A mold for extrusion molding includes an extrusion port and a plastic channel. The extrusion port is configured to extrude a plastic composition containing at least one kind of plastic. The plastic channel is configured to cause the supplied plastic composition to flow to the extrusion port. The plastic channel includes a first channel, a second channel, and a third channel. The second channel is connected to the first channel and has a channel cross-sectional area gradually decreasing downstream in a flowing direction of the plastic composition. The third channel is connected to the second channel and configured to cause the plastic composition to flow to the extrusion port. The third channel has a channel cross-sectional area gradually decreasing downstream in the flowing direction of the plastic composition.

This disclosure describes co-extruded multilayer articles including at least one continuous layer and one discontinuous layer, as well as systems and techniques for the manufacture of co-extruded multilayer articles. For example, a co-extruded multilayer article is described that includes a body having a plurality of layers, where a first layer of the plurality of layers is formed from a first material and is continuous along a longitudinal axis of the body, and a second layer of the plurality of layers is formed from a second material and is discontinuously co-extruded along the longitudinal axis.

This disclosure describes co-extruded multilayer articles including at least one continuous layer and one discontinuous layer, as well as systems and techniques for the manufacture of co-extruded multilayer articles. For example, a co-extruded multilayer article is described that includes a body having a plurality of layers, where a first layer of the plurality of layers is formed from a first material and is continuous along a longitudinal axis of the body, and a second layer of the plurality of layers is formed from a second material and is discontinuously co-extruded along the longitudinal axis.

It is an object of an embodiment of the present invention to provide: a poly(3-hydroxybutyrate)-based resin tube which exhibits excellent resistance to repeated bending; and a method for producing the poly(3-hydroxybutyrate)-based resin tube. The object is attained by providing a poly(3-hydroxybutyrate)-based resin tube which contains 95 wt % to 60 wt % of a poly(3-hydroxybutyrate)-based resin and 5 wt % to 40 wt % of an aliphatic-aromatic polyester-based resin and has an elongation at yield point in a tensile test, a tensile elongation of not less than 50% in the tensile test, and a thickness of 0.01 mm to 0.6 mm.

In the manufacture of extruded polymers there are a number of surface defects referred to as sharkskin, snakeskin and orange peel which all generally relate to the rheology of the polymer melt. A severe form of surface defect is “melt fracture” which is believed to result when the shear rate at the surface of the polymer is sufficiently high that the surface of the polymer begins to fracture. That is, there is a slippage of the surface of the extruded polymer relative to the body of the polymer melt. The surface generally can't flow fast enough to keep up with the body of the extrudate and a fracture in the melt occurs generally resulting in a severe loss of surface properties for the extrudate. A polymer extension process is disclosed wherein these undesirable surface defects are eliminated.

Provided is a production apparatus capable of producing a flexible tube whose hardness is naturally varied along the length direction thereof. This mixing valve includes: a first valve configured to distribute a first resin to a resin supply path and a resin discharge path; and a second valve configured to distribute a second resin to the resin supply path and the resin discharge path. In the mixing valve, the mixing proportion between the first resin and the second resin is increased or decreased in association with molding of the flexible tube, by changing a distribution ratio of the first resin in the first valve and a distribution ratio of the second resin in the second valve while keeping constant the total of the supply mounts of the first resin and the second resin supplied to a die.

A method for producing a tube, which includes: extruding a melt-fabricable fluororesin from a mold of an extruder into a form of a tube, leading the extruded melt-fabricable fluororesin to a cooling device to cool the extruded melt-fabricable fluororesin, and winding a resulting cooled tube onto a winding reel using a winding device. A gas is fed from a head end of the tube wound onto the winding reel into a hollow of the tube, the gas in the hollow is allowed to pass through a gas-introducing entrance of the mold and then through a gas-discharging hole of the mold to discharge the gas outside, thereby allowing the gas to flow along the hollow, and an internal pressure of the hollow is kept higher than atmospheric pressure and lower than 0.5 kgf/cm.sup.2.

A method to produce a container made of a plastic composition having an inner coating with a higher mechanical stability and/or a better adhesion to the container, includes preparing a plastic composition with at least one base polymer material and at least a first additive comprising globe-like particles having a hardness on the Mohs scale of at least 4,and extrusion blow molding of a container. The globe-like particles, which located on the inner surface of the container, increase the surface area and the hardness of the inner surface of the container. The method also includes applying the at least one metal layer of the inner coating onto the inner surface of the container, wherein the applied metal layer bonds to the globe-like particles of the first additive located on the inner surface of the container.

A method to produce a container made of a plastic composition having an inner coating with a higher mechanical stability and/or a better adhesion to the container, includes preparing a plastic composition with at least one base polymer material and at least a first additive comprising globe-like particles having a hardness on the Mohs scale of at least 4,and extrusion blow molding of a container. The globe-like particles, which located on the inner surface of the container, increase the surface area and the hardness of the inner surface of the container. The method also includes applying the at least one metal layer of the inner coating onto the inner surface of the container, wherein the applied metal layer bonds to the globe-like particles of the first additive located on the inner surface of the container.

Apparatus and methods for manufacturing compostable, biodegradable drink straws from polyhydroxyalkanoate (PHA) material are disclosed herein. Such apparatus may include a hopper that contains raw PHA material, an extruder that receives the raw PHA material from the hopper and produces extruded PHA material, one or more waters baths that cool the extruded PHA material, a puller that pulls a tubular stream of PHA material through the system, and a cutter that is configured to cut the stream of PHA material into finished straws. The finished straws may be soil- and marine-biodegradable, as well as home- and industrial-compostable.