JPH0493205A - Improved mechanical washing type colliding and mixing type mixing module - Google Patents

Abstract

PURPOSE:To obtain a mixing module where even at the time of a start and end of a discharge, a compounding ratio is unchanged, and removal of a liquid is not necessitated, by a method wherein the title mixing module is made into such a design that positions of discharge ports of a liquid A and liquid B are on the same circumference, both or either one of the liquids A, B is discharged linearly toward the central part of a mixing chamber and a number of the discharge ports and/or a ratio of areas are made so that they are within + or -50% of the compounding ratio between the liquid A and liquid B. CONSTITUTION:A number of both orifices and areas of a liquid A and liquid B are designed for A:B=1:2. which is the same as a volume ratio raw materials, as a spray head. Orifices for the liquid A are bored in two positions by making their mutual position into 180 degrees and orifices for the liquid B are bored in four position by making them into 90 degress. Respective discharge angles are prepared so that apexes are on a line where the two liquids are moved linearly toward the central part of a mixing chamber and positions of discharge parts are in existence on the same circumference and the two liquids are mixed up with each other under a state where rotary movement is not generated. A stripe pattern to be observed at the time of defective mixing is not seen and performance of molding without having removal of the liquid is possible. Hardness of a made sheet, a modulus, tensile strength, elongation and tear strength are all excellent and mixing properties also are favorable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention discharges liquids A and B of resin raw materials such as urethane, epoxy, and unsaturated polyester from a discharge port, mixes them by an impingement mixing method, and sprays or injects them. With regard to the collision-mixing type mixing module used during molding (a component in which the discharge ports [orifices] for liquids A and B and the mixing chamber for collision-mixing the two liquids are integrally molded), this improvement improves the timing at the start of dispensing and Even at the end of the process, it is possible to maintain the mixing ratio of the two components at the set value.
Mixing for spraying and casting that allows molding without the need for a drain to discard liquids that do not match the mixing ratio at the start and end of the process, as well as stable physical properties and improved spray conditions in the case of spray molding. Regarding modules.

[Conventional technology]

When molding a two-component fast-curing material with a high reaction rate, an impingement mixing method is usually used. This is because mechanical mixing and static mixing do not allow enough time to clean the mixing chamber because the reaction is fast. The collisional mixing method has the feature that after the mixed liquid is discharged, the mixing chamber can be cleaned in a short time by mechanically moving a rod in and out, or by using a solvent or air.

Examples of machine-cleaning impingement mixing heads that mechanically move rods in and out include the D-Gun, GX-7 Gun, and RIM (Reaction Injection Molding) spray and injection heads made by Gasmer. Examples include Toho Kikai, Krauss Mats Fai, and Canon. In the case of the D gun, rectangular holes are made on both sides of the integrated mixing chamber, one at the top and one at the bottom of the mixing chamber, and the liquid discharged into the mixing chamber is mixed in a swirl and then ejected. Used as a spray or injection. The problem with this gun is that since each hole has one hole, the mixing characteristics will deteriorate when handling high viscosity liquids, and since the mixing of the two liquids is mainly based on rotational movement, the mixed liquid will be ejected from the head. The rotational movement remains, and especially when spray molding, the spray condition (pattern) may be deformed and density differences may occur. Therefore, when spraying is performed, it is necessary to adjust the length of the mixing chamber by changing the retracted position of the pulping rod in accordance with the set conditions each time a molding operation is performed.

C; In the case of the X-7 gun, it has an integrated mixing module structure, and the A liquid is discharged from the front and the B liquid is discharged from the rear in the jetting direction of the mixed liquid, and the discharge angle is as follows.
Since both directions are perpendicular to the rod, there is no direct collision. For this reason, when the rod retreats and liquid is spouted out, the A liquid at the front will always be ejected alone into the mixing chamber first, and then the B liquid will be ejected.
At the start, a mixture with an incorrect mixing ratio is discharged, so
Draining operation is required. Furthermore, the same thing occurs when the process is finished, and it becomes necessary to drain the liquid. In spray molding, the gun first starts spraying somewhere other than the object (
After that, it is necessary to spray the gun onto the mold, etc., and at the end of the process, the gun is moved from the surface of the molded object to another area and then stopped, which reduces work efficiency and yields. Injection molding also requires a draining operation similar to spraying. Furthermore, if the work is not carried out reliably, physical properties may deteriorate due to changes in the blending ratio.

