JPH0569439A - Pelletizer - Google Patents

Abstract

PURPOSE:To enhance noise preventing effect by using a damping steel plate in a part or all of a pellet discharge port chuter, a main body frame and a machinery inspection door constituted of a steel plate in a pelletizer. CONSTITUTION:The machinery inspection door 10 attached to a main body frame 9 is formed from one of members easy to become a noise generation sources due to vibration. In such a case that some members are integrally constituted, a pulley cover 6, a taking-up roll cover 7 and a rotary blade cover 8 are collectively constituted of one cover. Effect is expected even if a damping steel plate is used at one place among respective places but, by replacing two or three places with the damping steel plate at the same time, larger effect can be expected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pelletizer (also called a strand cutter) for cutting organic polymer materials extruded in a strand form from an extruder into pellets.

[0002]

2. Description of the Related Art Most of thermoplastic resins are once pelletized and then molded into plastic molded articles. One of the methods for pelletizing is the strand cut method. In this method, the molten resin is extruded in the form of a string with a porous die attached to the tip of the extruder or the outlet of a gear pump, cooled, solidified, and then cut into short pieces with a pelletizer. Pelletizers generally consist of a string of plastics solidified by two take-up rolls on a table,
That is, the strand is sandwiched and taken out, delivered at a predetermined speed onto the strand support base surface between the take-up roll and the fixed blade tip, cut into pellets by a gear-shaped rotary blade,
The structure is such that these pellets fall onto the discharge port shooter, slide out, and are taken out from the pelletizer. Equipment such as electric motors and reduction gears are covered by the frame body, and covers such as the take-up roll, pulleys and rotary blades on the table are covered.

[0003]

The above-mentioned strand cutting method is widely used because it is economical and has a good pellet shape. However, the pelletizer used for this purpose has a problem that noise is great when cutting a strand that has been traveling at high speed for some time. Moreover, recently, the cutting of polymer materials with a high glass transition point and the strands of composite materials containing fiber reinforcement has become more frequent, and noise has become louder than before, and some noise prevention has become an issue in the work environment. It was I covered the equipment with a soundproof sheet and used antivibration packing, but the effect was not sufficient.

Further, Japanese Utility Model Publication No. 58-45065 discloses a pelletizer capable of sucking air from the groove portion of the rotary blade in order to reduce noise. However, the parts such as the rotary blade require considerably complicated machining, and the effect of preventing noise generated from parts other than the rotary blade cannot be expected. Therefore, it was necessary to implement more essential measures. The present invention has been completed for the purpose of solving such a problem of noise prevention.

[0005]

Means for Solving the Problems As a means for solving the above problems, the present invention relates to a pelletizer for cutting a strand delivered from a take-up roll between a rotary blade and a fixed blade and pelletizing the steel sheet. (A) Pellet outlet chute, (b) Body frame and cover that covers the machine part, (c) Part or all of the equipment inspection door attached to the body frame,
The present invention provides a pelletizer characterized by using a damping steel plate.

[0006]

The present invention will be further described. The pelletizer mechanically cuts the strands with a rotary blade and slides the pellets onto the outlet chute, so that the vibration can be reduced but not eliminated. In such a pelletizer, among the constituent materials, a member having a small vibration damping ability is likely to be a noise source. For this reason, we tried to prevent noise by selecting members with low vibration damping ability, design changes, and pasting anti-vibration materials.

Therefore, the present inventor has considered that if a material having a large vibration damping ability is used for the member of the pelletizer, there may be a noise prevention measure that is easy to put into practical use. It has been found that steel plates should be used. Metal-based damping materials include composite type and alloy type. However, at present, since the composite type is more economically available and the noise source is mainly composed of steel plates, we decided to use the composite constrained type vibration damping steel plate. ..

This damping steel plate is a sandwich steel plate in which a polymeric substance is sandwiched and bonded between two steel plates, and the sandwiched polymeric substance undergoes shear deformation to absorb external vibrations. The effect is particularly large with respect to vibration in a high frequency region such as noise of a pelletizer. As a result of various studies,
It has a great effect if it is used in a specific place such as a pellet discharge shooter, a body frame and cover that covers the machine part, an equipment inspection door attached to the body frame, and even if it is used in other places. , I learned that a great effect cannot be expected for processing and other costs.

