The present invention relates to the repair and refurbishment (which generally will be referred to herein as refurbishment) of thermoplastic drums, particularly of the sort commonly seen on road construction sites. These drums are frequently used to separate traffic on a road under repair from the construction zone, and as a result, the drums may be hit by passing cars or construction equipment. The drums usually are hollow, and when one is struck by a motor vehicle, the drum may dent, crumple, crease, or otherwise be deformed by the force of the impact, and often severely so. In addition, the drums often are unloaded from moving vehicles, being tossed into position by a construction worker, and some are damaged in this way.
With the seemingly ever increasing amount of road construction throughout the United States, such drums are in widespread use. When not in use, they usually are stored in a stacked configuration, one on top of the other. Prior to the present invention, there has been no reliable and repeatable way to refurbish the vast majority of damaged drums. In some cases, it is possible to xe2x80x9cknock outxe2x80x9d a smooth dent or depression, but generally, it is not possible to reuse damaged drums, and because they usually will not stack, their storage is problematic. One option is to recycle the thermoplastic material of which the drums are made. However, the drums typically have horizontal bands of reflective tape on their outer surface, which should be removed prior recycling. The removal of this reflective tape from a damaged drum can be difficult and costly to an extent that recycling the thermoplastic material is no longer cost efficient, especially in view of the relatively low cost of a new thermoplastic drum. As a result, drums which are damaged beyond use are often discarded. Consequently, there exists a need for an efficient, cost-effective way to refurbish damaged thermoplastic drums so that they can be used again, rather than discarded.
The present invention satisfies this need by providing an efficient, cost-effective method and apparatus to refurbish thermoplastic drums. One embodiment of the invention includes a method for refurbishing a damaged thermoplastic drum comprising heating at least a damaged portion of the drum until the damaged portion becomes softened; drawing the drum over a template for said drum, where the exterior dimensions of the template substantially match the desired interior dimensions of the refurbished drum; allowing the softened portion of the drum, while on the template, to harden sufficiently to assume the shape of the template; and removing the drum from the template. The drum may be heated by immersing at least the damaged portion of the drum, and possibly the entire drum, in a liquid having a temperature equal to or greater than the softening point of the thermoplastic from which the drum is fabricated. The drum may be hardened by spraying it with cool water, or water having a temperature substantially less than the softening point of the thermoplastic. The template over which the drum is drawn may include an upper surface comprising an ejection cap and an ejector, such as a pneumatic cylinder and piston, positioned within the template and in engagement with the ejection cap, such that the ejector can be made to cause the ejection cap to separate from the body of the template in a direction substantially parallel to the longitudinal axis of the template, thus partially removing a refurbished drum from the template. Using the method and apparatus of the present invention, damaged thermoplastic drums may be refurbished quickly and easily.