The ABCs of FIBCs: How Bulk Bags are Made

March 6, 2019 | Manufacturing

When choosing an FIBC bulk bag manufacturer, knowing the bulk bag specs such as the material of construction, size availabilities, coatings, and joinery methods can help you make the best choice for shipping your bulk powders and other granulated products. From the quality of the raw materials to the method of cutting, sewing, and forming, you will find the craftsmanship of your FIBCs will go a long way to extending their life cycle during service.

A quality FIBC manufacturer will adhere to industry-wide bulk bag specs and are guided by quality assurance programs such as ISO 21898:2004 for Packaging — flexible intermediate bulk containers (FIBCs) for non-dangerous goods. These companies consistently improve employee performance and will work to reduce waste while improving efficiency. You will also find a company-wide foundation based on quality control throughout business processes and manufacturing.

FIBC Bulk Bag Specifications

There are a number of bulk bag specs that are designed to meet Department of Transport (DOT) requirements for transport, including the thickness of individual threads (denier), the fabric weight (GSM), and the strength of the yarn and fabric. From these engineering specs, each bag can be specifically designed to pass a number of stress tests including drop and jerk forces that could affect the integrity of each bag during transport.

When purchasing an FIBC, the most important bulk bag specs are the bag capacity (or bag size) which can range when filled from 500 to 4000 pounds. Also, the styles and types of FIBC bags should be considered when choosing an FIBC to meet your product storage and transport applications:

• Type A FIBC – No Electrostatic Protection
• Type B FIBC – Surface Breakdown Voltage of <6kV
• Type C FIBC – Electrically Conductive or Groundable
• Type D FIBC – Static Dissipative

Within these FIBC bag types, you will find different styles to meet your bagging needs, including rectangular or four-panel bags, duffle top bags, and circular bulk bags. For each bag style, the manner in which they are constructed will be similar, other than the type of material, size, and shape.

How Bulk Bags are Made

• The making of a bulk bag begins with the feeding of polypropylene (PP) resin and other additives into an extruder to produce PP tapes that vary in thickness and width. The melted resin forms PP sheets that are stretched by rollers, then cut.
• The tapes are then wound onto bobbins to start the weaving process which will create the FIBC fabric. The fabric weaving is performed on special looms to make either circular shaped bags or U-panels for the various other FIBC bag styles.
• If the fabric is to be coated, the bags are vacuumed to release dust particles and passed through a static eliminator. A lamination process then applies a protective coating of polypropylene which will increase the bags resistance to moisture and sifting. Breathable fabric bags are left uncoated.
• At this point, the bags are printed with an FDA approved printing ink, suitable for food contact. The ink that is used will dry quickly to eliminate smears or running.
• Next, a computer program controls the precision cutting of the woven fabric from the rolls into the required sizes for the bag assembly process.
• Finally, highly-trained employees complete the manufacturing process by sewing the fabric pieces together to create each bulk bag. All bags are sewn in an FDA approved clean room to maintain sanitation requirements. Filler cords are sewn into the seams and the bags will move on through different types of testing to pass UN regulations.

Make Palmetto Industries Your Solution

When considering an FIBC supplier, choose Palmetto Industries, a leading manufacturer and distributor of various types, styles, and sizes of FIBCs. We provide a cost-effective solution to the transportation of powdered or granulated goods. From sales to design, production, quality control, and supply chain logistics, our sales team experts can guide you through choosing the right bulk bags for your transportation applications. Contact us at 706-737-7999 and come see what customers around the world have known for over 25 years.