WO2019220952A1

WO2019220952A1 - Mixing method and mixing device for compounding agents

Info

Publication number: WO2019220952A1
Application number: PCT/JP2019/018258
Authority: WO
Inventors: 実伏貫
Original assignee: Nok株式会社; Ｎｏｋエラストマー株式会社
Priority date: 2018-05-17
Filing date: 2019-05-07
Publication date: 2019-11-21
Also published as: JPWO2019220952A1; CN112041139B; JP2022058544A; JP7080312B2; CN112041139A; JP7212803B2

Abstract

According to a mixing method for compounding agents, prior to compounding multiple types of compounding agents with raw material rubber at a predetermined compounding ratio, the multiple types of compounding agents, in amounts in accordance with the compounding ratio, are enclosed in a bag body, the bag body is introduced into a rotary drum of a mixing device, the rotary drum is rotated to roll the bag body, and the multiple types of compounding agents enclosed in the bag body are mixed. The rotary drum rotates around a horizontal axis, and the bag body is rotated along the inner circumferential surface of the rotating rotary drum. Here, the rotation direction of the rotary drum is switched at predetermined intervals to change the rolling direction of the bag body.

Description

Method and apparatus for mixing compounding agents

The present invention relates to a blending method and a blending device for blending a plurality of kinds of blending agents.

Generally, for rubber, compounding agents such as fillers and additives are blended with raw material rubber at a predetermined blending ratio in order to provide necessary physical properties and functions. The blending operation is performed using a kneader such as a kneader or a roll.

A plurality of types of compounding agents are blended in the raw rubber at a predetermined blending ratio (see, for example, Patent Document 1). A compounding agent is mix | blended with raw material rubber | gum by the following process, for example.
(Step 1) A plurality of kinds of compounding agents are weighed, and an amount of the compounding agent according to the compounding ratio is sorted for each type. The various types of compounding agents are once put into a work box with the top surface opened.
(Step 2) The box is tilted by being inserted into the inlet of the kneader, and the compounding agent is charged from the box into the kneader. Alternatively, scoop up the compounding agent in the box with a scoop, insert the scoop into the kneading machine's inlet, and tilt it into the kneading machine.

JP 2000-212333 A

In the above step 1, since plural kinds of compounding agents are weighed for each type and sequentially put into the box, the plural kinds of compounding agents are hardly mixed in the box.

For this reason, in step 2 above, a plurality of types of compounding agents are charged into the kneader in a state where they are hardly mixed. As a result, in the raw rubber having poor dispersibility, a dispersion failure occurs such that the compounding agent is not mixed uniformly in the kneader, and the phenomenon that the necessary physical properties and functions cannot be obtained due to this dispersion failure occurs. There is. Such a phenomenon is particularly likely to occur in raw rubber with poor dispersibility such as fluorine-based rubber.

In order to prevent such a poor dispersion of the compounding agent, an operation of mixing a plurality of types of compounding agents in the box using a manual work or a scoop is performed. However, when mixing is performed in the box, the premixed compound may remain in the corner of the box and mixing may not be performed sufficiently. Improvement is required.

An object of the present invention is to allow a plurality of types of compounding agents to be uniformly dispersed in the raw rubber prior to compounding a plurality of types of compounding agents into the raw rubber at a predetermined mixing ratio.

The mixing method of the compounding agent of the present invention encloses the plurality of compounding agents in an amount in accordance with the compounding ratio in a bag before compounding a plurality of compounding agents in the raw rubber at a predetermined compounding ratio, The bag body in which the plural kinds of compounding agents are enclosed is put into the rotating drum of the mixing device that rotationally drives the rotating drum, and the bag body is rolled in the rotating drum by driving the rotating drum to rotate. The plural kinds of compounding agents enclosed in the bag are mixed with each other.

The mixing device of the compounding agent of the present invention accepts a bag body that encloses the plurality of compounding agents in an amount corresponding to the compounding ratio before compounding a plurality of compounding agents in the raw rubber at a predetermined compounding ratio. A rotating drum, a support portion that rotatably supports the rotating drum with the axial direction being transverse, and a drive portion that rotationally drives the rotating drum, and follows the inner peripheral surface of the rotating drum that rotates. The bag body is rolled by repeating the removal from the inner peripheral surface.

