JPH04255304A - Manufacture of resin shot material - Google Patents

Abstract

PURPOSE:To obtain improved resin shot material, that enables the automation of continuous production, the improvement of labor saving and the stability of material-quality by a method in which after the amino resin such as urea resin and melamine resin, etc., has been kneaded and extruded, it is crushed and pelletized and then is dry- and cure-treated. CONSTITUTION:Forming material is fed to a primary sieve 14 through the storing tank 12 receiving the forming material composed of the collected dust powder of urea resin packed in a flexible container 11 and a constant volume- discharging machine 13. Then after roughly granulated objects have been removed, the forming material is kneaded and extruded. A producing device is composed of the two axis-kneading and extruding machine 16 provided with the hopper 15 with a pushing mechanism, the crusher 17 crushing extrudate, the dryer 18 which cures the crushed and pelletized formed object to prescribed hardness and a secondary sieve 19 which collects the product of prescribed grain size.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing resin shot material. More specifically, the present invention relates to a method for producing a resin shot material for shot blasting, which enables automation of the production process, labor saving, and furthermore, stabilization of quality.

0002

[Prior Art] Conventionally, thermosetting amino resins such as urea resin and melamine resin with appropriate hardness have been used in granular form for shot blasting for surface treatment of plastics, soft metals, etc. and deburring from molding. It has been used as a shot material, and the manufacturing method for that purpose has also been established.

[0003] The conventional method for manufacturing this shot material is as shown in FIG. Pulverize the resin molded product formed by (c)
However, the general method was to further sieve the shot material (d) and recover it as a granular shot material product of a predetermined size (e).

0004

[Problem to be solved by the invention] However, in such conventional methods for manufacturing resin shot materials, the molding step (a) using a press or the like is indispensable, so the operation is troublesome and it is difficult to continuously automate the process. There are major restrictions on molding (a), and the quality of the cured product obtained by this molding (a) also varies.Furthermore, since the cured product is crushed (c), the load of the process is large, and the entire manufacturing process is It was difficult to automate processes, save labor, reduce production costs, and even stabilize quality.

The present invention was made in view of the above-mentioned circumstances, and aims to eliminate the drawbacks of the conventional resin shot manufacturing method, significantly streamline the manufacturing process, and improve automation for continuous production. The purpose of the present invention is to provide an improved method for producing resin shot material that enables improved labor savings and stable quality.

[0006]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a method for producing a resin shot material, which comprises pulverizing and granulating after kneading and extrusion, and then drying and hardening the material. do. This invention also allows for the production of shot materials made of thermosetting amino resins such as urea resin and melamine resin, and the use of dust collection powder recovered in the manufacturing process of these resin molding materials as raw materials. This is also considered one of the preferred embodiments.

FIG. 1 is a block diagram showing the manufacturing process of this invention. For example, as illustrated in FIG. 1, in the manufacturing method of the present invention, (1) a resin such as a thermosetting amino resin such as a urea resin or a melamine resin is selected depending on the object to which the shot material is applied and its purpose; Prepare molding material (1). At this time, these molding materials (1
) can also be used to collect dust collected from the manufacturing process. By using this powder, the product shot material can also be made cheaper.

[0008] The prepared molding material (1) is subjected to primary sieving (2) if necessary to remove extremely large lumps, and then guided to the kneading and extrusion (3) step. This kneading extrusion (3
) various extrusion devices can be used, for example 2
A axial kneading extruder can be used. This kneading extrusion (
In step 3), the heating temperature and extrusion speed are appropriately controlled so that the molded product after extrusion is in an appropriate hardness state such as semi-hardened.

[0009] By employing this kneading and extrusion step (3), it is also possible to use the dust-collecting powder as described above. ■ Next, the extrudate in a state of appropriate hardness is crushed (4). The type of crusher and operating conditions at this time can be selected as appropriate. It is crushed and granulated to have a predetermined particle size.

[0010] Subsequently, the obtained pulverized product is directly subjected to dry hardness treatment (5). The purpose of this process is to harden the crushed granulated product so that it has a hardness suitable for use as shot material. This is possible as a simple operation. For example, by processing at a temperature of 100 to 200° C. for about 60 to 180 minutes, a high quality, uniform and stable amino resin shot material can be achieved.

