Bulk Bag FAQ

What is a bulk bag?

A bulk bag is a large bag used for storing and transporting free flowing dry products. Usually made from woven polypropylene, with standard base dimensions of 35"x35" and a variable height generally up to about 96". Bulk Bag dimensions can vary widely, based on user need and usability. Bulk Bags typically hold about 2000-4000 lbs. of product. Bulk Bags can be placed on pallets or lifted by standard lift loops attached to the bags themselves.

What are bulk bags made from?

100% virgin polypropylene, which is a petroleum based product.

What is woven polypropylene made from?

Woven polypropylene is made from extruded polypropylene resin, which is made from petroleum feedstocks.

What sizes do bulk bags come in?

Bulk Bags come in many different sizes, they can be customized into just about any 3 dimension size possible. There are limits to the sizes of course, but usually you’ll see standard bulk bags with a standard base dimension of 35" x 35". The heights of a bulk bag can range up to 96 plus inches tall. Again, the size and dimensions of bulk bags are determined by safety, functionality and usability by the customer.

Are bulk bags water-tight or water proof?

No, since a bulk bag’s fabric is made from a woven material, the bag is not “water proof". Users usually want a coating or lamination as a moisture barrier, by moisture barrier we mean a light amount of condensation or light amount of water. Lamination is simply a moisture barrier, however the use of an internal poly liner works best in many typical applications, technically it still is not 100% water proof. The difference between using a coating/lamination and using a liner is in the amount of moisture that you are trying to keep out of the product, and how much you want to assure that this does not occur. Standard bulk bags are not water proof, and are not typically designed to carry wet products, however there are other type products in the market designed to hold liquid, i.e. liquid liners.

How do you pick up a bulk bag?

Bulk bags are lifted by 1 of several types of lifting application. Some examples are standard 10" lift loops, lifting sleeves, single point crane lift, and stevedore straps. There are other designs that are made to lift bulk bags as well. Lifting options can vary and are all custom-tailored, i.e. 15" lift loops.

What does FIBC stand for?

Flexible Intermediate Bulk Container is the official name for a bulk bag, although many companies refer to a bulk bag with their own brand name

Can I reuse a bulk bag?

Flexible Intermediate Bulk Container is the official name for a bulk bag, although many companies refer to a bulk bag with their own brand name Yes, bulk bags can be reused. This requires a multi-trip bulk bag, which is made with a 6:1 Safety Factor. This type of bag is designed to be used for a specific amount of uses. Some users reuse bulk bags with a 5:1 SF, in fact it is a common occurrence. We do not recommend this practice, as reusability must also take into consideration the reality that the bag may be worn, or have a small hole in the fabric, the loops could be unstable etc. Reuse of a 5:1 SF bulk bag, which covers the majority of bulk bags seen in the market, is not recommended.

What is coating?

Coating is a moisture barrier applied to the inside of the woven polypropylene fabric. A common type of “coating" is a 1 mil. Thick lamination of heated polypropylene, which is laminated to the inside of the fabric. The lamination provides a moisture barrier to protect the contents of the bag. Since a bulk bag’s fabric is made from a woven material, the bag is not “water proof". Lamination is simply a moisture barrier, however the use of an internal poly liner works better in many typical applications, and it still is not 100% water proof. Liners and Lamination are designed to keep water away from the product. For more specific requirements, such as oxygen barrier or liquid liners, we suggest a specialized liner.

What is bulk density?

Bulk density is the property of the product that you are filling into the bulk bag. It is the mass of the product divided by the volume it occupies. The volume includes the space between particles as well as the space inside the pores of individual particles.

How do you determine the cubic foot capacity of a bulk bag in cubic measurements?

Cubic measurements take all three dimensions into consideration – width, length and height. This will tell you the volume of a given area and is useful for such things as knowing how much air is in a room when sizing an exhaust fan or the volume of a foundation form when ordering concrete.

Volume of a room: To calculate the number of cubic feet in the room used in the examples above, multiply the width by the length by the height: (10′ x 12′ x 8′ = 960 cubic feet).

