CN2471522Y - Three screw rod extruder for polymer - Google Patents

Abstract

The utility model relates to a screw extruder for processing polymers. The wire splice of the centers of three screws is in the shape of an inverted equilateral triangle and arranged in a machine barrel, wherein two screws are arranged in the upper part in parallel, another screw is arranged in the middle part at the bottom, the three screws are all-geared to form three meshing zones, all the three screws rotate actively and in the same direction, each screw adopts triple thread, thus the utility model increases the meshing point dramatically, enables the screw with relatively small slenderness ratio and effectively improves the effect of mixing and dispersing main materials and additives during plastic processing.

Description

The Polymer Processing three-screw extruder

The utility model relates to the screw extruder that a kind of Polymer Processing is used.

The screw extruder that existing Polymer Processing is used is generally single screw rod or twin-screw, and twin-screw is a word order.Extrude and add man-hour, one of way of improving plasticizing, melting effect is to strengthen the draw ratio of screw rod.But draw ratio is big more, and screw rod is long more, can make the screw rod of cantilever support stressed bad.So the general control of screw slenderness ratio within the specific limits.The clear 61-35775 of Japan Patent discloses a kind of three-screw extruder that food processing is used that is used for, and a word or V word arrangement have three screw rods in machine barrel.This patent adopts increase screw rod radical to increase the region of engagement, thereby improves the mixed effect of food.But word order three screw rods can only constitute two region of engagements.This patent only is used for the not high food processing of operating pressure, power, torque demand in addition, is unsuitable for the simultaneous Polymer Processing of high temperature, high pressure, large torque and axial force.Chinese patent CN97202356.9 discloses a kind of three screw rod plastic extruders.Have a thick shape driving screw that is connected with main shaft, two thin shape sub-screws are respectively in driving screw both sides and its engagement, reverse rotation between the major and minor screw rod, and the thread direction is opposite.The setting of these patent three screw rods increases the region of engagement, thereby has increased output, has improved melting effect.Though this patent adopts three screw rods, but the diameter difference, being actually with thick shape driving screw serves as that main the plasticizing extruded, and thin sub-screw plays to strengthen rubbing and presses evenly and the booster action that rolls, and three screw rod word orders only can form two region of engagements.Continuous development along with the polymer modification material, mixing, the dispersion effect that need major ingredient and additive in the more effective raising plastic processing, and traditional strengthen the region of engagement with the increase screw slenderness ratio and improve the design philosophy of polymer melting effect and have certain limitation.

The purpose of this utility model: with less draw ratio, obtain more meshing point, thereby provide a kind of plasticizing, melting effect good, machine stress is reasonable, and compact conformation is suitable for the screw extruder of Polymer Processing.

Main technical schemes of the present utility model: mainly form by machine barrel, screw rod and the head of transmission device, sealing.Have three lines of centres to be the screw rod of inverted triangular arranged in the machine barrel, that is: upper parallel is arranged two, and the center, bottom is arranged one, constitutes three region of engagements.Three screw rods are initiatively, and screw flight head number is three or single head.

In order to bear since three screw rods be engaged on Polymer Processing the time high pulling torque and the axial force that produce, transmission device of the present utility model adopts following structure: motor is passed to shaft coupling with power, drive the gear on the one-level power transmission shaft, be transferred to secondary drive shaft, drive left and right two interior external gears by two external gears on the secondary drive shaft, wherein external gear connects two screw rods that are arranged in parallel by power transmission shaft in the left side, drive two screw rods and mesh rotation in the same way, two screw rods is supported by separately tandem thrust bearing respectively, the axial force that produces when bearing the two screw rods engagement.In right external gear by another power transmission shaft be arranged in a following screw rod and be connected, drive it and turn round, an end of this screw shaft is equipped with thrust bearing, to bear axial force.Be full engagement between the three above-mentioned screw rods, rotation in the same way reaches best mixed effect.Above-mentioned screw rod all adopts the threaded block of different rotation directions, different-thickness, the assembled screw rod of the kneading disk at different lead, different stagger arrangement angle.

Three above-mentioned screw rods are the three-start screw screw rod, and meshing point is multiplied.

Above-mentioned screw slenderness ratio is 15-30.

Effect of the present utility model: because three screw rods adopt inverted equilateral triangle to arrange, constitute three region of engagements, the region of engagement increases, and the suffered shearing number of times of material increases thereupon; And every screw rod adopts three-start screw, thereby realizes with less draw ratio; Increase meshing point and shear zone exponentially, greatly improve shearing, refinement, mixing, the dispersion effect of each component in the plastic processing.And this inversion equilateral triangle of three screw rods arranges that the area that can make charge door strengthens, and improves the transfer efficiency of delivery area, also can make the area of exhaust outlet be not less than conventional twin-screw, guarantees exhaust effect, is suitable for the conveying of polymer masses.

In addition, drive mechanism and load bearing that the utility model adopts satisfy the technological requirement of high moment of torsion, high power and axial force in the Polymer Processing preferably, compact conformation, stressed rationally.

Open in detail below in conjunction with embodiment and accompanying drawing to the utility model.

Fig. 1 is the utility model overall structure schematic diagram.

Fig. 2 is that the utility model three screw rods inversion equilateral triangle is arranged full mesh schematic representation.

Fig. 3, Fig. 4 are twin-screw and three screw rod word order region of engagement schematic diagrames in the prior art.

Fig. 5 is that the utility model three screw rods are inverted equilateral triangle layout region of engagement schematic diagram.

