Conical pails are widely applied in chemical packaging, commonly used to fill paints, glues, resins, inks, chemical products or other type of decoration material. In the past years, conical pails are usually produced manually, now a day, the fully automatic conical pail production line is more and more popular.
As a conical shape three piece welded container, its production process is a little different from other standard round cans, in this article, we will explain the manufacturing process of a standard conical pail.
A bucket is typically a watertight, vertical cylinder or truncated cone or square, with an open top and a flat bottom, attached to a semicircular carrying handle called the bail.
Pail can have straight or slanted sides and usually has a handle or bail. Pails are either "open head" with removable lids (covers) or are "tight head" with sealed heads and a screw closure.
Buckets generally have a circular shape because hoop stress allows for the most effective use of the tensile strength of the material, and thus allows for the thinnest material, reducing both weight and material cost.
Buckets generally have a tapered shape because this allows multiple buckets to be stacked (nested) inside each other, providing both dense and secure storage of large numbers of buckets.
Combining a circular shape with a tapered shape gives you a conical shape.
Conical pails require two-thirds less warehousing space when empty, pails can be completely emptied without leaving any residue.
Package handles, or carriers, are used to help people use packaging. They are designed to simplify and to improve the ergonomics of lifting and carrying packages. Handles on consumer packages add convenience and help facilitate use and pouring. The effect of handles on package material costs and the packaging line efficiencies are also critical. A handle can be defined as “an accessory attached to a container or part for the purpose of holding or carrying.” Sometimes a handle can be used to hang a package for dispensing or use.
A bail handle, or simply bail, is a handle that consists of an open loop that moves freely within two fixed mounts or ears. Several designs are available: bails are typically made of metal (wire) or plastic. It is a type of package handle which may be used for carrying an item, such as a tin can or bucket.
Flanging, a forming or bending operation that results in a 90-degree bending of the metal.
Flanging is a bonding and forming technology used in sheet-metal forming. By bending over the edge of metal sheets using a flanging machine, the process reinforces the bent edge or creates a connection consisting of multiple components.
The flanging process requires tools made from materials that have low friction properties and are capable of withstanding high mechanical loads.
Bead (Inside or Internal) – A rounded depression around the surface of a container or end. The bead is used to stiffen or improve its appearance. The bead is also used to secure the collar on the can.
Bead (Outside or External) – As above except convex rather than concave.
Concave (interior bead) or convex (exterior bead) area usually 1/8” wide spanning the circumference of the tin to provide additional strength and stability to the tin body.
The body blank is formed into basic shape as cylindrical, and welded on seam overlap.
Some conical pails specially require powder coating inside the weld seam, except, lacquer coating is enough.
If the welding seam is coated by powder or wet lacquer, the induction curing is necessary. Until this step, the pail body are cylinder shape
After the welding line, conical expander expands the cylindrical cans as conical shape.
Pail body can be pre-curled on top and flanged on bottom preparing for the pail bottom
Pail body is curled on top and beaded
The finished pail body is sealed with pail bottom
Lu welding for ears, mounting of wire handle onto conical pails, ear repair coating inside the welding spot.
In-line can leakage tester to detect all the cans produced
Nesting conical pails by making neat stacks that can be palletized.
Plastic film wraps the whole stack of conical pails