Bulk Bags FAQ & Terminology

Bulk Bags FAQ & Terminology

FIBCA Members

A proud member of the Flexible Intermediate Bulk Container Association (FIBCA), Halsted prides itself on helping our distributors educate their customers. The list below outlines several FAQ’s and definitions as it relates to bulk bags (FIBCs). Feel free to contact us if you have any questions about bulk bags.

Click on the image to the right for a downloadable PDF of the Glossary of Terms from FIBCA.

Glossary of Terms

Approval Drawing – A drawing supplied by the plant for the prospective customer’s review and approval, prior to production, in order to assure compliance with the customer’s needs and expectations.

Baffle – Pieces of fabric or other materials are sewn across each corner of a tubular or four-panel bag to improve a bag’s squareness, appearance, improve the stability of the load, and to more efficiently utilize storage or shipping space.

Bag Height – Height dimension of an FIBC measured from the top Seam to the Bottom Seam.

Belt Patch – A piece of fabric sewn either between the main fabric of the bag body and the Lift Belt or on top of the Lift Belt, within the belt sewn portion, used to improve sift resistance and/or the safe working load (SWL).

Bias Strap or Tape – Made of multifilament yarns, (MFY), polyester or polypropylene, and used to tie inlet and outlet spouts. Also called a Web Tie or Tie Strap.

Body Fabric – Main Fabric used on the body of a u-panel, four-panel, or circular bag.

Bottom Fabric – The bottom material of a tubular or four-panel bag.

Bottom Spout – Also called a Discharge Spout, used as an outlet to empty the contents of the FIBC.

Breathable Fabric/Bags – Uncoated or non-laminated fabric/bulk bags.

Circular Woven Bag – Also called a tubular bag, it is made from fabric woven on a circular loom, which is then cut to the proper length for a specified bag height, thereby eliminating the vertical seams on each of the bulk bag’s sides.

Cone Top – A variation of an inlet, where the top is a pyramid-type to allow overfilling of the bag. Also called a Conical Top.

Coated Fabric/Bags – Fabric or bulk bags that are coated/laminated with polypropylene (PP) to reduce moisture intrusion or sifting of the contents. Also called Non-breathable or laminated fabric/bags.

Cord lock – A closure device to hold the rope or cord in place on the spout – typically used on the discharge of bulk bags. They come in a variety of sizes and eliminate the need for hand-tied knots.

Denier – The weight of a yarn in grams per 9,000 meters.

Discharge Spout – Also called a Bottom Spout, used as an outlet to empty the contents of the FIBC.

Document Pouch – Typically made of either polyethylene or polypropylene, it is where shipping or identifying documents are usually placed. Also called a Pocket or Envelope.

Drawstring Closure – A type of spout construction similar in purpose as to a petal closure, but with the loop/string along the circumference of the closure.

Duffel Top – A type of FIBC top similar to a duffel bag whose inlet extends from the top seam and follows the bulk bags base dimensions. Also known as a skirt top

Extended Belt – A type of FIBC construction where the webbing extends around the bottom of the FIBC.  This construction is not applicable to U-panel FIBC’S.

Fabric Mesh – The measure of the density of the fabric weave, measured as the number of yarns per inch in both the Warp and Weft directions. Typical construction is a 12×12 mesh.

Fabric Weight – The measure of the fabric weight in ounces per square yard or grams per 100 square centimeters.  An example of a fabric weight is 6.5-ozs/sq. yd.

FIBC– Flexible Intermediate Bulk Container

Fill Spout – Also called an inlet spout or top spout, used as the inlet for filling an FIBC. It is designed to fit the customer’s filling chute during loading.

Filler Cord – Typically a polypropylene material used in manufacturing sift-resistant FIBC’S. A rope or braided yarn-like cord that is sewn into a seam to help prevent the escape of fine dust and powders.

Form-Fitted Liner – Designed to take the exact shape of the FIBC. Form-Fit Liners will allow improved filling and complete discharging of the product. Unlike a basic “tube liner”, Form-Fit Liners offer a flat top and bottom and incorporate a spout diameter and length to best compliment the FIBC’S fill and discharge spouts.

Full Open Discharge – A type of discharge whose outlet extends from the bottom seam and follows the bag’s base dimensions. Also called a Full Open Dump.

Hem/Hemming – A fold and sew, or glue operation, which prevents fraying of cut fabric and will add lift strength and seam strength to each of the bulk bags. This also provides a clean finish to the FIBC. It may be either towards the inside or outside of the bag. Hemming can be used to achieve desired FIBC dimensions.

Lay Flat Width – The width of tubular fabric if stretched or laid flat from edge to edge. A 14” diameter Fill spout would have a lay-flat width of 22”.

Loop Height – When laid flat the measurement from the top of the bulk bags to the apex of the loop.

Main Fabric – U panel of a U panel style bag.