Volume in cubic feet: There are 27 cubic feet in a cubic yard. So, if you would like to convert cubic feet into cubic yards, which is used for such things as dirt, gravel and concrete, just divide the number of cubic feet by 27 to arrive at the number of cubic yards. For example, if you have a form that is 2′ wide, 10′ long, and 1 1/2′ high, first figure the cubic feet, then convert to cubic yards: (2′ x 10′ x 1.5′ = 30 cubic feet / 27 = 1.11 cubic yards).

Volume in cubic inches: There are 1,728 cubic inches in a cubic foot. To convert the cubic feet in the above example into cubic inches, you would multiply by 1,728 (30 cubic feet x 1,728 = 51,840 cubic inches).

What is the difference between Circular and U-panel bulk bags?

Circular bags are made from fabric that has been woven on a circular loom. The fabric is woven into a continuous tube of fabric. The bag is then cut to the correct size height.

What does SWL mean?

Safe Working Load. A bulk bag’s safe working load is the amount of weight that the bag is rated and tested to hold safely.

What does 5:1 SF mean?

A standard bulk bag is rated at a 5:1 Safety Ratio, which means that the bag is specified to hold 5 times the amount of the bags safe working load. A 5:1 Safety Ratio is for single use or single trip bags. Bags that are designed for multi-use or multi-trip bags, are made with an increased SF ratio. The SF for a multi-trip bag is 6:1.

Are bulk bags recyclable?

Yes, new bulk bags are made from 100% virgin polypropylene.

What is a duffel top?

A duffel top is typically a 30" high “skirt" sewn to the top of a bulk bag. The duffel usually comes with a tie allowing the user to secure the duffel closed, at the same time allowing the user full access to the product.

What is the difference between duffel top and open top?

The main difference between the duffel top and open top, is the duffel itself. An open top bag is simply a bulk bag without a top closure, keeping the product exposed.

What is a fill spout?

A standard fill spout is a spout with a 14" diameter opening in the top (center) of the bag, usually 18" long. It’s designed to allow the user to fill the bag, minimizing dust occurrences as the bag is being filled. The length of a standard fill spout is 18" long. Spouts can be customized to fit an individual application.

What are lift loops (straps)?

Lift loops are the means by which a forklift raises the bag with its forks. In other words, they are loops attached to the 4 top corners of the bulk bag to enable a fork truck operator to put the fork in and lift the bag. Standard lift loops are 10" but can be customized to any workable size.

What is a lifting sleeve?

A lifting sleeve is a tube of polypropylene fabric used as a lifting application, designed to allow the forks of a forklift to fit into the sleeves and lift the bag.

Can I use a crane to lift a bulk bag?

Yes, however you must use the correct type of lifting straps designed specifically for a crane lift. You must follow the correct manufacturer recommendations when lifting a bulk bag.

What is a stevedore strap?

A stevedore strap is a long strap that is sewn to the body of one corner of the bag, extending to the opposite corner of the bag (opposite same side, not diagonally).

How do I attach my documents to the bag?

Typically documents are attached by use of a document pouch, which is usually a 10×12 polyethylene bag sewn to the seam of the bulk bag. A document pouch can have zip lock opening, or a standard opening and can be sewn where the users prefers.

Can you print on to a bulk bag?

Yes, bulk bags can be printed. Usually the printing is on the side panels of the bag. Print colors are usually one, two, or three colors, but we have the capability to print with more colors, which affects the cost of the bag. We can also print custom logos.

What are baffles?

Baffles are pieces of fabric that are sewn to the inside corners of a bag to maintain its cube shape after filling. The baffles have holes that allow the product to flow freely through them. The baffles also prevent the bag from bulging, which makes the bag stand up straight and in turn allows the bags to be more efficient in their use of space.

What is a perimeter band?

A perimeter band is a band sewn around the outside perimeter of the top of a bag, which is designed to give extra strength to loops when lifting.

What is a B-lock?

A B-lock is a spout accessory designed to assist in the closure to the spout. It is a quick and easy way to close a spout, manually regulating the flow of product. The device locks quickly and easily, and replaces the normal tie usually sewn to a spout.

What is a diaper bottom?

A diaper bottom bulk bag is a full open bottom bulk bag that has a flap that covers over the open bottom. Once the flap is untied, the bulk bag can be discharged quickly through the open bottom.

