Thin clamping

Adhesive bond line too thin Clamping pressure too high Lessen pressure... 

Adhesive bond line too thin Clamping pressure too high Curing temperature too high Starved joint Lessen pressure Use lower curing temperature Apply more adhesive... 

Wan KT, Mai YW (1995) Fracture mechanics of a shaft-loaded blister of thin flexible membrane on rigid substrate. Int J Fract 74(2) 181 Wan KT, Guo S, Dillard DA (2003) A theoretical and numerical study of a thin clamped circular film under an external load in the presence of a tensile residual stress. Thin Solid Films 425(1-2) 150... 

Let us consider a thin homogeneous isotropic beam of thickness 2s. We assume that the beam mid-line coincides with the segment (0,1) of the axis X. At the point y = 1/2, the beam has an inclined cut as a segment having the angle a with the vertical line, 0 < tana < 2e). We look for the function % = (W, w) of horizontal displacements W(x) and vertical displacements w(x) provided that the external forces g(x),f(x) are given. The condition of clamped edges... 

Acoustic Measurements. Measurement of the propagation of ultrasonic acoustic waves has been found useful for determining the viscoelastic properties of thin films of adhesives. In this method, the specimen is clamped between transmitting and receiving transducers. The change in pulse shape between successive reverberation of the pulse is dependent on the viscoelastic properties of the transmitting material. Modulus values can be calculated (267,268). 

The membrane system consists of multiple plate and frame stacks holding the thin-fHm composite membranes clamped together. The system capacity is iacreased by increasing the number of plates. 

Rupture Disks A rupture disk is a device designed to function by the bursting of a pressure-retaining disk (Fig. 26-15). This assembly consists of a thin, circular membrane usually made of metal, plastic, or graphite that is firmly clamped in a disk holder. When the process reaches the bursting pressure of the disk, the disk ruptures and releases the pressure. Rupture disks can be installed alone or in combination with other types of devices. Once blown, rupture disks do not reseat thus, the entire contents of the upstream process equipment will be vented. Rupture disks are commonly used in series (upstream) with a relief valve to prevent corrosive fluids from contacting the metal parts of the valve. In addition, this combination is a reclosing system. 

Another common shape which is moulded is a thin rectangular strip. Consider the centre gated strip as shown in Fig. 4.41(b). In the same way as before the clamping force, F, is given by... 

The specimens are clamped at an angle of 15° to the vertical in a baffled enclosure maintained at 50°C, and the exposure time is 24-96 h. Corrosive attack of inadequately sealed or thin films is shown by pitting. 

Vacuum forming has limitations due to the non-uniform wall thicknesses of its products. As the sheet is drawn into the mold, its thickness decreases, especially in the corners. For this reason, just as in blow molding, we design vacuum formed products to have rounded corners. If the depth of the cavity is excessive, walls can become locally so thin that they are unacceptably weak. One strategy that we use to alleviate this problem is to pump air into the cavity after the sheet has been clamped. This inflates the sheet, pushing it upwards and expanding its area approximately uniformly. When we subsequently apply a vacuum the expanded sheet is drawn back down into the mold. The finished product has a more uniform wall thickness than if we had applied the vacuum directly. 

We use plug assisted thermoforming when we wish to make thick-walled products or thin-walled, deep draw products. The principal steps of the process are illustrated in Fig. 16.2. The first two stages are similar to those of vacuum forming. Once the sheet has been clamped, a plug made from a material with low heat conductivity is thrust downwards into the cavity,... 

The final clamping action forces rubber through the sprue holes leaving a thin (0.13-0.25 mm) transfer pad. The mould is designed with load springs to break open the plates and to help support the top plate and plunger when bottom injection is used. 

A round-bottomed flask (capacity 1 1.) is provided with a wellfitting thin-walled double neck attachment (Eig. 30). An ascending Liebig condenser is clamped obliquely and its inner tube is joined by a short wide rubber tube to the oblique neck in such a way that the flask can be vigorously shaken without trouble. The upright neck, which serves for the introduction of the zinc dust required for the reduction, is closed with a cork. 

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