DE2008104A1 - - Google Patents

Description

The invention relates to a method and a device for Forcing a liquid and / or a gas into an elastomeric material.

In particular, the invention relates to a system with a mechanical screw press for introducing liquids, such as plasticizers, extenders or Antioxidants in elastomeric materials, such as natural or synthetic rubbers, being liquids preferably during a combined drying process Materials are introduced. A typical liquid can

009837/1470

Be oil, such as light process oil from Napthenis or slightly aromatic type. This oil serves as an intermolecular plasticizer and as a lubricant, which increases the plasticity and the machinability of the material, that it can be more easily formed into different shapes. An oil is also often used as an extender along with carbon black or printing ink for enlargement the bulk of the rubber connection in order to reduce costs, without any of the important ones. Properties would be remarkably reduced ', and in many cases under generation even better properties.

The present invention is directed to a continuous process or method and to an improved apparatus for treating elastomeric materials and the like by draining the material in a first stage of a screw press to a higher pressure and a higher temperature through friction »- t generate heat in order to remove the moisture through drainage and to melt it off.

A device of this general type, used for a different purpose and in different ways, is disclosed in U.S. Patent No. 3,111,080. The material is processed under pressure while the liquid is added at the same time. The liquid is quickly absorbed by the material and can be used in the second state of the press, as the pressure continues to rise, incorporated into the material

0Q9837 / 1UO - 3 -

When this general overall process is carried out in a multi-stage mechanical screw press "is not only effective drying is provided, but it has also been found that the liquid and / or the gas Mix effectively, thoroughly and evenly into the material »It is particularly desirable when using natural rubber, which previously involved mixing liquids, especially oils, has brought much trouble «The continuous process was also found to be effective Method intended for adding oil or other liquids to synthetic rubber instead of mixing it in of the liquid during the flocculation step, which is the previous process.

By controlling the temperature of the added liquid, it can still have a certain cooling effect on the Rubber material can be used and in addition to in the Material to be mixed in, so that thus the added liquid also has the additional function of temperature control dee material can meet during the process of moisture removal. By controlling and changing the liquid temperature, compensation for a «possible overheating of the rubber material is envisaged and thus an efficient continuous process is obtained, with the water or moisture from the chewing material is removed and oil is added to give an "oil extended" chew product. The drying and other long activities will continue all in one

009837/1470

"'■" ■. ■■ '.. ■■ - - h -

one-piece device and in a continuous process carried out in which the temperature of the material is kept within safe limits.

It is now the object of the present invention to provide a new continuous process or method for pressing and Provide mixing of a liquid in elastomeric materials, in particular adding and mixing of the liquid in a continuous activity with the Drying of the material is combined and the liquid can be used to control the temperature of the material, around such a process for producing oil-extended, drier natural rubber materials and the like, wherein the oil can be easily pressed into and miscible with the natural rubber is to create a thorough dispersion of the oil and a homogeneous oil-extended natural rubber product.

An advantage of the device is that the liquid can be easily) pressed into the elastomeric material treated, while at the same time the addition of the liquid is used to control the temperature of the material or to control them to an overheating of the material and avoid damage.

Further advantages and features of the invention emerge from the following description in conjunction with the drawings.

Show it

.009837 / 1470

Pig. 1 is a schematic view of a screw press showing an embodiment of the device for carrying out the method according to the invention, with one half of the conveyor removed to the Multi-stage construction to show, with a circuit for the introduction of the liquid is shown schematically,

FIG. 2 shows an enlarged detailed view of one of the injector parts shown in FIG. 1,

Fig. 3 is a side view showing the details of the valve and the Injector nose for adding the liquid to the materials treated in the device,

4 is an enlarged, partially broken away view through a part of the conveyor of the device, the cross pieces between the cross pieces making up the chamber walls provided openings are shown and

Fig. 5 is a view similar to Fig. 1, which is a modified one Representing embodiment of the press.

The figures show preferred embodiments of the invention. Fig. 1 shows, as it were, schematically an expression

dar aas chine on the type of screw or spiral machines, which can be used continuously, has an interrupted chain or an interrupted apron conveyor, furthermore

009837 / U70

- 6 - ·

an inlet hopper 10, through which materials to be processed and treated are supplied. The materials are taken up between the plate belts of the conveyor screw or spiral 12 and through them from the filling vessel IO into the Main body of the device: worn. This one is made of one constructed outer conveyor box 15, which is formed by two symmetrical halves screwed together · One half was shown in FIG. 1 removed to show the interior of the device.

