JP2005074710A - Resin pellet manufacturing equipment - Google Patents

Abstract

To provide a resin pellet manufacturing apparatus capable of reducing the water content in a pellet.
An apparatus for producing a resin pellet by extruding a molten resin from an extruder, cooling and solidifying the resin, and then cutting or crushing the resin, the extruder having a die for extruding the molten resin; An extruded resin cooling table disposed on the molten resin extrusion side of the extruder, the upper surface of which is inclined downward toward the resin extrusion direction, along the longitudinal direction of the cooling table for guiding the extruded resin to the upper surface A cooling table having a groove portion, a vibrating means for vibrating the cooling table, and a granulating means for cutting or crushing the solidified resin carried out of the cooling table to be granulated. A resin pellet manufacturing apparatus is used. The extruder has a tie die, the tie die has a plurality of die holes for extruding the molten resin, and the cooling table receives a plurality of groove portions for receiving and guiding the molten resin extruded from the plurality of hole portions. It is preferable to have.
[Selection] Figure 1

Description

  The present invention relates to a resin pellet manufacturing apparatus for manufacturing pellets by extruding a molten resin.

  Resin pellets used as raw materials for manufacturing plastic products, etc., are plastic strands that are plasticized by an extruder, strands are extruded from a die, and the extruded strands are cooled and solidified through a cooling water tank, and then cut finely by a strand cutting device. It is manufactured by a cut type pellet manufacturing apparatus (see, for example, Patent Document 1 and Patent Document 2). In some cases, cutting is performed immediately after the molten plastic is extruded from a die and water-cooled. In either case, the water-cooled pellets are made into a product by removing moisture with a centrifugal dehydrator or the like.

An example of the above pellet manufacturing apparatus is shown in FIGS. FIG. 7 is an overall view of a pellet manufacturing apparatus having an extruder 20, and plastic, which is a resin pellet raw material, is supplied from a raw material inlet 23 provided in a cylinder 22 of the extruder 20, and is crushed and melted inside the cylinder 22. It passes through a screen changer 24 that removes dust contained in the molten plastic, passes through a gear pump 25 that adjusts the pressure in the extruder, and is introduced into a pelletizer facility 21 that performs cooling and cutting. FIG. 8 is a cross-sectional view of the pelletizer equipment 21. 2 is a switching valve for discharging molten plastic to the outside of the apparatus (arrow C) when it is unsuitable for pellet production, and the molten plastic is confirmed to be in a good state by checking the state of the molten plastic (arrow D). Is introduced into the die 26, enters the cooling water (arrow E) through the die hole 27, and at the same time is cut into an appropriate length by the blade 28 rotating at a high speed to produce a product pellet. The pellet is discharged out of the apparatus together with water (arrow F). FIG. 9 is a view showing the surface of the die 26 of FIG. The productivity of pellets is improved by using a die 26 having a plurality of holes 27.
JP 2001-88124 A Registered Utility Model No. 3062965

  When pellets are manufactured, if the molten resin of the raw material contains a large amount of gas such as water vapor, and bubbles are formed and swelled, the bubbles shrink as soon as they enter the water for cooling, and water enters into them. To do. Furthermore, water also enters from a cutting opening formed by cutting with a blade, and the moisture content of the pellet increases. When pellets with a high water content are used to produce plastic products, etc., the moisture in the pellets evaporates on the production line and swells. Since roughness or the like occurs, it may be difficult to manufacture a product having good surface properties. In particular, when waste plastic is used as a raw material for pellets, the molten plastic contains a large amount of water vapor gas. Therefore, irregularities occur on the surface of recycled products manufactured using pellets made from waste plastic, which is discarded. There is a problem that the recycling of plastic is restricted.

  Accordingly, an object of the present invention is to provide a resin pellet manufacturing apparatus capable of solving the problems of the prior art and reducing the water content in the pellet.

The features of the present invention for solving such problems are as follows.
(1) An apparatus for producing a resin pellet by extruding a molten resin from an extruder, cooling and solidifying the resin, and cutting or crushing the resin, the extruder having a die for extruding the molten resin; An extruded resin cooling base disposed on the side of the molten resin extrusion of the extruder, the upper surface of which is inclined downward toward the resin extrusion direction, along the longitudinal direction of the cooling table for guiding the extruded resin to the upper surface It has a cooling stand having a groove, a vibrating means for vibrating the cooling stand, and a granulating means for cutting or crushing the solidified resin carried out of the cooling stand to granulate it. Resin pellet manufacturing equipment.
(2) The extruder has a tidy, the tidy has a plurality of die holes for extruding the molten resin, and the cooling table receives and guides the molten resin extruded from the plurality of holes. The resin pellet manufacturing apparatus according to (1), which has a plurality of grooves.
(3) The extruder has a pressure detector for measuring the pressure of the molten resin in the tie die and an opening / closing means capable of opening / closing at least a part of the die holes. The resin pellet manufacturing apparatus according to (2), wherein the resin pressure in the tidy can be controlled by opening and closing.
(4) The resin pellet manufacturing apparatus according to any one of (1) to (3), wherein surface treatment for preventing adhesion of resin is performed on the groove portion of the cooling table.

