Laminate, high-pressure decorative

In small pieces or as inserts, laminates may be used unsupported because they are quite stiff and strong. The modulus of a high pressure decorative laminate is about 7 GPa (106 psi) at room temperature. Thick laminates range up to 25 mm and are very strong, having flexual strength of 130 MPa (19,000 psi). These products are used unsupported as toilet partitions, laboratory tops, and so forth. 

The properties of standard grades of high pressure decorative laminates manufactured are shown in Table 1. Tables 2 and 3 show properties of industrial laminates (12,13). 

General-purpose type is a high pressure decorative laminate (HPDL) designed for both horizontal and vertical appHcations where appearance, durabiUty, resistance to stains, and resistance to heat up to 135°C (275°F) are requited. 

In addition to the S, F, and P types of high-pressure laminate considered so far there are several variants worthy of special mention—some admittedly outside the scope of BS EN 438 but which nevertheless could be described as high-pressure decorative laminates, as follows. 

Formica f6r- ml-k9, f9r-. A trademark of the Formica Corporation for high-pressure, decorative laminates of melamine-formaldehyde, phenolic and other thermosetting... 

Decorative laminates are standardized in NEMA publications LD3, High Pressure Decorative Laminates, and LD3.1, Performance, Applications, Fabrication and Installation of High Pressure Decorative Laminates. 

LD-3 Codes, High-Pressure Decorative Laminates, Washington, DC, NEMA, 1985. 

The most commonly used reinforcement for high pressure decorative and industrial laminates is paper (qv). The strong substrate layers, or filler, are kraft paper. Kraft is a brown paper made from a sulfate pulp process (8). It consists of both short cellulose fibers from hardwoods and long fibers from conifers. The long fibers impart most of the wet strength required for resin saturation processes. 

Amino Rosins. Amino resins are the reaction product of an aldehyde with a compound containing an amino (—NH2) group (see Amino Resins). Both urea and melamine react with formaldehyde, first by addition to form methy-lol compounds, and then by condensation to form cross-linked polymers through methylene bridge and methylene ether formation. The cross-linking reactions are exothermic and produce water and formaldehyde as volatile products in reactions similar to resole phenolics, illustrated in equation 3. Urea-formaldehyde and melamine-formaldehyde account for the bulk of the amino resins. Their characteristics include water solubility and unlimited colorability with dyes and pigments. Applications include decorative high pressure phenolic laminates, adhesives in the laminated wood and furniture industries, and as an additive to textile fabrics to impart wash and wear properties. 

In the past, the term high-pressure laminates was reserved for melamine and phenolic impregnated papers or fabrics compressed under high pressures (about 13.8 to 34.5 MPa, or 2,000 to 5,000 psi). They were heated to form either decorative laminates (for example Formica and Micarta) or industrial lami-... 

When describing in more detail the characteristics and methods of manufacture of laminated sheet materials of different types it is helpful to use the classifications below, each of which is covered by a British Standard High-pressure laminates Decorative continuous laminates Direct-faced boards Composite boards. 

BS EN 438 1991 Decorative high-pressure laminates (HPL)—Sheets based on thermosetting resins, Part 1 Specifications Part 2 Determination of properties. 

TM for high-pressure laminated sheets of melamine and phenolic plastics for decorative applications such as surfacing, adhesives for bonding laminated plastic to other surfaces. 

Surface Materials high-pressure laminates foils and printed paper, all for paper-based decorative surfaces (the Surface Materials division was divested in 2000). 

Melamine is a strong organic base, which is used primarily to produce melamine resin, which when combined with formaldehyde produces a very durable thermoset plastic. This plastic is often used in kitchen utensils or plates (often sold under the brand name Melmac), and is the main constituent of Formica and Arborite . Melamine tile wall panels are known as whiteboards. Melamine is also used to make decorative wall panels and is often used as a laminate. Melamine is produced from urea, mainly by either of two methods catalyzed gas-phase production or high-pressure liquid-phase production. 

As many as a dozen or more layers are piled up. For decorative purposes a printed rag or decorated cloth paper is put on top and covered with a translucent paper layer. The entire assembly is heated between smooth plates in a high-pressure press to carry out the thermosetting (curing) reaction that binds the sheets together into a strong, solvent-resistant, heat-resistant, and scratch-resistant surfacing material. The laminate, which is only about 1.5-mm thick, can be glued to a plywood base for use in tabletops, countertops, and the Kke. 

Kraft paper is widely used as a reinforcement. When saturated with phenolics, it is made into a common printed wiring board. When combined with melamine, it becomes a decorative high-pressure laminate used in furniture, countertops, and wall panels. Paper reinforcement is inexpensive and easy to machine, drill, and pxmch. It imparts good electrical properties, but it is sensitive to moisture and cannot withstand high temperatures. 

See also continuous laminate decorative laminate high-pressure laminate electrical laminate. 

Here, strips of decorative materials (high-pressure laminates, PVC, wood veneers), 15 to 25 mm wide, must be bonded on the sides of a panel, which is already laminated with the same decorative material. 

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