According to the present invention, it is possible to uniformly disperse a plurality of types of compounding ingredients in the raw rubber before blending a plurality of types of compounding ingredients in the raw rubber at a predetermined compounding ratio.

(A) which shows one Embodiment of the mixing apparatus of a compounding agent is a front view, (B) is a side view. The block diagram of the electrical connection of each part. The table | surface which shows the result of a comparative test.

The mixing method of the compounding agent of the present embodiment is performed before blending a plurality of types of compounding agents blended into the raw rubber at a predetermined blending ratio into the raw rubber. In this mixing method, plural kinds of compounding agents are mixed with each other by the following procedure.

As the plural kinds of compounding agents, for example, a combination of fillers such as white carbon (silica) and black carbon, a combination of fillers and additives, a combination of plural additives, and the like are used. In addition, various compounding agents such as fillers and additives generally used in the rubber industry, for example, fillers such as black carbon, white carbon (silica), talc, clay, graphite, calcium silicate, stearic acid Further, processing aids such as palmitic acid and paraffin wax, acid acceptors such as zinc oxide and magnesium oxide, antiaging agents, plasticizers and the like are used in appropriate combination.

The mixing method of the compounding agent of this Embodiment is performed by each following process.
[First step]
A bag body having a capacity capable of accommodating a plurality of kinds of compounding agents in an amount according to the compounding ratio is prepared. In this bag body, a plurality of kinds of compounding agents in an amount corresponding to the blending ratio are sequentially stored, and the opening of the bag body is closed. The bag body is a flexible bag body made of a thin film resin, for example, and may be a commercially available so-called plastic bag. Since a plurality of kinds of compounding agents are mixed in the bag, it is desirable that the capacity of the bag body is set so as to allow a sufficient amount of the compounding agent so that the compounding agent can move in the bag. The weighing of the compounding agent may be performed in advance before the compounding agent is accommodated in the bag, or may be performed while the bag is placed on a weighing machine (not shown) and the compounding agent is accommodated in the bag.

When carrying out the weight reduction of a compounding agent, storing a compounding agent in a bag body, a bag body is first mounted on a measuring machine and several types of compounding agents are sequentially accommodated in the bag body mounted on the measuring machine. At this time, the weight is reduced by a weighing machine each time each type of compounding agent is put into the bag. By this measurement, it is possible to know the weight of each type of compounding agent placed in the bag. More specifically, the weight of the compounding agent to be put in the bag body can be known as a difference from the weight of the compounding agent previously stored in the bag body. Therefore, each type of compounding agent can be sealed in the bag body at a compounding ratio converted to weight while putting each type of compounding agent in the bag.

[Second step]
The bag body in which a plurality of kinds of compounding agents are enclosed in the first step is put into the rotating drum of the mixing device. At this time, a plurality of bags may be charged simultaneously. Details of the mixing apparatus will be described later.

[Third step]
The rotary drum into which the bag is put in the second step is driven to rotate, and the bag is rolled in the rotary drum, whereby a plurality of kinds of compounding agents enclosed in the bag are mixed with each other after a predetermined time has elapsed. .

According to the mixing method including the first to third steps, a plurality of kinds of compounding agents enclosed in the bag can be sufficiently mixed, and poor dispersion occurs when the compounding agent is compounded into the raw rubber. Can be solved in advance. At this time, the operator only needs to perform the operation of instructing the weighing of the compounding agent and the enclosing in the bag body, the insertion of the bag body into the rotating drum, and the driving of the rotating drum, thereby reducing the burden on the operator. be able to. The operation time of the rotating drum is generally about 1 to 5 minutes although it depends on the amount of the compounding agent.

The mixing device of the present embodiment is configured as follows. This mixing apparatus is an apparatus for mixing a plurality of types of compounding agents with each other before compounding the raw material rubber, and is not an apparatus (kneading device) for compounding the compounding agent with the raw material rubber.

