The notched Izod impact toughness and tensile elongation of poly(lactic acid) (PLA)-homopolymers are increased by about 2 to about 4 times by blending therewith a PLA-copolymer having a difunctional flexible middle segment such as a polysiloxane or a polyether from about 0.6 wt. % to about 20 wt. %. The PLA-homopolymer-PLA-copolymer blend having a difunctional flexible polymer from about 0.5 wt. % to about 10 wt. % is thermally annealed to provide impact toughness of at least about 5 kJ/m.sup.2 and tensile elongation of greater than 12%. This exceptional improvement observed in the PLA blend is a synergistic effect of the addition of the difunctional flexible polymer of the copolymer and thermal annealing. The improvement observed in the mechanical properties with high PLA homopolymer content above about 90 to about 98 wt. % is unusual and results in an increased scope of molding and thermoforming applications. The annealed PLA-copolymers having a difunctional flexible middle segment have also been found to have improved notched Izod impact properties.

A method for producing a resin composition of the present invention is a method for producing a resin composition, the method including a step of obtaining a resin composition by heating and melt-kneading a mixture containing a particulate nucleating agent in which D.sub.50 is equal to or more than 0.1 μm and equal to or less than 300 μm and a thermoplastic resin using a twin screw extruder (100) including, inside a cylinder (10), a screw (50) having kneading discs (60), in which the step of obtaining a resin composition includes an extrusion step of extruding the mixture supplied into the twin screw extruder (100) in an ejection direction under kneading conditions in which X and Y satisfy 4.0≤X in a range of 6.0×10.sup.3≤Y≤7.0×10.sup.4 when a volume-based ejection amount is denoted by X (10.sup.−6.Math.kg.Math.h.sup.−1.Math.mm.sup.−3), and a strain rate is denoted by Y (min.sup.−1).

A multi-shaft extruder which has screw shafts which are rotatable in the same direction and at the same speed, and which has at least one gas venting opening, and which has, in the entry region of said at least one gas venting opening, screw elements with a particularly large pitch or screw elements which have an asymmetric screw profile or which are mounted eccentrically on the axis of rotation of the screw shaft. The invention also relates to the use of the extruder according to the invention for processing or manufacturing plastic materials, and to the use of the screw elements with a particularly large pitch or the use of screw elements which have an asymmetric screw profile or which are mounted eccentrically on the axis of rotation of the screw shaft, in the region of the gas venting opening of a multi-shaft extruder.

A multi-shaft extruder which has screw shafts which are rotatable in the same direction and at the same speed, and which has at least one gas venting opening, and which has, in the entry region of said at least one gas venting opening, screw elements with a particularly large pitch or screw elements which have an asymmetric screw profile or which are mounted eccentrically on the axis of rotation of the screw shaft. The invention also relates to the use of the extruder according to the invention for processing or manufacturing plastic materials, and to the use of the screw elements with a particularly large pitch or the use of screw elements which have an asymmetric screw profile or which are mounted eccentrically on the axis of rotation of the screw shaft, in the region of the gas venting opening of a multi-shaft extruder.

Disclosed is a recycling apparatus for a cross-linked polyethylene resin using a twin screw extruder. The recycling apparatus for a cross-linked polyethylene resin using a twin screw extruder according to an embodiment of the present disclosure includes: a raw material supply unit configured to supply a raw material that is a cross-linked polyethylene resin; and a twin screw extruder configured to receive the raw material from the raw material supply unit, the twin screw extruder including a cylinder and a twin screw installed inside the cylinder to rotate in the same direction, the twin screw extruder being configured to de-crosslink and recycle the raw material under a de-crosslinking reaction temperature and reaction pressure atmosphere while continuously transporting the raw material along the twin screw by the rotation of the twin screw.

A polyolefin material that is formed by solid state drawing of a thermoplastic composition containing a continuous phase that includes a polyolefin matrix polymer and nanoinclusion additive is provided. The nanoinclusion additive is dispersed within the continuous phase as discrete nano-scale phase domains. When drawn, the nano-scale phase domains are able to interact with the matrix in a unique manner to create a network of nanopores.

A mixing element for an extruder screw having a width extending in an x-direction of an x-y-z coordinate system, a length extending in a y-direction, and a thickness extending in a z-direction. The mixing element includes a base defining a passage extending along an axis in the y-direction for receiving the extruder screw. Projections extend radially outward from the base and define channels therebetween. The width and the depth of each channel vary along the length of the channel.

A method for producing a resin composition of the present invention is a method for producing a resin composition, the method including a step of obtaining a resin composition by heating and melt-kneading a mixture containing a particulate nucleating agent in which D.sub.50 is equal to or more than 0.1 μm and equal to or less than 300 μm and a thermoplastic resin using a twin screw extruder (100) including, inside a cylinder (10), a screw (50) having kneading discs (60), in which the step of obtaining a resin composition includes an extrusion step of extruding the mixture supplied into the twin screw extruder (100) in an ejection direction under kneading conditions in which X and Y satisfy 4.0≤X in a range of 6.0×10.sup.3≤Y≤7.0×10.sup.4 when a volume-based ejection amount is denoted by X (10.sup.−6.Math.kg.Math.h.sup.−1.Math.mm.sup.−3), and a strain rate is denoted by Y (min.sup.−1).

A resin extruder capable of efficiently improving performance of kneading a resin material is provided. A resin extruder (1) according to one embodiment includes a cylinder (20), and a rotor-type screw (33) that is disposed in the cylinder (20) and kneads a resin material (51). In the rotor-type screw (33), a top part (33b) of a flight (33a) is formed in such a way that a gap between the top part (33b) and an inner surface of the cylinder (20) is changed from a front point to a rear point of the rotor-type screw in a rotation direction in a cross section that is vertical to an axial direction.

A plastic composition consisting essentially of plastic matter, inorganic matter, and organic matter. The plastic composition has a notched izod impact above 12 J/m, a surface energy of at least 40 dyne/cm and, and when the plastic composition is subjected to injection molding, at least one of a tensile strength of above about 2.7 MPa, a tensile modulus of above about 600 MPa, a flexural modulus above about 690 MPa, a flexural strength above about 5.6 MPa, and a Charpy Impact above about 1.5 KJ/m2.