Adhesive, selection Subject

Table 1 hsts some common types of adhesives and their uses. Because of the different possible substrates and combinations of substrates, and because adhesives are subject to such a range of environmental conditions, it is no wonder that there are so many types of adhesives on the market. However, if one has some knowledge of how adhesives bond to substrates and the types of substrates being bonded, the task of selecting adhesives will not be overwhelming, see also Bonding Pauling, Linus. 

The UV-insensitive Novolak resins are expected to be inert upon exposure. Despite this expectation, the selection of proper Novolak resins is very important for such overall resist performance as lithographic sensitivity, resolution, thermal image stability, adhesion, and so on. The reasons why Novolak resins are so important as resist materials and why specific kinds of Novolak resins are being investigated are the main subject of this paper. 

Typical industrial plastic selection criteria have focused on pin-on-disk tests (involving plastic sliding over steel) and sand slurry abrasion tests. The CMP environment, however, is very different from these typical industrial tests. In CMP, the retaining ring plastic is subjected to a plastic-to-plastic adhesive force component involving the polyurethane pad, chemical attack from the chemicals in the slurry, as well as an abrasive component associated with slurry particles. 

Schematic representations of the typical response of cold-cure epoxies are depicted in Fig. 4.6. Naturally the relative importance of specific adhesive property data depends upon the application and the envisaged loading and environmental conditions that the real joint will be subjected to. Many analysts(32-34) advise that the strength of the adhesive equilibrated with the worst-case environment is the key to effective design. This implies laboratory tests conducted at high temperatures on specimens pre-equilibrated with high levels of water vapour or liquid water. For the application of adhesives to steel bridges in the USA. Albrecht era/.(34) selected a test environment of 49 °C and 90% r.h.

Adhesives in general and structural adhesives in particular are the subjects of much academic interest as well as commercial importance. Structural bonding, as a method of joining, offers a number of advantages over mechanical fastening. However, in order to achieve satisfactory results, the proper adhesive must be selected and the appropriate bonding procedures followed. 

In selecting a cyanoacrylate for a particular application, one of the most important considerations is the environment or surroundings to which the adhesive will be subjected. 

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