Pet Strap Semi-auto Winder Pneumatic Mandrels for Quick Bobbin Change

The CQ800 semi‑automatic PET strap winder comes standard with pneumatic mandrels for fast bobbin changes. The operator simply slides an empty core onto the mandrel, presses the inflation button, and the mandrel expands to lock the core securely. For unloading, deflate the mandrel, and the finished coil slides off easily. The entire process takes only seconds, requiring no tools. Whether in single‑mandrel or dual‑mandrel configuration, each mandrel is equipped with an independent pneumatic mandrel, making manual change‑over extremely fast. For frequent change‑over scenarios (small coils or multiple specifications), pneumatic mandrels significantly reduce auxiliary time, improving overall productivity in semi‑automatic mode.

• Second‑class core change - Inflate to lock, deflate to release; each core change <5 sec.
• No tools needed - Fully pneumatic operation, no wrench or pry bar required.
• Reliable locking - Expanded mandrel grips core inner wall tightly, no slipping.
• Dual‑mandrel same equipment - Each mandrel on single or dual version has pneumatic mandrel.
• Reduces labor intensity - No heavy lifting or hammering; easy mounting/unmounting.
• Customizable core diameters - Mandrel OD can be customized for special cores.
• Simple maintenance - Long seal life; periodic air line check only.

Inside the mandrel is a rubber bladder. When inflated, the bladder expands, pushing external keys or segments radially outward to grip the core inner wall. When deflated, the keys retract, and the core slides off.

A skilled operator can go from removing a finished coil to mounting a new core in under 10 seconds (including deflate, remove, slide new core, inflate). The mandrel's own action takes only 2-3 seconds.

No. The keys have smooth surfaces or rubber coatings. As long as the core inner wall is reasonably smooth, no significant marks or deformation will occur.

The mandrel OD must match the core ID. CQ800 standard is 406 mm, but we can customize the mandrel OD to your core size.

Mainly check for air leaks and key flexibility. Inspection every 3-6 months is sufficient; seal life can be several years.