March 5, 2018

Special Considerations When Filling Bulk Bags

Bulk bag fillers vary in complexity. Some fillers are quite simple, stand-alone units; others are extremely sophisticated systems created to fulfill the complex and specific requirements of the customer’s application. Many factors must be taken into consideration, including the design of the bags, the capacity, support structures, densification, settling, adjustability, budget, and so much more. If you’re trying to figure out what type of bulk bag filler you need, check out this previous blog post. Today we’re exploring some of the special considerations you may need to keep in mind when filling bulk bags.

bulk bag

Special Considerations When Filling Bulk Bags

Are your bags lined?
Lined bags, in particular loose lined bags, require pre-inflation prior to filling. This “seats” the liner within the bag, preventing the liner from being pulled into the bag or ripped. Pre-inflation can be completed in several ways – using a compressed air venture or expander, for example, or a positive displacement (PD) blower. Some of these systems incorporate diverter valves and adjustable CFM gates so that they can connect to dust-collection systems. Others incorporate an in-line filtration system for the displaced air and dust produced as the bag is filled.

Does your material have trouble settling?
Often material doesn’t settle well in bags, so some type of mechanical densification system is required when filling bulk bags. These systems can also assist with reaching a desired weight in a specific bag. Typically densification systems incorporate high-frequency/low-amplitude vibration or low-frequency/high-amplitude thumping. Although vibration is more common, depending on the characteristics of the application, thumping may be more effective. In special applications, both densification methods can be incorporated.

Do you regularly fill bags of varying heights or two bags on one pallet?
If you regularly fill bags of varying heights or fill two bags on one pallet, a system that accommodates for mechanical adjustments may be advantageous. These systems can incorporate air or hydraulic cylinders, mechanical cylinders, or gear tracks with live axel drives. Automatic indexing via servo-motors and/or photoelectric sensors (a.k.a. photo eyes) is also possible.

Do you ship your bags on pallets or not?
Bulk bags are typically shipped on pallets, but they can be shipped without pallets as well. When bags are shipped without the support of pallets, special considerations are necessary to ensure proper handling and support. In many cases, this simply involves the use of a slave pallet or a supportive pad/slip sheet. In other cases, it requires special lift loop designs and down-stream handling equipment. If you wish to use pallet-less shipping, you will need to discuss practical design and guidelines with your bag and equipment suppliers.

Are you interested in a fully automated system?
Many fillers allow for nearly 100-percent automation. Your system might include pallet feeding, bag filling (by weight), auto release and ejection of full bags, stretch wrapping, and accumulation of bags via powered or gravity roller conveyors. Fully automated systems that include bag placing, spouting, filling, discharge, and accumulation exist in a few places today, but they come at a high cost and special bags are typically required. However, fully automated systems are the future of bag filling in high-throughput applications.

FormPak has already engineered much of what is required for these types of fully automated systems, and we are actively looking for an end-user or partner with whom we can implement these ideas and concepts. If you have a special application to discuss with us, please give us a call at 800-936-7672 or contact us online.

Of course, these are only a few of the special designs and components possible for systems filling bulk bags. To discuss your application in more detail and receive a comprehensive solution and proposal, please contact your FormPak salesperson.

With over 50 years of combined experience in the dry materials field, we will use our expertise to find or create an efficient solution for your needs. You can count on our knowledgeable, skilled staff for support. FormPak can assist your company with bulk bag filling, unloading, lifting, as well as fully integrated batching systems, bag break stations, and flexible screws. To discuss the requirements of your bulk bag or dry material handling project, please give us a call or contact us online today.