Within this outer feeder box, there is a plurality of U _n teranordnungen of the sections 16, 17> 18, 19, 20, 21, 22 and 23 having portions 16 to 19 constituting the first stage of the press and sections 20 to 23, the form the second stage. Each of these sections is formed by a frame which holds a plurality of axially extending wall rails 25 shown in FIG. These are separated from one another in some sections by suitable small spacers 26. Further details of the construction of these subassemblies are disclosed in U.S. Patent 3,126,820. As far as the present device is concerned, it is important that these sections of the device, where the liquid flows off, are provided with so-called drainage openings, which are formed between adjacent tape rails which build up the section, while the sections in which the injection is carried out have no such openings, at least not near the injection point.

009837 / U70

m 7 "

Inside the elongated, cylindrical, through the housing or the chamber formed by the funding box is an & x number secured by collar members 32 on the main shaft 30, from some of which, as shown, may be tapered to the Cross-sectional area between the collar and the walls of the conveyor box area to zoom out. Pressure screws are attached between these collars and also for rotation with the shaft 35. These are essentially of the same construction, with a screw body 37 and an interrupted one Apron belt 38 'preferably on some shown in FIG Recessed bodies for a more thorough Shearing and processing of the device located in the device Material to be provided. The main difference between the various pressure screws 35 is that the screw bodies 37 have different diameters, the generally corresponding to the larger diameter of the following Collar increases progressively. The pressure screws pick up the material printed around the preceding collar and move it under pressure over and Tim the next one Collar and to the next pressure screw. The rotation of the shaft 30, which causes this activity, is controlled by a

ko

conventional drive / get a suitable power connection has and a gear or the like, through which the desired rotation of the screw conveyor and the Pressure screws is obtained.

The conveyor box 15 is preferably of constant diameter and has an inlet or supply opening where

009837/1470 _ ₈

the feed see corner 12 entering the conveyor box, and one Unloading opening formed by an unloading ring 42 at the opposite end of the conveyor box. This ring is preferred attached to a rotatable helical gear 43 carried on a threaded boss 44, so that the rotation of the adjusting worm gear 45 controls the gear 43 rotates and causes an axial adjustment movement of the removal ring 42.

The collar members 32 and the bodies of the screw member 37 cooperate with the inner walls of the conveyor box to provide an angled passage for the material. The cross-sectional area of this passage varies at the different points. In one embodiment of the invention, this passage gradually decreases in cross-section, so that the pressure on the material in the first stage increases up to the space around the collar member 5 °. This collar member has a T _e il on, which may be inwardly tapered such that the annular space between the collar and the feeder box walls on the downstream side of this collar zuniMat. In this section and within the following chamber part 52, which surrounds the next pressure screw, the pressure on the material can therefore be reduced by a certain amount as a result of the increase in volume, which allows material to expand within the zone. In this area, the spacers are not used to prevent drainage. If you now proceed to the removal end of the conveyor box, the pressure collars can again be slow in cross-section

.009837 / U70 - 9 -

increase and accordingly the screw body in their dimensioning that pressure is again applied to the material until it reaches the removal collar 55 , which extends at least partially into the removal ring kZ . The removal collar is preferably provided with a set of Bredn attachments 57 which interact with a rotatable comminuting device 58 with a rotary drive 59. The material passing through the discharge opening engages between the comminuting device 58 and the lugs or teeth 57 and is cut or torn into relatively small pieces which are discharged through the discharge ring k2 into a suitable collecting device.

A feature of the present invention relates to the relationship of the drainage or exit openings between the wall rails in the various sections of the conveyor box. As soon as the annular cross-sectional area of the passage through the device decreases, the pressure on the material increases. It will be understood that, during operation, the passage between the rotatable parts and the walls of the conveyor box is essentially filled with tightly packed material which is continuously processed and compressed. This leads to considerable frictional heating. If desired, this heating can be regulated by the flow of heat exchanging gases and / or liquids through suitable passages, such as shown in the aforementioned US Pat. No. 3,126,820; will. As soon as the pressure on the material increases, there is a tendency, certain parts dos material into the drainage holes,

