Tight-head drums

Tiger s eye Tight-head drums Tiglic acid [80-59-1]... 

In 1991, BASF placed a central drum-cleaning plant in service. The next year, some 330 000 empty drums were cleaned in three automatic cleaning lines. The drums varied in size, material (plastic and steel), and design (open-head and tight-head). Two lines are run with water (with additives) and one with solvent [255]. 

L (15, 20, 30, 35, 55, and 57 gal), with 208 L (55 gal) used most often. Drums are categorized as closed-head (or tight-head) or open-top. Open-top drums are used mostly for water-based products, and are easier to clean and reuse. Plastic drums are permissible for shipment of hazardous materiais provided the appropriate testing has been done and the containers are properly labeled. 

Surface tension Intermolecular forces do not have an equal effect on all particles in a liquid, as shown in Figure 12.16. Particles in the middle of the liquid can be attracted to particles above them, below them, and to either side. For particles at the surface of the liquid, there are no attractions from above to balance the attractions from below. Thus, there is a net attractive force pulling down on particles at the surface. The surface tends to have the smallest possible area and to act as though it is stretched tight like the head of a drum. For the surface area to increase, particles from the interior must move to the surface. 

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