Executive Summary
This rotary arm pallet stretch wrapping machine is designed for in-line wrapping of sack pallets, combining a rotary arm wrap station with a top sheet dispenser inside a fenced safety cell. The defining characteristic of the rotary arm configuration is that the pallet remains stationary during the wrap cycle: the arm rotates around the load rather than the load rotating on a turntable. This makes the machine particularly suitable for tall, loose, or unstable sack loads that cannot safely be spun.
The demonstrated workflow is fully conveyorized. Sack pallets enter the cell on a roller conveyor, a film top sheet is laid over the load to protect it from rain and dust, the rotary arm wraps the load with stretch film, and the wrapped pallet exits on rollers. Top sheet application and stretch wrapping are completed in a single station, keeping the process in line and minimizing handling.
Key benefits observed in the reference installation:
- Load stays still. The arm turns around the pallet, so tall or loose sack pallets are not spun during wrapping.
- Top protection. The film sheet covers the top of the sacks against rain and dust, with film wrapped over the sheet to hold it in place.
- Single-station operation. Top sheet and stretch wrap are applied in one pass.
- Guarded cell. The machine operates inside a fence with warning signs, designed to ISO 12100:2010.
Per-pallet settings — top sheet size, arm speed, wrap program, and film tension — are configured according to pallet footprint, throughput, load height and stability, and sack type.
Working Principle
The wrap cycle follows four sequential steps, as shown in the reference video (official video on YouTube):
| Step | What you see |
|---|---|
| Infeed | A sack pallet enters on the roller conveyor |
| Top sheet | A film sheet is laid over the load |
| Wrap | The rotary arm turns around the still pallet |
| Outfeed | The wrapped pallet leaves on rollers |
Infeed. The sack pallet is conveyed into the fenced cell on rollers and positioned in the wrap zone. The load does not rotate at any point in the cycle.
Top sheet application. A film sheet, sized to the pallet footprint, is dispensed and laid over the top of the load. This sheet seals the top surface against rain and dust ingress — a key requirement for sack goods stored or transported in open conditions.
Rotary arm wrapping. The rotary arm, carrying the film carriage, rotates around the stationary pallet. Because the arm turns rather than the load, the wrap cycle imposes no rotational stress on the pallet — the reason this configuration is preferred for loose or tall sack stacks that would risk shifting or collapsing on a turntable. The wrap program (number of revolutions, climb profile, reinforcement wraps) is set according to load height and stability, and film tension is adjusted to suit the sack type.
Outfeed. Once the wrap program completes, the wrapped pallet discharges from the cell on the roller conveyor, ready for the next stage of the line.
The four per-pallet settings and their dependencies:
| Setting | Depends on |
|---|---|
| Top sheet size | Pallet footprint |
| Arm speed | Pallets per hour |
| Wrap program | Load height and stability |
| Film tension | Sack type |
Published Specifications
Configuration parameters documented for this machine type:
- Top sheet dispenser — film sheet laid over the load, sized to the pallet footprint
- Rotary arm wrap mechanism — arm rotates around a stationary pallet
- Roller conveyor infeed and outfeed — for integration into an automated line
- Fenced safety cell with warning signs
- Adjustable settings — arm speed, wrap program, and film tension, set per pallet
No dimensional, electrical, or throughput ratings are published for this configuration; machine data is provided in the proposal stage (see Call to Action). The illustrative film calculation below shows how wrap parameters are derived for a given load.
Engineering Calculation
The following worked example is illustrative and shows how the number of film turns up a load is derived from film width, overlap, and pallet height. It is not a published machine rating.
| Item | Value |
|---|---|
| Pallet height (illustrative) | 1,800 mm |
| Film width (illustrative) | 500 mm |
| Overlap (illustrative) | 40% |
| Climb per turn, 500 × 0.6 | 300 mm |
| Turns up the load, 1,800 ÷ 300 | 6 (one climb; top and bottom wraps added) |
Method. With a 40% overlap, each revolution of the arm advances the film up the load by 60% of the film width — 300 mm for 500 mm film. Dividing the load height by the climb per turn gives the number of revolutions required for one full climb: 1,800 ÷ 300 = 6 turns. Top and bottom wrap counts are then added per the wrap program.
Per-pallet settings that follow from this calculation:
| Setting | Depends on |
|---|---|
| Top sheet size | Pallet footprint |
| Arm speed | Pallets per hour |
| Wrap program | Load height and stability |
| Film tension | Sack type |
Because the pallet remains stationary while the arm turns, the wrap geometry is determined by the arm’s rotation and vertical film carriage travel — not by load rotation. This makes the calculation consistent for tall or unstable sack loads that cannot be spun on a turntable.
Selection Checklist
Confirm the following before requesting a proposal:
- [ ] Pallet size and height.
- [ ] Sack type and weight.
- [ ] Pallets per hour.
- [ ] Top sheet needed or not.
- [ ] Film width.
- [ ] Conveyor layout.
Each item maps directly to a machine parameter: pallet dimensions define the wrap envelope and top sheet size; sack type and weight determine film tension settings; throughput drives arm speed; and the conveyor layout determines infeed/outfeed integration on rollers.
Safety
The machine operates in a fenced cell with warning signs, as shown in the reference video. Operational safety requirements:
- Stay outside the fence while the arm turns.
- Do not enter the cell while the line runs.
- Lock out before clearing a jam.
For CE markets, the machine is designed to ISO 12100:2010, which governs risk assessment and risk reduction for machinery design. Site operators should integrate these requirements into their own line-level risk assessment, particularly around conveyor transfer points and cell access doors.
FAQ
Q: Why use a rotary arm wrapper for sacks?
A: The pallet stays still while the arm turns around it, so loose or tall sack loads are not spun on a turntable. This reduces the risk of load shifting during the wrap cycle.
Q: What does the top sheet do?
A: The top sheet dispenser lays a film sheet over the top of the load before wrapping, keeping rain and dust off the sacks. Film over the sheet then holds it in place.
Q: How many film turns are needed per pallet?
A: In the illustrative worked example, a 1,800 mm pallet wrapped with 500 mm film at 40% overlap climbs 300 mm per turn, requiring 6 turns up the load, with additional top and bottom wraps added.
Q: Can the machine run in a conveyor line?
A: Yes. Pallets enter and leave the cell on roller conveyors, so the wrapper integrates into an in-line layout.
Q: Is the cell guarded?
A: Yes. The machine operates in a fenced cell with warning signs, as shown in the reference video.
Q: Which standards apply?
A: For CE markets, the machine is designed to ISO 12100:2010, which sets out risk assessment and risk reduction requirements for machinery design.
Call to Action
We match a rotary arm pallet wrapping machine to your line in three steps:
- Submit your layout drawing with pallet sizes and pallets per hour to info@fhopepack.com.
- Receive a proposal including machine data and layout after our engineers review your requirements.
- Book a site survey so we can confirm the conveyor line integration.
Include your sack type, load height, and whether a top sheet dispenser is required — these determine the wrap program and film specification.
