Adhesives continued

Because of their ease of use and their cost-effectiveness relative to other methods of assembly, pressure sensitive adhesives continue to penetrate all kinds of industrial applications. Some of the main reasons PSAs and PSA coated articles are prime candidates for industrial applications include the following ... 

The most prominent wood adhesives used over the last quarter of a century have been aminoplast and polyphenolic types (2). In the United States, polyphenolic adhesives continue to be predominantly used for production of weather-resistant wood products, such as structural plywoods and flake boards (3). Phenolic resin prices have increased over the past decade, generally paralleling phenol prices. This increase has occurred in part due to a continuing erosion of United States phenol manufacturing capacity and the corresponding increase in availability of phenol from other countries. Any significant increase in the price of oil (the source of phenol) itself or interruption in supply will only compound the problem and raise phenol prices even higher. 

Phenolic adhesives continue to be the most significant adhesives for the production of weather-resistant wood products. The energy crisis of the seventies, the cost of phenol, and the inevitable decline in petroleum reserves have caused the wood industry to focus attention on obtaining adhesive self-sufficiency (1). This concern arises primarily from the questionable longterm availability of resins and secondarily from the economics of adhesive resin use. Ready availability of adhesive resins is critical to the manufacture of bonded wood products. In practical terms, this means that new adhesive systems are needed in which part, or perhaps all, of the petroleum-derived phenolic component is replaced... 

Because the reaction between isocyanates and polyols continues for many days after lamination (i.e. the adhesive continues to cure), it is crucial to test laminates for residual isocyanates and for PAA release in a realistic manner. This must not be sooner or later than food packaging would conunence. One must also use realistic pre-test storage conditions for the film (especially with respect to temperature and humidity). Indeed, many laminators routinely determine the extent of the cure of the adhesive over time. Only when a predefined level of cure has been reached can a laminated film be considered to be ready for packaging food. 

Adhesion is due to van der Waals interaction with the surface, and, while polyparylene films exhibit excellent chemical stability, poor adhesion continues to be a major technological problem and limitation. Surface modification techniques, which result in covalent interaction between the polymer film and the surface, might greatly improve adhesion and hence render polyparylene films more protective. 

Id meet to qualify and assure a reliable part. This assignment, undertaken by NASA MSFC in 1974, led to the first document for the procurement of adhesives to be used in hybrid microcircuits. After further coordination and revisions, this initial document was formally released as a specification in 1978 and revised in 1982 as NASA MSFC-SPEC-592, Specification For The Selection and Use of Organic Adhesives in Hybrid Microcircuits." For the first time, the critical requirements for ionic contaminants, electrical resistivity, die-shear strength, corrosivity, and outgassing were specified. Work on the development and evaluation of adhesives continued into the mid-1980s and, as a result, several commercially available adhesives were qualified." ... 

The importance of acid-base interactions in adhesion continues to attract several researchers, however, still there seems to be a lack of consistency in the approaches as stated by K. L. Mittal in the Preface of [19]. It is hoped that Round Tables will be organized in order to define common strategies for polymers, fillers, fibers, etc. which will permit inter-laboratory comparison. 

The instant-fix solidification of Sikaflex -630 allows just-in-time production and packaging of the headlights, while fiorther cross-linking of the adhesive continues during subsequent storage and transport. 

One-Part Epoxy Paste Adhesives - continued. Epoxy Adhesives - Comparison Tabies 151... 

Thus, even though the blow-off pressure does not stay constant as the blister grows, Eq. (29), measured values can be employed with corresponding values of the blister height to calculate the strength of adhesion continuously no other parameters are needed. 

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