JP3099137B2 - Raw material supply device for molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a raw material supply apparatus for molding. More specifically, in order to color the molding material to a desired color (hue, saturation and lightness), particles for molding having different hues and the like are pneumatically transported in an amount corresponding to the molding amount, and the particles are collected. The present invention relates to a raw material supply device for molding that is captured by a molding machine.

[0002]

2. Description of the Related Art In molding a resin using a molding machine such as an injection molding machine or a single-screw or twin-screw extruder, the resin material and the molding material are colored in advance in order to color the molding material into a predetermined color. Coloring particles containing a high concentration of pigments, etc., and crushed particles of recycled materials (for example, resin for the purpose of recycling unnecessary parts of molding resin generated in the molding process, such as defective moldings and mold spools, etc.) Crushed products) and pneumatically transporting these particles at a predetermined ratio to a molding machine and mixing and molding to obtain a molded product colored in a desired color.

As an apparatus for supplying raw material particles using such pneumatic transportation, an apparatus having a schematic configuration shown in FIG. 4 is conventionally known. This apparatus comprises a storage means for storing the three types of particles for molding, that is, a storage tank 1 for storing raw resin particles (pellets) generally called virgin, and a storage tank 2 for storing coloring particles called master batch (MB). And screw feeders 4, 5 and 6 for feeding a predetermined amount of the particles from the storage tanks 1, 2 and 3, respectively, and a storage tank 3 for storing the crushed particles of the recycled material for recycling. A mixer 7 for accommodating and mixing three types of particles, a damper 8 for adjusting the storage amount of the mixed particles in the mixed raw material storage tank 9, and a mixer 7 connected to the mixer 7 via the damper 8 to accommodate the mixed particles. Mixed material storage tank 9, a blower 13 for generating an air flow for transporting the mixed particles in the mixed material storage tank 9, a piping system and a fan for dust removal. Ruta 15
A hopper 10 for collecting particles provided with a damper 14 at the lower part which communicates with the blower 13 and the mixed raw material storage tank 9 via the Mixed material supply tank 1 to be sent to molding machine 12
1 is provided.

That is, in this apparatus, a predetermined amount of raw material particles sent from the screw feeders 4, 5 and 6 are accommodated in a mixer 7 and uniformly stirred and mixed, and a damper 8 at the lower part of the mixer is opened and closed appropriately to mix. The mixed particles are stored in the raw material storage tank 9. The mixed particles in the mixed raw material storage tank 9 are sent to a hopper 10 using an air flow generated by the blower 13 as a transport medium. The mixed particles transported by air are collected by a hopper 10 and sent to a molding machine 12 via a mixed raw material supply tank 11. The mixed particles for molding are supplied to the molding machine 12 in this manner. Normally, at the time of pneumatic transportation, the damper 8 at the lower part of the mixer and the damper 14 at the lower part of the hopper are closed to improve the sealing property of the parts other than the passage of the transportation particles. Facilitates particle transfer. At this time, it is general that the mixed material storage tank 9 contains mixed particles in an amount of tens to several tens times the amount required for one molding (one shot injection amount).

However, in this apparatus, the raw material particles uniformly stirred and mixed by the mixer 7 are transferred from the mixed raw material storage tank 9 to the hopper 10.
During transportation of the particles to be sent to the mixed raw material supply tank 11 through storage, or during storage in the mixed raw material supply tank 11, the mixed three types of particles are separated due to differences in their specific gravities, shapes, etc., and segregation occurs. It may cause uneven coloring of the molded article. In particular, in the mixed raw material supply tank 11, segregation is apt to occur because the mixed particles are contained in an amount of ten to several tens times the amount required for one molding (one shot injection amount). In addition, this device mixes and stores the raw material particles, pneumatically transports the particles, and supplies the mixed particles to the molding machine through the collection and storage of the particles. There is a disadvantage that the equipment cost is high. In addition, a plurality of dampers are provided to maintain the airtightness of the transport route, and additional equipment such as an electric control system is required for opening and closing the dampers.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to simplify the transportation route of particles supplied to a molding machine, save space, reduce equipment costs and running costs, and color molded products. An object of the present invention is to provide a compact molding material supply device that does not cause unevenness.

[0007]

Means for Solving the Problems In order to prevent color unevenness due to segregation of particles and the like, the present inventors minimized the amount of raw material to be metered and mixed from the storage tank for each raw material particle and to reduce the amount of the raw material to be stored in the storage tank. When it is considered that it is effective for the discharge from the tank to be a mass flow, the intensive study is carried out, and as a result, the amount of particles for molding is transported from the amount required for one molding (one shot injection amount) to a certain range It was confirmed that there was no need to provide any special mixing means, and that the molded article did not have the problem of uneven coloring even if it was molded as it was, thereby completing the present invention. That is,
The present invention is directed to a storage tank for accommodating raw material particles, coloring particles, and crushed recycled material particles, respectively, and delivering the particles in the storage tank in a range of a minimum amount necessary for one molding to several times the amount. A particle supply means, a means for pneumatically transporting the particles sent out from the particle supply means, and a capture means for capturing the pneumatically transported particles and supplying the captured particles to a molding machine. It is another object of the present invention to provide a raw material supply device for molding.

