Manufacturing Process for Metal Pails and 55-Gallon Drums

Metal pails and drums are two storage containers that are similar in function, but vary in capacity and the components used to make them. Notice that pails hold only 7 gallons or less, while steel drums can hold far more. Also, the higher the gauge size of the material, the thinner it is. Pails are made up of 22-24 gauge metal while steel drums are composed of 20 gauge and under making them stronger. Pails typically have bails or handles attached to them for ease of carrying while drums do not.

Many components that make up a steel drum, which is a much more complex design. Items such as fittings are indeed part of each item, though not labeled on both illustrations. These are the openings of the containers, which make it possible to pour out the contents of the container, and typically come in 3/4", 1-1/2“ &  2" sizes in both the Rieke and Tri-Sure brands. Other components include ears, which are attached to can or pail to hold bails/handles; beads (rolling hoops), which are rounded depressions on the surface of a container to improve its performance and the chime, which is a sort of “lip” on the top or bottom of the pail or drum.

Manufacturing

All metal containers must meet certain standards. The most important of these is compliance with UN Regulations. Such regulations mandate that steel pails and drums used in the U.S. need to comply with Department of Transportation standards if they are to be used in the transport of hazardous materials (Hazardous Materials Regulations Performance-Oriented Packaging Standards).

To manufacture steel drums, plants complete the process during a formation phase. To start, the sheet metal to be used in making each drum enters an edge grinder, a machine that rids sheets of jagged edges, smoothing them instead. The steel sheets then enter a bender, which has a cylindrical mold, proceeding to curve and bend the metal.

Next, various welding processes are employed. Once the metal is bent, it is fed by a worker into a spot welding machine, which begins to connect the two ends of the metal sheet into a tube by welding several points along the edge. After this, the two somewhat connected ends are seamed together completely by entering a seam welding machine, welding up and down the entire joint of sheet ends.

Once the basic body of the drum has been created, it undergoes a rigorous manipulation process. The flanging operation includes feeding the drum into flange insertion machine to create rim indentations and edges on the top and bottom of the container. Following the creation of these edges, drums enter a bead expander, a machine that takes the drum horizontally and expands beads or rolling hoops around the circumference of the container. These hoops are created by cranking rods around the inside of the drum and serve to strengthen the body of the item. These outward facing hoops or beads are combined with inward facing circumferential indentations along both the top and bottom of each drum. The indentations are corrugated and are created with a corrugating machine.

Now that the body has been created to the above specifications, the bottom piece of the container must be created and then connected. Drum bottoms first go through a cutting and embossing process. The bottoms are stamped down and cut in a pressing machine using special dies/molds. Once the container bottoms have been made, they enter a pre curler, a machine which smoothes the edges of each bottom piece to prepare it for seaming to the drum body. Ready to be added to containers, bottom pieces enter a seaming machine along with a drum body which rotates and presses the two pieces together. The now-seamed item prevents leakage of materials that the container will eventually hold.

A freestanding container now formed, it’s time to add a top piece to the drum. Drum tops are formed in a similar manner as bottoms.  Once created, drum tops must be punched via a machine which will punch out holes in specific sizes and positions. These holes will hold flanges to be inserted next. The flange insertion process involves bending the insides of metal rings within a flange fitting die set/mold machine and inserting them into the drum openings/holes. These openings will later be the point at which drum contents are poured into or out of the container. When all is said and done, the top, now complete with flanged openings, is seamed to the body in a process not unlike that for bottom seaming to create a functional container. This completes the basic steel drum.

Optional processes are employed, however, in steel drum production, depending on preference and end usage. Each drum may enter a paint booth machine, in which the drums are fed horizontally and rotated while the machine sprays and coats the drum exterior with paint. To complete the paint process, the containers are cooked in an oven to help dry and bring the paint to the correct shade.

Much goes into understanding how metal containers work and how they are made. As these items are fairly large storage containers, both pails and drums do get most of their use in industrial settings such as holding chemicals, paints, coatings and petroleum products. Metal containers afford us many benefits as well, including capacity and strength.

To see Qorpak's product selection, visit the pails pages.