The head used for RIM molding usually has one head on each side.
Many of them are two-liquid or direct collision mixing types with multiple orifices, and since there may be problems with the mixing characteristics, it is necessary to install remixing auxiliary devices such as an "after mixer" or a film gero on the mold side, at the beginning and end of the mold. The mixture is designed to escape or remain in a part of the after mixer, and measures are taken to prevent the inappropriate mixture mentioned above from entering the product, and to deal with variations in the blending ratio that occur at the start and end of dispensing. ing.

[Problem to be solved by the invention]

When liquids A and B of resin raw materials such as urethane, epoxy, and unsaturated polyester are discharged from the discharge port and sprayed or injection molded using the collision mixing method, the conventional mixing method has various drawbacks as described above. The inventors of the present invention have found that it is possible to perform molding without discarding the liquid at the start and end of dispensing (draining the liquid), and at the same time, it has stable physical properties and a good spray condition (pattern) in the case of spray molding. The purpose of this study was to determine the mixing module for spraying and casting that could be obtained.

[Means to solve the problem]

When considering the cleaning characteristics of collision mixing heads, air cleaning and solvent cleaning methods cannot completely clean them, and as the number of times they are used, the mixture accumulates in the mixing chamber and nozzle, causing changes in the mixing characteristics. For this reason, the spray conditions (pattern) change in spray molding. Therefore, the mechanical cleaning method is reliable, and the mixing efficiency is less likely to change or deteriorate. In order to always maintain the blending ratio at the start and end using a mechanical cleaning method, it is necessary to open the orifices for liquid A and liquid B at the same time, and it is necessary to keep both orifices on the same circumference. This is an essential requirement. Due to the second feature, it is possible to perform molding without discarding the liquid (draining the liquid) at the start and end of discharging.

For impingement mixing, the orifice size accuracy and position accuracy are important factors and influence the mixing characteristics. Therefore, by making the orifices for liquids A and B integrally molded, it is possible to prevent variations in mixing properties. In addition, it is extremely effective to increase the contact opportunities between the two liquids in order to improve the mixing characteristics and obtain stable physical properties. Specifically, it is extremely effective to increase the contact opportunities between the two liquids. Specifically, the number and/or area of the orifices should be adjusted to match the raw materials used. Designed within ±50% of the blending ratio.

When using materials with different mixing ratios, it is preferable to adjust the number of orifices rather than the area in order to improve the mixing characteristics. In addition, if the viscosity of the raw materials used is the same, the number and area of the orifices may be the same, but in reality, the viscosity of the two liquids often differs (in other words, the discharge of the raw material with a higher viscosity will be delayed). It is possible to adjust the viscosity by varying the temperature of the liquid, but it is effective to slightly change the orifice size or to expand the working range during molding.Normally, this range of change is ±50. We will respond with an increase or decrease within %.

Furthermore, in order to obtain a good spray condition during spray molding, it is important to change the mixing of the two liquids from mixing only by rotation to mainly collision, so that no rotation remains in the mixed liquid. That is, the mixing chamber part where the two liquids collide is a module that is integrally molded, and the CIIA liquid and the B liquid each have two or more discharge ports (orifices), and (2) the discharge ports (orifices) of the CIIA liquid and the B liquid 80 positions are on the same circumference, (3) both or one of liquids A and B are discharged linearly toward the center of the mixing chamber, (4) the number of discharge ports and/or Alternatively, by designing the area ratio to be within ±50% of the blending ratio of liquids A and B, a mixing module is created in which the blending ratio does not change even at the start and end of dispensing and does not require draining. I can do things.