  According to the present invention, since resin pellets can be produced without direct contact with water, resin pellets having a low water content can be obtained without incurring costs for cooling water treatment. For this reason, a plastic product having a smooth surface and good surface properties can be produced.

  The present invention is an apparatus for producing resin pellets by extruding a molten resin from an extruder, cooling and solidifying the resin, and then cutting or crushing the resin, and an extruder having a die for extruding the molten resin; An extruded resin cooling table disposed on the molten resin extrusion side of the extruder, the upper surface of which is inclined downward toward the resin extrusion direction, along the longitudinal direction of the cooling table for guiding the extruded resin to the upper surface A cooling table having a groove portion, a vibrating means for vibrating the cooling table, and a granulating means for cutting or crushing the solidified resin carried out of the cooling table to be granulated. This is a resin pellet manufacturing apparatus. A cooling stand is installed so that the resin extruded into a rod shape from the extruder is received by the groove, and the extruded resin is formed by the inclination of the cooling stand (downward inclination), the vibration of the cooling stand, and the extrusion force of the molten resin. Is moved in the groove and cooled by contact with the groove during the movement to solidify. Therefore, the cooling table desirably has a cooling mechanism, and is preferably water-cooled so as not to directly contact the molten resin.

  The inclination angle of the groove of the cooling table is preferably about 3 to 10 degrees.

  Water or the like can be used as the vibration means of the cooling table. The frequency is preferably about 10 to 60 Hz.

  In order to produce the resin pellets efficiently, it is preferable that the extruder has a tidy. The extruder has a tie die so that a plurality of molten resins are simultaneously extruded from a tie die having a plurality of die holes, and the cooling table also has a plurality of groove portions as many as the plurality of hole portions in order to cool the same. The tie die preferably has a plurality of die holes for extruding the molten resin, and the cooling stand preferably has a plurality of grooves for receiving and guiding the molten resin extruded from the plurality of holes.

  Further, the extruder has a pressure detector for measuring the pressure of the molten resin in the tie die and an opening / closing means capable of opening / closing at least a part of the die holes, and the opening / closing of the die holes by the opening / closing means. It is preferable that the resin pressure in the tidy can be controlled by performing. The pressure detector can be installed near the inlet of the tidy, and the pressure in the tidy can be inferred from the pressure of the molten resin sent to the tidy. The gate plate is slid by the flow rate adjusting valve, and the number of holes that can be pushed out of the tidy is appropriately changed to control the resin pressure in the tidy substantially constant. Thereby, there is an effect that the pellet is stably manufactured.

  The groove portion of the cooling table is preferably subjected to surface processing for preventing adhesion of resin. When the extruded molten resin adheres to the groove, pellets cannot be produced. Therefore, it is preferable to subject the resin contact portion on the surface of the groove to a surface treatment such as a fluororesin.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic plan view of an embodiment of the pellet manufacturing apparatus of the present invention. 2 is a longitudinal sectional view of a part of FIG. 1 in the line direction (A direction), FIG. 3 is a front view of the tidy, FIG. 4 is a plan view of the tidy, and FIG. 5 is a sectional view of the cooling stand (B in FIG. 6). FIG. 6 is a plan view of the cooling table.

  The pellet manufacturing apparatus 1 includes an extruder 20 having a die 3 for extruding a molten resin, an extruded resin cooling table 6 disposed on the molten resin extrusion side of the extruder, and a vibration means for vibrating the cooling table. (Not shown) and a granulation means 9 for cutting or crushing and solidifying the solidified resin carried out from the cooling table, and a raw material inlet 23 for introducing plastic as a resin pellet raw material An extruder 20 having an extruder cylinder 22 or the like that crushes and melts the raw material inside, a screen changer 24 that removes dust contained in the molten plastic, a gear pump 25 that adjusts the pressure in the extruder 20, Switching valve 2 for introducing the molten plastic into the tidy (die) 3 or discharging it out of the apparatus, and the tidy 3 that spreads the molten plastic in the plane direction , A pressure detector 4 for measuring the inlet pressure of the tidy 3 and an opening / closing means 5 which is a flow rate adjusting gate for opening and closing the die hole 11 which is a molten plastic outlet hole of the tidy so as to keep the pressure in the tidy constant. A cooling table 6 whose upper surface is inclined downward toward the resin extrusion direction and has a groove 12 along the longitudinal direction of the cooling table for guiding the extruded resin on the upper surface, and a guide for guiding the cooled solidified plastic 7 and a granulating means 9 which is a crusher having a plurality of blades 8 for cutting or crushing plastic into an appropriate length into pellets, and selecting an appropriate size among the cut pellets. And a sieve 10 for the purpose.

