Adhesives, cost

If this method proves to be commercially feasible, a renewable and abundant waste product of forest products manufacture could replace expensive petrochemicals. Additionally, use of an inexpensive waste product from processing of forest products could materially reduce adhesive costs and expand opportunities for manufacture of structural materials from low-quality wood. This benefit is particularly important since the difficulty in producing large, strong, structural members from timber resources of declining quality is growing exponentially with time. The cost-benefit ratios of replacing PRF resins with extracts from conifer barks are, therefore, quite favorable in a honeymoon system. 

Within this wide range there are many possibilities. The adhesive purehase price and the required addition rate are major factors in determining the overall adhesive cost for a panel (Table 12.3). Performance requirements, partieularly durability may limit the available choice. Overall UF systems provide the lowest eost solution for MDF and particleboard and are used in the greatest proportion of these panels, in excess of 95% for MDF. 

High expenditure for mixing and dosing devices are mostly compensated by lower adhesive costs (no losses due to excess pot life) and a higher quality standard of the bonded joints. 

A fuse manufacturer replaced a 30 min epoxy used in a heat cure process to assemble stainless steel inserts into phenolic holders. By utilizing an aerobic adhesive bonding process, the assembly was complete in 30 s at room temperature. The resulting increase in productivity more than offset the higher adhesive cost. A cyanoacrylate bonding process was even faster, but did not resist aging in a moist atmospheric environment or pass a drop test for impact resistance. 

Adhesive cost 5 cents/part 20 cents/part... 

Fillers (calcium carbonate, calcium sulfate, aluminum oxide, bentonites, wood flour) increase the solid content of the dispersion, and they are added up to 50%, based on PVAc. The purpose of their addition is the reduction of the penetration depth, a thixotropic behavior of the adhesive, gap filling properties, and the reduction of the adhesive costs. Disadvantages can be the increase of the white point and possibly the more marked tool wear rate due to greater hardness of the adhesive. Other components in PVAc formulations are defoamers, stabilizers, filler dispersants, preservatives, thickeners (hydro-xyethylcellulose, carboxymethylcellulose), poly(vinyl alcohols), starch, wetting agents, tackifiers, solvents (alcohols, ketones, esters), flame retardants, and others. 

The cost per pound of adhesives is an important, though not a limiting, consideration on the choice of an acrylic adhesive. The cost of assembly usually far outweighs adhesive cost per pound. Generally, cyanoacrylates cost the most per pound, followed by anaerobics, aerobics, and then second-generation acrylics. 

Table 5.10 lists polymers used for both water- and solvent-based adhesives. Water-based adhesives cost less than the equivalent solvent-based compounds. Even inexpensive organic solvents are costly when compared to water. The use of water eliminates problems of flammability, emission, and toxicity associated with organic solvents. However, in most cases, water-based adhesives must be kept from freezing during shipment and storage because of possible permanent damage to both the container and the contents. 

Brush Brushing action provides good wetting of surface, resulting in good adhesion. Cost of equipment is lowest. Poor thickness control not for precise applications. Coating of individual components, spot repairs, or High labor cost. maintenance. ... 

Adhesive costs are often quoted by weight for liquids, pastes and solid forms or by area for sheets and films. 

The supply of raw materials for adhesives is closely tied to the availability of petroleum. Toluene and other raw materials for the synthesis of phenol are also used as octane boosters for unleaded gasoline. Availability and price are often volatile. Adhesive manufacturers are challenged by opportunities to use alternate raw materials. Board manufacturers are challenged by variable adhesive costs. Naturally occurring... 

Polyurethanes Mar resistance Elongation Softness and adhesion Cost... 

The key parameters to control are formulation water content, clay/latex ratio and resin/latex ratio, depending on the desired adhesive cost structure. Not surprisingly, too much filler or too little resin and/or oil will result in inferior properties. Excess water will result in slower drying, and probably the need for more water sensitive thickeners. Like many other SBR based adhesives, HSL based flooring mastics include in-can and dry-film preservatives as well as an antioxidant package to ensure long-term performance. 

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