009837/1470

to squeeze between the wall rails 25. It is therefore desirable to achieve a balance between the maximum dimension of the opening for the best possible drainage and such a reduction in size of the opening, as mentioned above, in order to avoid complete clogging of the same by materials squeezed into the openings. Where the pressure on the material first decreases, such as in the chamber part 52 at the end of the first stage, the dimensioning or size of the drainage opening has increased, thereby ensuring the best possible exit and the best possible removal of the vapors and liquids. In one embodiment of the invention, the drainage openings between the wall rails 25 in section 16 are approximately O * 15 nm (0.06 inches) in width. Similar openings in section 17 are reduced to about 0.1 cm (0.04 inches); in section 18 the openings are reduced to about 0.07 cm (0.03 inches) and in the first part of section 19 the drainage openings are further reduced to 0.05 cm (0.02 inches) in width. In the last part of section 19 the opening size has increased to about 0.15 cm (0.06 inches), then in section 20 there are no openings. The size of the drainage openings in sections 21, 22 and 23 decreases according to the sizes for sections 17, 18 and 19. By operating the device of this type , it has been found that the vapors tend to flow to the point of low pressure, in other words, to the entrance to the chamber part 52 around the collar 50. By having larger drainage openings at this point it possible to achieve an optimal exit, thereby ensuring

009837 / U70

is that all vapors are quickly removed from the chamber. '-

As shown in Figure 1, there are stationary disconnect stops 6O is provided to prevent the rotation of the material with the collar 32 and with the recessed ones Worm plates 38 to work together so that a pulling, Shearing and processing of the material is achieved. A However, feature of the invention is directed to the specific Formation of the separating stops 62, as shown in FIG. 3. The separating stop 62 is at a distance from the outside of the collar within the chamber part 52. A shown in Fig. 2, controlled injection nozzle 63 is fixed in the extension 62, around plasticizing or softening oil in the chamber part 52 close to the adjacent screw body and thus essentially in the middle of the mass of material in this Chamber part.

Details of a nozzle are shown in FIG. The barrel-shaped body 65 is fitted into the socket and a valve boss 66 carries a head 68 which cooperates with a seat 69 to control the flow into the chamber. The rod has a threaded part 70 , which is received in a piston 71 _r which is movable in a cylinder 72. Oil is fed under pressure into the tangent egg sub-chamber 73 when it is to be injected. This will automatically open the nozzle. Entering the oil under pressure to the opposite chamber 74 will shut off the nozzle. the

00 9837 / t470 - «-

~ 12 -

20081OA

Extending rod 75 provides means for securely attaching the nozzle, if desired, and there is a visible indication of the position of the nozzle.

The liquid plasticizer to be mixed with the rubber material is supplied from a pipe or manifold 80 which receives this liquid and / or gas from a reciprocating cylinder exhaust pump 82. Particularly in the treatment of natural rubber and the like, a liquid such as oil is used to provide a so-called ^H oil-extended ^M rubber product. This oil comes from a suitable tank 85 which is connected by line 86 to a conventional heat exchanger 88 which is used to heat the oil to a desired temperature. The oil thus remains at a certain temperature which can be controlled by suitable control of the heat exchanger 88. This oil temperature is preferably slightly less than the temperature of the material in the chamber part 52 of the press, so that the oil tends to absorb some heat from the frictionally heated rubber material and thereby cause a cooling effect on the rubber which prevents it from overheating and prevents the destruction of the rubber material. At the same time, the heated oil is thoroughly mixed into the rubber material by means of the mechanical working of the material of the recessed pressure claw plates and the cooperation of these plates with the collars and the separation bars. A secondary line 90 around the

009837 / U70 " ¹³ "

Heat exchanger 88 is provided. A control valve 92 is trapped in the bypass, creating cool oil can be conveyed from the tank directly to the cylinder 82, if an additional cooling effect should be necessary.

The cylinder 82, as shown in Fig. 1, works double when reciprocating. It takes oil to be injected through the control valves 95 and delivers oil through the control valve 6 into a manifold 97 * which leads to the inlet pipes 75 of the injector. A pressure relief valve 98 is provided, which now has a Neb @ n-

the oil
line / returns to tank 85 when the pressure rises above a predetermined limit. This arrangement ensures effective pumping at relatively high pressure and ensures that the oil is injected into the material within the press just as effectively.

The pump 82 is driven by a double acting reciprocating motor 100 which is connected to the pump via a coupling 101. A separate hydraulic circuit for driving the motor 100 includes a tank T2 from which the hydraulic fluid is pumped by the pump IO3 to a conventional servo-operated vehicle IO5. The · «· valve has the ends old _f the opposite heads of the motor 100 connected FÜJirungezyllnder i 06, so that once the motor-tange" inen limit of your Kolbenhube achieved, dor Druckbewirkt at its opposite "that the appropriate bar 106 d & s valve I05

■; ■,; ■ Λ: - ": \ ■ '-'""■.'- ■■ '■ -. 1k - ■. 0Q9837 / 147Q

20081

switches. As a result, the pressure connections to the Motor 100 and thus its direction reversed. At the same time, the return connection to tank T 2 in vice versa in the same way. An adjustable bypass valve 108 is in communication with the outlet side of the pump 103. By adjusting the pressure of the pump outlet this valve makes it possible to increase the reciprocating speed of the motor 100 or to humiliate and. thereby controlling the rate of the pump 82 or the delivery rate.