■ Further, if necessary, secondary sieving (6)
Then, the resin shot material (7) with a predetermined particle size is collected. For example, the manufacturing method of the present invention, which consists of the above-mentioned steps, can be significantly streamlined compared to the conventional press-forming manufacturing method, improve automation and labor savings through continuous integrated production, and Quality can be highly stabilized.

[0012] Furthermore, production costs can be reduced, and in particular, by using dust-collecting powder, it is possible to manufacture inexpensive shot materials. Of course, there are no particular restrictions on the resin material (1). Amino resins such as urea resins and melamine resins, polyamide resins, polyimide resins, sulfado resins, and various other thermosetting resins can be used.

[0013] The manufacturing method of the present invention will be explained in more detail below with reference to Examples.

[0014]

EXAMPLE A urea resin shot material was produced using the apparatus illustrated in FIG. This device includes, for example, a storage tank (12) that stores a molding material made of a flexible container (11) filled with dust-collecting powder of urea resin, and a quantitative discharge machine (13).
), the molding material is sent to the primary sieve (14), where coarse particles are removed, and then the molding material is kneaded and extruded using a twin-screw kneading extruder (1) equipped with a hopper (15) with a pushing mechanism.
6), a crusher (17) for crushing the extrudate, a dryer (18) for curing the crushed and prepared molded article to the required hardness, and a secondary sieve (18) for recovering the product with a predetermined particle size. 19
).

[0015] Using this device, a twin-screw kneading extruder (16)
As a self-cleaning system and with a 3-stage heater,
Front stage: 70°C Middle stage: 60°C Back stage: Heated to room temperature and extruded at a rotation speed of 100 rpm (peripheral speed 0.157 m/min).

[0016] In the case of amino resin, the number of rotations is 80 to 1
30 rpm, l/D=14-20, temperature 60-100°C
It may be operated as a condition of degree. After this extrusion, the screen of the pulverizer (17) was pulverized to a size of 2 mm. Then, hardness treatment was performed in a dryer (18). Grinding machine (17
Table 1 shows the shot material particle size distribution according to ). This is a value measured using a JIS standard sieve, and is in the range where 30 mesh ON and 38 to 48 mesh products become products. 78% is used as a product.

Table 2 shows the hardness after treatment with the dryer (18). It was measured using a Kiya type hardness meter. As is clear from Table 2, the hardness of the shot material is significantly improved compared to the case without hardness treatment, and also compared to the existing American shot material and conventional products. It can be seen that the characteristics have been greatly improved.

[0018] Thus, it can be seen that by the method of the present invention, high quality shot material can be continuously and stably produced with excellent productivity.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Effects of the Invention] As explained in detail above, the manufacturing method of the present invention achieves significant rationalization compared to the conventional method.
Continuous integrated manufacturing enables automation and labor savings. Moreover, high-quality shot material can be manufactured as a low-cost product with stable quality.

[Brief explanation of the drawing]

FIG. 1 is a process block diagram illustrating the manufacturing method of the present invention.

FIG. 2 is a configuration diagram of a process apparatus illustrating an embodiment of the present invention.

FIG. 3 is a process block diagram showing a conventional manufacturing method.

[Explanation of symbols]

1 Molding material 2　Primary sieving 3 Kneading and extrusion 4. Grinding 5 Dry hardness treatment 6 Secondary sieving 7 Resin shot material 11 FIBC 12 Storage tank 13　Quantitative discharge machine 14 Primary sieve machine 15 Hopper with pusher 16 Twin screw kneading extruder 17　Crusher 18 Dryer 19 Secondary sieve machine 20 Products

Claims (3)

[Claims] 1. A method for producing a resin shot material, which comprises pulverizing and granulating the material after kneading and extrusion, and then subjecting it to dry hardness treatment. 2. The manufacturing method according to claim 1, wherein the dust-collecting powder from the resin material manufacturing process is kneaded and extruded. 3. The manufacturing method according to claim 1, wherein the amino resin such as urea resin or melamine resin is kneaded and extruded, followed by pulverization and granulation and dry hardness treatment.