Mechanical clamping

For in-mould decoration or in-mould labelling, a decorated film or printed label is precisely located in the empty mould. The molten plastic then adheres onto the film or label during injection. Film is mechanically clamped. The label can be fixed in the mould by electrostatic charge. 

Other factors, such as mechanical clamping, damping in the electrical circuit, and temperature also affect the absolute accuracy. For this reason it is necessary to use calibration curves for quantitative work. In spite of these limitations, the quartz microbalance is an extremely sensitive and versatile sensor. 

Other common means for determining the direct d33 coefficients of bulk samples include Berlincourtstyle approaches. Berlincourt meters are available commercially from several sources. In most cases, the sample to be measured is mechanically clamped between jaws with pressures on the order of a few N. The charge output due to a small mechanical oscillation (forces 0.1-0.3N) is then determined. It is important to note that this technique is appropriate for measurements of bulk samples with stable domain states, only. Measurement accuracy is also better when highly resistive samples are used. 

As a final note on this section, whichever method is used, it is also necessary to consider how the pyroelectric is mechanically mounted in the system. Any mechanical clamping (such as bonding the material to a substrate of different thermal expansion coefficient) can lead to spurious currents due to changes in the stress on the sample, coupling via one or more of the piezoelectric coefficients. 

Only very few studies with alternative materials and fabrication methods have been published. Ekstrom et al. [35] demonstrated the feasibility of structuring inexpensive polymeric materials by means of a microfabricated master for the production of microchannel systems. The structured polymer film was mechanically clamped between two glass plates to form a closed channel system. Recently, a similar route for the fabrication of microchannel chips that relies on casting of an elastomeric polymer material against a microfabricated master has been presented by Effenhauser et al. [36] (see Sect. 3.4). 

The permeability is also affected by stress the induced change decays logarithmically with time as a form of disaccommodation. Inductors are usually made in two parts so that the winding can be introduced on a bobbin the parts must then be joined closely together to prevent the permeability from being affected by an uncontrolled air gap. If a mechanical clamp is used, the force must not be excessive and must be the same in similar units. Its effect must be allowed to decay before the inductance value is finally adjusted. 

Thin films with a thickness of 50 pm of a commercially available PS-PB-PS triblock copolymer (e.g. from BASF, 74% PS, 26% PB) are prepared by solution casting from a 3% solution in toluene onto TEFLON -foil, which is placed in a precleaned petri-dish. The solvent is slowly evaporated over a period of 2 weeks. Residual solvent is then removed and films are annealed under reduced pressure in a vacuum oven at 120°C (48 h). Finally, the films are removed from the support and are uniaxially stretched at a constant strain rate of 0.1 s 1 beyond the yield point at room temperature. ARM investigations are carried out on prestretched samples that are mechanically clamped or fixated by double-sided sticky tape onto the AFM sample holder. 

For movement of the hand/arm, two hands are better than one. Using two hands takes more time and effort, but more is produced so cost/unit is lower. When one hand (generally the left) is acting as a clamp, consider it as idle and use a mechanical clamp instead. 

Several techniques can be used for the clamping unit (1) hydraulic clamps, in which the hydraulic cylinder operates on the movable parts of the mold to open and close it (2) toggle or mechanical clamps, in which the hydraulic cylinder operates through a toggle linkage to open and close the mold and (3) various types of hydraulic mechanical clamps that combine features of (1) and (2). 

A manufaeturer of high-speed printers also requires 5 min of assembly time before fixture occurs in a 10 mil shimmed bondline gap. In this application, a number of ferrite magnets are bonded to metal frames and assembled in the proper geometrical arrangement in one step. This adhesive process replaees a combination of mechanical clamps, spacers, and holding screws. 

The sprayed anodes are widely used in the United States for impressed current cathodic protection. Originally, the mesh anodes were mechanically clamped to the pile. In later versions, a GRP jacket containing the zinc mesh is attached to the pile and filled with gront after connecting the zinc to the reinforcement (Figure 7.6). All these systems and their performance in Florida are discussed in Kessler et al. (1995, 2002). 

To perform the mold movements, the clamping unit needs a drive mechanism. Two fundamentally different systems are used as drives. There is thus a basic distinction between mechanical clamping xmits and hydraulic clamping units. 

The TM ions usually used for passive g-switching of infrared solid-state lasers include Cr" " (940-1100 nm range), (1.30-1.35 pm), and Co " (1.3-1.6 pm). Although aU these ions can be doped in cubic materials, i.e., Cr and in garnets and Co " in spinels, only Cr YAG ceramics have been reported for ceramic SA g-switches [37, 42, 132, 133]. The SA materials are usually used as components together with the Nd laser-active materials in the cavity. In this case, if the laser materials and the g-switch materials have a same host, such as Nd YAG lasers passively g-switched with Cr" YAG, the difference in refractive index between them should be very small, so that there is no reflection at the interface when the two materials are intimately joined. For single crystals, they can be either diffusively bonded or mechanically clamped. In contrast, when one or both of them... 

Examples of good preventive maintenance activities include (1) establish the frequency of lubrication and what types of oil or grease must be used (2) check for oil leaks and have a procedure to correct/eliminate them (3) check heaters, thermocouples, pressure transducers, and so on (4) set up schedules and procedure to clean machines and molds/dies (barrels, screws, sliding mechanisms, clamps, etc.) (5) check control circuits (electrical, hydraulic, mechanical, etc.) (6) schedule checks of conditions wherever questions of alignment, level, parallelism (mold parts, mold press, die system, etc.), and other similar situations exist (7) set up a schedule to check safety devices on all equipment and (8) schedule sessions to repeat instructions on safety equipment procedures to all personnel. Figure 11-8 shows where accidents usually occur (324, 325). 

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