Adhesion consolidation

Natural and synthetic resins are organic compounds easily found in art objects either as varnishes and protective coatings or binding media, adhesives, consolidants and finishing layers. They are mainly used in manufacturing paintings, but also in pottery, furniture and wooden objects, sculptures, musical instruments and works on paper. In addition, natural and synthetic resins have widespread use as conservation materials. 

Dry When a liquid dries to form an adhesive, consolidant or coating, it sets as a result of loss of solvent. ... 

Adhesive-Coated Material. The addition of an adhesive-coated material [335] to proppants decreases the flowback of the particulates. Such adhesive-coated materials can be inorganic or organic fibers, flakes, and the like. The adhesive-coated material interacts mechanically with the proppant particles to prevent the flowback of particulates to the wellbore. The consolidation of a proppant also may occur via a polyurethane coating, which will slowly polymerize after the fracturing treatment because of a polyaddition process [1856]. 

Injecting epoxy, furan, or furan-formaldehyde resins into poorly consolidated formations to consolidate them was a common sand control practice for thin highly productive formations (44-46). Organic solvents (46) and silane coupling agents (47) are used to promote adhesion of the resin to the rock surface. Excess resin is flushed deeper into the formation to minimize resin hardening in the flow channels since this would reduce formation permeability. 

C.V Horie, Materials for Conservation, Organic Consolidants, Adhesives and Coatings, Butterworth Heinemann, Oxford, 1987. 

Each painter had his own technique the binding medium was thus prepared using different additives, giving rise to a variety of recipes for each technique. For example, it is believed that fig latex (a white liquid exuded by the fig tree) was commonly added to the egg tempera, and that animal or plant resins were added to oil- and wax-based binders. On account of their adhesive properties, these materials were used not only as paint binders, but also as consolidants in restorations, as ingredients in varnishes used to finish paintings, and as ingredients of mordants to apply metallic leaf decorations. 

Organic substances can be identified both as the main constituents of an artwork or a cultural heritage object, and as secondary components, mixed with inorganic compounds. Organic materials can be found in the finish or decoration of the surfaces, or as residues of commodities, such as in ceramic or glass vessels. Moreover, the majority of restoration products applied as consolidants, adhesives, restoration paints and varnishes are of an organic nature. 

Similar to cleaning operations, consolidation and adhesion treatments are usually under analytical control. Measurements of the chemical, morphological, and physical properties of the consolidated material are indispensable to assure the efficiency of the operation. Changes in mechanical strength, color, and gloss, as well as chemical composition are assessed. Studies of stability of consolidants are frequently performed by means of namral and accelerated aging trials. 

When it announced the acquisition of Solutia s resins, additives, and adhesives business in December 2002, UCB surprised analysts as well as employees, who were all expecting an acquisition in pharmaceuticals rather than in chemicals. The acquisition, however, was not completely opportunistic. UCB Chemical s business development department was continuously on the lookout for value-creating opportunities to give the business more critical mass in an industry where suppliers and customers were rapidly consolidating, which made a concentration wave in the resins industry inevitable over time. In this context, the acquisition was a clear no-regret move the acquisition price was attractive and could easily be financed by UCB, and there were many complementarities as well as synergies. In addition - and as clearly stated at the time - the increased scale created more options for the future, including a possible spin-off or divestment. 

Many wood species, both hardwoods and softwoods, are used for particleboard however, the density of the particleboard should be higher than the density of the raw material to efficiently utilize the adhesive system. The compression of the particles, which is required for consolidation into the finished product, enhances the particle-particle contact, producing more inter-particle adhesive bonds as well as reducing the total void volume in the panel. With wood of density higher than the finished particleboard, the compression of the particles is lower and the resultant reduced interparticle contact and higher void volume adversely influence the physical and mechanical properties of the parti cleboard. 

As the continuous ribbon is conveyed from the forming station it may or may not be consolidated by a cold press. This prepressing operation reduces the mat thickness and increases the mat density which improves the handling characteristics of the mat, but does not initiate adhesive polymerization. The continuous ribbon is also trimmed to width and cut into individual mats, the length of which is equal to the length of the hot press. The individual mats are placed in the press loader which serves as a temporary storage area for the mats prior to hot pressing. 

Pressing Operation. The consolidation of the particle mat and polymerization of the adhesive to produce a particleboard panel is accomplished in a hot press. The mat is compressed and held at the desired thickness until the adhesive on the particle surfaces has polymerized and established adequate bridges between particles. The panel is then removed from the press, cooled, and sent to the finishing phase. 

Barly findings from this work were published in the Paris Conference proceedings of the XXC on Adhesives and Consolidants (13). This paper gave examples of the results obtained with different acrylic and methacrylic monomers. The monomers were selected because they had suitable physical characteristics and were already used in conservation work. The problems which occur with aged and woody based papers were highlighted. This paper also indicated that the use of certain solvents such as methanol to improve monomer penetration had a detrimental effect on the strength of the paper, in particular its fold endurance. 

Particleboards are composed of discrete particles of wood bonded together by a synthetic resin adhesive, most commonly urea-formaldehyde or phenol-formaldehyde. The material is consolidated and the resin cured under heat and pressure. The strength of the product depends mainly upon the adhesive and not upon fiber... 

The results presented in Table III show that only the treatment with cotton fibrils (3.5% add-on) improved the tensile strength (13% increase), whereas the other treatments weakened the fabrics. Add-ons obtained with the CMC and fibril-adhesive mixtures were extremely high, ranging from 24.5 to 72.0%. The affinity between substrate and consolidant in these cases was very poor. 

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