The lamination process

Generally, lightweight foams are produced by a few specialists on specific equipment with customized methods including the addition of blowing agents or gas injection. 

The moulding of expandable beads is commonly used for EPS packaging by some manufacturers. 

The structural foams are more widespread and are processed on less-specific equipment by expansion in situ of blowing agents. 

Syntactic foams are composites made up of micro-balloons or hollow macrospheres bound into a plastic matrix. 

The pentane (or other hydrocarbons) used as the blowing agent is highly inflammable and fire regulations must be considered for transport, handling, storage, processing... 

---

Free mono- and multilayer films may be adhesive- or extmsion-bonded in the laminating process. The bonding adhesive may be water- or solvent-based. Alternatively, a temperature-dependent polymer-based adhesive without solvent may be heated and set by cooling. In extmsion lamination, a film of a thermoplastic such as polyethylene is extmded as a bond between the two flat materials, which are brought together between a chilled and backup roU. 

In the lamination process, films of different materials are bonded using heat and/ or biodegradable adhesives [23, 34]. A metallized film (e.g., from PLA) with high barrier and stiffness can also be laminated on a Ecoflex /starch or Ecovio compound with good welding performance to produce e.g., a stand pouch for detergents. 

The texturing sheet may also contain a plastic coating that transfers to the laminate surface during the laminating process to provide special surface properties. The caul plate itself may be smooth or textured and act directly as the release. Immediately beneath this release sheet, there may be a decorative layer or a ply that imparts special properties such as a metallic foil for electrical conductivity or a static dissipating layer. If the decorative layer is a printed... 

Laminating lends itself to the manufacture of resilient products with a large flat surface area and excellent surface properties. These products can be converted to their final form by thermoforming and insert molding. This method avoids the use of paint with its negative side effects, that is, the influence of solvents on the physical properties of the injection-molded part (tension and plasticizing effect). The lamination process also circumvents the optical problem of flow and weld lines. 

It is known that the resin behaves as an incompressible and Newtonian fluid (7), at least for a significant portion of the lamination process during which resin flow occurs. The Reynolds number of the flow is usually so small that the inertia temis in the equations of motion can be neglected. Also, because the aspect ratio, R/h (h being the thickness of the lay-up), is much greater or greater than unity in our experiments, we assume v, > > v and (dp/dr) > > (dp/dz) w here v, is the lateral velocity (in the r direction), v is the axial velocity (in the z direction) and p is dynamic pressure defined as the pressure above the ambient. Under these conditions, the resin flow satisfies... 

The major application fields of urethane-modified isocyanurate foams lie in budding aj lications, such as warehouses, high-rise buildings and residential houses. In the USA, laminates are one of the major applications of urethane-modified foams. Figure 35 shows an example of the laminate process (72). 

In Japan very large quantities of metal-siding board (consisting of metal sheet/phenolic foam/flexible-facing material) are manufactured as exterior materials in budding construction. This material is also manufactured using the same principle as that in the laminate process. 

In general, very little data have been published on the outgassing properties of the skins for vacuum panels, even though they can contribute, in some cases, in a non-negligible way to the deterioration of the pressure inside the VIP. This can be due to the outgassing properties of the materials used as barrier layers and/or the lamination process, which may introduce volatile substances or trap gases in between the various sheets. 

P(6) Components to be joined shall be correctly supported or clamped during the lamination process to ensure that the required geometrical tolerances are met. 

During the lamination process the excessive use of resin at the bondUne should he avoided. 

However, the application of the model to industrial processes should also consider the complex then processes associated with the polymerization reaction as a con uence of die geome of the laminate, and of the heat transfer from the air and tool to the prepregs. In this case, a simple scaling of DSC results is not sufficient and the kinetic model must be included in a general model considering the characteristics of the lamination process (2). 

Adhesive film n. A thin film of dry resin, usually a thermoset, used as an interleaf in the production of laminates such as plywood. Heat and pressure applied in the laminating process cause the film to bond the layers together. 

Adhesive materials used in vinyl lamination processes are discussed in detail. Characteristics of cold line epoxies and water-based emulsions are discussed. Information is presented on the lamination processes and applying the adhesive. Vinyls most commonly used are said to be Opaque Top Printed Laminate (OTPL)ZKlear View, Opaque Embossed (OE)/Solid Colour Film, Reverse Printed (RP) and Top Printed (TP). 

The aspects of interest concerning the laminates are the relative contributions of the polypropylene and polyurethane layers to tan 6 in the region 4 to 10 K. Any changes that the PP-F layers undergo due to heat or other effects associated with the laminating process must be taken into account in this connection. 

---