JP2005059240A - Synthetic resin supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synthetic resin supply device capable of supplying a synthetic resin to the female mold of a compression molding machine without damaging a preform and a bottle obtained by the blow molding of the preform. <P>SOLUTION: The synthetic resin supply device has a cutting means for cutting the synthetic resin extruded in a molten state from an extrusion opening formed to the leading end of an extrusion nozzle and a holding means including a first grasping member having a first grasping wall and a second grasping member having a second grasping wall, both of which are positioned in opposed relationship so as to leave an interval in a lateral direction with respect to a resin extruding direction and constituted so that at least one of the first and second grasping members is movable to prescribe a grasping position and an open position, and holding the synthetic resin cut by the cutting means to supply the same to the molding machine. A recessed part is formed to the first grasping wall and/or second grasping wall of the holding means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a synthetic resin supply device for supplying a synthetic resin in a molten state extruded from an extrusion opening of an extrusion nozzle to a compression molding device, and more specifically, when supplying the synthetic resin into the molding device, The present invention relates to a synthetic resin supply device that can effectively prevent a cut edge of a synthetic resin from coming into contact with the surface of a female mold and can prevent damage to a preform and a bottle.
[0002]
[Prior art]
As containers for filling beverages and the like, those made of synthetic resin such as polyethylene terephthalate are widely used, and such containers are formed by injection molding of synthetic resin to form a bottomed preform whose size is considerably smaller than the final container. A method is employed in which the preform is preliminarily heated to its stretching temperature, stretched in the axial direction in a blow mold, and blow-stretched in the circumferential direction (see, for example, Patent Document 1).
[0003]
In addition, as a method for producing such a preform, since the residence time in the molding machine is short and the deterioration of the resin is small, and there is no gate part at the bottom, it is already known that the resin is produced by compression molding. . For example, a compression mold having a closed bottom and a cavity forming a preform shape is prepared, a thermoplastic resin is molded into a precursor, and the precursor is placed in the compression mold, where the precursor is entirely contained in the cavity. The precursor is not completely filled with the compression mold but is supported in a predetermined manner in the cavity of the compression mold before being compressed to the final shape. There is proposed a method for manufacturing a preform, which comprises heating a precursor prior to putting the precursor into a compression mold, and compressing the heated precursor in the compression mold (Patent Literature). 2).
[0004]
In the preform molding by such compression molding, the synthetic resin is supplied to the female mold means or the male mold means before the male mold means and the female mold means are closed and the mold space is defined between them. The synthetic resin is supplied by, for example, a synthetic resin supply device (for example, Patent Document 3), but in the conventional synthetic resin supply device, the synthetic resin is separated from the extrusion opening of the extrusion nozzle. The synthetic resin is once received by the receiving means set in the closed state, and then transferred to the upper position of the female mold of the compression molding apparatus by the intermittent movement of the receiving means, and the female mold is started only by setting the receiving means in the open state. Therefore, the form of conveyance and the whole structure of the transfer mechanism are complicated.
[0005]
From this point of view, the present inventors have proposed a synthetic resin supply device that can hold the molten synthetic resin cut off from the extrusion opening of the extrusion nozzle as it is and transport it to the required part of the molding apparatus. According to such a synthetic resin supply device, it is possible to shorten the conveyance time from the extrusion opening of the extrusion nozzle to the required part of the molding device, and to improve the production efficiency.
[0006]
[Patent Document 1]
JP-A-4-154535 [Patent Document 2]
International Publication No. 97/32706 Pamphlet [Patent Document 3]
Japanese Patent Laid-Open No. 2-134222 [Patent Document 4]
Japanese Patent Laid-Open No. 2000-108127
[Problems to be solved by the invention]
According to such a synthetic resin supply device, the molten synthetic resin separated from the extrusion opening of the extrusion nozzle can be held as it is and transported to the required part of the molding device, and has excellent productivity. It was confirmed that a preform formed by supplying a synthetic resin to a compression molding apparatus using a resin supply apparatus or a bottle formed by blow-molding such a preform has a scratch.
