Pavements slabs are not only functional but can also be decorative. The usual method of holding stone stacks together to transport them from the factory to the building site is not enough in this case. The delicate surface and edges have to be protected. This is done by putting layers between the slabs and then strapping at a high tension. Film or cords that separate the individual layers to keep them stable prevent scratching and scraping Strapper XF 172 M.
Pavement slabs three times strapped The slabs are laid either on top of each other or stood side by side on the pallet which means the delicate surface is either on top or facing sideways. If the slabs are laid flat then a film is put between each layer. The top of the stack is then also protected with film. The stack is then ready for more layers or automatically protected from rain. There are machines which automatically attach the intermediate layers.
If the slabs are arranged in standing position on the pallet the plastic film or something similar has to be applied manually. This method is very rarely used because of the high costs involved. In this case strapping is about the only possible protective measure to secure the stack. Movement of the slabs in each stack is to be expected if the straps slacken or are not applied precisely. The pallets are subject to vibration during transport. After a time the stacks on the pallets settle which results in a perimeter reduction, steel straps then become slack.
PET straps however usually remain tight due to their elastic recovery capability. Unlike PP straps PET straps don’t loose their tension in the long run. They have to be highly tensioned from the beginning. Our new strapping machine XF 172 M with CFH-1 head is designed for high tension capability up to 5.500 N.
The first strap can be applied 4 cm from the ground and is sufficient for the first layer.