The position of the sealing head is one of the factors that needs to be considered when specifying an automatic pallet strapping system.
Top-seal and side-seal machines position the strapping head differently in relation to the palletised load. The correct arrangement depends on the required strapping direction, pallet and product configuration, surrounding equipment and how the machine will be incorporated into the production line.
Understanding the difference helps when planning a new installation or adding automatic strapping to an existing pallet handling system.
What Is the Sealing Head on a Strapping Machine?
The strapping head performs the tensioning and sealing stage of the strapping cycle.
Once the strap has travelled around the required path, the machine tensions it around the load and seals the strap. On the TOSA machines used by Phoenix Handling Solutions, strap sealing is by hot welding.
The position of this head varies between machine configurations. It can be located at the side of the load or above it depending on the machine and the required strapping operation.
This is what is meant by top-seal and side-seal pallet strapping machines.
What Is a Side-Seal Pallet Strapping Machine?
On a side-seal machine, the strapping head is positioned at the side of the palletised load.
Within the TOSA range, the CAM 31 and CAM 34 automatic horizontal strapping machines both use side-mounted sealing heads. They are designed to apply horizontal straps around palletised loads.
The CAM 31 incorporates automatic pallet-height detection using photocells and a strap reel carriage with strap recovery. Depending on the machine configuration, additional options can also be specified around pallet handling and strap tensioning.
This arrangement allows horizontal straps to be applied at the required height around the palletised load.
What Is a Top-Seal Pallet Strapping Machine?
A top-seal machine positions the strapping head above the palletised load.
The TOSA CAM 41 is an automatic vertical strapping machine equipped with a top-mounted sealing head. A retractable bayonet passes the strap through the pallet so that the strap can travel vertically around the palletised load.
The CAM 41 also uses photocells for automatic pallet-height detection and incorporates lateral compensation of the strapping head for double tensioning.
The top-mounted arrangement therefore forms part of a different machine configuration from the side-seal horizontal strapping systems.
Top-Seal vs Side-Seal: What’s the Difference?
The most obvious difference is the physical position of the strapping head, but machine selection should not be based on head position alone.
A side-seal configuration such as the CAM 31 or CAM 34 is used on TOSA’s horizontal pallet strapping machines. A top-seal configuration such as the CAM 41 is used on its vertical pallet strapping system.
| Specification | Side-Seal | Top-Seal |
|---|---|---|
| Sealing head position | Side of the palletised load | Above the palletised load |
| TOSA examples | CAM 31 and CAM 34 | CAM 41 |
| Strapping configuration | Horizontal on the CAM 31 and CAM 34 | Vertical on the CAM 41 |
| Pallet height detection | Automatic detection on CAM 31 and CAM 34 | Automatic detection on CAM 41 |
| Strap path | Around the sides of the load | Over the load and through the pallet on the CAM 41 |
The required strap path should therefore be established first. The appropriate machine and sealing-head arrangement can then be selected around that requirement.
When Is a Side-Seal Machine Used?
A side-seal machine is relevant where horizontal straps need to be positioned around the sides of a palletised load.
The required height and number of straps depend on the product and pallet configuration. Where loads vary in height, automatic pallet detection can form part of the machine’s operating sequence.
For example, both the CAM 31 and CAM 34 use photocells for automatic pallet-height detection. The CAM 34 also incorporates double tensioning to apply equal strap tension to both sides of the load.
The required horizontal strap positions and range of pallet heights should therefore be established when the system is specified.
When Is a Top-Seal Machine Used?
A top-seal arrangement can be used where the required machine configuration applies straps vertically over the load and around or through the pallet.
On the CAM 41, a retractable bayonet passes the strap through the pallet. The machine can also be supplied with lateral shifting on linear guides for automatic detection of strap position.
This makes pallet type and the required strap position particularly important when specifying the system.
The CAM 41 can also be equipped with a 90-degree rotating platform with powered rollers where pallet orientation needs to form part of the strapping sequence.
Does Sealing Head Position Affect the Production Line Layout?
Yes. The position and movement of the strapping equipment need to be considered alongside conveyors, guarding and surrounding machinery.
