Submitted to: Journal of Thermoplastic Composite Materials
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/24/2012
Publication Date: 5/22/2014
Citation: Bajwa, S.G., Bajwa, D.S., Holt, G.A., Wedegaertner, T.C. 2014. Commercial-scale evaluation of two agricultural waste products, cotton burr/stem and module wraps in thermoplastic composites and comparison with laboratory-scale results. Journal of Thermoplastic Composite Materials. 27(6):741-757. Interpretive Summary: Utilizing cotton gin byproducts and plastic module wrap in the manufacture of thermoplastic composites has been evaluated in laboratory-scale research studies. This study looked at taking the laboratory-scale findings and making thermoplastic composite material in a commercial facility. Scaling up to a commercial facility significantly impacted all properties evaluated except nail holding capacity. Laboratory-scale testing showed 25% cotton gin byproducts could be added without negatively impacting the physical properties of the composite. Commercial production showed 12.5% inclusion without negative impacts, half of what the laboratory-scale testing showed. The plastic module wrap could be included at levels as high as 30% without adversely impacting the composites physical properties. The levels of inclusion noticed on the commercial testing can be significant enough to warrant commercial processing of cotton gin byproducts for use in thermoplastic composites.
Technical Abstract: Laboratory-scale research had shown the potential of using cotton burr/stem (CBS) as a fiber filler in thermoplastic composites. This study evaluates the potential of using waste materials from cotton harvesting/ginning operations, CBS, and cotton module wraps (CMW) as a filler and substrate in thermoplastic composites at commercial scale. The study also compares the effect of scale-up from laboratory to commercial scale on the properties of the thermoplastic composite materials. Two separate commercial trials were conducted to manufacture thermoplastic composite boards with (a) 0, 12.5, 25, and 37.5% by weight of CBS and (b) up to 30% by weight of CMW. Testing of these samples showed that commercial scale samples with 12.5% CBS had all properties comparable to those made with wood filler. At higher substitution rates, CBS tended to increase water absorption and coefficient of thermal expansion and increase nail holding capacity and hardness in commercial scale samples. This study also showed that CMW can be substituted by up to 30% by weight without deterioration of properties in comparison to a commercially available product. Scaling of the process had significant influence on all properties tested, expect nail holding capacity.