Multilayer Lamination

The stress-strain relations in arbitrary in-plane coordinates, namely Equation (4.5), are useful in the definition of the laminate stiffnesses because of the arbitrary orientation of the constituent laminae. Both Equations (4.4) and (4.5) can be thought of as stress-strain relations for the k layer of a multilayered laminate. Thus, Equation (4.5) can be written as... 

Kymissis et al. have examined the possibility of generation of electrical power parasitically from devices built in a shoe, a wearable subsystem for the soldier. Merits of three different types of piezoelectric devices are compared. They are a unimorph strip piezoceramic composite, a stave of multilayer laminate of PVDF foil, and a shoe-mounted rotary magnetic generator as a part of technology demonstration a piezoelectric embedded shoe has also been postulated to periodically broadcast a digital radio frequency identification (RFID) signal as the wearer walks. 

It has been established that in analogy to Ohm s law the overall resistance to diffusion of a multilayer laminate is given simply by the sum of the separate resistances of the layers (Figure 20.2). For example, the total resistance of skin being composed of stratum corneum, viable epidermis, and dermis may be expressed as... 

Infrared microscopy has become a useful technique for analyzing small samples such as surface defects, forensic samples, or trace contaminents in multilayer laminates [4,26]. The primary advantages of IR microscopy are not only related to improved optical and mechanical design, but also to manipulative capability [26]. 

Thermoformable multilayer laminates are known in the vehicular arts as providing acceptable surface preparation when applied to various automobile components without distorting the quality of the underlying surface or substrate. Multilayer laminates have traditionally been formed in a variety of methods, including (37) ... 

Co-extrusion methods are especially desirable. Multilayer laminates formed by co-extrusion are advantageous economically and generally exhibit improvements in cohesion and adhesion relative to the various layers making up the multilayer laminate. 

Thermoplastic multilayer laminate composed from an outer layer of resorcinol arylate poly(ester)s, a middle layer comprising a polycarbonate), e.g., LEXAN 131, and an inner-tie layer made from ASA or ABS have been described (37). Resorcinol arylate poly(es-ter)s may be understood as an isophthalic terephthalic resorcinol bisphenol A copolymer. 

M.S. Davis, M. Lindway, M.T. Roland, J.A. Suriano, H. Wang, V.H. Watkins, G.S. Zafiris, and H. Zhou, Formable thermoplastic multilayer laminate, a formed multi-layer laminate, an article, and a method... 

The concept of monolithic module design is associated with Argonne National Laboratories [111, 112]. Power density of about 8 kW/kg or 4kW/1 and fuel efficiency over 50% are expected to be achieved with monolithic SOFCs. The monolithic structure started with a co-flow version where the cell consists of a honeycomb-like array of adjacent fuel and oxidant channels that look like corrugated paperboard, as shown in Fig. 42. Multilayer laminates of the active cell components (anode-elec-ttolyte-cathode) are appropriately corrugated and stacked alternatively between flat multilayer laminates in the following sequence anode- interconnection material-cathode. Tape casting [111] and hot-roll calendering [113, 114] are used to fabricate the monolithic structure. A cross-flow version where oxidant and fuel channels are... 

Branebjerg, J., Larsen, U. D., Biankenstein, G., Fast mixing by parallel multilayer lamination, in Widmer, E., Verpoorte, E., Banard, S. (Eds.), Proceedings of the 2nd International Symposium on Miniaturized Total Analysis Systems, Analytical Methods and Instrumentation, Special Issue pTAS 96, Basel, 1996, 228—230. 

Coextrusion produces multilayer laminates in a single process step. Two or more extruders feed different molten polymers into a multi-manifold die which layers them directly, or into a modular feedblock which layers them before feeding them into the die. This is used primarily in the packaging field, to sandwich an impermeable barrier layer between two commodity outer-film layers, and often includes adhesive tie layers to bond the barrier layer to the outer layers. 

Substrate is the material on which the print is applied. Substrates are, for example, glass, tin plate, aluminium foil, paper and board, plastics or multilayer laminates. 

Tin is frequently used in the production of aerosol cans by electroplating it onto sheet steel to improve corrosion resistance and facilitate soldering. In contrast, aluminum is used in its pure form as foil. Often, aluminum foil is used as an impermeable layer in a multilayer laminate that may include paper and plastics as well. Aluminum foil can be formed into rigid containers, semirigid containers, blister construction, or laminates. 

Figure 7. Calculated complex permittivity maps for a three-phase multilayered laminate for different ratios of conductivity in the third (transition zone) and first (soft) phases. For all curves st/s, = 0 and et = e% — es. For s3 = s3 the first and third phases are equivalent and the resulting arc is a semicircle.

Multilayer boards are formed by adding unetched, single-sided laminates on either side of an etched single or multilayer laminate by using an interface of partially cured resin and (usually) glass mats. In the mass-lamination approach, large arrays of boards can be produced, although the technique is usually limited to about ten layers. 

As with trapping, the delivery mechanisms for the pheromones are important. They must be able to provide a nominated dose over an extended period, often under adverse weather conditions. Thus, various slow-release methods have been devised for field use and incorporated into the delivery systems. These have involved the use of hollow fibres as reservoirs which can be applied aerially on to the canopy of plants twisted rope formulations consisting of wire-based sealed polyethylene tubes filled with disruptant that are twisted around the base of plants other polyethylene or rubber tube or polymeric ampullae dispensers, multilayered laminates of acrylic polymer flakes, resin-treated filter paper and micro-encapsulated formulations. 

In addition to internal or external coatings, barrier enhancers can be incorporated into the plastic as additives. These can include various metal oxides, glass fibre, mica, etc. Incorporating a foil ply between layers of plastic is a further way of obtaining excellent barrier properties, e.g. multilayer laminated tubes, cold formed blisters, and additional overwraps should not be ignored. 

The initial design for retort pouches, and the one still used by the military, was a multilayer lamination containing an outside layer of polyester, a layer of aluminum foil, and an inside layer of polypropylene. The polyester provides strength and puncture resistance, the aluminum provides barrier, and the polypropylene provides the sealant and product contact layer. A significant disadvantage of this structure is that the food cannot be heated within the pouch by microwaving. 

Multilayered laminates with an ABS outer layer can be produced by coextrusion. In this process two or three different polymers may be combined into a multilayered film or sheet. Adhesion is enhanced by cooling the extruded laminate directly from the melt rather than in a separate operation after the components of the sheet have been formed and cooled separately. In one process flows from individual extruders are combined in a flow block and then conveyed to a single manifold die. All the polymer streams should have approximately the same viscosity so that laminar flow can be maintained. 

The article has 3 layers A-B-A. The layer B is so designed that it has heat distortion temperature higher by at least 3°C than layer A (in the example given in the table, heat distortion temperatures for A and B are 68 and 83°C, respectively). The multilayer laminate is produced by coextrusion and shaped by thermoforming. 

In PEN/PET multilayer laminates, this property results in uneven thickness, opaqueness, and poor strength for the oriented PET layer due to a reduction in strain hardening during the stretching of PET at the higher temperatures. 

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