Pig. 5 shows a modified Ausführungsfor: dor invention. The structure of the prices has generally been described in greater detail in a parallel application. (US Serial No. 763 64?). The device shown in FIG. 5 has been found to be particularly advantageous in drying natural rubber. It differs from the device shown in FIG. 1 primarily with regard to two features. In the chamber of the press there is a central throttle ring 110, upstream of the injector nozzle 112, which extends through the rod 114 and which has the same structure as shown in Fig. 3 and described above.Secondly, instead of the crushing device according to Fig. 1 an extruder section II5 is provided at the outlet end of the press, which has a non-perforated extruder tube 116 which has a smaller diameter than the mean diameter of the press cylinder double

009837 / U7Ö

Screw extruder screw 118 operates in this tube II6. At the outlet of the tube II6 a drawing iron 120 is attached, through which the rubber material is dispensed. A rotating knife 122, driven by a separate motor, not shown, cuts through the Die extruded material into relatively small parts. In this In the device, the rubber material is essentially moisture-free while being injected through the nozzle 112 Oil is added to the material.

By using the screw press device described above one can add liquids to rubber material easily and completely in the same operation get through which liquid is removed from the material will. This is particularly beneficial in treatment and the processing of natural rubber materials where the addition of liquid "n required very complicated processes up to now, In addition, the liquid thoroughly mixed into the final product also helps control the temperature of the rubber material and thus prevents overheating and a Destruction of the rubber material.

While the shape of the device described herein represents a particular embodiment of the invention, the Invention, of course, does not relate to this precise training the device limited. Changes can be made without falling outside the scope of the invention

00 9837/147 0

Claims (1)

Claims iJ Process for the continuous injection of a liquid in an elastomeric material, characterized in that the material is continuously fed through the chamber of a mechanical screw press, which has an initial progressive This causes the pressure to rise within the material, while simultaneously causing the material to pass through the chamber is processed that a liquid is injected into the material when it is processed under pressure, and then the pressure on the material within the chamber is increased while processing of the material continues and the liquid is mixed thoroughly into the material under pressure. 2. The method according to claim 1, characterized in that the moisture from the material during the initial pressure increase is removed to dewater the material and then liquid is added to the material. 3 · The method according to claim 1, characterized in that the liquid to be injected is heated to a certain temperature. k. A method according to claim 1, characterized in that the material is extruded through a die after the liquid has been mixed in. 009837 / U70 - ¹⁷ - _ «Tr - 5. Screw pressing device for continuous drying of a rubber material and for mixing in a liquid and / or a gas in the material during the drying process, characterized in that a wall has a elongated chamber with drainage openings made in it forms, conveying and processing devices are provided with a shaft rotatably mounted in the chamber and Drive means and a plurality of successive collars or borehole openings are provided and screw bodies with plates located thereon, which are fastened on the shaft, with at least the screw bodies for rotation with the shaft with this in connection, stationary separating stops, which are located between the screw plates for an interaction with these for shearing and processing the Extend material that the chamber in at least first and second stage is subdivided, in each of which the processing and conveying devices the pressure of the conveyed through the chamber Materials progressively increases, a means of forming a zone formed between the stages in which the pressure on the material is effectively reduced -that the Drainage openings are progressively reduced in size, according to the increase in the diameter of the working and conveying device to allow the extrusion of the material through the Keep openings to a minimum if the pressure increases while the moisture and steam released by the material can escape that the wall is not provided with holes immediately downstream of the expansion zone and one - 18 - 009837/1470 Device for injecting a liquid into the through. The area surrounding the non-perforated wall is provided for mixing the liquid in the material within the second stage. 6. Apparatus according to claim 5 t, characterized in that that the injection device has an injector nozzle, which extends through one of the separation stops to the "Release liquid near the center of the chamber. 7. Apparatus according to claim 6 _f, characterized by a positive displacement pump for dispensing the liquid under pressure to the nozzle. 8. Apparatus according to claim 6, characterized in that the injector nozzle has a valve device that can be actuated from outside the press for controlling the flow through it the nozzle. 9. Device according to one of claims 5t 6, 7 or 8, characterized by a non-perforated extruder section which receives the material from the delivery end of the second stage, and by a die or mold attached to the end of the extruder section with openings through which the liquid-stretched material issued by the press. 009837 / U70