摘要:
A method of forming a plastic material by using a mold 30 that has a split-mold structure forming air vent 39 in the split surfaces which are the butt surfaces of split molds, the air vent 39 being communicated with gas passages 37, wherein a resin is fed into the mold 30 so as to be formed, and after the formed article is taken out from the mold but before the rein is fed into the mold 30 so as to be formed in the next cycle, a cleaning gas G is fed through the gas passages 37 into the air vent 39 in a state where there is formed at least part of the mold 30 inclusive of the air vent 39, the cleaning gas G being discharged through passages separate from the gas passages 37. The method is capable of effectively preventing the oligomers from building up in the vent groove and, therefore, automatically executing the cleaning without the need of halting the forming cycle.
摘要:
A composite foamed container forming, in the body portion 23, thereof, a foamed region in which foamed cells 1 are distributed, the foamed region including a first gradationally foamed region A having a gradational distribution of the foamed cells of which the length L in the direction of maximum stretch gradationally decreasing from the outer surface side of the body portion 23 toward the inner surface side thereof and a second gradationally foamed region B having a gradational distribution of the foamed cells of which the length L in the direction of maximum stretch gradationally decreasing from the inner surface side of the body portion 23 toward the outer surface side thereof. The container has a large resistance against the pressure exerted on the outer surface, good liquid-dispelling property and, at the same time, has improved appearance and heat resistance.
摘要:
A plasticizing process in which a molten resin that has been plasticized and dissolved in a foaming gas is sent to the front end side of a heating cylinder 20 by means of a screw 21 that rotates in a heating cylinder 20, and the screw 21 retreats according as the molten resin accumulates in the front end side of the heating cylinder 20; a transfer process in which the screw 21 is advanced with rotating and transfers the molten resin accumulated in the front end side of the heating cylinder 20 from a plasticizing unit 2 to an injection unit 3, and an injection process in which the molten resin is injected from the injection unit 3 are conducted and repeated to produce a foamable injection molded product. By this method, in injection molding of a foamable injection molded product dissolved in a foaming gas such as an inert gas, plasticization of a raw material resin and impregnation of a plasticized molten resin with a foaming gas in a molding cycle can be improved, whereby productivity can be improved.
摘要:
A foamed and stretched plastic bottle having, in the body portion thereof, a foamed region in which foamed cells are distributed, wherein, in at least a portion of the foamed region, the lengths of the foamed cells in the axial direction of the bottle are so distributed as to gradually decrease as the positions of the foamed cells shift from the outer surface side of the body portion toward the central portion thereof and then gradually increase as their positions shift from the central portion thereof toward the inner surface side thereof. The foamed and stretched plastic bottle of the invention exhibits excellent light-shielding property.
摘要:
A stretched and foamed plastic formed body forming, in at least a portion thereof, a foamed region which incorporates foamed cells therein, wherein the foamed cells have a flat shape with a maximum thickness of not more than 30 µ m and an average aspect ratio of not less than 4 as viewed in cross section of the formed body perpendicular to a direction in which the formed body is stretched to a maximum degree, and a non-foamed plastic skin layer having no foamed cell distributed therein is formed on the outer surface of the foamed region. The formed body is, further, blended with a non-lustrous pigment as the coloring agent, which is different from a lustrous pigment such as flaky pigment, and exhibits a metal color over the foamed region thereof. The foamed formed body exhibiting a metal color and, specifically, a gold color or a silver color is thus provided without using any expensive lustrous pigment such as metal powder pigment or flaky pigment.
摘要:
A foamed and stretched plastic container having a basic structure which includes a mouth portion and a body wall continuous to the mouth portion and is stretch-formed, the body wall forming a foamed region where foamed cells are distributed, and the mouth portion being an unfoamed region where no foamed cell is present, wherein the foamed cells present in the foamed region have a flat shape being stretched in the direction of stretch, and the foamed cells positioned in the central portion in the direction of thickness of the container wall have the largest lengths in the direction of maximum stretch.