FIBC bags provide a safe and cost-effective system for transporting a wide range of materials.
Big bags offer advantages compared to bulk handling and require low initial investment compared to special transport and handling equipment.
Fibc big bags reduce product waste and can easily be accurately metered.
They can perform the function of the mobile hopper and they are far less labor-intensive than 50 pound bags. They do not involve manual handling and therefore prevent back injuries. They require less space to pack and ship. They are quicker to fill and discharge. They reduce the risk of product damage, contamination and pilferage.
FIBCs are most often made of thick woven polyethylene or polypropylene, either coated or uncoated, and normally measure around 110cm in diameter and varies in height from 100cm up to 200cm. Its capacity is normally around 1000 kg but the larger units can store even more. A bulk bag designed to transport one metric ton of material, will itself only weigh 10kg.
Transporting and loading is done on either pallets or by lifting it from the loops. Bags are made with either one, two or four lifting loops. The single loop bag is suitable for one man operation as there is no need for a second man to put the loops on the loader hook. Emptying is made easy by a opening in the bottom such as a discharge spout, of which there are several options, or by simply cutting it open.
Although precautions are taken during handling, shipping and stowing processes, the fact is that Cargo will be handled several times before reaching its destination. During carriage, some Big-bags become affected by ship-engine vibration combined with stacking stress, which cause the compression of content, and some of the bag-base edges to stretch and depress below the pallet surface level, causing obstruction where the forks are deployed to handle the pallet.
A relatively high percentage of inadequately packaged Big-bags containing cement or other products, end-up damaged, with part of their content lost due to perforation, before reaching their final destination. Consequent losses and replacement of this particular cargo can be very costly.
FIBC materials vary so most standards are based on performance. We based performance testing the bags at rated capacity with a much heavier weight six times more heavy for standard FIBC’s and eight times more for heavy duty FIBC. Five times more for single use FIBC.
Big bag performance should also be judged with respect to tear resistance, stacking, toppling, dropping, dragging and vibration.
The most common forms of damage are split seems, broken loops, torn fabric, abrasion and sifting. In addition to performance tests that are relevant tests for bag fabric and liner, including tensile strength and moisture vapor transmission.
The owners of ships arriving with cargoes of cement in big bags often face problems connected with claims from receivers. Among the other factors, damage to packing occurs when the stowage instructions of producers and packers of this cargo are ignored. Most packing of big bag FIBC’s should be stowed by shippers not more than two tiers in height.
This is clearly marked on the packing manufacturers’ label attached to the bag. Contrary to such requirements the majority of vessels carry FIBC cargo stowed on board 4 and 5 tiers high. In such cases bags in the lower 2 – 3 tiers cannot endure the weight of the bags in the upper tiers and they burst sometimes causing collapse of the load. In some cases the contents of the lower tiers can be damaged by compaction and become hardened.
It is understandable that ship owners will try to carry as much cargo as possible, but they should be aware of the potential risks involved.
Awareness of the problem and its consequences when contracting shipments is benificial.