JP2011079223A - Screw of plastication apparatus and plastication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw of a plastication apparatus which can easily draw gas generated from a molten resin from the rear side of a heating cylinder by devising its shape and the plastication apparatus fitted with the screw. <P>SOLUTION: From the rear part toward the front part of the screw 15 of the plastication apparatus 11 which is installed at least rotatably in the heating cylinder 12 and in which a flight part 31 and groove parts 32a, 33a, 34a, 35a, and 36a are formed, the first zone 32 in which the whole groove part 32a is formed into a deep groove, the second zone 33 in which a groove rear part 33b is formed to be shallower gradually from the deep groove, and a groove front part 33c is formed successively into a deep groove, a third zone 34 in which a groove rear part 34b is formed into a shallow groove, and a groove front part 34c is formed successively into a deep groove, a fourth zone 35 in which a groove rear part 35b is formed into a shallow groove, and a groove front part 35c is formed to be shallower gradually from the deep groove, and the fifth zone 36 in which the whole groove part 36a is formed into a shallow groove is formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a screw of a plasticizing apparatus in which a flight part and a groove part are formed and provided at least rotatably in a heating cylinder, and a plasticizing apparatus in which the screw is disposed.

  As a plasticizing apparatus for plasticizing a molding material with a screw rotatably provided in a heating cylinder, those described in Patent Documents 1 to 4 are known. Among them, Patent Document 1 and Patent Document 2 are for sucking negative pressure in the heating cylinder. Patent Document 1 is a so-called vent type injection molding machine, in which a vent hole is provided in an intermediate portion of a heating cylinder, and gas generated in the heating cylinder is sucked under a negative pressure from the vent hole. However, in the case of this vent type, there is a problem that a negative pressure suction cannot be performed due to a phenomenon called vent up in which the molten material rises into the vent hole. Patent Document 2 solves the above problem, and an exhaust means is provided in a portion of a feed device connected to a dropping port. However, in Patent Document 2, there is a problem that the distance between the part where the molding material is plasticized in the heating cylinder and the gas is generated and the exhaust means are long. Especially when the supply amount of the resin material is large, the inside of the groove at the rear part of the screw is resin. There was a problem that it was filled with pellets and hindered gas suction.

  Further, Patent Document 3 and Patent Document 4 do not draw negative pressure in the heating cylinder, and therefore, the configuration and operational effects of the present invention and the plasticizing apparatus are different, but are taken up as those related to the screw shape. In Patent Document 3, a part of the groove of the compression zone of the screw is gradually made shallower at the rear part of the groove near the front surface of the flight, the front part of the groove near the rear surface of the flight is made into a deep groove, and the molten molding material is made into the shallow groove part. In order to ensure the uniformity of the molten resin. However, in Patent Document 3, the front part of the groove is gradually shallower with respect to the part where the rear part of the groove is the same shallow groove as the metering zone, the rear part of the groove is a shallow groove, and the front part of the groove is a deep groove. There is no section. Therefore, the gas generated from the molten resin that generates heat between the shallow groove at the rear of the groove and the inner hole of the heating cylinder cannot be sufficiently removed from the rear side of the heating cylinder using the groove front that is a deep groove. It was.

  Also in Patent Document 4, the land 67 near the front surface of the flight in the first half of the transition portion 109 (corresponding to the compression zone) of the screw and the shaft 39 near the rear surface of the flight gradually become shallow grooves, respectively. The rear part is a shallow groove, and there is no deep groove section in the front part of the groove. Accordingly, since the shaft 39 is also shallow at the portion where the land 67 is a shallow groove, the gas generated from the molten resin generated by shearing between the land 67 (the rear portion of the groove) and the inner hole portion of the heating cylinder is transferred to the shaft 39. It was not possible to sufficiently pull out from the rear side using (groove front). Further, in Patent Document 4, since the land 67 is connected from the screw thread 92 of the supply portion 106 (corresponding to the feed zone), there is little molding material supplied along the front surface of the flight. Therefore, there is also a problem that the molding material is not melted by the direct shear heat generation at the land 67 as a result.

