How Do You Choose the Right Container Liner for Drums and Pails?
Choosing the right container liner for your application is more important than many companies realize. The right drum and pail container liners help protect your product from contamination, extend the life of your containers, reduce cleanup time, and improve product recovery. From material selection and thickness to liner style and compatibility, every detail plays a role in performance. Whether you are mixing, storing, pumping, or shipping liquids or solids, this FAQ will help you understand your options so you can confidently choose the liner that fits your operation, budget, and product requirements.
Q: What is a "Container Liner”?
A: A container liner is a bag or cylinder that goes inside a drum or pail and keeps the container clean after emptying. It also protects the product from possible contamination by contact with the interior of the container.
Q: How do liners extend the life of a pail or drum?
A: Drums and pails are widely used in industry for batch mixing paint and other materials, and for mixing solids or powders into liquids. Liners are an inexpensive way to keep an empty drum or pail clean inside so it can be used over and over – drastically reducing operating cost. Liners reduce or eliminate wasted product by helping you get it all out – making them more than worth their cost to use.
Q: What kind of liner should I use?
A: There is no simple answer to this question. Each type of liner has its own advantages and disadvantages. The right liner depends on the product that will go into the container, how it will be mixed, pumped, or poured, and of course your budget. Generally, the thinner the liquid, the lighter the liner can be. Thinner liners are harder to install and can also stretch or tear more easily. Convenience, cleanliness and safety also play a part.
Q: What are container liners made of?
LDPE is the most common material for container liners. They’re typically made with FDA-approved resin, so they’re great for foods, water-based liquids, and other mild products. They won’t hold up with solvents, and you shouldn’t fill product at temperatures of more than 120°F.
HDPE is also food-grade, and offers food-grade broader chemical compatibility and somewhat more heat resistance.
PP permits hot-filling up to 200°F. Food grade.
Q: What are the differences between flat, round-bottom, and molded liners?
Flat Bag Liners are the most common type. They’re like giant sandwich bags with a straight heat-sealed seam at the bottom. Typically, 4 mil (.004”) or 6 mil (.006”) polyethylene film. For free-flowing liquids, choose a shorter liner that folds back over the top of the container and works with a separate cover disc. For thicker liquids like powders and other dry products, choose a longer liner that gathers at the top and is closed with a twist tie. Flat liners are usually the lowest cost, but the straight seam at the bottom creates folds and pockets as it conforms to the round bottom of the container. Product can get trapped and is more difficult to remove.
Round-Bottom Bag Liners are flexible film with a circular welded bottom seam. The finished liner fits the container perfectly so it installs easier. There are no folds to trap the contents, so the product comes out much easier. There’s less strain on the liner and the seam, so there’s less chance of a leak. Typically, 4, 8, or 10 mil polyethylene film. For thicker liquids like powders and other dry products, you can use a longer liner that gathers at the top and is closed with a twist tie. Round bottom bags are also available in heavier gauge polyethylene and polypropylene for hot-fill applications and greater durability.
Molded Liners are one-piece and seamless, so there’s no chance of a leak. They closely fit the container, and they’re semi-rigid so they’re easy to install and they stay put as product comes out, even if you’re dumping or pouring. They have a molded-in lip that keeps the liner in place during filling. Molded liners for drums are typically made from 15 to 30 mil low density polyethylene. Molded liners for pails are typically made from 15 mil high density polyethylene.
Q: Can I use a liner with flammable products?
A: HDPE and PP liners can be used with flammables. You should check for chemical compatibility when choosing a liner material. Special care must be taken to avoid sparks and open flame when handling flammables.
Q: What’s an Anti-Static Liner? Do I need one?
A: When a flowing product moves, static electricity can build up. If the product is flammable a spark can cause an explosion and fire. Anti-static liners are made with static-dissipating materials designed to dissipate static electricity and minimize sparks.
Q: Do liners work with UN-rated hazardous material containers?
A: You can certainly USE a liner in a UN-rated container, but you may not SHIP a filled UN-rated drum with a liner unless the container was originally certified with that liner. Doing so invalidates the drum manufacturer’s UN certification.
Q: What liner is best for liquids versus solids?
A: For a free-flowing liquid, use a flat or round-bottom liner that’s about 40” tall. It’s long enough to pull back over the outside of the container. Then use a polyethylene cover disk over the top. For thicker liquids and solids you can use a liner that’s about 65” tall. It’s long enough to gather up at the top and seal with a twist tie.
Q: What liner makes product removal easier?
A: Flat liners create folds at the bottom when they try to fill a cylindrical container, which makes it harder to get out heavier or viscous products like grease, honey, or adhesive. Round-bottom and molded liners are cylindrical so they conform perfectly to the container. In addition, molded liners have no seams and have a molded lip at the top. Product comes out smoothly and the liner stays in the container as the product comes out. top,
Q: What liners are best for pumping product out of a drum?
A: Just about any liner will work with a hand-operated pump. The product is more free-flowing and the pumping action isn’t likely to pull the liner into the pump. But flat-bottom liners create folds, so the pump can’t get all the product out. Round-bottom liners and molded liners do better at resisting the suction of a powered pump and there are no folds to trap product.
Q: Can I use a liner with a follower-plate type pump?
A: A follower plate pushes down on heavier fluids like grease and helps the pump operate more efficiently. You should use a molded liner in this situation because it has no folds, resists tearing, and also will not be sucked into a high-suction follower-plate type pump.
With so many choices, you need expert advice to pick the Right one. BASCO delivers.
No matter what your product or package, we’ll help you get the liners you need to get your job done right. We have 75+ years of experience in the drum biz, and the best trained and most knowledgeable customer service people.
When you need a Liner, get it Right ... get it from BASCO!