[0008]

The apparatus according to the present invention is a compact apparatus configured to pneumatically transport and collect particles for molding according to a molding amount in a collecting tank above the molding machine. Since the mixed particles are directly supplied to a molding machine, uneven coloring of a molded product due to segregation of mixed particles as in a conventional apparatus does not occur.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of the present invention will be described below based on embodiments. FIG. 1 is a diagram illustrating a schematic configuration of an example of a molding material supply apparatus according to the present invention. The molding particles used in this apparatus are the virgin, masterbatch and crushed recycled material particles described with reference to FIG. That is, particles of a raw material resin (virgin) of a molded article, coloring particles (master batch) in which a coloring agent is blended at a high concentration with the resin,
There are three types of crushed particles of recycled materials for recycling. It is preferable to use those particles whose particle size has been adjusted in advance. As shown in FIG. 1, the apparatus of the present invention comprises means for separately storing the above three types of particles, that is, a storage tank 21 containing raw material particles and a storage tank 22 containing coloring particles.
And a storage tank 23 for storing the crushed particles of the recycled material. The blower 29 generates three kinds of particles sent out from the storage tanks 21, 22, and 23 through screw feeders 24, 25, and 26 in a predetermined amount. A molding machine (in this example, an injection molding machine) 27 is used as a transport medium the airflow flowing between the pipes 31 and 32 in the blower direction.
Tank 2 for collecting and supplying the particles provided at the top of the tank
8 by direct pneumatic transportation.

In the present invention, the amount of particles to be transported by air is
It is selected from the minimum amount (one shot injection amount) necessary for one molding to several times the amount. Preferably, it is in the range from the minimum amount necessary for one molding to three times the amount. If the amount of the particles to be pneumatically transported is much larger than the amount required for one molding, the size of the collecting tank 28 becomes large, and the apparatus cannot be made compact. Further, particles may be segregated in the supply tank 28 to cause uneven coloring of the molded product. Storage tanks 21 and 22
And 23 have a shape capable of accommodating the particles,
Although the size may be the same or different, a portion other than the particle sending portion (in this example, a connection portion with the screw feeder at the lower portion of the storage tank), for example, a lid that can open and close the particle storage ports 33, 34, and 35 can be used. Etc., or a structure in which a hopper for collection can be attached when charging by pneumatic transportation. From the storage tanks 21, 22, and 23, a predetermined amount of particles for molding is sent out for pneumatic transportation.
As a means of this feeding, it is easy to control the feeding amount, and it is preferable to use screw feeders 24, 25 and 26 which can adjust the feeding amount appropriately by controlling the number of rotations of the motor M or controlling the rotation time. The size of the screw feeders 24, 25 and 26 and the shape of the screw used are not particularly limited. A predetermined amount of particles sent out from the screw feeders 24, 25, and 26 are supplied to a supply tank 28 (in this example, a particle collection device) at the upper part of the molding machine 27 via a transport pipe 31 through which the particles and air can flow. Pneumatic transport to possible cyclones).

The collection tank 28 collects three types of particles transported by air and supplies them to the molding machine 27. In this example, the collection tank 28 is formed of a cyclone capable of collecting particles. However, the collection tank 28 is not limited to this, and instead of the cyclone, the collection of particles is performed using a filter cloth or the like. May be configured by a bag filter or the like that performs the following. Among these, it is preferable that the supply tank 28 itself, which can be easily made compact, is constituted by a cyclone. A blower 29 and a fan are generally used as a means for generating an air flow as a medium for transporting particles, but compressed air or the like can also be used. In addition, these generating means are usually provided in the latter stage of the supply tank 28 as shown in FIG. The apparatus of the present invention can be applied to various molding machines generally used for resin molding, such as an injection molding machine, a single-screw or twin-screw extruder. An injection molding machine having a closed structure is preferably used.

FIG. 2 is a view for explaining a schematic configuration of a preferred example of a molding raw material supply apparatus according to the present invention, and FIG.
FIG. 4 is a partially cutaway plan view of a supply tank 28 of the device of FIG. This apparatus has a storage tank 21 for storing raw material particles, a storage tank 22 for storing coloring particles, as in the apparatus shown in FIG.
A storage tank 23 containing recycled material crushed particles, screw feeders 24, 25, and 26 for feeding predetermined types of particles from these storage tanks 21, 22, and 23, and air serving as a transport medium for these particles. Piping flow 3
And a blower 29 for generating particles between 1 and 32, and a collecting tank 28 for collecting the particles and supplying the particles to a molding machine (injection molding machine) 27 is provided at least partially with a cyclone 36 and a lower portion thereof. Is formed of a transparent member 38.
And a transparent member 3 of the cylindrical member 37.
8, a raw material detection switch 39 for detecting the amount of the particles 41 inside the cylindrical member is provided.