MFY – Multi-filament yarns, used in the weaving of bias tape/straps and lifting belts. May be constructed of polypropylene or polyester threads.

Multi-Trip FIBC’s – Bulk Bags designed in accordance with ISO 21898 for multiple trips.

Perimeter Belt or Band – Bias tape/strap sewn around the top seam as a reinforcement or identifying mark. Also known as Safety Belt.

Petal Closure – A four-petal like a spout construction used to hold in the spout during transport.

Petal-Type Patch – A type of petal closure that is separate from the bottom fabric used to hold in and protect the spout during transport. Also referred to as reinforcement square.

Polyester – A type of polymer often used in producing monofilament multifilament yarns and threads. It is typically not easy to recycle with a polypropylene FIBC or poly bulk bags since the polymers are virtually incompatible.

Polypropylene – A type of polymer used in producing monofilament and multifilament yams and threads.

Port Hole – A type of outlet construction without a spout. The hole cut is reinforced with bias tape/strap.

Production Drawings – A set of documents prepared by the manufacturer which contains the detailed description of an FIBC’s dimensions, features, components, and special instructions as approved by the customer.

Reinforced Section – Section of the FIBC where the lift belt is sewn onto the fabric. This section of fabric has additional Warp yarns, which contributes to the strength of the bag. It is also called a Tramline.

Remote Open Discharge (R.O.D.) – A type of outlet that has provisions for the discharge of material without an operator reaching under the bag to open the spouts.

Safe Working Load – SWL is the amount of load, (in pounds or kilograms), which a bag is designed to carry.

Safety Factor –  It is an industry-standard requiring the FIBC to handle five or six times its Safe Working Load, (SWL), normally written as a ratio, “5:1 or 6:1 SF”.

Sanitary Flap – A bottom diaper that protects the entire bottom surface of the bag for cleanliness and wearing. May also be referred to as a protective bottom.

Seam – A sew line made by the attachment/assembly of two or more components.

Side Panel – A fabric component of a sewn bag style of construction. This can be either two pieces attached to the U-Panel, or four pieces, which form the Four Panel bag.

Shelf-Life of FIBCs – As of this present date, the FIBCA is not aware of, nor has it ever been presented with any data, test reports, or studies determining the shelf life of an FIBC. Any recommendations in regards to the shelf life of an FIBC are solely the responsibility of each company making such declarations.  The Flexible Intermediate Bulk Container Association does not endorse any typical shelf life for an FIBC / Bulk Bag. Variables such as UV inhibitor used, construction (fabric weight, thread, webbing, etc.), exposure to environmental hazards (UV, temperature, and humidity), storage methods, handling methods, and the contents of the FIBC can dramatically impact the shelf life of an FIBC.  The best method for determining if an FIBC remains suitable for use is to conduct periodic performance testing (top lift, UV, etc.) on samples and compare the results to the results from the newly manufactured samples from the same lot. Samples should continue to meet industry standards such as those set forth in ISO 21898

Sift-Resistant Construction – A type of FIBC construction that provides resistance from product sifting when the bag is filled with very fine materials. Also referred to as “Sift ¬proof’ construction. This typically utilizes coated fabric and filler cord in the sew lines.

Single Trip Bag – An FIBC designed in accordance with ISO 21898. For one time use.

Spout Cover – Also called a petal cover, it is a piece of fabric sewn between the spout and the petal closure used to hold in/protect the spout.

Spout Diameter – A dimension of the spout measured across the circular opening.

Spout Height – Height dimension or length of the spout measured from its point of attachment on the top/bottom fabric to its free end.

Stevedore Strap – It is a belt connecting either two adjacent lift loops, or all four loops, used for single-point lifting

Stitches per Inch – A sewing specification requiring “X” number of stitches per inch.

Top Fabric – The top fabric used on an FIBC.

Tube Liner – A liner with no spouts or contours, it is a straight cylinder, which may or may not have one end heat-sealed.

UV Stabilized – A feature of an FIBC fabric that provides protection from prolonged exposure to the sun’s degrading UV rays.  An additive that blended with the resin prior to extrusion of the yarns to provide this protection.

Volume – The size, or amount of material, an FIBC can hold. It is generally measured in Cubic Feet.

Warp – Yarn or tape in a fabric, oriented perpendicular to the weft yarn during weaving. This would go from top to bottom in the body fabric. Also identified as the yarn in the “machine direction”.

Web Tie – Made of multifilament yarns, polyester, or polypropylene and used to tie the inlets and outlets. Also called a Bias Strap, Tape, or Spout Ties.

Weft – Yarn or tape in a fabric, orientated perpendicular to the Warp yarn during weaving. This would go from left to right in the body fabric. This is identified as the yarns placed by the bobbins of the looms.

Yarn/Tape – Extruded PP sheet slit and stretched to form part of the woven fabric for the FIBC.

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