A General Overview of the Bulk Bag / FIBC Manufacturing Process
Here the mix of virgin polypropylene granules, ultra violet inhibitor, calcium carbonate, and sometimes color pigment are being melted and converted into tapes in an extrusion plant. At the end of the extrusion line these tapes are wound on bobbins of required a size. This is the first stage of process which determines the tensile strength of the tape.
Extruded tape bobbins are loaded in the circular/tubular weaving loom or setup for the flat (Sulzer) loom. Here the tapes will be woven into fabric of a required specification and size and will be wound in roll form. These woven fabrics are used not only for the body of the FIBC, but also the fill and discharge components.
Lamination / Coating (Optional)
Polypropylene fabric is laminated with a semi-clear PP film that is bonded to the woven material to create a moisture barrier. This is an optional process as per the requirement of the customer.
The fabric in rolls is run through an automatic cutting machine and is cut to a specific size. This automatic process is adopted to get better accuracy in cut size.
The body fabric panels are then fed into a printing machine to make a printing impression on the fabric.
Heavier polypropylene tapes along with multifilament thread are woven into webbing which forms the lift loops of the bulk bag.
All the components used to manufacture the bulk bag are brought together. The gathered parts are assembled to form an FIBC or bulk bag by highly skilled and trained laborers under the supervision of technically qualified supervisors.
Each and every bag will be inspected by a technically qualified person from the quality control department to ensure that each and every bag produced is safe to use.
Top Lift Testing
Random bags will be selected from a particular lot and will be tested to ensure the safe working load (SWL) is achieved. Generally, these tests are conducted with the sample bags before commencing production, but also after completion of the production random samples are taken for top lift test to ensure the weight rating is met or exceeded.
After the bags are produced, inspected, and tested, they are compressed with the help of a press and neatly packed as per the requirement of the customer.
Packing / Baling / Palletizing
Once the bags are baled/palletized, they are immediately shifted to a clean storage room.