Reliable Air Shafts for Secure and Efficient Core Gripping

DJH Machinery offers a full range of durable and precision-engineered Air Shafts designed for reliable core holding in both unwind and rewind applications. Choose from Key Lock (lug type) Air Shafts for high-torque performance, Slat Type Air Shafts for gentle handling of fragile cores, and Segmented or Leaf Type Air Shafts (also known as Tile-lock) for versatile core diameters and materials. Each option ensures concentric gripping, fast roll changes, and consistent performance across various converting operations.

Featured Air Shaft

Name	Outer Diameter	Structural Features
Key-Lug Type Air Shaft (1"–12")	25mm, 36mm, 48mm, 74mm, 100mm, 118mm, 150mm, 200mm, 300mm	Simple structure, cost-effective
Heavy-Duty Air Shaft (3"–6")	Φ74–150mm	High load capacity, supports over 1 ton
Slat Type Air Shaft (3"–6")	Φ74–150mm	Large contact surface, excellent stability
Key-through Type Air Shaft (3"–6")	Φ74–150mm	High friction coefficient, no damage to paper cores

Versatile Air Shaft Applications in Web Converting

From high-speed paper mills to precision film production, DJH’s air shaft systems deliver reliable core gripping, rapid changeover capabilities, and precise concentric positioning across diverse web converting applications requiring consistent tension control and superior roll quality.

Secure Core Gripping Applications

High-performance air shafts engineered for reliable, non-slip core engagement across paper, film, foil, and nonwoven materials—maintaining secure grip even during aggressive acceleration and deceleration cycles in demanding production environments. Eliminates core slippage and maintains consistent web tension for uninterrupted high-speed production.

Rapid Roll Changeover Systems

Advanced air shaft solutions available in comprehensive diameter ranges (from 1" to over 12") with custom length capabilities, designed for converting lines requiring frequent roll format changes and minimal downtime between production runs. Maximizes operational efficiency and significantly boosts overall line productivity.

Multi-Core Size Compatibility

Versatile air shaft configurations accommodating diverse core specifications and web widths, featuring adjustable expansion systems that adapt to various core dimensions without requiring different shaft assemblies for each application. Delivers maximum operational flexibility across diverse converting applications and material types.

Precision Concentric Operations

Engineered air shaft systems ensuring accurate core centering and uniform expansion pressure distribution, resulting in consistent roll buildup, reduced web handling vibration, and superior finished roll quality critical for downstream processing. Enhances finished roll quality while improving equipment stability and reducing maintenance requirements.

Engineered for Performance: Inside Air Shaft Technology

1. Precision Core Construction

Every air shaft starts with a high-strength steel or aluminum alloy body, machined to exact tolerances (±0.01 mm) for optimal balance and minimal runout. This ensures reliable expansion under continuous load and prevents web tracking errors in high-speed operations.

2. Reliable Expanding Mechanism

An internal pneumatic bladder drives evenly spaced mechanical lugs or rubber expansion strips against the core. This fast, tool‑free system delivers uniform pressure distribution, secure torque transfer, and repeatable grip—critical for slitting, rewinding, and tension‑sensitive processes.

3. Durable Surface Finishing

Shafts receive anti‑corrosive coatings (e.g., zinc plating) or anodizing, plus precision grinding to achieve surface roughness below Ra 0.4 µm. The result is superior resistance to wear, oxidation, and solvents, plus smoother rotation that maintains consistent web tension.

4. Smart Material Selection

Steel Air Shafts: Offer high load capacity, minimal deflection, and longevity in heavy‑duty environments.
Aluminum Air Shafts: Provide lightweight handling, reduced inertia, and lower shipping costs.

Both can be fitted with safety chucks, key‑way locking, or ball‑lock mechanisms based on your application requirements.

5. Enhanced Safety & Maintenance

Integrated pressure relief valves prevent over‑inflation, while visual pressure indicators let operators verify grip at a glance. Modular bladder cartridges and replaceable seals simplify routine maintenance, minimizing downtime and extending service life.

6. Customization & Modular Design

Choose from a wide range of core diameters (Ø50–Ø300 mm) and flange widths to fit any roll core ID. Optional features include quick‑change adapter plates, end‑face key slots, and friction‑welded collars—tailored for specific machine interfaces or rapid changeover systems.

Air Shaft: Get Our Free Samples

Curious about the performance of our air shafts? We’re happy to offer free samples for your evaluation! Simply share your application requirements, and we’ll confirm the right sample specifications with you promptly. Feel free to contact us anytime!

What Are Are Air Shafts?

Air shafts are mandrel-like cores that expand radially to grip the inner diameter of rolls on winding and unwinding equipment. By injecting compressed air into an internal bladder or segment, the shaft’s outer surface expands uniformly, ensuring secure holding without mechanical fasteners. Commonly constructed from aluminum or steel, air shafts deliver quick roll changes, reduced downtime, and consistent tension control. Their principle of operation leverages pneumatic expansion to replace mechanical locking cones or pneumatic chucks, offering faster setup and repeatable performance.

Different Types and Specifications of Air Shafts

Standard Pneumatic Air Shafts

Standard Pneumatic Air Shafts feature a multi-segment rubber bladder and rigid metal segments, expanding at typical pressures of 4–7 bar. Available in diameters from 50 mm to 300 mm, they suit general converting and slitting lines.

