11-09-1992 Council Packet - Laserfiche WebLink

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about the other plastic foams Plastic foams and plastic foam products'have mul tiplied since Dow introduced STYROFOAM brand products back in the 1940 ’s. Besides polystyrenes, many other chemicals are now foamed into everyday items. Among these are polyethylenes, polyurethanes, latexes, and even silicones. New foaming processes have been developed. \\S MOLDED PRODUCT -,i_J Molded polystyrene products are formed in molds. Here, the two halves of a mold are opening to eject the product. MOLD OPENS TO EJECT PRODUCT cups, chests, coolers, et al Easily, among the most ubiquitous plastic foam products in today ’s American lifestyle are cups and coolers. Convenient, disposable, and inex pensive, they keep the coffee hot, the lemonade or food cold. Millions are used each year. These products are made by molding expandable polystyrene beads. Each bead is about the size of the ball in a ballpoint pen. Each holds a bit of entrapped gas, a blowing agent. To make a molded polystyrene product, preex panded beads are poured into a mold of the size and shape desired. Heat is applied. The gas ex pands, and the beads swell to fill the mold. There is just enough melting to fuse the beads together, giving the product solid form. This molding process, using beads of different sizes, yields a multitude of familiar items. Among them are cups, ice chests and picnic coolers, wig forms, swim ming pool float boards, and tight-fitting shipping cases fo ’' cameras, TV sets and other fragile goods. Boards and panels of “headboard ” insulation also are made this way. But NO products molded from beads carry the trademark STYROFOAM. Nor can STYROFOAM brand plastic foam be used in a molding process. So the trademark STYROFOAM should not be used in relation to these products. This photograph shows the structure resulting from molding expandable beads. •> thermoforming Thermoforming is ths process used to produce such plastic foam articles as egg cartons, meat trays, and disposable picnic plates. In thermoforming, a thin sheet of flexible polysty rene foam is ted into a press and heated, making it more flexible and susceptible to forming. Next, the sheet is placed between dies which stamp shut to form the desired shape. Finally, the formed items are removed and trimmed. But NONE of the thermoformed products carry the trademark STYROFOAM. Nor can STYROFOAM brand plastic foam be used in the thermoforming process. So the trademark STYROFOAM should not be used in relation to these products. in-place foaming In-place foaming, cavity-fill foaming, and spray-on foaming are variations of the same technique for producing plastic foams. Most commonly, this technique involves mixing two liquid chemicals which react to form the plastic foam. Chemically, most foams made this way are urethanes. In-place foaming is used to make such articles as lightweight decorative “beams ” having the look of old timbers when stained. For this, the chemiceils are poured into a mold of the desired shape and dimension. The chemicals react to form the foam, which fills the mold and solidifies. Spray-on foaming is used to apply insulation to industrial storage tanks and similar structures. In this procedure, the two liquids are piped to a common spray nozzle, where they begin to mix ' and react — and form the foam as the spray hits the surface being insulated.