[0009]

Embodiments Embodiments of the pelletizer according to the present invention will be described below in detail with reference to the drawings.
FIG. 1 is a front view of an embodiment of a pelletizer of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a plan view thereof.

A strand 1 extruded from an extruder or the like and solidified is guided to a guide roll 2 and taken up by a take-up roll 3 and further sent to a cutting position 15 where a rotary blade 4 and a fixed blade (not shown) are connected. It is cut between and pelletized. The pellets 14 drop on the discharge port shooter 5, slide down on a transporting device, for example, a belt conveyor, and are carried away from the pelletizer. The discharge port shooter 5 is usually a stainless steel plate or the like processed into a bowl shape or a cylindrical shape, and is one of the members that are a source of noise due to vibration when the pellets fall or slide. ..

The body frame 9 is usually a rotary blade 4
It is a steel plate that is located below the table 12 to which the take-up roll 3 is attached and covers the electric motor and the reducer attached to the fixed base 13. In rare cases, an electric motor or speed reducer covered with the main body frame may be attached to the side surface of the rotary blade or the take-up roll. The body frame 9 is also one of the members that easily become a source of noise due to internal rotating equipment, strand cutting, and other vibrations. The cover means the pulley cover 6, the take-up roll cover 7, the rotary blade cover 8 and the like on the table, and is a cover attached mainly for the purpose of worker's safety. A thin steel plate is processed, and it is usually attached so that it can be easily opened and closed or removed with a hinge so that the strands can be guided and the inside can be inspected. is there.

Further, the equipment inspection door 10 attached to the main body frame 9 is also one of the members that easily become a source of noise due to vibration. Reference numeral 11 is an instrument panel.

What has been described above is an example of a typical pelletizer, and the pelletizer to which the present invention is applied does not necessarily have all of these members.
In some cases, some members are integrally formed. For example, the pulley cover 6, the take-up roll cover 7, and the rotary blade cover 8 may be integrated into a single cover.

It is also effective to use a damping steel plate at one of the above-mentioned locations, but at the same time two locations are used.
Alternatively, a larger effect can be expected by substituting damping steel plates at all three locations. Of course, at the same time, the vibration-damping steel plate may be used in other places, or it may be used in combination with other noise prevention means.

[0015]

[Examples] A discharge port shooter of a pelletizer (TMS type manufactured by Tanaka Iron Works Co., Ltd.) having substantially the same structure as that shown in the figure, a main body frame for covering machine parts, a pulley cover,
The take-up roll cover, the rotary blade cover, and the equipment inspection door attached to the body frame were modified and replaced with damping steel plates (product name: NAS Zerophone, manufactured by Nippon Yakin Co., Ltd.).

Install this pelletizer in the assembly plant,
Twenty-one strands of polyamide resin having a diameter of 3 mm were cut into a length of 3 mm at a strand feeding speed of 40 m / min and compared with noise before modification. Noise is 1 on each side
At the point m, measurement was performed using a commercially available sound level meter. The measurement result is about 85 to 90 phons, which is about 8 to 12 phons lower than that of the conventional pelletizer.

[0017]

When the pelletizer of the present invention using the damping steel plate is used for the discharge chute, the main body frame and the cover for covering the machine part, and the inspection door attached to the main body frame, noise is reduced and the glass When pelletizing a polymer material having a high transition point or a composite material including a fiber reinforcing material, noise generation is reduced, which has a great effect on improving the working environment. Since these members are easy to process, even if vibration-damping steel plates are used, the increase in manufacturing cost is small, and it is an economical low-noise pelletizer.

[Brief description of drawings]

FIG. 1 is a front view of an exemplary embodiment of a pelletizer of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a plan view of FIG.

[Explanation of symbols]

1: Strand 2: Guide roll 3: Take-up roll 4: Rotating blade 5: Ejector shooter 6: Pulley cover 7: Take-up roll cover 8: Rotating blade cover 9: Main frame 10: Instrument inspection door 11: Instrument panel
12: Table 13: Mounting base 14: Pellet 1
5: Cutting position

Claims (1)

[Claims] 1. A strand delivered from a take-up roll,
In a pelletizer that cuts between a rotary blade and a fixed blade to pelletize, it is made of steel plate. (A) Pellet discharge port shooter; (b) Main body frame and cover that covers machine parts; (c) Main body A pelletizer characterized by using damping steel plates for some or all of the equipment inspection doors attached to the frame.