Also, this module has improved mixing characteristics, so it is possible to stabilize the physical properties and obtain a good spray condition in the case of sub-I no molding.

The machine-cleanable impingement mixing type mixing device having the structure according to this design can be used for spray heads, casting bore heads, and injection with a nozzle connected to the tip of the head, and can also be used for reaction injection. However, from the viewpoint of liquid sealing performance and spray pattern control, Gasmer's GX-7W mixing module, which has orifices arranged uniformly on the circumference, has a high degree of freedom in design and is therefore suitable.

It is also possible to change the liquid used to a one-way type with a circulating type, a fixed head type with better control of liquid temperature, and a hand-held gun type with a smaller size.

As an example of the high-pressure two-liquid bath machine used in the molding of the present invention, any type that can increase the liquid pressure to about 100 kg/cm can be used regardless of the type. Actual examples include the THD-2K made by Toshi Engineering Co., Ltd., which uses a gear pump as the pump, and the NR-230 made by Toho Kikai Kogyo Co., Ltd., which uses an axial piston pump. (USA) H-2000W, Glasscraft Co. (USA) T-3H, etc.

〔Example〕

The present invention will be explained below with reference to Examples.

A spray type head is most suitable for investigating the mixing performance of a mixing head and the condition of the liquid discharged, and the following examples show the results of studies using a spray head. Casting and injection heads can also be made and used with similar designs.

(Explanation of terms) (1) Spray situation (pattern): Visual observations were made regarding the following items and the results are shown.

Concentration distribution - Difference in concentration of particles sprayed from the gun, streaking, etc. - Particle size: Check the size of particles sprayed from the gun, atomization status - Shape: Shape of the sprayed material sprayed on the target, Confirmation of deformation, etc. (2) Tack-free time: Lightly touch the surface of the sprayed or injected material with your fingers, and measure the shortest time until the material does not transfer to your fingers.

(3) Striped pattern on the surface: If the blending ratio or mixing characteristics of the two liquids is poor, a striped pattern remains in the poorly mixed area.

(3) Surface quality: polypropylene root soil with a thickness of approximately 211I
I was spray molded and the surface smoothness and presence of pinholes were examined.

(4) Physical property test: Based on JIS K-6301, measurements were performed at 23° C. and after curing for one week at 55% humidity.

(Molding material) Rim spray (Mitsui Toatsu Chemical quick curing 2
(liquid type urethane spray material) was used.

The following two brands with different blending ratios and viscosities were used.

Table 1: Properties of materials used (catalog values) All materials are fast-curing and react and harden immediately after being sprayed, so it is essential to use an impact mixing gun when mixing.

Liquid A: Isocyanate component [The main ingredient is a modified product of diphenylmethane diisocyanate (MD[-PH), manufactured by Mitsui Toatsu Chemicals] Liquid B nyresine component (high-pressure two-component dispensing machine) Uses H-2000 model from Gasmer, USA did. This machine is a one-way type hydraulically driven double-action plunger pump that can be used for injection and spraying. The hydraulic pressure is 2000psi (approximately 140kg/
cd), and the liquid temperature can be set separately for liquid A and liquid B.

Hereinafter, the present invention will be explained in detail with reference to drawings and examples.

Figures 1 and 2 show the improved GX- used in Example-1.
A cross-sectional view and a front view showing the configuration of the mixing module for 7 guns, Figures 3 and 4 are for the improved G used in Example-2.
A sectional view and a front view showing the configuration of a mixing module for an X-gun, FIGS. 5 and 6 are a sectional view and a front view showing another improved mixing module for a GX-7 gun used in Example-3, 7 and 8 are side and front sectional views showing an improved mixing module for a D gun shown in Example-4.

In the figure, 1 is a mixing module, 2 is a pulping rod, la is an inflow hole for liquid A, lb is an inflow hole for liquid B, and lc is an injection hole for mixed liquid.