As a result of diligent research on the cause of scratches on the preform or bottle, the present inventors have cut the edge of the melted synthetic resin supplied from the synthetic resin supply device to the female mold of the compression molding device, that is, the extrusion nozzle. This is because the end of the cutter mark generated when the resin extruded from the extrusion opening is cut by the cutting means first contacts the surface of the female mold, and this is stretched while adhering to the surface of the female mold. I understood it.
[0008]
Accordingly, an object of the present invention is to provide a synthetic resin supply apparatus capable of supplying a synthetic resin to a female mold of a compression molding apparatus so that the preform and the bottle formed by blow-molding the preform are not damaged. It is.
[0009]
[Means for Solving the Problems]
According to the present invention, the cutting means for cutting the molten synthetic resin extruded from the extrusion opening formed at the tip of the extrusion nozzle, the first clamping member and the second clamping wall having the first clamping wall A first clamping member, wherein the first clamping wall and the second clamping wall are positioned to face each other at an interval in the lateral direction with respect to the resin extrusion direction. And a holding means for holding the synthetic resin cut by the cutting means and supplying it to the molding apparatus, wherein at least one of the second holding member is movable and defines a holding position and an open position. The synthetic resin supply device is characterized in that a recess is formed in the first clamping wall and / or the second clamping wall in the holding means.
[0010]
In the synthetic resin supply device of the present invention,
1. The shape of the recess is such that the upper part is wider and deeper than the central part and the lower part,
2. A protruding portion is formed below the second holding wall, and the protruding portion becomes larger as going downward.
3. Minute irregularities are formed on the surface of the first sandwiching wall and / or the second sandwiching wall including the surface of the recess, and in particular, the surface roughness is 0.1 in terms of centerline average roughness (JIS B0601). ~ 50 μm,
Is preferred.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Generally speaking, the synthetic resin supply apparatus of the present invention holds a cutting means for cutting a molten synthetic resin extruded from an extrusion nozzle, and a holding means for holding the synthetic resin cut by the cutting means and supplying it to a molding apparatus. In the present invention, it is an important feature that a recess is formed in the first holding wall and / or the second holding wall of the holding means.
[0012]
FIG. 1 is a schematic view for explaining a process of molding a synthetic resin supplied from a conventional synthetic resin supply device into a preform by compression molding. Similarly, FIG. 2 is a schematic view of the synthetic resin supply device of the present invention. It is the schematic for demonstrating the process of shape | molding the supplied synthetic resin into a preform by compression molding.
FIG. 1 and FIG. 2A are views showing a state in which the synthetic resin drop 6 is held by the holding walls 4, 5 of the first holding member 2 and the second holding member 3 of the holding means 1. is there. FIG. 1 and FIG. 2B are views showing a state in which a drop of synthetic resin is supplied from the holding means to the female mold through the throat 8. (C) of FIG.1 and FIG.2 is a figure which shows the state which the female type | mold raises and the synthetic resin is compressed by the male type | mold. (D) of FIG.1 and FIG.2 is a figure which shows the state by which the female type | mold rose completely and the preform was shape | molded by the female type | mold and the male type | mold.
[0013]
As apparent from FIG. 1 (A), in the holding means 1 of the conventional synthetic resin supply device, the synthetic resin 6 cut by the cutting means (not shown) is prevented from dropping except at a predetermined position. The inclined portions 4a and 5a are formed so that the distance between the sandwiching walls decreases as the upper portions of the sandwiching walls 4 and 5 of the sandwiching member 2 and the second sandwiching member 3 go downward.
As is clear from FIGS. 1A and 1B, the upper end 6a of the synthetic resin drop is a cut surface (cutter mark) cut by a cutting means, and is an end of the drop and cut by a cutter. This is the most cooled part of the molten synthetic resin supplied to the molding apparatus.
[0014]
When the synthetic resin drop 6 having such a shape is supplied into the female die 7 of the molding device via the throat 8, the end 6b of the cutter mark comes into contact with the female die surface 7a. The cutter mark end 6b in contact with the female mold surface 7a does not adhere and move (FIG. 1 (B)). In this state, the female mold 7 rises and the synthetic resin cutter mark is formed on the lower part 9a of the male mold 9. When the compression of the synthetic resin proceeds by contact with 6a, the cutter mark 6a is compressed and stretched together with the resin flowing in the molding space 10 formed by the female mold 7 and the male mold 9 (FIG. 1C). ), The cutter mark disappears in the molded preform 11, but both ends 12 a and 12 b of the stretched cutter mark remain as scratches (FIG. 1D).