  The switching valve 2 has a rotating part inside, and switching is performed so that the molten plastic is sent to the tie die 3 or is discharged out of the apparatus by the rotation of the rotating part. The tie die 3 widens the molten plastic that enters from one joint so as to exit from the entire plurality of die holes 11. On the other hand, the pressure fluctuation in the tidy due to the fluctuation of the discharge amount of the extruder is adjusted so that the internal pressure of the tidy 3 becomes constant by appropriately increasing / decreasing the number of the die holes 11 by opening / closing the die holes 11 by the opening / closing means 5. . The molten plastic discharged from the die hole 11 of the tie die 3 is introduced into the groove portion 12 of the cooling table 6. By inclining and vibrating the cooling table 6, the discharged plastic gradually moves downstream. In addition, by cooling the cooling table 6 with water (as indicated by arrows in FIG. 2, the cooling water is passed directly through the cooling table so that the cooling water does not directly contact the molten plastic), and the discharged plastic is cooled. . The solidified rod-shaped plastic (strand) is guided by a guide 7 having a groove so as to be inserted into the granulating means 9 in an orderly manner. The rod-shaped plastic that has entered the granulating means 9 is cut by a plurality of rotating blades 8. The cutting length can be adjusted by changing the number of rotations of the plurality of blades 8 of the crusher that is the granulating means 9. The plastic cut into a pellet shape is selected as a product pellet by selecting one having a predetermined length by the sieve 10 provided at the lower part of the granulating means 9. In the sieve 10, for example, two stages of screens are installed and sorted into a long product, a non-defective product, and a short product (powder). Defective products can be used as pellet raw materials again.

It is the schematic of the plane which shows one Embodiment of the pellet manufacturing apparatus of this invention. It is a longitudinal cross-sectional view of the line direction of one Embodiment of the pellet manufacturing apparatus of this invention. It is a front view of Tidai. It is a top view of Tidai. It is sectional drawing of a cooling stand. It is a top view of a cooling stand. It is a general view of the conventional extruder and pellet manufacturing apparatus. It is sectional drawing of the conventional pellet manufacturing apparatus. It is a figure which shows the surface of the dice | dies of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pellet production apparatus 2 Switching valve 3 Tidy 4 Pressure detector 5 Opening / closing means 6 Cooling stand 7 Guide 8 Blade 9 Granulating means 10 Sieve 11 Die hole 12 Groove part 20 Extruder 21 Pelletizer equipment (conventional pellet production apparatus)
22 Extruder Cylinder 23 Raw Material Input 24 Screen Changer 25 Gear Pump 26 Die 27 Die Hole 28 Blade

Claims (4)

  An apparatus for producing resin pellets by extruding a molten resin from an extruder, cooling and solidifying the resin, and cutting or crushing the resin, an extruder having a die for extruding the molten resin, and the extruder An extruded resin cooling table disposed on the molten resin extrusion side, the upper surface of which is inclined downward toward the resin extrusion direction, and has a groove along the longitudinal direction of the cooling table for guiding the extruded resin on the upper surface. Resin pellet manufacturing, comprising: a cooling table; vibration means for vibrating the cooling table; and granulating means for cutting or crushing the solidified resin transported from the cooling table to granulate apparatus.   The extruder has a tie die, the tie die has a plurality of die holes for extruding the molten resin, and the cooling table receives a plurality of groove portions for receiving and guiding the molten resin extruded from the plurality of hole portions. The resin pellet manufacturing apparatus according to claim 1, comprising:   The extruder has a pressure detector for measuring the pressure of the molten resin in the tidy and an opening / closing means capable of opening / closing at least a part of the die holes, and the opening / closing means opens / closes the die holes. Accordingly, the resin pressure in the tidy can be controlled, and the resin pellet manufacturing apparatus according to claim 2. The resin pellet manufacturing apparatus according to any one of claims 1 to 3, wherein surface processing for preventing adhesion of resin is performed on the groove portion of the cooling table.

Images