Apparatus for processing plastic material

An apparatus for treatment of plastic material, the apparatus comprising:

• a container configured to hold the plastic material for initial treatment, wherein the container comprises a sidewall having an outlet aperture configured to pass initially treated plastic material from the container;
• a mixing and/or comminution implement comprising first and second blades configured to rotate about an axis of rotation in a first direction of rotation so as to initially treat the plastic material in the container by at least one of mixing, heating, and comminuting the plastic material, each of the first and second blades protruding convexly in the first direction of rotation;
• and
• a conveyor, comprising:
• a housing comprising an intake aperture configured to receive the initially treated plastic material from the outlet aperture of the container, and
• a screw in the housing, wherein the screw is configured to rotate within the housing in a second direction of rotation to further treat the initially treated plastic material by at least one of plastifying and agglomerating the initially treated plastic material and to convey the initially treated plastic material away from the intake aperture in a first direction,
• wherein an imaginary continuation of a central longitudinal axis of the screw infinitely extending in a direction opposite the first direction, does not intersect the axis of rotation of the mixing and/or comminution implement,
• wherein a scalar product of a first direction vector that is parallel with the first direction and a second direction vector that is tangential to a circle described by a radially outermost point of the mixing and/or comminution implement at a point on the circle nearest the outlet aperture is zero or negative,
• wherein a ratio (V) of an active container volume (SV) to a feed volume (BV) of the container, where V=SV/BV, conforms with 4≤V≤30, where the active container volume (SV) is defined by the formula
• SV
• =
• D
• 3
• ⁢
• π
• 4
• where D is an internal diameter of the container, where the feed volume (BV) is defined by the formula
• BV
• =
• D
• 2
• ⁢
• π
• 4
• ·
• H
• ,
• and where H is a height of the intake aperture with respect to a bottom surface of the container,
• wherein a ratio (VS) of the feed volume (BV) of the container to a screw volume (SE) at the intake aperture complies with 20≤VS≤700, wherein the screw volume (SE) is defined by the formula
• SE
• =
• F
• ·
• L
• ⁢
• ⁢
• π
• 4
• ⁢
• (
• 2
• ⁢
• dT
• -
• T
• 2
• )
• ,
• where L is an effective length of the intake aperture extending in the first direction, factor F >0, and T is a flight depth of the screw,
• wherein the first and second blades are separated by an empty space configured to receive a portion of the plastic material for initial treatment, wherein a line from the first blade to the second blade intersects the empty space, and wherein the axis of rotation of the mixing and/or comminution implement intersects the empty space,
• wherein a scalar product of the first direction vector and a third direction vector that is tangential to a circle described by a radially innermost point of the mixing and/or comminution implement adjacent the empty space at a point on the circle nearest the outlet aperture is zero or negative,
• wherein a substantially planar surface of each of the first and second blades of the mixing and/or comminution implement is parallel with the bottom surface of the container, and defines a plane which intersects the outlet aperture, and
• wherein the sidewall defines a radius, and wherein an outermost portion of the planar surface of the first and second blades of the mixing and/or comminution implement when nearest the outlet aperture is spaced apart from the outlet aperture by about 5% of the radius,
• wherein when one of the first blade and the second blade is in a position closest to the screw of the conveyor, the one of the first blade and the second blade protrudes convexly in a second direction opposite to the first direction.