[0015]
On the other hand, in the synthetic resin supply device of the present invention, a concave portion is provided in the first holding wall and / or the second holding wall for holding the synthetic resin in the holding member of the synthetic resin supply device, so that the molding device The diameter of the cut surface of the synthetic resin to be supplied is made smaller than that of the other parts, so that the end of the cutter mark is prevented from coming into contact with the surface of the female die when supplied to the female die.
That is, as shown in FIG. 2 (A), in the synthetic resin supply apparatus of the present invention, since the concave portions 12 and 13 are formed in the first clamping wall 4 and the second clamping wall 5, The diameter of the drop 6 is reduced by rounding the upper end and the lower end according to the shape of the recess, and the diameter of the cutter mark portion 6a is smaller than that of the conventional drop. This effectively prevents the cutter mark end portion 6b from coming into contact with the female mold surface 7a even if a drop is supplied to the female mold 7 (FIG. 2B).
Next, when the female mold 7 is raised, the cutter mark 6a made of synthetic resin adheres to the tip 9a of the male mold 9 and is pressed as it is, but the cutter mark 6a is located near the bottom 11a on the inner surface side of the preform 11 (FIG. 2 (C) and (D)), even if the preform 11 is blow-molded, the bottle is not damaged.
[0016]
Next, the synthetic resin supply apparatus of the present invention will be described in detail. In the specific example of the synthetic resin supply device described later, the basic configuration and operation of the holding means excluding the configurations of the first clamping member and the second clamping member are disclosed in Japanese Patent Application Laid-Open No. 2000-108127. It can be performed in the same manner as the synthetic resin supply apparatus described in the publication.
FIG. 3 is a diagram showing the relationship of a series of apparatuses for molding a preform by compression molding using the synthetic resin supply apparatus of the present invention. The extruder 40 includes a synthetic resin supply apparatus 20 and an extrusion nozzle 41. A compression molding apparatus 50 and a take-out mechanism 60, which are molding apparatuses, are shown.
FIG. 4 is a side view of the cutting / holding mechanism portion of the synthetic resin supply apparatus of the present invention. In FIG. 4, the synthetic resin extruded and cut from the extruder is held by the holding means. It is a figure which shows a state.
[0017]
The extruder 40 shown in FIG. 3 is configured to convey the synthetic resin while being heated and melted and kneaded, and continuously extrude it from the extrusion nozzle 41. In this embodiment, the extrusion opening of the extrusion nozzle is directed vertically downward and extruded vertically downward. The compression molding apparatus 50 includes a rotary mold 51 including a rotary support 51 and a plurality of female molds 52 disposed on the rotary support 51. The extruder 40, the compression molding device 50, and the take-out device 60 may adopt a conventionally known configuration with respect to the devices themselves and the relationship between these devices.
[0018]
Further, the synthetic resin supply device shown in FIG. 3 includes a turntable 21, which is rotationally driven in the clockwise direction in FIG. 3, and receives the synthetic resin from the extruder and discharges it to the compression molding device at a predetermined position. Done.
As is clear from FIG. 4, the cutting / holding mechanism in the synthetic resin supply apparatus holds the cutting means 22 for cutting the synthetic resin from the extruder and the synthetic resin 100 cut by the cutting means 22 as described above. And holding means 23 that can selectively set a holding state for holding the synthetic resin and an open state for releasing the cut synthetic resin. The cutting means 22 is comprised from a conventionally well-known cutter member, and is attached to the lower surface side of the turntable 21 with the 1st clamping member 24 of a holding means.
[0019]
The holding means 23 has a first clamping member 24 and a second clamping member 30.
