JP2005280089A - Method for manufacturing melt-molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for uniformly sticking a liquid additive on the surface of a synthetic resin granular raw material by a simple apparatus and method when the liquid additive is incorporated into the synthetic resin granular raw material continuously fed into a molding machine. <P>SOLUTION: The liquid additive is incorporated into the synthetic resin granular raw material continuously fed into the molding machine by a definite ratio to the amount of feeding of the synthetic resin granular raw material, and melt molding is performed. The method for manufacturing a melt-molded article comprises the steps of spraying the additive in a mist, and sticking and dispersing the mist-like additive in a feeding pipe for the synthetic resin granular raw material on the surface of the synthetic resin granular raw material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a method for uniformly adhering to the surface of a synthetic resin granule raw material with a simple apparatus and method when adding a liquid additive to the synthetic resin granule raw material continuously supplied to a molding machine.

Conventionally, as a method of adding additives such as liquid lubricants and dispersants to synthetic resin granule raw materials, (1) the additive is weighed with a measuring machine such as a gear pump or a piston pump and directly kneaded with the synthetic resin granule raw materials. Or (2) Weighing the additive with a measuring machine and adding it to the synthetic resin granule raw material, then supplying the synthetic resin raw material to the container and stirring in the container Mixing by rotating blades, screws, etc., or mixing by rotating the container itself, or (3) Feed additives into the synthetic resin granule raw material supply pipe and feed them by air A method of dispersing an additive on the surface of synthetic resin particles (Patent Document 1) is generally known.
JP 09-057443 A

However, in the first method, when it is required that the additive uniformly adheres to the surface of the raw material before the raw material is supplied into the molding machine, the request cannot be satisfied. In order to carry out the second method, it is necessary to incorporate a device for mixing the raw material and the additive by the rotation of the stirring blade in the container or the rotation of the container itself in a part of the continuous supply line of the raw material. Therefore, the equipment configuration becomes complicated and expensive, and it is not preferable in terms of maintenance. In addition, when using air transport as in the third method, since a certain length of piping is required for air transport, the distance from the additive feed port to the molding machine is long. Thus, there is a problem in that a great deal of labor is required for cleaning the air-feeding pipe and the piping equipment when cleaning of the pipe is required when switching the additive by changing the additive. The present invention has been made in order to solve these problems. When adding a liquid additive to a synthetic resin granule raw material continuously supplied to a molding machine, the surface of the synthetic resin granule raw material can be obtained with a simple apparatus and method. It is an object of the present invention to provide a method for uniformly adhering to a film.

When adding the liquid additive at a constant ratio with respect to the synthetic resin particle raw material supply amount, the inventors added the liquid additive by atomizing the additive in the synthetic resin particle raw material supply pipe. The present inventors have found that it is possible to attach and disperse the agent on the surface of the synthetic resin granular material. That is, the present invention has the following configuration.
(1) When a liquid additive is added to a synthetic resin granule raw material continuously supplied to a molding machine at a constant ratio with respect to the synthetic resin granule raw material supply amount and melt-molded, the additive is atomized to form a synthetic resin. A method for producing a melt-molded product, characterized by adhering and dispersing the mist-like additive in the granular material supply pipe on the surface of the synthetic resin granular material,
(2) The method for producing a melt-formed product according to claim 1, wherein the additive is added in an amount of 0.01 cc / min or more,
(3) The method for producing a melt-molded product as described in (1) above, wherein the additive is a polyoxyethylene alkyl ether dispersant.

According to the present invention, after adding a certain amount of liquid, there is no complicated device configuration such as installing a stirring device for mixing the additive, and the addition position is close to the extruder. Therefore, it is possible to uniformly adhere to the surface of the synthetic resin granular material with a simple apparatus and method without spending a great deal of labor for cleaning the inside of the raw material piping and the piping equipment.

