Steam Expansion of EPS Loose-fill Resin Theory and Practice

3 STEAM EXPANSION OF EPS LOOSE-FILL RESIN THEORY AND PRACTICE 

Conditions for expansion and aging will vary significantly between sea level and higher altitudes such as found in Colorado Springs, Colorado (altitude 6035 ft/1839 m). Because of the difference in boiling points, more steam and longer expansion times are required to achieve densities equivalent to those easily attainable at sea level to 1000 ft in altitude. 

First pass aging bag Second pass aging bags 

Loose-fill is either bagged or shipped in bulk truck to the customer. Bags vary in size from 10 to 20 ft3, depending on the customer need and the particular geographic market. Bulk systems are popular with companies that use large quantities of loose-fill and have many packaging stations. The trucks used to transport the loose-fill are specially equipped with flexible duct that connects to the duct and bagging system at the customer. This way, 2500-3000 ft3 of loose-fill can be shipped to the customer at short notice and unloaded with a minimal amount of manpower involved. 

In the late 1980s, environmental concerns led to the development of photo-degradable resins being incorporated in the polymer mix. Methyl isopropenyl ketone (MIPK) at a level of 5 % was found to be effective in making the loose-fill pieces photodegrade to polymer dust with 10-12 months of exposure to sunlight [134]. 

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