FIG. 5 is an exploded view for explaining a part constituting the first clamping member 24. The first clamping member 24 has a predetermined thickness and has a substantially rectangular shape. 25, extending vertically downward by a predetermined length from the lower surface of one side portion of the mounting portion 25 in the width direction, substantially upstream from one end 25a in the longitudinal direction, and substantially perpendicular to the front end of the upstream wall 26 And a first clamping wall 27 extending from one side of the mounting portion 25 toward the other side in parallel with the one end 25 a of the mounting portion 25. The upstream wall 26 and the first clamping wall 27 are substantially L-shaped. Two mounting holes 28 are formed in the mounting portion 25. The upstream wall 26 extends from one end 25 a along the one side of the mounting portion 25 to substantially the middle in the longitudinal direction. The lengths from the upper surface of the mounting portion 25 to the lower end surfaces of the upstream wall 26 and the first holding wall 27 are defined to be substantially the same, and the upper end surface of the upstream wall 26 and the upper end surface of the first holding wall 27 subsequent thereto. Is positioned on a plane coinciding with the upper surface of the mounting portion 25, and the other part (tip portion) of the upper end surface of the first holding wall 27 is formed slightly higher than the plane.
[0020]
In the synthetic resin supply device of the present invention, as described above, it is an important feature that the concave portion 29 is formed in the first clamping wall 27 of the first clamping member 24. 5 is an enlarged view of the recessed portion in FIG. 5. In FIG. 6, (A) is a plan view, and (B) is an XX cross-sectional view in (A). The specific example shown in FIG. Then, as is clear from FIG. 6A, the planar shape of the concave portion 29 is substantially circular at the upper portion A, and the central portion B and the lower portion C following the concave portion 29 are narrower than the upper portion A, and have a lower end. A substantially rectangular recess having a rounded portion is formed. In addition, as is apparent from FIG. 6B, the recess 29 has a substantially circular upper portion A whose depth is deeper than the substantially rectangular central portion B and lower portion C. The surface forms a gentle curved surface without extreme irregularities. As described above, when the concave surface is a gentle curved surface having no extreme unevenness, it is possible to effectively prevent local distortion from occurring in the preform to be molded.
[0021]
FIG. 7 is an exploded view for explaining a portion constituting the second clamping member 30, and the second clamping member 30 is formed in a rectangular substrate portion 31 and one end portion of the substrate portion 31. The second holding wall 32 is arranged upright. The portion of the substrate portion 31 on the side opposite to the first clamping wall 32 is the same as a conventionally known configuration, so that the description thereof is omitted.
The second holding wall 32 extending to one end of the substrate part 31 has a substantially rectangular shape as a whole, and the upper end on one end side of the second holding wall 32 is slightly more than the other part. Highly formed.
[0022]
In the synthetic resin supply apparatus of the present invention, it is an important feature that the concave portion 33 is formed in the second clamping wall 32 of the second clamping member 30. In the specific example shown in the figure, the concave portion 33 is , Has the same shape as the recess 29 formed in the first clamping wall 27 described above.
In the specific example described above, the recess is formed in both the first sandwiching wall and the second sandwiching wall. Of course, the diameter of the cut end surface of the synthetic resin may be reduced as compared with other portions. In addition, as long as the cutter mark end of the supplied synthetic resin does not contact the female mold, the concave portion may be formed only on either the first clamping wall or the second clamping wall.
[0023]
In the present invention, it is particularly preferable that a taper-like protruding portion whose protruding amount increases as it goes downward is formed below the concave portion of the first holding wall and / or the second holding wall. In the specific example shown in FIG. 7, a tapered projecting portion 34 is formed below the concave portion 33 of the second sandwiching wall 30 so that the projecting amount increases as going downward. Thereby, it is possible to prevent the synthetic resin held by the first clamping wall and the second clamping wall from falling outside the predetermined position.
[0024]
Moreover, in the synthetic resin supply apparatus of this invention, it is preferable that the micro unevenness | corrugation is formed in the surface of the 1st clamping wall containing the recessed part surface, and the 2nd clamping wall. By having such a surface with fine irregularities (such as a satin finish), it is possible to improve the releasability of the synthetic resin from the clamping wall surface, particularly from the inside of the recess, and to supply a stable resin to the molding apparatus. Become. The surface roughness of the surfaces of the first clamping wall and the second clamping wall including the concave surface is 0.1 to 50 μm, particularly 1.0 to 20 μm, in terms of centerline average roughness (JIS B0601). Is particularly preferred. The first sandwiching wall and the second sandwiching wall having such a surface roughness and including the concave surface can be formed by performing a conventionally known sandblasting process or the like.
