Лако-красочные материалы — производство

Polymer. The polymer determines the properties of the hot melt. Variations are possible in molar mass distribution and in chemical composition (copolymers). The polymer is the main component and backbone of the hot melt adhesive blend as it gives strength, cohesion, and mechanical properties (filmability, flexibility). Ethylene vinyl acetate (EVA) is the most used type […]

Hot melts are 100% solid thermoplastic compounds, which are compounded and applied in the molten state at elevated temperature, the resultant properties being obtained by cooling. Due to the quick cooling, bonds can be established in a very short time. Also a hot melt can be melted again, when already in the glue line. The […]

Lignins are large three-dimensional polymers produced by all vascular terrestrial plants; they are second only to cellulose in natural abundance and are essentially the ‘‘natural glue’’ that holds plant fibers together. Lignins are phenolic materials. They are primarily obtained as a byproduct in wood pulping processes with estimates exceeding 75 million tonnes per annum. Therefore […]

The main parameter for the application of tannins as adhesives for wood-based panels is the content of reactive polyphenols and the reactivity of these components towards formalde­hyde. Tannins can be used as adhesives alone (with a formaldehyde component as cross­linker) or in combination with aminoplastic or phenolic resins. These resins can react chemically with the […]

Tannins are polyhydroxyphenols of vegetable origin, which are soluble in water, alcohols, and acetone and can coagulate proteins. They are obtained by extraction from wood, bark, leaves, and fruits. Other components of the extraction solutions are sugars, pectins and other polymeric carbohydrates, amino acids, and other substances. The nontannin substances can reduce wood failure and […]

Bio-based adhesive resins have been under investigation for a long time; however, exten­sive industrial application, at least in Europe, has not yet occurred. The use and applica­tion of adhesives based on natural and renewable resources is often thought of by the industry as well as the general public as a new approach that requires novel […]

Polyurethane adhesives are formed by the reaction of various types of isocyanates with polyols. The polar urethane group enables bonding to various surfaces. Depending on the raw materials used, glue lines with either rubberlike behavior or elastic-to-brittle hard behavior can be achieved. The end groups determine the type of the adhesive, whether it is a […]

A. Adhesives for Wood-Based Panels (Polyisocyanates) Adhesives based on isocyanates (especially PMDI) have been used for more than 25 years in the wood-based panel industry [40,41,200-203], but still have a relatively low consump­tion volume compared to systems based on UF, MUF, or PF resins. The main application is the production of waterproof panels, but there […]

Table 12 summarizes the various glue mixes for different applications. Table 12 Examples of PF Glue Mixes for Particleboard, Oriented Strandboard, and Plywood Parts by Weight Components Particleboard core layer Particleboard face layer OSB OSB AW100-Plywood PF-resin A 100 — 100 — — PF-resin B — 100 — — — PF-resin C — — — […]

Similar to the investigations described above for the aminoplastic resins, NMR results of the liquid phenolic resins can be correlated with certain board properties [199]. For this purpose various structural components are determined by means of 13C-NMR and the ratios of the amounts of the various structural components are calculated, e. g.: methylol groups to […]