Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/26/2015
Publication Date: 6/10/2015
Citation: He, Z., Chapital, D.C., Olanya, O.M. 2015. Adhesive properties of water washed cottonseed meal on poplar, douglas fir, walnut, and white oak. Proceedings of the 69th Forest Products Society (FPS) International Convention, June 10-12, 2015, Atlanta, GA. Track 1.2.1.
Interpretive Summary: Cotton is a non-food crop and provides a major fiber source for textile industry. Cotton is produced along the southern-most portion of the USA in 17 states from California to Virginia. Although cotton is mainly planted as a fiber source, for every 100 kg of lint fiber ginned from cotton bolls, 150 kg of cottonseed is produced. Currently, cottonseed accounts for only 15-20% of the value of this crop, which is mainly from the oil fraction as it is edible and used in food industry. Although the defatted meal is mainly composed of protein and carbohydrates, it is not suitable for consumption by human and monogastric animals due to the presence of toxic gossypol. Therefore, to increase the value of the cottonseed meal fraction, we investigated the dry and wet adhesive strength of water washed cottonseed meal on four wood species (i. e. poplar, Douglas fir, walnut, and white oak) and the effect of the swelling characteristics of wood samples on the water resistance of the meal-based adhesive. Our observations suggested that the dimensional changes were not a dominant factor on water weakening the bonding strength of these wood pairs.
Technical Abstract: The interest in natural product-based wood adhesives has been steadily increasing due to the environmental and sustainable concerns of petroleum-based adhesives. In this work, we reported our research on utilization of water washed cottonseed meal (WCM) as wood adhesives. The adhesive strength and water resistance of WCM on poplar, Douglas fir, walnut, and white oak were tested with press temperature at 80, 100, and 130 oC. Our data indicated that raising the hot press temperature from 80 0C to 100-130 oC greatly increased the bonding strength and water resistance of WCM. The general trend of the adhesive strength of WCM on the four wood species was Douglas fir > poplar ˜ walnut ˜ white oak. The dimensional expansion of the bonded wood pairs due to water soaking was in the order: thickness> width (i.e. perpendicular to the wood grain) > length (i.e. parallel to the wood grain) changes. The greatest dimensional changes observed were with Douglas fir. However, the highest decrease in adhesive strength by water soaking was with poplar. These observations suggested that the dimensional changes were not a dominant factor on water weakening the bonding strength of these wood pairs.