As shown in FIG. 1, the mixing device 1 includes a frame-shaped pedestal 2, a pair of left and right drive rolls 3 disposed on the pedestal 2, and a driven roll 3 that is driven and rotated on the drive roll 3. A rotating drum 4 that rotates, an electric drive source (not shown) for rotating the drive roll 3, and an operation unit 5.

The pair of left and right drive rolls 3 are rotatable rollers and play a role as a support portion for mounting and supporting the rotary drum 4. These driving rolls 3 are arranged in parallel to each other, and the rotating drum 4 is placed with the axial directions thereof aligned. At this time, the rotary drum 4 is merely placed on the pair of drive rolls 3 and is not restrained in position by another structure.

As shown in FIG. 2, the mixing apparatus 1 includes a motor M as a drive source for rotationally driving the pair of drive rolls 3. The mixing device 1 includes a transmission mechanism (not shown) that transmits the rotation of a rotation shaft (not shown) of the motor M to the drive roll 3. The transmission mechanism may be configured to transmit the rotation of the motor M only to one drive roll 3 or may be configured to transmit to both drive rolls 3.

As shown in FIG. 2, the mixing apparatus 1 includes a control unit 11. The motor M is connected to the control unit 11 via the motor drive circuit 12. The operation unit 5 is also connected to the control unit 11 via the input / output circuit 13. The control unit 11 is an integrated circuit that sequentially executes logic for receiving an input signal from the operation unit 5 and outputting a drive control signal for the motor M. The control unit 11 that has received an input signal from the operation unit 5 via the input / output circuit 13 outputs a drive signal for the motor M. The motor drive circuit 12 closes an energization circuit (not shown) connected to the motor M in accordance with the drive signal received from the control unit 11. The motor M and the motor drive circuit 12 function as a drive unit that rotationally drives the rotary drum 4.

The logic of the control unit 11 is set to repeat forward and reverse rotation of the motor M. That is, the logic repeats a driving signal for rotating the motor M in one direction and a driving signal for rotating the motor M in the opposite direction in a predetermined cycle. In accordance with this logic, the control unit 11 causes the drive roll 3 and the rotating drum 4 driven thereby to rotate forward (arrow x) at a predetermined rotational speed, and then reversely rotate (arrow y) at a predetermined rotational speed. The motor M is controlled to repeat this at a predetermined cycle. The predetermined rotation speed is, for example, 75 rpm.

The pair of left and right drive rolls 3 has a rotation center axis (not shown) such that one roll end (axial end) 3a is positioned higher than the other roll end (axial end) 3b. ) Is set at an angle. The inclination angle of the rotation center axis is, for example, about 15 degrees.

As a result of the rotation center axis of the pair of left and right drive rolls 3 being inclined, the rotary drum 4 placed on the drive roll 3 also has one drum end (axial end) 4a and the other drum end (axial end). Part) The rotation center axis 4c is set so as to face an oblique direction so as to be positioned higher than 4b. Needless to say, the inclination angle of the rotation center axis 4 c is, for example, about 15 degrees that coincides with the rotation center axis of the pair of drive rolls 3.

The rotating drum 4 is open on the drum end 4a side and closed on the drum end 4b side. A drum opening 4d is provided at the drum end 4a that opens. The outer peripheral surface of the rotating drum 4 is a cylindrical peripheral surface portion 4 e that contacts the drive roll 3. A bottom surface portion 4f is provided on the other drum end portion 4b that is closed.

Between the pair of driving rolls 3 and the outer peripheral surface of the peripheral surface portion 4e of the rotating drum 4, when the driving roll 3 rotates, a frictional resistance that the rotating drum 4 follows without causing slippage is generated. In order to generate such a frictional resistance, the drive roll 3 is covered with, for example, a rubber-like elastic body. The entire rotating drum 4 is made of metal. The rubber-like elastic body forming the outer peripheral surface of the drive roll 3 generates a frictional resistance with the outer peripheral surface of the metallic rotating drum 4 and transmits the rotation of the driving roll 3 to the rotating drum 4 without causing slippage. .

