Glasses lapping process

Through-holes are only possible in very thin substrates. This process can be combined with other means of structuring glass for example, microsandblasting or ultrasonic lapping (Figure 2.14). 

The roughness of the finished surface is Rz 2-4 pm. Surfaces treated by lapping and microabrasion are similar. In contrast to what happens to photostructured glass, only the areas without a mask are processed the covered parts of the wafer surface remain virtually intact. Figure 2.20 shows various examples of one-sided and doublesided structuring. 

This paper presents results from a study of assemblies composed of glass fibre reinforced epoxy composites. First, tests performed to produce mixed mode fracture envelopes are presented. Then results from tests on lap shear and L-stiffener specimens are given. These enabled failure mechanisms to be examined in more detail using an image analysis technique to quantify local strain fields. Finally the application of a fracture-mechanics-based analysis to predict the failure loads of top-hat stiffeners with and without implanted bond-line defects is described. Correlation between test results and predictions is reasonable, but special attention is needed to account for size effects and micro-structural variations induced by the assembly process. 

Despite the antiquity of filtration processes involving nonwovens, e.g. felts, laps, paper etc. media developmoits continue to appear involving modem fibres prepared from polymers, glass, fluorocarbons, etc. These are used alone, or in mixtures with traditional fibres such as wool, cotton, cellulose, etc., to produce a vast array of media aimed at solid-liquid separation. A detailed listing of the relevant phydcal properties of these fibres is available in the literature jPurchas, 1981]. 

The process of adhesion at the contact zone of two thick films of amorphous high-molecular-weight polymers with glassy bulk has been investigated by means of a lap-shear joint method. The kinetics and temperature dependence of strength a at both symmetric and asynunetric polymer-polymer interfaces have been found to follow the repetition mechanism of chain diffusion and an Arrhenius-like behavior, respectively. A new method to measure the surface glass transition temperature of thick... 

Figure 8.7 Effect of immersion in water at 40 °C on the tensile lap-shear strength of glass fibre reinforced plastic (GRP) substrates bonded with a two-part acrylic adhesive [40]. The surface pretreatment was simply an abrasion/solvent-cleaning process.

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