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
  • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
  • B29B7/7438—Mixing guns, i.e. hand-held mixing units having dispensing means
  • B29B7/7442—Mixing guns, i.e. hand-held mixing units having dispensing means with driven stirrer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/05—Stirrers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/71—Feed mechanisms
  • B01F35/717—Feed mechanisms characterised by the means for feeding the components to the mixer
  • B01F35/7174—Feed mechanisms characterised by the means for feeding the components to the mixer using pistons, plungers or syringes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/71—Feed mechanisms
  • B01F35/717—Feed mechanisms characterised by the means for feeding the components to the mixer
  • B01F35/71805—Feed mechanisms characterised by the means for feeding the components to the mixer using valves, gates, orifices or openings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/75—Discharge mechanisms
  • B01F35/754—Discharge mechanisms characterised by the means for discharging the components from the mixer
  • B01F35/7547—Discharge mechanisms characterised by the means for discharging the components from the mixer using valves, gates, orifices or openings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
  • B01F35/80—Forming a predetermined ratio of the substances to be mixed
• • 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
  • B29B7/30—Mixing; Kneading continuous, with mechanical mixing or kneading devices
  • B29B7/34—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices
  • B29B7/38—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices rotary
  • B29B7/40—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices rotary with single shaft
  • B29B7/44—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices rotary with single shaft with paddles or arms
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F2101/00—Mixing characterised by the nature of the mixed materials or by the application field
  • B01F2101/19—Mixing dentistry compositions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F2101/00—Mixing characterised by the nature of the mixed materials or by the application field
  • B01F2101/2305—Mixers of the two-component package type, i.e. where at least two components are separately stored, and are mixed in the moment of application
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F33/00—Other mixers; Mixing plants; Combinations of mixers
  • B01F33/50—Movable or transportable mixing devices or plants
  • B01F33/501—Movable mixing devices, i.e. readily shifted or displaced from one place to another, e.g. portable during use
  • B01F33/5011—Movable mixing devices, i.e. readily shifted or displaced from one place to another, e.g. portable during use portable during use, e.g. hand-held
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05C17/00—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces
  • B05C17/005—Hand tools or apparatus using hand held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces for discharging material from a reservoir or container located in or on the hand tool through an outlet orifice by pressure without using surface contacting members like pads or brushes
  • B05C17/00503—Details of the outlet element
  • B05C17/00516—Shape or geometry of the outlet orifice or the outlet element
• • 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
  • B29B7/7438—Mixing guns, i.e. hand-held mixing units having dispensing means
  • B29B7/7447—Mixing guns, i.e. hand-held mixing units having dispensing means including means for feeding the components