The rotating drum 4 having such a configuration is placed on the pair of drive rolls 3 so that the drum end 4a is positioned higher than the drum end 4b. This facilitates taking in and out of the bag body from the drum opening 4d. At this time, since the drum end 4a is positioned higher than the drum end 4b, there is no possibility that the bag body will spill out of the drum opening 4d. It has a structure. Of course, the opening / closing lid is not necessarily provided, and as another embodiment, an opening / closing lid may be provided.

Two engaging portions 4g are provided on the inner peripheral surface of the rotating drum 4, that is, the inner peripheral surface of the peripheral surface portion 4e. These engaging portions 4g have a rod-like shape, and are arranged along the axial direction of the rotating drum 4 in a state of being in contact with the inner peripheral surface of the peripheral surface portion 4e. When viewed from the inner peripheral surface of the peripheral surface portion 4e, the engaging portion 4g has a protruding shape. Such an engaging portion 4g plays a role of facilitating rolling of the bag body by the bag body being caught while the rotary drum 4 is rotating. This point will be described in detail later.

As shown in FIG. 1, the engaging portion 4 g of the present embodiment is two linear ridges that are equally spaced and extend along the rotation center axis 4 c of the rotating drum 4. The height of the engaging portion 4g, that is, the projecting dimension from the inner peripheral surface of the rotating drum 4 is, for example, about 10 mm.

The engaging portion 4g may be any member that plays a role of assisting the rolling of the bag body by the bag body being caught while the rotary drum 4 is rotating. Various forms of the engaging portion 4g are allowed for the shape, the number of installed portions, and the arrangement position. As long as this condition is satisfied, the shape and the number of the engaging portions 4g are not particularly limited. The number of installations may be 2 to 6, for example. The engaging portion 4g may be arranged in a non-contact state with respect to the inner peripheral surface of the rotating drum 4.

In such a configuration, if the operator puts a bag body in which a plurality of kinds of compounding agents are sealed into the rotary drum 4 from the drum opening 4d (the second step), the operator 5 enters the third portion. An instruction is given to execute the process. That is, it instructs rotation of the rotating drum 4.

The control unit 11 outputs a drive signal for driving the motor M in response to an input instruction from the operation unit 5. As a result, the rotation shaft of the motor M rotates, the drive roll 3 is driven to rotate, and the rotary drum 4 rotates following the rotation of the drive roll 3.

When the rotating drum 4 rotates, the bag body in which a plurality of kinds of compounding agents stored in the rotating drum 4 is entrained rotates following the inner peripheral surface of the rotating drum 4. At this time, the bag body is caught by the engaging portion 4g, and slipping between the inner peripheral surface of the rotating drum 4 and the bag body is suppressed.

The control unit 11 outputs a drive signal so as to switch the rotation direction of the motor M at a predetermined cycle. By outputting a drive signal so as to switch the rotation direction from the control unit 11, the rotating drum 4 repeats forward rotation (arrow x) and reverse rotation (arrow y), and a bag body in which a plurality of types of compounding agents are enclosed. Repeats forward and reverse rotation. As a result, a plurality of kinds of compounding agents can be mixed more sufficiently in the rolling bag.

At this time, the following state of the bag body with respect to the rotation of the rotating drum 4 varies depending on the size of the bag body in the rotating drum 4 and the frictional resistance between the rotating drum 4 and the bag body.

In the present embodiment, a relatively small bag body is used with respect to the inner diameter of the rotating drum 4, and a plurality of kinds of compounding agents are accommodated in the bag body. When the rotating drum 4 rotates, the bag body follows the rotating drum 4 by being caught by the engaging portion 4g and is carried upward. The bag body carried upward falls by dropping from the engaging portion 4g. Plural kinds of compounding agents accommodated in the bag are mixed by the rising and falling of the bag.

At this time, the rotation angle of the rotary drum 4 at which the bag body falls depends on the state of the bag body being caught by the engaging portion 4g. If the engaging portion 4g is relatively large with respect to the bag body, the bag body is less likely to drop off from the engaging portion 4g, and if the engaging portion 4g is relatively small with respect to the bag body, the bag body is not engaging with the engaging portion 4g. It becomes easy to drop off. The ease of dropping off the bag body also depends on the shape of the engaging portion 4g. If the engaging portion 4g has a shape such as a hook or nail, the bag body is unlikely to fall off the engaging portion 4g.

