Method for producing resin strand

Abstract

The present invention can eliminate a breakage of strands on the way to increase yield, significantly suppress formation of adhered consecutive pellets, and obtain pellets having a low moisture content by a method for producing a resin strand comprising melt-kneading a resin composition in an extruder, extruding a strand-shaped molten resin onto a conveyor, and cooling the resin strand with cooling water, wherein the conveyed strand-shaped molten resin is brought into initial contact with the cooling water at a position downstream ranging from 20% to 70% of the total length of the conveying part of the conveyor.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a method for producing a strand in which, when the strand is cooled on a conveyor, a breakage of the strand can be suppressed to significantly improve the yield of pellets, to a strand obtained by the production method, and to pellets obtained by cutting the strand. The present invention further relates to a method for producing a resin strand for uniforming melt viscosity of a resin strand, improving strand draw-off stability, and obtaining a thermoplastic resin composition consistently excellent in impact resistance by stably feeding one or more compounds selected from the group of maleic acid, citric acid, fumaric acid, and an anhydride thereof, and to a preblend that can be stably fed. [0003] 2. Description of the Related Art [0004] An example of processing equipment widely used for the production of thermoplastic resin pellets is an extruder. Examples of the methods for obtainin...

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Benefits of technology

[0007] The present invention intends to solve the subject of preventing a breakage of strands and significantly suppressing formation of adhered consecutive pellets by optimizing the method of cooling strands. Furthermore, the present invention intends, in polymer alloys, to improve the stability of resin strands by optimizing the method of adding a compatibilizer.

[0008] As a result of intensive study, the present inventors have found that the above described subject can be solved by performing a specific cooling method using a conveyor and achieved the present invention. Further, the present inventors have found that, in a polymer alloy comprising polyamide, polyphenylene ether, and a compatibilizer selected from maleic acid, citric acid, fumaric acid, and an anhydride thereof, stable extrusion without surging or the like can be achieved by previously mixing the compatibilizer with part of the polyphenylene ether and that the resulting resin composition has improved impact strength and flowability, and have achieved the present invention.

[0027] The use of the production method of the present invention not only eliminates a breakage of strands during production to increase the yield, but also significantly suppresses formation of adhered consecutive pellets to improve product quality and enables the moisture content of pellets to be significantly suppressed. In addition, it makes the extrusion stable and thereby reduces surging and the like to improve the properties of the resulting resin composition.

Problems solved by technology

In the latter case, a phenomenon of a partial narrowing of strands is liable to occur because the strand-shaped molten resin cannot be cooled uniformly.

As a result, there has been a problem that strand are broken between the conveyor and strand cutter.

Moreover, there has been a further problem that formation of pellets referred to as adhered consecutive pellets (pellets in which two or more pellets are adhered) is liable to occur by contact of the strand-shaped molten resins with each other.

Unstable feed of compatibilizers causes a periodic variation of the strand diameter which is called surging, resulting in a problem of making the resin strand unstable.

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