Moreover, it is preferable that the surface temperature of the first clamping wall and the second clamping wall is controlled, and in particular within the range of 5 to 60 ° C., the releasability is combined with the surface roughness. The resin can be stably supplied to the molding apparatus.
[0025]
【The invention's effect】
According to the present invention, the cutting means for cutting the molten synthetic resin extruded from the extrusion opening formed at the tip of the extrusion nozzle, the first clamping member and the second clamping wall having the first clamping wall A first clamping member, wherein the first clamping wall and the second clamping wall are positioned to face each other at an interval in the lateral direction with respect to the resin extrusion direction. And a holding means for holding the synthetic resin cut by the cutting means and supplying it to the molding apparatus, wherein at least one of the second holding member is movable and defines a holding position and an open position. In the holding means, when the synthetic resin is supplied into the molding apparatus, the cut edge of the synthetic resin is formed on the surface of the female mold by forming a recess in the first clamping wall and / or the second clamping wall in the holding means. Preform surface that can effectively prevent contact Scratches, or it has become possible to effectively prevent the occurrence of a bottle of scratch.
[Brief description of the drawings]
FIG. 1 is a schematic view for explaining a process of molding a resin supplied from a conventional synthetic resin supply apparatus into a preform by compression molding.
FIG. 2 is a schematic view for explaining a process of molding a resin supplied from the synthetic resin supply apparatus of the present invention into a preform by compression molding.
FIG. 3 is a view showing the relationship of a series of apparatuses for molding a preform by compression molding using the synthetic resin supply apparatus of the present invention.
FIG. 4 is a side view of a cutting / holding mechanism portion of the synthetic resin supply apparatus of the present invention.
FIG. 5 is an exploded view for explaining a portion constituting the first clamping member.
6 is an enlarged view of a recessed portion in FIG. 5, in which (A) is a plan view and (B) is an XX cross-sectional view of (A).
FIG. 7 is an exploded view for explaining a portion constituting the second holding member.
[Explanation of symbols]
1: holding means, 2: synthetic resin, 3: second clamping member, 4: first clamping member,
5: second clamping wall, 6: second clamping wall, 7: female mold, 8: throat, 9: male mold,
10: Cutter mark, 11: Preform, 20: Synthetic resin supply device,
22: cutting means, 23: holding means, 24: first clamping member,
27: first clamping wall, 29: recess, 30: second clamping member,
32: 2nd clamping wall, 33: Recessed part, 34: Protruding part, 40: Extruder,
50: compression molding apparatus, 60: take-out mechanism, 100: synthetic resin

Claims (5)

Cutting means for cutting the molten synthetic resin extruded from the extrusion opening formed at the tip of the extrusion nozzle, the first clamping member having the first clamping wall and the second clamping having the second clamping wall And the first clamping wall and the second clamping wall are positioned to face each other with a gap in the transverse direction with respect to the resin extrusion direction, and the first clamping member and the second clamping member A holding unit that holds the synthetic resin cut by the cutting unit and supplies the synthetic resin to the molding apparatus, wherein at least one of the movable unit is movable and defines a sandwiching position and an open position.
A synthetic resin supply device, wherein a concave portion is formed in the first clamping wall and / or the second clamping wall in the holding means. The synthetic resin supply device according to claim 1, wherein the shape of the recess is such that the upper part is wider and deeper than the central part and the lower part. The synthetic resin supply device according to claim 1 or 2, wherein a protruding portion whose protruding amount increases as it goes downward is formed below the second holding wall. The synthetic resin supply apparatus in any one of Claims 1 thru | or 3 with which the fine unevenness | corrugation is formed in the surface of the 1st clamping wall including the said recessed part surface, and / or the 2nd clamping wall. 5. The synthetic resin supply according to claim 4, wherein the surface roughness of the first clamping wall and / or the second clamping wall including the surface of the recess is 0.1 to 50 μm in terms of centerline average roughness (JIS B0601). apparatus.

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