As described above, the mixing method and the mixing device of the compounding agent of the present embodiment rotate the rotating drum 4 with the axial direction being transverse and, more precisely, the rotation center axis 4c is inclined with respect to the horizontal. The bag body is rolled by following the inner peripheral surface of the rotating drum 4 that rotates. The follow-up in this case does not mean to follow the rotating drum 4 by 360 degrees, but means follow-up of an angle range from dropping from the engaging portion 4g to dropping.

As another embodiment, a bag having a size close to the inner peripheral surface of the rotating drum 4 may be used. If the bag body is larger as it comes closer to the inner peripheral surface of the rotating drum 4, the frictional resistance of the bag body with respect to the inner peripheral surface of the rotating drum 4 increases, so that the bag body follows the rotating drum 4 without slipping. At this time, the bag body follows the rotating drum 4 by 360 degrees. Plural kinds of compounding agents accommodated in the bag are mixed by rotation of the bag.

Even when a relatively small bag is used with respect to the inner diameter of the rotating drum 4, the bag becomes slippery with respect to the inner peripheral surface of the rotating drum 4 as the size of the bag decreases. At this time, the engaging portion 4g exhibits its function, and the bag body becomes difficult to slip by being caught by the engaging portion 4g, and follows the rotation of the rotating drum 4.

As described above, the mechanism in which the bag body rolls in the rotating drum 4 following the rotation of the rotating drum 4 and the manner in which the bag rolls are related to the size relationship between the inner diameter of the rotating drum 4 and the bag body, and the frictional resistance. It varies depending on the relationship, etc., and is not uniform.

When the bag body is small with respect to the rotating drum 4 and the bag body follows the inner circumferential surface of the rotating drum 4 by a certain angle range and then falls off, the rolling of the bag body causes the bag body to rise. And fall. As described above, a plurality of kinds of compounding agents contained in the bag are mixed by the rising and falling of the bag.

When the bag is relatively large with respect to the rotating drum 4 and the bag rotates following the rotation of the rotating drum 4 within a range of 360 degrees, the rolling of the bag means the rotation of the bag. As described above, a plurality of types of compounding agents contained in the bag are mixed by the rotation of the bag.

According to the present embodiment, by mixing the compounding agent using the mixing device 1, it is possible to sufficiently mix a plurality of types of compounding agents enclosed in the bag body, and thus mixing the compounding agent into the raw rubber. It is possible to eliminate the occurrence of poor dispersion when blended. Since plural kinds of compounding agents are mixed by the rotation of the rotating drum 4, the burden on the operator can be reduced.

Various changes and modifications can be made to the mixing method and mixing apparatus 1 of the compounding agent of the present embodiment.

For example, although an example in which the axial direction of the rotating drum 4 is inclined with respect to the horizontal is shown in the above embodiment, this is not essential. As long as the rotating drum 4 rotates laterally in the axial direction, the rotation center axis 4c does not necessarily have to be inclined with respect to the horizontal. Alternatively, as another embodiment, the rotation center axis 4c of the rotary drum 4 may be directed vertically, for example, in the vertical direction, instead of horizontally.