Fig. 6, Fig. 7, Fig. 8, Fig. 9, Figure 10, Figure 11, Figure 12 are that the utility model three screw rods screw channel in service district area changes schematic diagram by 0 °, 30 °, 60 °, 90 °, 120 °, 150 °, 180 ° respectively.

Figure 13 is the vertical and horizontal exchange schematic diagram of materials flow between the utility model screw channel.

Figure 14 is the mesh plate schematic diagram of the utility model high shear forces.

Figure 15 is the utility model transmission system schematic diagram.

Figure 16 is the utility model transmission system meshing relation schematic side view.

As shown in Figure 1, extruder is mainly by buncher 1, and shaft coupling 2, reduction box 3, combination machine barrel 4 and head 5 are formed.The screw rod 6 that three inverted triangular arranged are arranged in the machine barrel, upper parallel is arranged two, and the center, bottom is arranged one, constitutes three region of engagements (as shown in Figure 5).Screw slenderness ratio is: 22, three screw rods are initiatively, adopt three-start screw, are full engagement, rotation in the same way between the screw rod.For the full engagement that realizes three screw rods and axial force and torque when handling three screw engages, employing is with underdrive and thrust support structure: as shown in figure 15: motor 1 is passed to shaft coupling 2 with power, drive the gear 7 on the one-level power transmission shaft, be transferred to secondary drive shaft 8, by two external gears 9 on the secondary drive shaft, 10 drive 11,12 two interior external gears, the internal tooth of wherein interior external gear 11 drives two gears that are arranged in parallel 13,15, by output shaft 16, the two screw rod 6A that are arranged in parallel above 17 rotating drive, 6B meshes rotation in the same way, output shaft 16,17 rear ends are respectively arranged with the thrust bearing 14 of tandem, to bear the axial force that produces when two screw rods meshes.The internal tooth of interior external gear 12 drives output shaft 18, drives to be arranged in a following screw rod 6C and top two screw rods turn round in the same way, and an end of this screw shaft is equipped with aligning thrust roller bearing 19, to bear bigger axial force.Because this example is in operation, three screw rods are is inverted the equilateral triangle layout, has constituted three region of engagements, all quite a pair of twin-screw engagement in each region of engagement.As seen from Figure 5, the axial formation of per two screw rods many " C " die cavity chamber, these chambers are along forming continuous passage between the screw channel direction is from the charge door to the head, and material flows to another root screw rod along this passage from a screw rod.To shown in Figure 12, material is pushed ahead a screw channel needs two cycles at least as Fig. 6, three region of engagements, and the increase of region of engagement, and the suffered shearing number of times of material increases thereupon.Single from the screw rod normal section area change of screw channel come comparison: with 0 ° as original state, this moment is because screw channel appearance material space is little, be compressive state, differ 30 ° of angles between later on every adjacent two states, when screw rod turns over 60 °, it is big that the screw channel volume becomes, pressure reduces, forward 90 ° to, the screw channel volume continues to increase, and pressure continues to reduce, material is in relaxation state, when screw rod turned over 120 °, volume diminished, and pressure increases, material is got back to original state, the periodic cycle of screw channel volume when rotating along with screw rod, material also constantly repeat the process of " compression-recovery-expansion-recovery-recompression again ", when wherein the volume during maximum rating is about minimum state 2 times.If three screw rods are one start screw, then the ratio of maximum rating and minimum state is up to more than 4 times.Obviously, its extruding, pinch, refine effect and great raising is arranged than twin-screw; In addition, the area of three screw rod centers along with the rotation of screw rod from large to small, change from small to big again, constantly change, make the material of central area under the acting in conjunction that pressure and viscosity pull, take back screw channel by the spiral shell rib, mix once more with unclassified stores, continue to advance.As shown in figure 13: per two screw rods of three screw rods in length and breadth to all being to open, axially constituting three continuous passages, running along with screw rod, article three, passage intersects mutually, material all will change the original flow direction at each infall, has therefore formed material dispersed, merging, metathesis.Gap between spiral shell rib and the machine tube inner wall is the high shear zone of screw rod, kneading disk also belongs to the high shear element, from the normal section, three-start screw three screw rods and triangular kneading disk have nine high shear zone (seeing Figure 14), increased the number of times that material stands to shear exponentially, strengthened shearing, stretching, refining effect greatly material.

Claims (3)

1, a kind of Polymer Processing three-screw extruder, machine barrel, screw rod and head by transmission device, sealing are formed, it is characterized in that: have three lines of centres to be the screw rod of inverted triangular arranged in the machine barrel, upper parallel is arranged two, and the center, bottom is arranged one, is full engagement between three screw rods, constitute three region of engagements, three screw rods are initiatively, rotation in the same way, and three screw rods adopt three-start screw or one start screw.

2, three-screw extruder according to claim 1 is characterized in that: screw slenderness ratio is 15-30.

3, three-screw extruder according to claim 1, it is characterized in that: motor is passed to shaft coupling with power, drive the gear on the one-level power transmission shaft, be transferred to secondary drive shaft, drive two left sides by two external gears on the secondary drive shaft, external gear in right, wherein external gear connects two screw rods that are arranged in parallel by two power transmission shafts in the left side, drive two screw rods and mesh rotation in the same way, two screw rods is supported by separately tandem thrust bearing respectively, in right external gear by another power transmission shaft be arranged in a following screw rod and be connected, drive its running, an end of this screw shaft is equipped with thrust bearing.

Images