What is a conical discharge?

A conical discharge many times is designed to help in the flow of discharge of the product in a bulk bag. Many times, depending on the type of product being filled into a bulk bag, the product does not flow well when discharging, the product may tend to pile up in the corners of the bag, which creates issues for the discharger and sometimes the user has to shake or tap the bag to assist in the discharge flow. The conical discharge is a design that tapers the bottom of the bag into a discharge, which essentially eliminates a bottom panel of the bulk bag. When the bulk bag is lifted, all of the product flows into the cone and makes the product flow easily.

What is a UV inhibitor?

A UV inhibitor is an additive that is added to the resin during the extrusion process. It will assist in protecting the bulk bag from the harmful effects of UV rays, thereby protecting it from degrading and becoming unstable and unsafe.

What color fabric can I choose from?

The standard fabric color is white, however, we can make specific colored fabric. Colored fabric is considered a special order and has minimum requirements.

What does sift proofing, or sift resistant sewing mean?

Sift proofing is designed to prevent product from leaking out of the bag. Since a bulk bag (FIBC) is a woven product, sewn together, there is the possibility of product leaking out of seams and areas where the bag has been sewn. Sift proofing or anti-sift sewing is a method of using a felt or a spongy type yarn in the sewing process. The sewing operator, feeds the sift cord along the seam of the bulk bag while sewing. The sift cord fills in the areas near the needle hole in the seam. When using felt as sift resistant material, the felt is sewn either along with the threaded seam or in between the fabric panels. There are many ways to utilize sift proofing, these are some of the ways that sift proofing has been used to prevent product from sifting out of the seams.

What is chain and overlock stitching?

There are several styles of stitching used when sewing a bulk bag. Chain and Overlock stitching are two of the most common styles used. Chain stitching is series of looped stitches forming a chain-like pattern. Overlock stitching sews over the edge of two pieces of fabric. Many manufacturers use this style of stitching to assure a tight seam, which assists in reducing sift occurrences.

What different fabric weights are there?

Fabric weights are related to the amount of product that the bulk bag will be holding (SWL). There are 4 main fabric weights used for bulk bag construction. 3 oz., 5 oz., 6.5 oz., and 8 oz. Fabric weights can be customized to a specific weight, i.e. 7 oz. usually the Safe Working Load of the bag will determine what fabric weight to use for making a bulk bag.

Can bulk bags have liners?

Yes, liners can be inserted loosely or attached to the bag as well. There are different types of liners for different applications, but the main two are tube liners and form fit liners.

Are there any types of specialized liners available?

Yes, we can supply you with several types of liners. Form fit liners, Tabbed liners, Oxygen/Moisture barrier liners, liquid liners and foil liners.

What size bulk bag do I need for my product?

In order to accurately determine the correct size, you will need to consider the following items: bulk density of product, filling and discharging special requirements, shipping and storage requirements.

What is an anti-static bulk bag?

An anti-static bulk bag is a bulk bag made with a static protective fabric, which allows static electricity to discharge safely without the use of a groundable tab, commonly seen in Type C bulk bags. This is referred to as a Type D bulk bag.

What is Crohmiq®?

Crohmiq® is a brand name of static protective fabric by Texene Packaging Fabrics. www.texene.com

What is a Type A, Type B, Type C and Type D bulk bag?

Type A – plain coated fabric, no static protection–Used with non-flammable products.

Type B – uncoated fabric or fabric with thin coating and with breakdown voltage < 6 kV–Used with less sensitive flammable powders.

Type C – interconnected conducting yarns, resistance to ground < 108 W–Used with flammable powders and where flammable solvents are present–MUST BE GROUNDED (very dangerous when grounding fails).

Type D – quasi-conductive yarns, not interconnected – does not require grounding–Used with flammable powders and where flammable solvents are present–Safe replacement for Type C

How do I keep a liner from sliding down into the spout when discharging product?

The best way to solve this issue is to attach the liner in some way to the bulk bag. There are two ways to achieve this: first, is to insert a tabbed liner into the bulk bag. The tabs are glued to the liner and then the tabs are sewn to the body of the bag. A second effective method is to glue a form fitted liner directly to the bag walls.

