.4 | 3.6 | 3.8 | 4 | 4.2 | 4.4 | 4.6 | 4.8 | 5 | |||
| Pull Force (N) | 6.3 | 6.8 | 7.3 | 7.6 | 8.0 | 8.3 | 8.5 | 8.7 | 9.0 | 9.3 | 9.5 |
25 mm Dual-Key Slip Ring Pull Force
Test condition: four 8 mm pistons, 25 mm wide dual-key slip ring.
| Air Pressure (kg/cm2) | 0 | 0.5 | 1 | 1.5 | 2 | 2.5 | 3 | 3.5 | 4 | 4.5 | 5 | 5.5 | 6 | 6.4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pull Force (N) | 0.2 | 0.7 | 1.5 | 2.1 | 2.5 | 3.2 | 3.6 | 4.1 | 4.6 | 5.0 | 5.4 | 5.7 | 6.2 | 7.6 |
Compare piston control with low-pressure and contact alternatives
Low Tension Slip Shaft
For a film application defined by a 0.1 kg/cm² start, compare the dedicated low-tension structure rather than assuming every air-shaft ring has that starting characteristic.
View DetailsDS Slip Shaft
A medium-tension laminate line can be compared with DS, provided its stated 0.8 kg/cm² starting pressure meets the winding requirement.
View DetailsBall Slip Shaft
If the air-shaft project is driven by very narrow slit widths, compare the ball family, whose stated minimum slitting width starts at 5 mm subject to the ring layout.
View DetailsDouble Ball and Roller Slip Shaft
For a change from piston-based pneumatic expansion to extended cylindrical core contact, review the roller arrangement and its rubber, aluminum or paper core options.
View DetailsKey Slip Shaft
Where rectangular metal or rubber core-contact keys are required instead of the air-ring expansion arrangement, inspect the key-ring widths and material options.
View DetailsSend an air-ring drawing for a piston and air-path check
Have a drawing of your shaft or a photo of the old rings? Send it on WhatsApp or to sales@kendoric.com — we check fit before quoting.