That is, in this apparatus, the collecting tank 28 is provided with a cyclone 36 for collecting particles, and a cylindrical member 3 at the lower part of which is formed of a transparent member 38 at least partially communicating with the molding machine 27.
7 and an integrated structure, and a raw material detection switch 39 is provided near the transparent member 38 of the cylindrical member 37, thereby facilitating the control of the amount of particles transported by air. According to the supply tank 28, the amount of particles inside the cylindrical member 37 can be easily grasped from outside through the transparent member 38 of the cylindrical member 37. Further, based on the information detected by the raw material detection switch 39, the screw feeders 24, 25 and 26 below the storage tanks 21, 22 and 23 are provided.
Is started, the particles can be appropriately supplied to the molding machine 27 in an amount corresponding to the molding amount. At this time, the supply tank 2
8, a connecting means between the cyclone 36 and the cylindrical member 37 is provided with a blocking means such as a slide gate 40 for blocking the communication between them.
When the raw material is filled in the cylindrical member 37, the cyclone 3 is used.
An amount of raw material necessary for the next molding may be kept in standby in 6. Although the transparent member 38 is provided at least in part of the cylindrical member 37, the cylindrical member 37 itself may be made of a transparent material such as glass or acrylic resin. Also, the material detection switch 3
9 can be a known type such as a proximity detection type or a light detection type.

The apparatus of the present invention pneumatically transports particles for molding from the storage tanks 21, 22 and 23 to the supply tank 28 above the molding machine 27 according to the molding amount as described above. In the present invention, the mixing machine 7, the mixed raw material storage tank 9, and the mixed raw material supply tank 11 in the conventional apparatus shown in FIG. 4 are unnecessary, and the transportation route of the particles is simplified. In addition, since it has a substantially closed structure except for the transport path of the particles, the device can be made compact without the need to use the dampers 8 and 14 and the like. In addition, the particles supplied to the molding machine 27 via the supply tank 28 range from the minimum amount necessary for one molding to several times the amount, which causes uneven coloring of the molded product as in the conventional apparatus. No segregation of particles occurs. In the present invention, the number of the particle storage tanks can be increased or decreased as necessary, and is not limited to the above.

[0015]

As described above, according to the present invention, particles for molding can be pneumatically conveyed to a molding machine corresponding to the molding amount by a compact apparatus. In addition, since the pneumatically transported particles are supplied directly to the molding machine in the range of the minimum amount required for one molding to several times the amount, the molded article does not have uneven coloring.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an outline of an example of a raw material supply device for molding according to the present invention.

FIG. 2 is a diagram illustrating an outline of a preferred example of a molding raw material supply apparatus according to the present invention.

FIG. 3 is a partially cutaway plan view of a supply tank according to the raw material supply device for molding of FIG. 2;

FIG. 4 is a diagram illustrating an outline of a conventional apparatus for supplying particles for molding to a molding machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage tank 2 Storage tank 3 Storage tank 4 Screw feeder 5 Screw feeder 6 Screw feeder 7 Mixer 8 Damper 9 Mixed raw material storage tank 10 Hopper 11 Mixed raw material supply tank 12 Molding machine 13 Blower 14 Damper 15 Filter 21 Storage tank 22 Storage tank 23 Storage Tank 24 Screw Feeder 25 Screw Feeder 26 Screw Feeder 27 Molding Machine 28 Supply Tank 29 Blower 30 Filter 31 Piping 32 Piping 36 Cyclone 37 Tube 38 Transparent Member 39 Raw Material Detection Switch 40 Slide Gate 41 Particle

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-14930 (JP, A) JP-A-61-293812 (JP, A) JP-A-1-123707 (JP, A) JP-A 57- 150518 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 31/00-31/10 B29C 45/18

Claims (5)

(57) [Claims] 1. A storage tank for accommodating raw material particles, coloring particles and crushed recycled material particles, respectively, and an amount in a range of a minimum amount required for one molding to several times the number of particles in the storage tank. Particle supply means for sending out, means for pneumatically transporting the particles sent out from the particle supply means, and capture means for collecting the pneumatically transported particles and supplying the collected particles to a molding machine, A raw material supply device for molding. 2. The method according to claim 1, wherein the amount of the particles in the collecting means ranges from a minimum amount necessary for one molding to three times the amount.
A raw material supply device for molding according to 4. 3. The molding material supply apparatus according to claim 1, wherein the supply means is a cylindrical member that communicates with a cyclone and a molding machine in which at least a part of a lower portion of the cyclone is formed of a transparent member. 4. The raw material supply device for molding according to claim 3, wherein a raw material detection switch is provided near the transparent member of the capturing means. 5. The method according to claim 1, wherein the molding machine is an injection molding machine.
The molding raw material supply device according to 2, 3, or 4.