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the synthetic resin granule raw material is continuously supplied to the molding machine 1 through the raw material supply pipe 3. The synthetic resin granule raw material used in the method of the present invention is not particularly limited to the type thereof, and any synthetic resin granule raw material represented by polyester or polyamide may be used. The shape of the raw material is not particularly limited, such as a spherical shape, a cylindrical shape, or an elliptical cylindrical shape, but the size is preferably about 0.5 to 10 mm. The additive used in the present invention is a liquid such as a dispersant. Moreover, it is preferable that it is 0.1-100 centipoise as a viscosity of an additive, More preferably, it is 1-30 centipoise. The atomization method for atomizing the liquid is not particularly limited, such as a method of supplying a certain amount of liquid to the venturi nozzle with a pump or the like and causing the compressed gas to act, but the atomized particle diameter Is preferably 10 μm or less. In addition, compressed air or inert gas is generally used as the compressed gas to be actuated, but it is not particularly limited as long as it is suitable for the manufacturing process. As shown in FIG. 1, the addition of the additive is performed by putting the additive atomized by the atomizer 5 into the raw material supply pipe 3, and details of the addition portion are shown in FIG. 2. As shown in FIG. 2, the mist additive 8 is introduced into the pipe by the nozzle 7 and adhered to the synthetic resin granular material 6. The mist additive 8 first contacts the raw material surface of the grain surface 9, and thereafter, the additive is diffused on the particle surface by the flow of each particle of the synthetic resin granular raw material 6 moving, and finally molded. The additive uniformly adheres to the surface of all particles supplied to the machine 1. At this time, in order for the additive to spread and uniformly adhere to the surface of all the particles supplied to the molding machine 1, when the mist additive 8 contacts the raw material surface of the grain surface 9 in the pipe of the additive addition part. The contact area, that is, the area of the grain surface 9 is preferably as large as possible, and it is better to have a shape that is at least 10 times, more preferably at least 20 times the cross-sectional area of the raw material flow path in the raw material supply pipe. In addition, when moving the raw material to the molding machine after that, it is preferable to move the particles while fluidizing, and the raw material supply pipe leading to the molding machine is provided with a bent part, a baffle plate, the moving speed of the raw material It is preferable to make a difference.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited only to a following example.

  Example 1 As a synthetic resin granule raw material, pellet-shaped nylon 6 having a diameter of 1 mm and a length of 2 mm was used and supplied to an extruder at a supply rate of 40 kg / Hr through a pipe having a pipe inner diameter of 80 mm to perform melt molding. Polyoxyethylene alkyl ether having a viscosity of 3 poise was used as an additive, supplied to the atomizer at a supply rate of 0.03 cc / min, and the atomized additive was added at a pressure of 0.02 MPa. A conical pot with a diameter of 500 mm and a height of 300 mm was installed in the middle of the raw material supply pipe so that the contact area of the additive with the synthetic resin raw material was increased, and a nozzle was arranged on the vertical line from the top of the pot. The distance between the nozzle and the raw material grain surface was about 250 mm, and the spray angle of the additive sprayed from the nozzle was 60 degrees. As a result, the contact area when the mist additive contacts the raw material surface of the raw material grain surface in the pot is about 15 times the inner diameter area of the raw material supply pipe. The pipe inner diameter of the pipe from the pot to the extrusion molding machine is 50 mm, the pipe length is 1 m, and the pipe angle is 30 degrees from the floor vertical direction. Sampling was performed from a sampling pipe in the middle of the piping just before the raw material inlet of the extruder. Since this additive is a nonionic surfactant and accurate quantification is difficult, the adhesion state of the additive was determined as follows. The synthetic resin particle raw material to be used is charged to 4 to 5 kV in advance. At this time, the charged synthetic resin particle material easily adheres to the metal surface due to the electrostatic induction phenomenon. If the additive is uniformly attached to the raw material surface, the specific resistance of the raw material surface becomes small, and the synthetic resin granular raw material does not adhere to the metal surface. Therefore, the sample is put in a metal container, and if no synthetic resin particle raw material is attached to the metal wall surface, it is determined that the additive is uniformly attached to the raw material surface, and the synthetic resin particle raw material is attached to the metal wall surface. If even one grain adhered, it was determined that the additive was not uniformly adhered to the raw material surface. When the sample amount was 50 g and sampling was performed ten times every 10 minutes, the objective could be achieved without any synthetic resin material adhering to the metal wall surface.