Definitions

• the present invention relates to a dynamic mixer for mixing at least two paste components with different volume ratios, comprising a housing which has a delay chamber for the paste component with the larger volume fraction.
• the mixer is particularly suitable for mixing paste components with a relatively high viscosity, for example greater than 800 Pas.
• a mixer for the production of pastes from components with unequal volume fractions which has a delay chamber. This forms a detour channel that extends the path from an inlet opening to a mixer element and runs along an arc around the longitudinal axis.
• This mixer represents a further development of the dynamic mixer known from EP 0 492412 A1.
• static mixers which, in contrast to a dynamic mixer, have no moving parts. Such mixers are only suitable for mixing and dispensing relatively thin liquids, cf. EP 0 885 651 A1, EP 0664 153 A1 or EP 0584428 A1.
• the mixing of the static or flow mixer is carried out by repeated strand division.
• the paste component either flows directly into the mixing chamber or the paste component enters the mixing chamber offset by about 90 °, so that the flow direction of the paste component changes again.
• the delay chamber can extend both in only one direction with one outlet and in two directions with a corresponding two outlets.
• the dynamic mixers known hitherto can therefore only be used for mixing pastes which have a medium consistency and stability.
• Such pastes usually have a viscosity in the range of 200 to 800 Pas.
• the primary object of the present invention is therefore to provide an improved mixer, in particular for mixing highly viscous pastes.
• the boundary wall is part of the delay chamber and is regularly located at the point which is furthest away from the inlet opening which opens into the delay chamber. Since the delay chamber is usually designed in the manner of a ring segment and runs along an arc around the longitudinal axis of the mixer, the boundary wall represents an end face of the ring segment which, depending on the embodiment, can be planar or curved.
• No boundary wall of the delay chamber in the sense of the invention is a baffle arranged opposite the inlet opening, which the inflowing paste component strikes immediately after entering the mixer without being substantially deflected.
• the delay chamber is initially largely completely filled before the paste component enters the actual mixing space. This can be explained by a flow resistance generated by the rotating mixing blades, which prevents the paste from entering the mixing chamber until the delay chamber is filled.
• Paste component is only slightly deflected depending on the arrangement of the opening after filling the delay chamber.
• the paste component flowing into the delay chamber is first deflected by about 90 ° when it flows in and fills the delay chamber without essentially getting into the mixing chamber. Since the mixing chamber is not yet filled in this state, the delivery forces to be applied here are relatively uncritical.
• the dynamic pressure that builds up causes the paste component to enter the mixing chamber through the recessed opening.
• the forces to be conveyed by the mixing device decrease with increasing distance of the opening from the boundary wall, so that too highly viscous materials can be mixed dynamically with the mixer according to the invention.
• the mixer according to the invention thus allows pastes to be prepared which, in the component with the larger volume fraction, have viscosities which are significantly higher than 800 Pas, without causing a mechanical overloading of the system, including the mixing device, the inserted cartridge and the mixer.
• the viscosity can be determined, for example, with a Brookfield DV III rheometer (spindle HB 5, bar width 15.5 mm, speed 5 rpm, reading 20s after start).
• the viscosity can be determined in the following ways:
• a commercially available mixing device e.g. Pentamix ® 2 from 3M ESPE AG.
• the filling height should be at least 30mm.
• the filled measuring cup is then placed in the cup holder stand and the measuring spindle is lowered into the center of the paste. Now the test is started.
• the measured value shown in the display as mPas is read 20 seconds after the start of the measurement.
• opening in the sense of the present invention means both inlet openings and outlet openings. This depends on the direction in which the substances to be mixed flow or are pressed.
• a mixer usually has two inlet openings and only one outlet opening.
• the device according to the invention preferably has at least two, but possibly also three or four openings.
• the device according to the invention in the form of a dynamic mixer usually comprises at least three components, in particular a base plate, into which the inlet openings and the receiving opening for the drive shaft are embedded, and a rotor which is rotatably mounted in the base plate, are attached to the mixing blades and a molded groove for receiving the drive shaft and the housing in which the rotor runs.
• the shape of the groove for the drive shaft is arbitrary, provided that sufficient power can be transferred from the drive shaft to the mixing blades for mixing.
• Openings in angular form have proven to be favorable for the transmission of the torque from the drive shaft to the rotor.
• the shaped groove for the drive shaft is preferably triangular, square, square, pentagonal, hexagonal, heptagonal, octagonal or has another angular geometric shape.
• a delay chamber in the sense of the invention is to be understood as a chamber or a detour channel through which a paste component must pass before it can enter the mixing chamber.
• the delay chamber has an inlet opening which usually coincides with the inlet opening of the mixer and at least one outlet opening which opens into the mixing chamber.
• the shape of the delay chamber is basically arbitrary. A shape extending along an arc around the longitudinal axis of the mixer has proven to be advantageous in order to keep the overall length of the mixer short.
• the delay chamber preferably has the shape of a ring segment which extends over an angular range from greater than 0 to less than 180 °, preferably in the range from 90 to less than 180 °.
• the chamber a boundary wall located in the flow direction of a paste component, on which the paste component jams.
• the chamber also has at least one opening which opens into the mixing chamber and which is arranged set back from the boundary wall.
• the term set back in the sense of the invention is to be understood as an arrangement in which the opening does not directly adjoin the boundary wall, but is arranged offset from it. If the delay chamber has only this one opening in the mixing chamber, this has the effect that the pent-up paste component does not get into the mixing chamber at the point at which the boundary wall is located, but only at a point set back in relation to this in the flow direction.
• This opening is preferably set back in relation to the boundary wall along the circumferential direction, in particular by an angle with a center in the mixer axis in the range from 90 to 180 °.
• the paste component with the larger volume fraction is therefore usually first carried out in an arc around the longitudinal axis, stowed there on the boundary wall and comes into contact with the paste component with the smaller volume fraction only in the area of the mixing element.
• the paste component flowing into the mixer and having the greater volume fraction, until it enters the mixing chamber advantageously only experiences a directional deflection which is less than 90 °, preferably less than 45 °. In this way, a reduction in the force that is required to apply particularly high-viscosity pastes, for example with a viscosity greater than 800 Pas, can be achieved.
• the ratio of the volume of the delay chamber to the volume of the mixing chamber is usually in the range from 1: 1 to 1:20, preferably in the range from 1: 3 to 1: 5.
• the delay chamber usually has an absolute volume in the range from 0.1 to 10 ml , preferably in the range of 0.3 to 2 ml.
• the volume of the delay chamber also includes the area of the inlet opening that opens into the delay chamber.
• the volume of the mixing chamber is the difference between the total volume provided by the housing of the mixer minus the volume of the delay chamber and the volume that is taken up by the mixing spiral.
