Source from :http://www.ehow.com/
Melamine Sheets Vs. Plastic Laminate
By Arlene Miles
Melamine sheets and plastic laminate are sometimes used interchangeably when referring to surfaces used in construction and remodeling of items such as cabinets, housing for electronics and some types of furniture. More accurately, melamine sheets often form one of the layers of plastic laminate, which is typically bonded together with particleboard or another backing material.
Low Pressure Laminate
Also called low pressure or direct pressure laminate, melamine is manufactured under 300 to 500 pounds of pressure per square inch. It gets its name from the melamine resin that is used to saturate the layers of paper transformed into a solid, plastic surface through thermal fusion. Melamine, when bonded with plastic laminates, is the surface that gives products such as Formica its decorative look.
On its own, melamine is softer and more prone to dents and gouges than plastic laminate. The biggest complaint is that when made to resemble wood, melamine obviously looks fake. Because it is normally attached to particleboard that easily warps, melamine is not good for applications where water is involved. Particleboard also has voids in the end grain, necessitating what is termed “edge banding” with melamine to cover this area.
What is Plastic Laminate?
At its simplest, plastic laminate is multiple layers of kraft paper soaked in plastic resin. It is manufactured under 1,400 pounds of pressure per square inch, more than three times what is used to make melamine sheets. Plastic laminate comes in three different grades: general purpose, vertical surfacing and post forming. It is adhered to a substrate with contact cement, the substrate being most commonly particleboard. Medium-density fiberboard, however, as well as plywood are also commonly used.
How is Laminate Manufactured?
Four steps are involved in the manufacture of plastic laminate. The first involves soaking strips of paper used with plastic resin. The desired thickness of the paper determines how many sheets are used. These sheets are placed into a drying chamber. Afterward sheets are set in layers with decorative layers placed on top of simple kraft layers before thermosetting, the process by which laminate is manufactured. In the final step, plastic laminate is cut into desired sizes.
Laminate finishes often determine how it used. Patterns or finishes, however, are often specific to the end-use type. Those with a matte or fine-matte finish are often used as countertops, which are often custom made by the manufacturer. Vertical grade laminate is usually used for cabinets or other surface that do not require much human touch. Post forming laminate is flexible and is used for curved or rolled substrates. Thinner plastic laminate is also used to save photographs and other documents.