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July / August 2003
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Dr. Herbert Kielbassa, managing director of the world renowned LABORDATA International Materials Testing Institute, has an unrivalled knowledge of the global FIBC industry.

Safety Factors 3:1 and 4:1, or 5:1 and 6:1 ?

Japan versus Rest of the World

According to all national and international standards
the permissible load capacities or safe working loads (SWL) of non-dangerous-goods FIBCs depend on the results of cyclic top lift tests and on the safety factors to be considered. The first definitions of rules for performance of top lift tests and definitions of safety factors took place in 1983 in British Standard 6883.
Two years later in 1985 the EFIBCA Standards were introduced. Then followed in quick succession: the French Standard H34-012 in 1986, the Japanese Standard JIS Z1651 in 1988, the Australian Standard 3668 in 1989, and others – eg the standards of the Scandinavian countries. Now after a long break the European standard EN 1898 has been published in 2001. From that date all national standards of the European countries became invalid, so there are at the moment only four standards which play a part on the world stage:

EFIBCA 001-008
AS 3668
JIS Z1651
EN 1898

These standards differ slightly in certain areas. However, in all of them the cyclic top lift tests and the safety factors are identical – with one exception: the Japanese created divergent variants of this test and – what is especially of more critical importance – they lowered the safety factors. The details are explained in the diagrams.
Lower safety factors allow lighter constructions, i.e. lower strength, which ultimately means lower demands for quality. FIBCs certified on the basis of Japanese standards cannot be used in the area if application of the other standards because they do not fulfil the requirements that apply there. To prove this point we have carried out a series of tests using eight precisely identical FIBCs, performing all test variants of the cyclic top lift tests specified in the standards mentioned above. The results are as follows and can be corroborated from the diagrams:

 

Single-trip FIBCs (JIS: One way Containers)
Diagram Standard SWL SF
A EN/EFIBCA/AS 1600kg 5:1
C JIS 2500 3:1

Multi-trip FIBCs (JIS: Running Containers)
Standard-duty reusable FIBCs
Diagram Standard SWL SF
D EN/EFIBCA/AS 1350kg 6:1
F JIS 1900kg 4:1


The tables show extreme differences in the safe working loads for single-trip FIBCs as well as for multi-trip FIBCs. Japanese ‘Running Containers’ do not fulfil the test conditions even of European single-trip FIBCs. Conversely, European FIBCs show very high safety reserves if they are tested according to Japanese rules. The diagrams B and E show this very clearly.
The top lift test for heavy-duty reusable FIBCs is defined only in EN and EFIBCA standards. Therefore it cannot be included in a comparison. The test result is mentioned here merely for reasons of completeness. The same applies to dangerous-goods FIBCs which are completely outside the scope of this article (see diagrams G and H).

Heavy-duty reusable FIBCs
Diagram Standard SWL SF
G EN/EFIBCA 1000kg 8:1

Dangerous-goods FIBCs
Diagram Standard SWL SF
H UN regulations 1200 6:1


It is to be hoped that the global FIBC standard ISO 21898, currently under preparation, will be introduced soon. Then we shall have to deal just with two competing regulations for non dangerous goods FIBCs: ISO and EFIBCA. Whether the EFIBCA standards will survive in this constellation, only time can tell. I believe that in their present form their chances are very slim.


Dangerous-goods FIBC acc. UN regulations
No cycles, SWL = 1200kg, SF = 6:1
Minimum load required 7200kg kept for 5 minutes
Breaking load 8020kg


Single-trip FIBC acc. EN/EFIBCA/AS
30 cycles to 2 X SWL = 3200kg, SWL = 1600kg, SF = 5:1
Minimum final load required 8000kg, reached 8190kg


One-way Container acc. JIS
30 cycles to 2 X SWL = 3200kg, SWL = 1600kg, SF =3:1
Minimum final load required 4800 kg kept for 5 minutes
Breaking load 8150kg


One-way Container acc. JIS
30 cycles to 2 X SWL = 5000kg, SWL = 2500kg, SF = 3:1
Minimum final load required 7500kg kept for 5 minutes. Breaking load 7730kg


Multi-trip FIBC acc. EN/EFIBCA/AS
70 cycles to 4 X SWL = 5400kg, SWL = 1350kg, SF = 6:1
Minimum final load required 8100kg, reached 8610kg


Running Container acc. JIS
70 cycles to 2 X SWL = 2700kg, SWL =1350kg, SF = 4:1
Minimum final load required 5400kg kept for 5 minutes
Breaking load 8280kg


Running Container acc. JIS
70 cycles to 2 X SWL = 3800kg, SWL = 1900kg, SF = 4:1
Minimum final load required 7600kg kept for 5 minutes
Breaking load 8250kg


Heavy-duty reusable FIBC acc. EN/EFIBCA
70 cycles to 6 X SWL = 6000kg, SWL = 1000kg, SF = 8:1
Minimum final load required 8000kg, reached 8370kg

Comments are welcome and these may be sent by letter to Dr Kielbassa, c/o INDUSTRIAL BULK WORLD, 25 West Cottages, Off West End Lane, London NW6 1RJ, UK. Alternatively, he can be contacted direct (tel: +49 531 33 9011, fax: +49 531 33 9013; email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it ).


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