• the shape of the opening that opens into the mixing chamber is basically arbitrary. Essentially round, rectangular and triangular openings are suitable.
• the opening area is usually only a few mm 2 , preferably 1 to 100 mm 2 .
• the delay chamber has several, in particular two or three, openings which open into the mixing chamber. The further openings can also be located directly in the area of the boundary wall or adjoin it.
• An opening in the mixing chamber located directly in the area of the boundary wall is advantageous if it is to be ensured that the air, which would be compressed in the delay chamber by the inflow of the paste component to be delayed, can escape into the mixing chamber. This is particularly advantageous if it is to be ensured that no air should be trapped in the paste to be mixed. If the paste is a dental impression material, air trapped in the mixed paste leads regularly deteriorates in quality of a denture impression taken using the mixed paste.
• the delay chamber can be arranged symmetrically or asymmetrically in the mixer. It can only extend in one direction of rotation, but also in both directions of rotation.
• the recessed opening in the delay chamber is arranged such that it faces the inlet opening into the delay chamber at least at one point.
• the opening in the delay chamber, which opens into the mixing chamber is preferably half-offset from the inlet opening.
• a baffle is arranged opposite the inlet opening into the delay chamber, which prevents the paste component from entering the mixing chamber without being deflected into the delay chamber.
• This baffle surface usually results automatically when the opening of the delay chamber, which opens into the mixing chamber, is arranged somewhat laterally offset from the inlet opening, as seen in the direction of flow.
• approximately 50% of the opening area which opens into the mixing chamber is opposite the inlet opening.
• the presence of an impact surface may not be absolutely necessary.
• the flow resistance generated by the rotating mixing blades can be sufficient so that the one paste component before it is in the Mixing chamber is mixed with the other paste component and applied, enters the delay chamber.
• the area ratio of the openings of the inlet for the paste component with the larger volume fraction to the outlet opening of the mixer for the mixed paste is usually in the range from 1: 1 to 1: 5. A ratio which deviates from this has become particularly evident when mixing highly viscous pastes as a result of the Loss of friction proved to be disadvantageous.
• Suitable materials from which the mixer can be made include metal, glass and / or plastics, the latter being preferred.
• Suitable plastics are, for example, those which have a modulus of elasticity in the range from 200 to 3000 N / mm 2 and / or an elongation at break in the range from 50 to 200%.
• Suitable materials for the mixer include PA, PE, OPP, PP, PTFE, PC, PS and / or POM.
• the materials can also be used in fiber reinforced and / or filled form.
• Suitable fibers and fillers include glass fibers / particles and carbon fibers / particles.
• Suitable mixers and / or cartridge fronts can be produced, for example, in the injection molding process, if appropriate in a 2-component injection molding process. Production by machining processes is also conceivable.
• the mixer according to the invention can be used in all fields of technology, in particular for mixing highly viscous, pasty and / or viscous masses.
• Examples include: adhesives, joint sealants, lacquers.
• the mixers according to the invention can preferably be used in the dental field.
• the devices according to the invention are particularly suitable for mixing highly viscous impression materials, for example made of tubular bags, which are inserted into suitable cartridges, are pressed out using electrically driven pistons. It is also conceivable and possible to dispense the materials from suitable cartridges which are filled directly with the material without using a tubular bag. Silicones, polyethers, polyether silicones, epoxies and polyurethanes may be mentioned as examples of materials.
• the invention also relates to the combination of a dynamic mixer and an electrically operated mixing device on which the mixer can be placed or attached.
• Suitable mixing devices have a mixer shaft and one or more delivery pistons.
• the present invention also relates to a method for mixing at least two paste components with different proportions by volume.
• the method comprises the following steps: a) dispensing at least two paste components A and B from a container, preferably from a cartridge-like container into which tubular bags can optionally be inserted, b) introducing components A and B into a dynamic mixer, the can be connected to the container, c) mixing components A and B using the dynamic mixer, d) discharging the mixture of A and B from the mixer.
• the mixer used has a mixing chamber and a delay chamber in front of it, which has a boundary wall stopping the paste flow in the direction of flow.
• the paste component A entering the mixer with the larger volume fraction fills the delay chamber and is stowed there on the boundary wall before it is mixed with the paste component B and discharged from the mixer.
• Figure 1 shows an exploded view of a mixer according to DE 298 18 499 U.
• Figure 2 shows an exploded view of the mixer according to the invention.
• Figure 3 shows an exploded view of the mixer according to the invention according to Figure 2 in rear view.
• Figure 4 shows a sectional drawing through the input area of the mixer.
• the mixer according to FIG. 1 is known from the prior art. It has a base plate 1 with two inlet openings 2 and 3, a housing 9 with an outlet opening 4 and a mixing element 6.
• the mixing element 6 is provided with mixing blades 7.
• the delay chamber 10 extends along an arc around the longitudinal axis of the mixer and is closed off by a boundary wall 14.
• a boundary wall 14 Immediately on the boundary wall 14 is an opening 12 for the paste component A, which opens into the mixing chamber.
• the paste component B with the smaller volume fraction opens into the mixing chamber via the opening 11.
• the paste component A runs initially along the surfaces 1 and 15 and is stopped by the boundary wall 14 arranged transversely thereto.
• the opening 13 for the exit of component A from the delay chamber into the mixing chamber is arranged set back in the baffle plate 15 at a distance from the boundary wall 14 against the initial paste flow direction of component A.
• FIG. 2 shows an embodiment for a mixer according to the invention in one
• the mixer has essentially the same
• the mixer according to the invention has an opening 13 which is opposite the Boundary wall 14 is set back.
• the opening 12, which directly adjoins the boundary wall 14, is optional.
• the delay chamber 10 preferably extends along an arc around the longitudinal axis of the mixer and is formed, inter alia, by the boundary wall 14, the underside of the base plate 1, the baffle plate 15 located opposite the inlet opening 2 and the circular segment-shaped element 16.
• FIG. 3 shows the mixer according to FIG. 2 from a different perspective.
• the two inlet openings 2 and 3 for the two paste components A and B, which are molded onto the base plate 1 can be seen, the receiving opening 5 for the mixing spiral 6 and the hexagonal shaped groove 8, into which the drive shaft for the mixing spiral 6 can intervene.
• FIG. 4 shows a sectional drawing through the inlet area of the mixer according to FIGS. 2 and 3.
• the flow channels for the two paste components A and B can be seen in particular.
• the paste component B enters the mixer through the opening 3 and passes through the opening without substantial deflection 11 into the mixing chamber in which the mixing blades 7 rotate.
• the paste component A enters the mixer via the opening 2, meets the baffle plate 15, is deflected there by approximately 90 ° and passed into the delay chamber along the circular segment.
• the flow of paste is stopped by the boundary wall 14, the jammed air can escape through the opening 12.
• the paste component A can enter the mixing chamber via the opening 12 and in particular the opening 13 set back with respect to the boundary wall.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Mixers Of The Rotary Stirring Type (AREA)
• Engine Equipment That Uses Special Cycles (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Related Child Applications (2)