EXAMPLE In the production of rubber (hydrogenated NBR composition) having the following composition, white carbon (reinforcing silica) and black carbon (FEF carbon black) are mixed in advance and used as a plurality of compounding agents. And mixed. After mixing, the mixture was put into a kneader and kneaded with other compositions for 6 minutes.
<Composition>
Hydrogenated NBR (AN25%, iodine value 15, ML1 + 495) 100 parts by weight Reinforcing silica (specific surface area 100 m2 / g) 60 parts by weight FEF carbon black 10 parts by weight Zinc oxide 5 parts by weight Polymerized (2,2,4- (Trimethyl-1,2-dihydroquinoline) 0.5 parts by weight 2-mercaptobenzimidazole 2 parts by weight dioctyl sebacate 10 parts by weight dicumyl peroxide 5 parts by weight triallyl isocyanurate 5 parts by weight
Comparative Example When producing a rubber (hydrogenated NBR composition) having the above composition, white carbon (reinforcing silica) and black carbon (FEF carbon black) are not mixed in advance and are added to the kneader. And kneading for 6 minutes.
Results As a result of the dispersion confirmation by each test piece, in the comparative example, as shown in the upper part of the table of FIG. 2, “white matter (large)” was generated in the cross section, and “evaluation: x”. In the example, as shown in the lower part of the table in FIG. 2, “white matter (large)” was not generated in the cross section, and thus “evaluation: ○” was obtained. Therefore, it was possible to confirm the effect of eliminating the dispersion failure by the mixing method and mixing apparatus of the compounding agent of the present embodiment.

DESCRIPTION OF SYMBOLS 1 Mixing device 2 Base part 3 Drive roll 3a One roll edge part 3b The other roll edge part 4 Rotating drum 4a One drum edge part 4b The other drum edge part 4c Rotation center axis 4d Drum opening part 4e Circumferential surface part 4f Bottom face part 4g Protruding engagement part 5 Operation part M Motor (drive part)
11 Control Unit 12 Motor Drive Circuit (Drive Unit)
13 Input / output circuit

Claims

Before blending a plurality of kinds of compounding ingredients in the raw rubber at a predetermined compounding ratio, encapsulate the plural kinds of compounding ingredients in an amount along the compounding ratio in a bag body,
Into the rotating drum of the mixing device that rotationally drives the rotating drum, the bag body in which the plural kinds of compounding agents are enclosed is charged,
Rotationally driving the rotating drum to roll the bag body in the rotating drum, and mixing the plural kinds of compounding agents enclosed in the bag body with each other;
Mixing method of compounding agents.
Rotating the rotating drum with the axial direction being transverse, and rolling the bag body by following the inner peripheral surface of the rotating drum,
The mixing method of the compounding agent of Claim 1.
Slip between the inner peripheral surface of the rotating drum that rotates and the bag body is suppressed by an engaging portion provided along the axial direction inside the rotating drum.
The mixing method of the compounding agent of Claim 2.
The rotating drum rotates in a state in which one end portion is opened and the axial direction is inclined with respect to the horizontal so that the opened end portion is at a higher position than the opposite end portion.
The mixing method of the compounding agent of Claim 2.
Periodically switching the direction of rotation of the rotating drum,
The mixing method of the compounding agent as described in any one of Claims 1 thru | or 4.
Place the bag on a weighing machine,
The plurality of kinds of compounding agents are sequentially accommodated in a bag placed on the weighing machine,
Each time the individual kinds of the compounding agents are put in a bag, the weight is reduced by the weighing machine, and the compounding agent of the blending ratio converted to the weight is enclosed in the bag body.
The mixing method of the compounding agent of Claim 1.
A rotary drum that receives a bag body that encloses the plurality of types of compounding agents in an amount according to the compounding ratio before compounding a plurality of types of compounding agents in the raw rubber at a predetermined compounding ratio;
A support portion that rotatably supports the rotating drum with the axial direction being transverse;
A drive unit for rotationally driving the rotary drum;
And rolling the bag body by following the inner peripheral surface of the rotating drum that rotates.
Compounding device.
An engagement portion is provided along the axial direction inside the rotating drum.
The mixing device of the compounding agent of Claim 7.
The rotating drum has one end open,
The support portion supports the rotating drum in a state where the axial direction is inclined with respect to the horizontal so that the opening end portion is positioned higher than the opposite end portion.
The mixing device of the compounding agent of Claim 7.
Periodically switching the direction of rotation of the rotating drum,
The mixing device of the compounding agent of Claim 7.
The support portion supports the rotating drum with a pair of rotatable rollers arranged in parallel with the rotating drum in the axial direction.
The drive unit rotationally drives at least one of the pair of rollers;
The mixing device for a compounding agent according to any one of claims 7 to 10.