Example 1 A GX-7 gun with a mechanical cleaning method manufactured by Gasmer was used as a spray head, and the mixing module is shown in FIGS. 1 and 2.

The schematic diagram in Table 2 shows the discharge angle of liquid A and liquid B into the mixing chamber and the collision angle of these two liquids. The number and area of orifices for liquids A and B were designed to be the same as the volume ratio of the raw materials, A:B=1:2. The orifices for liquid A (isocyanate component) are 180 degrees apart from each other.
Two orifices for liquid B (resin component) or four holes are opened at 90 degrees to each other, and the discharge angle of each is on a line that goes straight to the center of the mixing chamber for liquid B (resin component), and The positions of the discharge ports were arranged to be on the same circumference. That is, the two liquids are mixed without rotational movement. Orifice diameter is always 0.40
6mm, and the diameter of the mixing chamber is 3.175
mm. The material is polyacetal resin (Delrin,
Du Pant Co., Ltd. trademark). A spray tip (J212: fan-shaped pattern) was attached to the tip of the gun to perform molding. For raw materials, use Rim Spray PD-450 (liquid A, liquid B = 1:2 volume ratio), and adjust the liquid temperature to 50' for liquid A.
C and B liquids each have a pressure of 112k at 65°C1 discharge ratio.
The conditions were g/alf and 120 kg/Cl1lf.

As shown in Table 2, the tack free time was 9.
It cured quickly in ~11 seconds, and the tack disappeared rapidly as the curing proceeded. Since liquid A and liquid B were ejected in a mixed state at a predetermined mixing ratio from the start of ejection, no striped pattern observed when the mixing ratio was out of order or there was poor mixing was observed.

Further, it was possible to perform molding without discarding the liquid (draining the liquid) at the end of the molding, and when a 2-thick sheet was molded for measuring physical properties, the yield rate was as good as 90%. When the spray condition (pattern) was observed, the concentration distribution was uniform, the particle size was fine, and the shape was fan-shaped and normal, and no deformation was observed. The surface of the molded product was smooth and no irregularities were observed. Curability was sufficient, and physical property test results of the prepared sheet showed that it was excellent in hardness, modulus, tensile strength, elongation, and tear strength, and also had good mixing characteristics.

Example 2 As in Example 1, a GX-7 gun was used, and a mixing module having the structure shown in the sectional view and front view of the mixing module shown in FIGS. 3 and 4 was used. In addition, a schematic diagram of the flow direction of liquid A and liquid B is shown in Table 2.

The number and area ratio of orifices was the same as the blending ratio of raw materials, A liquid: B liquid = 1.1. Four orifices for liquid A (isocyanate component) are opened with the holes at 90 degrees to each other, and the orifices for liquid B (resin component) are angled so that they are discharged linearly toward the center of the mixing chamber. The positions of the holes were set at 90 degrees, and the liquid discharge angle for the four holes was the same as that for liquid A, and the two liquids were designed not to cause rotational movement.

The diameter of all orifices was 0.406 m, and the diameter of the mixing chamber was 3.175 B. A spray tip (#212: fan-shaped pattern) was attached to the tip of the gun to perform molding.

The raw materials are Rim Spray PD-190 (A liquid: B liquid 1:
1 volume ratio), and the liquid temperature was 65°C for liquid A and 5°C for liquid B.
The conditions were 0° C. and the pressure at discharge of 116 kg/a+f and 108 kg/Cxl, respectively. As shown in Table 2, the results showed that the tack-free time was 12 to 14 seconds, resulting in fast curing, and the tack disappeared quickly.As in Example 1, the A and B components were mixed in the specified manner from the start. The mixture was discharged at the same ratio, and the striped pattern observed when the mixing ratio was incorrect or the mixing was poor was not observed, and it was possible to perform molding without draining the liquid. When the spray condition (pattern) was observed, the concentration distribution was uniform, the particle size was fine, and the shape was fan-shaped and normal, and no deformation was observed. The surface of the molded product was smooth and no irregularities were observed.