Publications (2)

Family

ID=7677835

Family Applications (1)

Country Status (9)

Cited By (9)

Families Citing this family (62)

Citations (3)

Family Cites Families (39)

• 2001
  • 2001-03-15 DE DE10112904A patent/DE10112904C5/de not_active Expired - Lifetime
• 2002
  • 2002-03-06 AU AU2002336234A patent/AU2002336234B2/en not_active Ceased
  • 2002-03-06 AT AT02752876T patent/ATE329682T1/de active
  • 2002-03-06 CA CA002435913A patent/CA2435913C/en not_active Expired - Lifetime
  • 2002-03-06 EP EP02752876.9A patent/EP1368113B2/de not_active Expired - Lifetime
  • 2002-03-06 WO PCT/EP2002/002481 patent/WO2002074426A1/de not_active Ceased
  • 2002-03-06 US US10/471,912 patent/US7287898B2/en not_active Expired - Lifetime
  • 2002-03-06 JP JP2002573131A patent/JP4153307B2/ja not_active Expired - Fee Related
  • 2002-03-06 CN CNB028064399A patent/CN1269559C/zh not_active Expired - Fee Related
  • 2002-03-06 DE DE50207198T patent/DE50207198D1/de not_active Expired - Lifetime
• 2007
  • 2007-10-29 US US11/978,395 patent/US7674033B2/en not_active Expired - Fee Related

Patent Citations (3)

Also Published As

Similar Documents

Legal Events