Placard Technology

The minimum specification required by DOT for placard construction is 125 pounds per ream of 24 x 36 white tagboard with the ability to pass a 60 psi Mullen test, and the ability to withstand open weather exposure for 30 days without a substantial reduction in effectiveness. Again, some shippers and transporters have determined this specification to be much too risky for their longer durability requirements and have sought out more durable materials for this purpose. Indeed, a number of alternatives do exist. 

The most common device for displaying tagboard placards, particularly on tank cars, is a slide holder. The holder is manufactured of either aluminum or heavy duty steel, and permits the insertion and removal of a tagboard placard. More recently, a 20 mil rigid vinyl has been introduced which is far more durable than tagboard and may be reused for dozens of trips. 

One of the most popular substitutes for tagboard has been a 4 mil flexible vinyl with a removable pressure sensitive adhesive. This material has the virtue of complete exterior durability, yet it can be removed easily, when required, without leaving a residue. A slide holder is not required. Instead, these placards are affixed directly on the tank. 

With regard to dry freight, the majority of trucks and trailers have been equipped with what has come to be known as a permanent flip-placard system. Provided in aluminum for highway use, and in heavy duty steel for rail use, these assemblies are made up of all the placards, and simply flip from one to the other as required. 

The class number on a CORROSIVE placard must be white, and on a COMBUSTIBLE placard with a white bottom as prescribed by 172.332(c)(4), the class number must be red or black. 

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Transportation Labels and Placards Technology 79 THE TECHNICAL ASPECTS OF LABEL PRODUCTION... 

He then proceeds to a discussion of label technology, covering various types of labels, their advantages and disadvantages, as well as the problems associated with their use in different contexts, including transportation. He provides the reader with relevant excerpts from the laws and regulations governing the production and use of such labels. In addition, there is also a discussion of the history and use of placards which are functionally related but different from the label itself and have different production problems associated with them. 

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