Quick-Lock Air Shafts

Quick-Lock Air Shafts combine cam-action hubs with pneumatic bladders for both mechanical and air-assisted locking, enabling ultra-fast roll changes in high-speed printing and laminating.

Rubber-Pad Air Shafts

Rubber-Pad Air Shafts use replaceable rubber pads for low-pressure gripping on delicate films and papers, minimizing core slip and damage.

Shaftless Air Mandrels

Shaftless Air Mandrels omit end shafts entirely, mounting directly into the machine, ideal for lightweight cores and automated material handling.

High-Pressure Air Shafts

High-Pressure Air Shafts support pressures up to 10 bar for heavy-duty applications, such as metal foil or thick paper rolls.

Custom Air Shaft Parameters and Specifications

Custom air shafts can be tailored to meet the precise demands of your production line, combining engineered components and materials to deliver the ideal balance of speed, grip, and longevity. By carefully specifying each parameter—from core dimensions to surface treatment—you ensure seamless integration, consistent tension control, and minimal downtime during changeovers.

When specifying an air shaft for your line, precise mandrel length and shaft diameter are paramount. The mandrel must span the full width of your widest roll plus any additional clearance for end fittings or telescoping hubs. Shaft diameters must match your core inventory—commonly 1 ”, 3 ”, or 6 ”—with tight tolerances (±0.05 mm) to ensure reliable expansion and retraction. Hub type selection—whether a traditional keyway, quick‑change taper lock, or cam‑action coupling—affects installation speed and mechanical stability, so choose the style that aligns with your machine’s drive system and changeover requirements.

Bladder material and pad design control the gripping force and longevity of the shaft. EPDM bladders are general‑purpose and resist aging, while nitrile options excel in oily or solvent‑rich environments. Pad thickness (typically 1–3 mm) and compound hardness determine the friction coefficient against the core: thicker, softer pads provide higher grip at low pressures, whereas thinner, firmer pads allow faster deflation and release in high‑speed applications. Always match bladder compound and pad durometer to your core material and operating pressure.

Uniform expansion hinges on optimal placement of air inlets. A single‑port design is cost‑effective for shorter shafts (<1 m), but longer or larger‑diameter shafts benefit from dual or multiple inlet ports to evenly distribute air pressure along the entire mandrel. Dual‑port configurations minimize pressure drop and ensure simultaneous segment expansion, preventing core misalignment or uneven gripping that can lead to runout or slippage.

The shaft’s outer finish balances core engagement and release ease. Anodized aluminum surfaces offer corrosion resistance and a moderately smooth profile for general‑purpose use. For applications demanding extra bite—such as high‑tension unwinds of slick films—a light knurl or micro‑textured finish increases mechanical interlock without damaging the core. Conversely, polished or micro‑polished finishes facilitate clean release of delicate substrates and minimize marking on cores. Select the finish that complements your material handling priorities.

Supplier Selection and Quality Considerations

Choosing the right air shaft supplier is as critical as selecting the shaft itself—your supplier’s expertise, manufacturing rigor, and support infrastructure directly impact shaft performance, delivery reliability, and long‑term value.

Manufacturing Capabilities

A top‑tier supplier should demonstrate comprehensive in‑house production capabilities, including precision CNC machining to maintain concentricity and tight dimensional tolerances, dynamic balancing equipment to ensure low runout at high speeds, and proprietary bladder fabrication for consistent expansion performance. Suppliers who control these steps internally can more rigorously test each shaft, respond quickly to custom requirements, and guarantee repeatable quality across production batches.

Certifications and Compliance

Quality certifications offer objective assurance of a supplier’s processes and product standards. Look for ISO 9001 certification to confirm a robust quality management system, ATEX compliance if your operation involves explosive or hazardous atmospheres, and FDA‑approved materials for shafts used in food, pharmaceutical, or medical device manufacturing. These credentials not only safeguard safety and regulatory compliance but also signal a supplier’s commitment to continuous improvement and customer peace of mind.

Technical Support and Service

Beyond product delivery, superior suppliers provide dedicated application engineering assistance to help you match shaft specifications to your unique process conditions. On‑site commissioning services, training sessions, and troubleshooting support accelerate installation, optimize tension settings, and minimize operational hiccups. A responsive technical team—available by phone or on‑site—can drastically reduce downtime when unexpected challenges arise.

Customization Flexibility

Your production needs may evolve, and a supplier’s ability to offer rapid prototyping, small‑batch runs, or private‑label solutions can prove invaluable. Rapid prototyping services enable you to validate custom designs before full‑scale production, while small‑batch capabilities accommodate pilot runs or seasonal demands without prohibitive minimum order quantities. Private‑label options let you maintain a consistent brand experience across all core components. Flexibility in customization ensures your air shafts remain perfectly aligned with both current and future operational goals.

Our Manufacturing Prowess & R&D Capabilities

Production Scale & Qualifications

R&D and Innovation

Quality Certifications

Unmatched After-Sales Service & Support

We have a growing network of overseas service points and authorized agents in Southeast Asia, Europe, and the Americas to ensure prompt local support for your slitting and rewinding machine.