Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/02—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type
  • B29B7/06—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices
  • B29B7/10—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices rotary
  • B29B7/18—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices rotary with more than one shaft
  • B29B7/20—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices rotary with more than one shaft with intermeshing devices, e.g. screws
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/02—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type
  • B29B7/06—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices
  • B29B7/10—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices rotary
  • B29B7/18—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices rotary with more than one shaft
  • B29B7/183—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices rotary with more than one shaft having a casing closely surrounding the rotors, e.g. of Banbury type
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/02—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type
  • B29B7/06—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices
  • B29B7/10—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices rotary
  • B29B7/18—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices rotary with more than one shaft
  • B29B7/183—Mixing; Kneading non-continuous, with mechanical mixing or kneading devices, i.e. batch type with movable mixing or kneading devices rotary with more than one shaft having a casing closely surrounding the rotors, e.g. of Banbury type
  • B29B7/186—Rotors therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
  • B29B7/7476—Systems, i.e. flow charts or diagrams; Plants
  • B29B7/7495—Systems, i.e. flow charts or diagrams; Plants for mixing rubber

Definitions

• the present invention relates to internal mixers which are used for
• components such as rubber, fillers,
• At least one rotor turns within the chamber, the
• the rotor has to perform a number of functions. Firstly bulk
• the temperature of the material within the chamber must be increased by the application of stresses and strains.
• the temperature increase is
• the major criteria in applying stress are firstly that the material is in contact with machine surfaces and secondly that there is relative movement between the material and the surfaces.
• the mixed compound must be plasticized in order to achieve the
• the rotors comprise projections or nogs supported on generally J cylindrical shafts, the radially outer end of the nogs on one rotor
• the rotors serve to ingest the materials into the cavity, to
• the nogs on the rotors provides a degree of circulatory flow within the
• rotors serve to propel the compound downwards and outwards through
• temperature control is generally the most significant.
• mixer comprising at least one rotor supported to rotate about a
• said at least one rotor defining projection edges of different geometries
• the rotating means rotates
• projection is formed such that the shapes of its leading and trailing edges are different, whereby the mixing action to which material within the
• the invention also provides a method for operating an internal
• mixer comprising at least one rotor supported to rotate about a
• leading and trailing edges are different, wherein a batch of material is
• the or each rotor is rotated in a first direction to
• At least one rotor is provided defining at least two projections, the or each
• edge of at least one projection is relatively steep so as to grip material to
• one other projection is relatively less steep so as to encourage material to
• the present invention is based upon the realisation that in an
• one rotor can have a leading edge which ensures rapid
• the first edge is the leading edge during initial
• the first leading edge may be inclined at an angle of less than 45°
• That steep edge may be provided with an undercut so as to
• the or each projection may be provided with indentations and
• the present invention is applicable to a variety of internal mixer
• Figure 1 is a view from above of two rotors of a conventional
• Figure 2 is a sectional view on the line-to-to of Figure 1;
• Figure 3 is a sectional view corresponding to that of Figure 2
• Figure 4 illustrates a later stage in the mixing process shown in
• FIG. 5 illustrates the structure of an alternative internal mixer of
• Figure 6 is a view similar to that of Figure 2 but showing
• Figure 7 illustrates in cross-section the rotors of a reversible mixer
• each rotor has been modified in the same manner as the rotor of
• Figure 10 illustrates in cross-section the rotors of a mixer in which
• each rotor rotates in only one direction but the rotors have been modified
• the illustrated mixer comprises a casing defining an
• the rotor 2 is
• the rotor 3 is supported on shaft 4 and in use is rotated in the direction of arrow 6.
• the rotor 2 has a cylindrical outer surface from which
• projections 7, 8 and 9 extend towards the wall 1.
• the rotor 3 supports
• projections 7 and 10 define portions of a helix and the rotors are arranged
• the projection 10 defines a leading edge 13 which subtends an
• angles 14 and 16 are substantially the same
• the projection 11 defines a leading edge 17 defining an
• leading and trailing edges are relatively minor however and are generally
• the casing incorporates an inlet 21 in which a ram 22 is slidably
• the casing also comprises an outlet beneath the nip between the
• FIG. 3 illustrates the operation of the mixture of Figures 1 and 2
• the polymer is generally
• the introduced material may be pressed down by the ram into the
• the material is also worked between the
• components of the material to be mixed are to be adequately stressed and
• the projections is partly a function of the steepness of the leading edge of
• the leading edges of the projections are not as steep as would be ideal for
• the present invention relies upon a realisation that a rotor can be
• a rotor can be designed which
• Figure 6 illustrates a rotor modified in accordance with the present
• Figure 7 illustrates in cross-section the two rotors of the
• ingestion is increased and the gap between the rotors may be increased to further improve the speed of ingestion and discharge and to increase the
• Figure 8 illustrates one simple modification to a projection
• Figure 8 shows the projections having straightened out the
• the dotted line shows the configuration of a modified projection in
• the arrow 30 represents the
• the arrow 31 represents the direction of movement of the
• Figure 9 illustrates yet another conceivable configuration for a
• leading edge in the direction of arrow 30 is undercut so
• the projection could move in the direction of arrow 30, the rotor direction
• a mixing cycle can also be controlled by
• the rotors can be designed to optimise ingestion
• the relatively steep edges of the projections may be given surface
• undercuts may be formed but alternatives are
• rotor between the projections may be provided with indentations and
• the discharge door is fixed in position and thus serves as a high pressure
• projection surfaces provides an extra control variable which can be used
• This embodiment comprises contra-rotating rotors 32 and 33 but the
• edges 35 and 36 of the projection on rotor 32 have been made relatively
• the trailing edges 37 and 38 are of conventional shape, corresponding to
• edges 41 and 42 are of conventional shape.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
• Mixers Of The Rotary Stirring Type (AREA)
• Medicinal Preparation (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=10774442

Family Applications (1)

Country Status (7)

Families Citing this family (4)

Family Cites Families (7)

• 1995
  • 1995-05-13 GB GBGB9509742.4A patent/GB9509742D0/en active Pending
• 1996
  • 1996-05-13 CA CA002220935A patent/CA2220935A1/en not_active Abandoned
  • 1996-05-13 AU AU56576/96A patent/AU5657696A/en not_active Abandoned
  • 1996-05-13 CZ CZ973586A patent/CZ358697A3/cs unknown
  • 1996-05-13 JP JP8533886A patent/JPH11504566A/ja active Pending
  • 1996-05-13 EP EP96913656A patent/EP0827420A1/en not_active Withdrawn
  • 1996-05-13 WO PCT/GB1996/001128 patent/WO1996035507A1/en not_active Ceased

Non-Patent Citations (1)

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