Although no value has been established for the allowable or required 

 elongation of the materials, the unreinforced polyurethane would probably 

 elongate excessively and be detrimental to its performance as containment 

 boom. 



Based on the data available, the Shelter Rite 7128 and the nitrile 

 rubber fabric have the highest breaking strength. However, the Shelter 

 Rite material achieves this strength with considerably less material 

 weight. It is anticipated that the polyurethane /polyester combination 

 will exhibit similarly good strength to weight characteristics. 



CONCLUSIONS 



1 . Although certain containment boom material requirements such as 

 breaking strength are dependent somewhat on the particular boom design, 

 for the most part, the properties required in boom materials apply 

 universally to all booms intended for in-harbor use. 



2. For coated fabrics, the mechanical properties of breaking strength, 

 elongation, flexibility, and tear resistance are functions of the woven 

 fabric substrate. 



3. The fabric weaving technique, as well as the inherent properties of 

 the yarn, determines the mechanical characteristics of the fabric. 



4. The physical and chemical resistive properties of a coated fabric 

 are primarily determined by the coating material and its thickness. 



5. The lamination method of coating fabrics does not result in the 

 substrate yarns being as well encapsulated or chemically tied to the 

 coating and is, therefore, not as desirable as the knife edge, dip, or 

 calendering methods. 



6. A coating containing no plasticizer can be expected to maintain its 

 properties over a longer period of time than one with plasticizers. 



7. The substrate material exhibiting the most desirable characteristics 

 for use in containment boom is polyester, followed by nylon. 



8. The coating materials exhibiting the most desirable characteristics 

 are chlorosulfonated polyethylene, polyurethane with a polyether base, 

 chlorinated polyethylene, and PVC (when properly formulated to resist 

 ultraviolet light degradation) . 



9. The large variations in material properties afforded by changes in 

 coating formulations, weaving techniques, and processing methods prevent 

 the identification of one combination of substrate and coating as the 

 best for use in containment booms. 



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