The interactions between wax and UF resin in medium density fibreboard

Abstract

Through the use of fluorescently labelled paraffin wax and UF resin, fluorescence microscopy has been used to simultaneously visualise wax and resin components on medium density fibreboard (MDF) fibre. To simulate differing application methods, the wax and resin were applied to fibre either separately or as a mixture. Visualisation on unpressed fibre and in panels suggests the application order can lead to differing wax-resin behaviours and how each interact with fibre. Both qualitative and quantitative analyses of wax and resin distribution on fibre established that the main differences in behaviours were due to wax and occur on pressing. Applying wax first to fibre led to wax droplet agglomeration in panels whereas applying wax after resin or as a mixture appeared to allow wax to be retained as relatively smaller droplets within the resin matrix. This also manifested itself in differences in wax overlap with resin in panels, where a relatively low overlap was observed when applying wax first, despite a substantially higher overlap in unpressed fibre. Application of wax after resin or as a mixture resulted in the wax generally staying with the resin. The observed differences in wax distribution were also correlated with panel cold water soak properties. Wechselbeziehungen zwischen Wachs und UF-Harz in mitteldichten FaserplattenZusammenfassung Mit fluoreszenzmarkiertem Paraffin und UF-Harz wurden Wachs-und Harzkomponenten auf MDF-Fasern mit dem Fluoreszenzmikroskop simultan visualisiert. Um verschiedene Auftragsmethoden zu simulie-W. Grigsby ( ) · A. Thumm Science Leader, Scion, Private Bag 3020, ren, wurden Wachs und Harz entweder einzeln oder als Mischung auf die Fasern aufgetragen. Die Visualisierung auf ungepressten Fasern und in den Platten ergab, dass die Art des Auftrags das Verhalten zwischen Wachs und Harz und deren Verteilung auf der Faser beeinflusst. Sowohl die qualitative als auch die quantitative Untersuchung der Wachsund Harzverteilung auf der Faser zeigten, dass die Hauptunterschiede auf das Wachs zurückzuführen sind und beim Pressen auftreten. Wird Wachs zuerst auf die Faser aufgetragen, führte dies zu einer Tröpfchenagglomeration in den Platten. Umgekehrt, wenn Wachs nach dem Harz oder als Mischung aufgetragen wird, schien sich das Wachs in relativ kleineren Tröpfchen in der Harzmatrix zu verteilen. Dies zeigte sich auch in der unterschiedlichen Vermischung von Wachs und Harz in den Platten, wobei eine relativ geringe Vermischung zu sehen war, wenn das Wachs zuerst aufgetragen wurde, trotz einer wesentlich höheren Vermischung auf den ungepressten Fasern. Wird Wachs nach dem Harz oder als Mischung aufgetragen, blieb das Wachs generell mit dem Harz verbunden. Die beobachteten Unterschiede in der Wachsverteilung korrelierten auch mit dem Verhalten der Platten nach Kaltwasserlagerung.

Improved interfacial properties of carbon fiber/UHMWPE composites through surface coating on carbon fiber surface

“…The mechanical performance of advanced composites depends to a large extent on whether the mechanical stresses can be efficiently transferred from the matrix to the reinforcing fibers . It is established that the interfacial properties of composites are mainly determined by the reactivity and compatibility between the matrix composition and the surface properties of reinforcing fiber . Ultra‐high molecular weight polyethylene (UHMWPE) is one of promising matrix materials due to its high wear resistance, low friction coefficient, high chemical resistance, and bioinertness.…”

The improvement in interfacial shear strength of wood fiber/epoxy composite by sizing with epoxy sizing agent containing MWCNTs

“…Depending on the treatment method, wood fibers with different morphology and composition can be obtained. For example, wood flour is a relatively native form of wood, usually obtained by mechanical grinding or as saw mill waste product, while lignocellulose fibers are obtained after thermomechanical or chemical treatments . Because CNTs are 1‐dimensional nanostructure with high surface area and electrical conductivity, they can be used as probe materials and transducers .…”

“…For example, wood flour is a relatively native form of wood, usually obtained by mechanical grinding or as saw mill waste product, while lignocellulose fibers are obtained after thermomechanical or chemical treatments. [4][5][6][7] Because CNTs are 1-dimensional nanostructure with high surface area and electrical conductivity, they can be used as probe materials and transducers. 8 The production of CNTs using various transition metal particles has been extensively studied for potential applications together with nonenzymatic glucose sensing materials.…”

The influence of surface treatment on the tensile and tribological properties of wood fiber‐reinforced polyimide composite

“…Wood fiber is well known for the excellent mechanical property, high flame resistance, high thermal stability, and good resistance to creep, chemicals, and abrasion among all commercial synthetic polymer fibers, which have a wide application in military and business fields. Especially, wood fiber has great potential applications as reinforcement fibers for advanced composites . Polyimide and its composites attract extensive concern from tribological scientists worldwide because of their high mechanical strength, acceptable wear resistance under certain conditions, good thermal stability, high stability under vacuum, good antiradiation, and good solvent resistance .…”