The curability was sufficient, and physical property test results of the prepared sheet showed that it was excellent in hardness, modulus, tensile strength, elongation, and tear strength, and the mixing properties were also good.

Example 3 As in Example 1, a GX-7 gun was used, and a mixing module having the structure shown in FIGS. 5 and 6 in cross-sectional view and front view was used. The number and area ratio of orifices are designed to be A:B = 1:l, and as shown in the schematic diagram in Table 2, there are four orifices for liquid A (isocyanate component) with the holes positioned at 90 degrees to each other. The angle of discharge into the mixing chamber is set in the direction in which the liquid rotates, and four orifices for liquid B (resin component) are opened at 90 degrees to each other, and the discharge angle of the liquid is set at the center of the mixing chamber. No rotational motion occurred on the opposite line.

In other words, the design was such that only the A component rotates and the B component is mixed without rotating.

The diameter of all orifices was 0.406 mm, and the diameter of the mixing chamber was 3.175 mm. Spray tip C#212 at the tip of the gun (fan-shaped pattern)
was installed and molded.

The raw materials are rim spray PD-190 (liquid A, liquid B = 1
:l volume ratio) and set the liquid temperature to 65°C for liquid A and 50°C for liquid B.
The pressure at the time of discharge of °C1 is 112 kg/aI and 1, respectively.
The condition was 0.06 kg/al. As shown in Table 2, the results showed that the tack-free time was 12 to 14 seconds, indicating fast curing, and no striped patterns were observed at the start or end of ejection, making it possible to mold without draining. there were. When the spray condition (pattern) was observed, the concentration distribution was uniform, the particle size was fine, and the shape was fan-shaped and normal, and no deformation was observed. The surface of the molded product was smooth and no irregularities were observed. Curability was sufficient, and physical property test results of the prepared sheet showed excellent hardness, modulus, tensile strength, elongation, and tear strength, and good mixing properties.

Example 4 A D-gun manufactured by Gasmar was used, and the mixing module had the structure shown in Fig. 7 (side sectional view) and Fig. 8 (front sectional view), and the number and area ratio of orifices were A: B. liquid=
The one designed in 1.1 was used. Three orifices for liquid A (incyanate component) and three orifices for liquid B (resin component) are opened on each side, and as shown in Table 2, all liquid discharge angles are directed toward the center of the mixing chamber. The two liquids collide directly with each other and mix.

The size of the orifice was 0.15 mm x 2 mm, and the diameter of the mixing chamber was 1.32 mm. A spray tip cannot be attached to the tip of the gun. The raw materials are
Using Rim Spray PD-190 (liquid A:liquid B = 1.1 volume ratio), the liquid temperature was set to 65°C for liquid A, and the pressure at the time of spraying 50'C1 for liquid B to 74 kg/cnf and 73 kg/cnf, respectively.
CD condition (because the pressure resistance of this gun is 70 kg/al).

As shown in Table 2, the results show that the tack-free time is 13 to 16 seconds, which indicates rapid curing, and the A and B components are discharged at a predetermined mixing ratio from the start of jetting. There were no irregularities or striped patterns observed during poor mixing, indicating that the mixing characteristics were good. Also, since the two liquids were mixed or directly collided, there was no rotational movement left in the liquid, and the spray conditions were good. Although the surface of the molded product was slightly uneven, it was at an excellent level with no problems in practical use. Curability was sufficient, physical property test results of the prepared sheet showed no problems in hardness, modulus, tensile strength, elongation and tear strength, and good mixing properties.

Comparative Example 1 As in Example 1, a GX-7 gun was used, and the mixing module was the same Cod 1o type manufactured by Gasmer.

