Global-Pak has always taken pride in the quality of the manufacturing partners and quality of bags that we sell. We are proud to announce that we have ordered a top lift test rig that we hope to have up and running by the release of our third quarter newsletter. The top lift test machine will allow Global-Pak to increase the spot checks on our manufacturing partners and continue to improve our product quality as well as to be able to test bags for our customers allowing them to understand what design changes may or may not be acceptable to maintain a 5 to 1 SWL.

We at Global-Pak feel this is an important step to allow us to continue our improvement as a company. Stay tuned for updates.

The 5 to 1 Safe Working Load

We often get questions on what a Safe Working Load is and why do we need a Safety Factor of 5 to 1 to handle our bags safely? In the following few paragraphs we will try to give you the background of where the Safe Working Load has its origins and the core test procedures used to ensure a bulk bag or FIBC design that allows you to have the peace of mind to ensure your customer’s safety as well as your employees.

these are not bulk bag or FIBCA standards, but general lifting standards that have contributed to FIBC handling guidelines.

The SF is given as 5:1 for single use bags. Safety Factor of 5:1 indicates a single use bag and 6:1 means UN rated or multiple use bag.

The safety factor of 5:1 means that the filled bag when subjected to hydraulic pressure should sustain a minimum of 5 times the SWL after 30 cycles of 2 times the SWL. After the 30 cycles of 2 times the SWL it is taken on the final 30 cycle to destruction, meaning it is subjected to maximum hydraulic pressure until the bag fails.　 During this final cycle the bag must pass 5 times the SWL or it is not suitable for normal use. 　The maximum pressure the bag design can withstand is called the peak load test. So if the SWL is 2200 lbs (1000 kgs) with SF of 5:1, the bag when subjected to the cyclic test and peak load test is considered passed if it breaks at 11000 lbs (5000 kgs) or greater.

A safety factor of 6:1 means that the filled bag, when subjected to hydraulic pressure, should sustain a minimum of 6 times the SWL after　70 cycles of at 4 times the SWL. If the bag breaks before 6 times the SWL pressure then it is not suitable for the required duty for UN rating or as a multi trip bag. So if the SWL is 2200 lbs (1000 kgs) with SF of 6:1, the bag when subjected to the cyclic test and peak load test is considered passed only if it breaks after 13200 lbs (6000 kgs) pressure or greater.

These standards were established by EFIBCA in 1985 to ensure maximum safety while designing the FIBC. The latest standard is ISO 21898.

As mentioned earlier, 5:1 indicates a single use of the bag. When we talk of single use FIBC it means the whole process from taking the FIBC from filling the bag to the discharge of the material from the bag. Any FIBC will typically be handled as follows and this process will be defined as "single use":

1) bag is filled with the material
2) after filling it is moved to the warehouse of the producer
3) from the warehouse it is moved to the truck for transportation to customer.
4) at the customer the bag is moved from the truck to the warehouse
5) the filled bag is then moved from warehouse to the shop floor for discharging
6) material from the bag is discharged.

We are hoping that you find the information that we put out as helpful as we at Global-Pak find that sharing information and knowledge with our customers helps everyone to have a better experience with their bulk bags. If you have further questions please contact your sales rep or reach out to us at [email protected] for more information.