Japanese Utility Model Publication No. 3-25953 (Claim 1, FIG. 1) JP 2008-143022 (0011, FIG. 1, FIG. 2) JP 10-113962 A (0024, FIG. 1, FIG. 2) JP-T 62-502677 gazette (6th page, 8th page, FIG1, FIG4C)

  In the present invention, in view of the above-described problems, the screw of the plasticizing device that can easily remove the gas generated from the molten resin from the rear side of the heating cylinder by devising the shape, and the plastic in which the screw is disposed. An object of the present invention is to provide a device.

  The screw of the plasticizing device according to claim 1 of the present invention is a screw of a plasticizing device in which a flight part and a groove part are formed and provided at least in a heating cylinder so as to be rotatable. A first zone in which the entire groove portion is formed as a deep groove, a second zone in which the groove rear portion is formed so as to gradually become shallower from the deep groove and the groove front portion is continuously formed in the deep groove, and the groove rear portion A third zone is formed in the shallow groove and the groove front portion is continuously formed in the deep groove, and a fourth zone is formed in which the groove rear portion is continuously formed in the shallow groove and the groove front portion is gradually shallowed from the deep groove. The present invention is characterized in that a zone and a fifth zone in which the entire groove is formed as a shallow groove are provided.

  The screw of the plasticizing device according to claim 2 of the present invention is the screw according to claim 1, wherein the shallow groove at the front part of the groove and the rear part of the groove generates shear heat between the molding material and the inner hole part of the heating cylinder. The screw of the plasticizing apparatus according to claim 1, wherein the screw has a depth to be formed.

  The screw of the plasticizing device according to claim 3 of the present invention is characterized in that, in claim 1 or 2, the ratio of the groove rear portion to the entire groove portion is 30 to 70%.

  The screw of the plasticizing apparatus according to claim 4 of the present invention is the screw according to any one of claims 1 to 3, wherein the rear portion of the groove is once shallow from the shallow groove between the third zone and the fourth zone. An open zone is provided which is formed deeper than the groove and below the deep groove, is formed again as a shallow groove, and the groove front portion is formed so as to be gradually shallower from the deep groove or the deep groove. .

  According to a fifth aspect of the present invention, there is provided the plasticizing apparatus according to any one of the first to fourth aspects, wherein the screw of the plasticizing apparatus according to any one of the first to fourth aspects is disposed in the heating cylinder, Is sucked from the rear side of the heating cylinder including the charging port.

  The screw of the plasticizing apparatus of the present invention is a screw of a plasticizing apparatus in which a flight part and a groove part are formed, and is provided so as to be rotatable at least in a heating cylinder. Is formed in a deep groove, a second zone in which a groove rear portion is formed so as to gradually become shallower from the deep groove, and a groove front portion is continuously formed in the deep groove, and a groove rear portion is formed in the shallow groove. And a third zone in which the front part of the groove continues to be formed in the deep groove, a fourth zone in which the rear part of the groove continues to be formed in the shallow groove and the front part of the groove gradually decreases from the deep groove, and the entire groove part Since the fifth zone formed in the shallow groove is provided, the gas generated from the molten resin can be easily extracted from the rear side of the heating cylinder.

FIG. 1 is a view showing a plasticizing apparatus and a screw according to this embodiment. Drawing 2 is an explanatory view showing typically each zone of the screw of the plasticizing device of this embodiment. FIG. 3 is an enlarged cross-sectional view of the groove portion of the third zone of the screw of the plasticizing apparatus of the present embodiment. FIG. 4 is a schematic explanatory view schematically showing the case where the molding material is supplied and plasticized in a low-starvation state using the screw of the plasticizing apparatus of the present embodiment. FIG. 5 is a schematic explanatory view schematically showing the case where the molding material is supplied and plasticized in a highly starved state using the screw of the plasticizing apparatus of the present embodiment. FIG. 6 is a schematic explanatory view schematically showing a case where the supply of the molding material is supplied in a low-starvation state and plasticized using a general screw of the prior art. FIG. 7 is a schematic explanatory view schematically showing a case where the supply of the molding material is supplied in a highly starved state and plasticized using a general screw of the prior art. Drawing 8 is an explanatory view showing typically each zone of a screw of a plasticizing device of another embodiment.