  Example 2 The additive supply amount was set to 0.008 cc / min, and other than that, the additive was added under the same conditions as in Example 1, and the adhesion state of the sample additive was confirmed. Since the amount added is small, it is considered that it took time until the initial additive uniformly spread on the raw material surface, but the additive was added to the raw material surface by the determination method described in Example 1 at the first sampling after 10 minutes. It was confirmed that it was uniformly attached.

  Example 3 The additive was added under the same conditions as in Example 1 except that polyethylene glycol monooleate was used as the additive. As a result of confirming the adhesion state of the sample additive by the determination method described in Example 1, it was confirmed that the additive was uniformly adhered to the raw material surface.

  Comparative Example 1 The additive described in Example 1 is weighed with a gear pump, and the raw material is directly fed into the extruder together with the synthetic resin granule material described in Example 1, which is continuously supplied to the extruder at a supply rate of 40 kg / Hr. It was continuously supplied to the hopper at the mouth at a supply rate of 0.03 cc / min. Sampling was performed at the lower limit of the raw material hopper, and the adhesion state of the sample additive was confirmed by the determination method described in Example 1. As a result, it was determined that the additive was not uniformly adhered.

  Comparative Example 2 2 kg of pelletized nylon 6 is placed in a mixer having a stirring blade, 0.1 cc of the additive described in Example 1 is weighed by a gear pump and supplied into the container, and the stirring blade is rotated in the container. As a result of confirming the adhesion state of the sample additive by the determination method described in Example 1, the additive was uniformly adhered to the surface of the obtained raw material. Since the raw material was shaved and the powder accumulated after long-term use, it was necessary to perform cleaning to maintain the quality, which was not preferable from a maintenance standpoint.

  Comparative Example 3 A pipe having an inner diameter of 50 mm, a pipe having a length of 10 m was set up vertically, and the pipe was extended horizontally through a 90 ° elbow with a flow rate of 20 m / sec and a solid-gas weight ratio of 10: 1. Feed by air, put the additive horizontally at a position 5m from the vertical pipe, sample the raw material from the sampling pipe provided at intervals of 10m in the middle of the pipe, and use the determination method described in Example 1 As a result, it was confirmed that the additive did not uniformly adhere to the raw material surface unless it was at least 50 m away from the additive addition position. If the pipe length is long in this way, when switching the additive by changing the additive, it is necessary to clean the inside of the piping and the piping equipment if cleaning inside the pipe is necessary. is expected.

It is the figure which showed the whole structure for demonstrating the form of this invention. It is the figure which showed the additive addition part detail for demonstrating the form of this invention.

Explanation of symbols

1: Molding machine 2: Raw material hopper 3: Raw material supply piping 4: Valve 5: Atomizer 6: Synthetic resin granular material 7: Nozzle 8: Atomized additive 9: Grain surface

Claims (3)

When a liquid additive is added to a synthetic resin granule raw material continuously supplied to a molding machine at a fixed ratio to the synthetic resin granule raw material supply amount and melt-molded, the additive is atomized to form a synthetic resin granule raw material. A method for producing a melt-molded product, comprising: adhering an atomized additive in a supply pipe to a surface of a synthetic resin granule material and dispersing the additive. The method for producing a melt-molded product according to claim 1, wherein the additive is added in an amount of 0.01 cc / min or more. The method for producing a melt-molded article according to claim 1, wherein the additive is a polyoxyethylene alkyl ether dispersant.

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