According to mechanical theory, adhesion occurs by the penetration of adhesives into pores, cavities, and other surface irregularities of the surface of the substrate or adherend. The adhesive displaces the trapped air at the interface. Therefore, it is concluded that an adhesive penetrating into the surface roughness of two adherends can bond the two. A positive contribution to the adhesive bond strength results from the “mechanical interlocking” of the adhesive and the adherends.
Electrostatic (Electronic) Theory
This theory proposes that adhesion takes place due to electrostatic effects between adhesive and adherend. An electron transfer theoretically takes place between the adhesive and the adherend as a result of unlike electronic band structures. Electrostatic forces in the form of an electrical double layer are thus formed at the adhesive-adherend interface. These forces account for the resistance to separating. This theory gains support from the fact that electrical discharges have been observed when an adhesive is peeled from a substrate.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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