A schematic diagram showing the flow directions of liquid A and liquid B is shown in Table 2. There are two orifices for the base agent (isocyanate component) in the front, and two orifices for the resin in the rear, and the discharge angle of each is perpendicular to the cleaning lot, so that the two liquids are in the mixing chamber. Since the structure is such that the liquid flows parallel to and is discharged, neither of the liquids directly collides with each other, nor does rotation occur. All orifices had a diameter of 0.194 mm.

As shown in Table 2, the molding test results show a discharge amount of 5.1 kg.
/min, which is about 1.6 times that of Example-1, and the Raynozzle number is higher, making it more moderate than Example-1. The spray conditions were normal with fine particle size and fan-shaped shape, but the concentration distribution was thicker at the edges and was uneven with streaks. Tack-free time is 9 to 11 seconds in Example-1
Although they were the same, liquids A and B were not mixed at the predetermined mixing ratio from the time the jetting started, and while a striped pattern was observed, the tackiness of the surface was strong and did not disappear even with the passage of time. Furthermore, the mixture sprayed out at the end had a striped pattern similar to that at the start, and the tack was strong and remained sticky for a long time. Therefore, with this mixing module, it was impossible to perform molding without discarding the liquid (draining the liquid). When forming a sheet with a thickness of 2I [ll11,
When the liquid was drained, the yield rate was 45%.
It was about half of 1.

The physical property test results were low in all items, and the mixing efficiency is considered to be poor.

Comparative example-2 Mixing module (52L) for Gasmar D gun
was used for installation. A schematic diagram showing the flow of liquids A and B in this mixing module is shown in Table 2.

Further, this mixing module has an integrated structure and has one rectangular slotted chair with the same diameter on each side.

The orifice size is 0.3 x 3 mm, and the liquid is discharged into a cylindrical mixing chamber that is mechanically cleaned in a direction that causes rotation in the same direction. The machine body and raw materials were the same as in Example-6. As shown in Table 2, the ejection amount was 3.
．． The amount of ejection was moderate at 2 kg/min. Curing and reactivity were a little slow with a tack-free time of 14 to 18 seconds. When the spraying conditions were observed, it was found that the sheet had poor smoothness due to the large particle size, and the surface was highly uneven. There was a difference in the concentration distribution in the spray situation, and streaks appeared at the edges and the shape changed at the same time. With this gun, the length of the mixing chamber can be changed by adjusting the position of the rod to change the spray conditions, so I tried this, but the deformation and concentration distribution did not improve much. Physical property test results include hardness, modulus, tensile strength,
Both elongation and tear strength are quite low.
This was a result of insufficient mixing.

〔Effect of the invention〕

In the method of mixing two-component fast-curing materials by mechanically cleaning collision mixing, by using the structure of the present invention in which the mixing chamber part where the two liquids collide is an integrally molded product, the predetermined timing is maintained even at the start and end of dispensing. It becomes possible to secure the blending ratio, and there is no need to drain the liquid, reducing l
) Improvement in yield 2) Stabilization of physical properties of products 3) Improvement in workability can be achieved. In addition, in the case of spray molding, the spray conditions (pattern) are always stable and there is no need to adjust the working conditions.

and the front view, FIGS. 7 and 8 are shown in Example-4,
FIG. 3 is a side and front cross-sectional view of an improved mixing module for a D-gun.

Claims (1)

[Scope of Claims] In an apparatus that discharges liquids A and B of resin raw materials such as urethane, epoxy, and unsaturated polyester from a discharge port and mixes them using a collisional mixing method, a mixing chamber portion that causes the two liquids to collide, It is a module that is integrally molded. (1) It has two or more discharge ports (orifices) for liquid A and liquid B, and (2) The positions of the discharge ports for liquid A and B are on the same circumference. (3) both or one of liquid A and liquid B is discharged linearly toward the center of the mixing chamber; and (4) the number and/or area ratio of the discharge ports is equal to that of liquid A and liquid B. An improved mechanically washable impingement mixing type mixing module characterized in that the blending ratio of liquid B is within ±50%.