Bonding processes rework

In general, hot-melt adhesives are in solid form at temperatures below 79°C, and as the temperature is increased beyond this point, the solid adhesive material rapidly melts to a relatively low-viscosity fluid that can be applied easily. Upon cooling, the adhesive solidifles rapidly. Since these adhesives are thermoplastics, the melting/resolidiflcation process is repeat-able with subsequent heating/cooling cycles. Consequently, these adhesives allow reworking of the bonded parts, when necessary. Typical application temperatures of hot-melt adhesives are 149-188°C. 

Defective products due to malfunctioned parts bonded adhesively or to inappropriate adhesion are very bad in terms of environment protection because they become a waste without any use. Therefore, dismantlable adhesive can be used to avoid the situation because bonded parts or inappropriate bonded areas can be separated in order to be repaired. This process is called reworking of defect products and involved in the processes of reducing wastes and reusing other nondefective parts in terms of 3R. This topic will be discussed in more detail in O Sect. 58.4. 

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