Most of a dragonfly's life is spent in the larval stage where it molts from six to fifteen times. Depending on altitude and latitude, larval development varies from the common one or two years to as many as six years.
HOME. OPS (Biaxially Oriented Polystyrene Sheet) is a thermoformable sheet produced by stretching polystyrene in two directions, lengthwise and crosswise. OPS can be used widely for transparent containers such as lids, trays, and foldable food containers because it has high transparency, rigidity and hygiene.Manufacturing Process of OPS Applications of OPS Most of OPS are used for food packaging containers such as food packs, trays, lids and fruit containers.PS can be used widely for transparent containers such as lids, trays, and foldable food containers because it has high transparency, rigidity and hygiene. Manufacturing Process of OPS Applications of OPS Most of OPS are used for food packaging containers such as food packs, trays, lids and fruit containers.
Polystyrene, which already had been invented, was a good insulator but too brittle. McIntire tried to make a new rubber-like polymer by combining styrene with a volatile liquid called isobutylene under pressure. The result was a foam polystyrene with bubble, and was 30 times lighter than regular polystyrene. The Dow Chemical Company introduced Styrofoam products to the United State in 1954. How Are Foamed Polystyrene or Styrofoam Products Made. Foamed polystyrene starts as small spherical beads that contain an expanding agent called hydrocarbon.