Ask Dr. Dan

Q: Why, when I ask for "frosted" acrylic from my current suppliers, can't I get a straight answer? Is this a complex question? What exactly is "frosted" acrylic?

A: Well, it wasn't always a difficult question, but with all the new product introductions from a number of manufacturers the definition of "frosted" products has become blurred. To that end, let me endeavor to set the record straight.

First off, there is no one definition of "Frosted" products which can be created to meet a uniform description of "Frosted" products?

I would say the answer is to break the "Frosted" products down into two categories:

1. Those products with the combination of translucent color throughout the thickness of the sheet combined with a matted surface texture are considered truly "Frosted".

AND

2. Those products which combine transparent colors with surface only matte finish, whether cell cast or co-extruded, are simply "matte finished" products.

The Chart below gives an overview of the products commonly referred to as "Frosted."

To elaborate, in the past what was commonly referred to as "frosted" acrylic was colorless or clear acrylic sheet with one of two types of matte finish. The first matte finish, which was fairly coarse, was called "P80". The second type of matter finish, which is still readily available, is called "P95" and is offered only in cell cast acrylic sheets. The term frosted was coined to describe the amount of light diffusion caused by the matte finish through the clear sheet. In time, several manufacturers also applied this finish to other transparent and opaque colors.

It is important to note that the frosted appearance is only at the surface of these sheets. If you were viewing these products on edge, they still appear transparent or glossy. This is a key part in the confusion.

Additionally, some newer product introductions from Acrilex, Ineos, Elf Autochem, Spartech, and CYRO have created a new element of confusion in the market place.

Acrilex, Inc. produces a frosted series of colors which have a combination of translucent color which is apparent throughout the thickness of the sheet, and also add a matte finish on one side or two to give the illusion of sandblasted glass. This combination of color and finish give a deeper perceived level of frosting. These products are cell cast acrylic only.

CYRO Industries also produces cell cast sheets that match this description, but not on a stock basis. These products are custom only in CYRO's Acrylite GP line of cell cast acrylic.

However, CYRO has recently introduced a new extruded sheet series called "Crystal Ice" which is a coextruded version of what looks like a P95 finish without the need to use special casting cells. This is an alternative to buying domestic cell cast clear or green edge P95 material. Again, this finish option is on the surface only, and at the time of this writing, is offered on only one side of the sheet. The appearance of translucency does not run throughout the sheet thickness.

Ineos Acrylics offers a product called Lucite Myst. This product is extruded acrylic sheet with a translucent color to produce the "frosted" appearance. It is also combined with a "non-glare" finish to more closely resemble the more heavily matted look of a P95 finish, although it is not quite as matted.

Elf Atochem's product "Frosted" Plexiglas utilizes a new combination of resin and filler to produce both the translucent color throughout the sheet thickness and the matte texture, without the need of special extruder rollers or P95 molds. The filler itself causes the matting of the sheet surface. Therefore it is automatically produced with the matte finish on both sides of the sheet.

Finally, Spartech Plastics, offers an impact modified "Frosted" acrylic sheet called Acrylloy. This product is similar to the Elf Atochem product with the exception of being offered only in an impact-modified form. It is available in 100% or 70% impact modified formulations.

With luck, this will help specifiers of plastics to better understand the nature of the appearance of the materials they are specifying, but even more importantly this should help plastic resellers to better understand the nature of the products they are selling.

Written by Daniel A. Rustin, Marketing Manager for Acrilex Inc., manufacturers of Acriglas® cast acrylic sheet.

For more information, or to ask Dr. Dan a question, e-mail him at drustin@acrilex.com or write to "Ask Dr. Dan," Acrilex Inc., 230 Culver Avenue, Jersey City, NJ 07305, 800-222-4680, Fax: 201-333-1237, Web: www. acrilex.com.