Is the fabric breathable?

Woven polypropylene is breathable. Air and water will flow through an uncoated bulk bag. For applications that require a great deal of breathability, some users use a ventilated bulk bag.

Can bulk bags be stored outside? If so, then how long?

Yes, but bulk bags will degrade as a result of UV exposure. A standard bulk bag has a UV inhibitor added into the fabric at the manufacturing level. Manufacturers add enough UV inhibitor to resist UV rays for approximately 1600 hrs. Although this is dependent upon where the actual bag is located on the globe. In other words, UV rays vary in strength and degree in different parts of the world.

What is UN Certification?

UN Certification is a testing certification done by an independent testing facility that puts the specified bulk bag through a set of rigorous test, i.e.: drop test, topple test, and tear test. A UN test can include a vibration test which will certify the bag for DOT as well.

Do you stock UN Certified bulk bags?

The UN Certified bulk bags that we stock are made specifically for our customers as custom bags. There are multiple variants to UN certifications so it is not feasible to carry them as stock items. Bulk Bags that are tested by a third party testing facility. If the bag passes the test requirements, it is issued a specific UN Certification number, which is associated specifically to that bag. The UN number is specific to that particular bag being filled with a specific product, and tested for a specific packing group. The UN number has an expiration date, giving the bag a shelf life for usage.

What are food grade bulk bags?

Food grade bulk bags are bags that are made with the intent of using the bulk bags in a food grade facility for the packaging of food products. True food grade bags are manufactured in an AIB or BRC certified facility. Many suppliers say that their bulk bags are food grade, however, in reality they are food grade “ish" bulk bags. The qualifying question for your current supplier is, are your bags made in an AIB or BRC Certified facility? If yes, then they will have no trouble providing a copy of their AIB or BRC Certificate.

What is an AIB certified bulk bag?

An AIB certified bulk bag is a bulk bag that is made in a facility that has undergone an audit by the American Institute of Baking, which is the gold standard for food grade requirements.

Do your food grade bulk bags meet FDA requirements?

Yes. All of the resin used to make our bags meet the FDA requirements for food contact packaging.

Are your food grade bulk bags AIB certified?

Our food grade bulk bags themselves are not certified. However, the manufacturing facility that the bags are made in has been audited and awarded a certificate from the American Institute of Baking (AIB).

Do you have a HACCP plan?

Yes, our manufacturer has a HACCP plan in place for manufacturing bulk bags.

What is HACCP?

Hazard Analysis Critical Control Points – HAACP is a systematic preventive guideline to food safety. HACCP is used in the food industry to identify potential food safety hazards, where actions, known as Critical Control Points (CCP’s) can be taken to reduce or eliminate the risk of the hazards occurring.

What does HACCP stand for?

Hazard Analysis and Critical Control Point.

Is your company ISO certified?

No, our company is not ISO certified; however, our manufacturer that makes the bulk bags is ISO certified. ISO 22000

Are your bulk bags ISO certified?

A bulk bag in and of itself is not certified by ISO, however the manufacturing factory has been audited and achieved an ISO certification.

What does ISO stand for?

International Organization for Standardization, which are international standards and specifications for quality assurance.

Are bulk bags traceable?

Bulk bags are traceable by lot numbers given at the time of manufacturing. Each bag has a specific lot number associated with its manufacturing date and lot.

How much does a bulk bag cost?

Bulk Bag costs vary and are dependent on a variety of design and specification requirements. Since the product is made from pp resin, which is made from petroleum, the resin price fluctuates with the crude oil market. As polymer resin prices rise and fall, so do the prices for bulk bags.

Can I patch a bulk bag?

Patching a bulk bag is possible, but not recommended, and solely at the users discretion and risk. We sell a patch tape for this purpose.

Where can I get a copy of MSDS for my bulk bags?

We cannot provide a MSDS for a bulk bag, but we can provide an MSDS for the resin used to make the fabric of a bulk bag.

Does The Bioterrorism Act of 2002 affect you as a supplier of bulk bags?

No, since our bags do not fall within the requirements of the Bioterrorism Act of 2002. Click here for more.