A machine cannot be selected solely from the required pallet dimensions. The complete installation needs to accommodate the strapping head, strap reel, machine frame and any movement required during the cycle.
Access for inspection and maintenance also needs to be considered.
When adding a strapping machine to an existing line, the available space, conveyor arrangement, pallet direction of travel and the equipment immediately upstream and downstream all need to be established.
For more detail on machine selection, see our guide to choosing an automatic pallet strapping machine.
Can Top-Seal and Side-Seal Machines Handle Different Pallet Heights?
This depends on the individual machine, but the TOSA CAM 31, CAM 34 and CAM 41 all incorporate photocells for automatic pallet-height detection.
The maximum pallet size specified by TOSA for all three machines is 1200 × 1000 × 2000 mm high.
Automatic height detection does not remove the need to establish the complete operating range. Minimum and maximum load dimensions and any variation between products should still be provided when the machine is specified.
Does the Sealing Head Position Affect Throughput?
Sealing head position alone does not determine machine throughput.
The machine configuration, strapping sequence and surrounding pallet handling system also need to be considered.
TOSA specifies the CAM 31 side-seal horizontal machine at up to 40 pallets per hour. The CAM 34 side-seal horizontal machine and CAM 41 top-seal vertical machine are both specified at up to 50 pallets per hour.
This is why throughput should be assessed against the particular machine and complete required cycle rather than assuming that either top-seal or side-seal is inherently faster.
Integrating Top-Seal and Side-Seal Strapping Machines
The CAM 31, CAM 34 and CAM 41 can all be configured with service conveyors at the entry, exit and through the machine.
This allows the strapping operation to form part of an automated pallet handling sequence.
For an integrated installation, the required strap position, pallet movement, conveyor height, available space and production sequence should be established before the final machine layout is determined.
Phoenix Handling Solutions supplies automatic pallet strapping machines as standalone equipment and as part of integrated end-of-line systems.
Choosing Between a Top-Seal and Side-Seal Strapping System
The decision should start with how the pallet needs to be strapped rather than choosing a sealing-head position in isolation.
If horizontal straps need to be applied around the sides of the load, a horizontal machine with a side-mounted sealing head may be appropriate. Where the strap needs to pass vertically over the load and through or around the pallet, a vertical system such as the top-seal CAM 41 provides a different configuration.
Pallet dimensions, strap positions, production rate, conveyor arrangement and available installation space then determine the detailed machine specification.
Phoenix Handling Solutions can assess these requirements and specify a horizontal or vertical pallet strapping machine for a standalone application or an integrated production line.
If the product needs to be compressed before the straps are applied, see our guide to compression strapping machines for corrugated and compressible loads.
Frequently Asked Questions About Top-Seal and Side-Seal Strapping Machines
Is a top-seal strapping machine better than a side-seal machine?
Neither configuration is inherently better. The appropriate sealing-head position depends on the required strap path, machine configuration, palletised product and production-line layout.
Is side-seal the same as horizontal strapping?
Not as a general definition. Side-seal describes the position of the sealing head, while horizontal describes the direction in which the strap is applied. Within the TOSA range discussed here, the CAM 31 and CAM 34 are horizontal strapping machines equipped with side-mounted sealing heads.
Is top-seal the same as vertical strapping?
Top-seal describes the position of the sealing head rather than the strapping direction itself. The TOSA CAM 41 combines a top-mounted sealing head with a vertical strapping configuration.
Can a top-seal strapping machine be installed on an existing packing line?
Yes. TOSA states that the CAM 41 can be installed on an existing packing line. The available space, conveyor arrangement, pallet dimensions and required operating sequence still need to be assessed for the individual installation.
Can a side-seal machine handle different pallet heights?
Yes, on suitably specified machines. The TOSA CAM 31 and CAM 34 both use photocells for automatic pallet-height detection. The full range of pallet dimensions still needs to be established when specifying the machine.
What information is needed to choose between top-seal and side-seal?
The main information includes the required strap direction and positions, product and pallet dimensions, number of straps, production rate, conveyor arrangement, available installation space and surrounding equipment.