  An embodiment of the present invention will be described with reference to FIGS. 1 and 5. As shown in FIG. 1, the plasticizing device 11 of the injection molding machine also has an injection device. A nozzle 14 is connected to the front of the heating cylinder 12 via a fixed cylinder head portion 13. A screw 15 is at least rotatably disposed in the inner hole portion 12a of the heating cylinder 12, and the rear end of the screw 15 is connected to a measuring motor 16 via a member such as a screw sleeve (not shown). . Further, a housing plate 17 is fixed to the rear side (the side opposite to the nozzle) of the heating cylinder 12. In addition, the plasticizing device 11 that also has an injection device is provided with an injection motor and an injection mechanism (not shown) that cause the screw 15 to move forward and backward in the heating cylinder 12. A heating means such as a band heater (not shown) is attached to the outside of the heating cylinder 12, and the heating cylinder 12 can be temperature controlled for each zone such as a rear zone 18, a middle zone 19, and a front zone 20. . The temperature of the nozzle 14 is also controlled by a band heater or the like, similar to the heating cylinder 12.

  The inlet 21 of the heating cylinder 12 and the housing plate 17 is connected to a feed device 22 for resin pellets P, which is a molding material. The feed device 22 includes upper and lower shutter devices 23a and 23b that can always keep the inside of the heating cylinder 12 in a vacuum state, a feed screw 24a that can adjust and supply resin pellets P, a drive motor 24b, and the like. The resin pellet P is supplied into the heating cylinder 12 from a storage tank of the resin pellet P (not shown) through the feed device 22 and the inlet 21 of the heating cylinder 12. Therefore, in this embodiment, the supply amount of the resin pellets P into the heating cylinder 12 can be freely adjusted by the feed device 22 such as a high starvation state or a low starvation state.

  A suction port 27 connected to a vacuum pump 26 that is a suction means for sucking the inside of the heating cylinder 12 at a negative pressure is formed in the cylinder portion 25 of the feed device 22 in which the feed screw 24a is disposed. O-rings are inserted between the heating cylinder 12 and the base 28 of the screw 15, between the feed device 22 and the housing plate 17, and between the housing plate 17 and the heating cylinder 12, and the inside of the heating cylinder 12 is sealed from the outside. It has become. The suction means includes a rear side of the heating cylinder 12 including the inlet 21 (for example, the rear zone 18 of the heating cylinder 12, the vicinity of the inlet 21 and the inlet 21, the rear side further than the inlet 21 of the heating cylinder 12, Negative pressure suction may be performed from the rear end of the heating cylinder 12 and the base portion 28 of the screw 15 or the like.

  The screw 15 disposed in the heating cylinder 12 is formed of five zones except for a base portion 28 that is slidably held via an O-ring or the like with respect to the inner hole portion 12a of the heating cylinder 12. Yes. At its tip, a backflow prevention valve such as a ring valve 29 and a conical screw head 30 are attached. In the present embodiment, the screw 15 is provided with a continuous spiral flight portion 31 (main flight), and the flight portion 31 is similarly provided with a spiral groove portion 32a and the like. The flight portions 31 of the screw 15 are provided at equal intervals in each zone, and are provided so that the outer peripheral diameter of the flight portion 31 and the inner diameter of the inner hole portion 12a of the heating cylinder 12 have a slight clearance that does not cause galling. It has been. Therefore, it is almost impossible to expect the gas generated during plasticization (during measurement) to be sucked to the rear side of the heating cylinder 12 through the clearance. The L / D obtained by dividing the axial length of the portion of the screw 15 where the flight portion 31 is formed by the diameter of the screw 15 is, for example, about 16 to 30, more preferably 20 to 28. Slightly longer than typical length. The screw 15 is subjected to a surface treatment such as hard chrome plating. In addition, the said screw shape, the surface treatment method, etc. are examples and are not limited to what was described.

  Next, each zone of the screw 15 will be described in order from the rear (input 21 side) to the front (nozzle side). As shown in FIGS. 1 and 2, the inlet 21 of the heating cylinder 12 and the portion in front thereof are a first zone 32. As for the 1st zone 32, the groove part 32a (shaft part) between the flight parts 31 is formed in the deep groove whose groove part is the groove depth similar to the groove depth of the feed zone of a general screw. The bottom surface of the groove portion 32a and the wall surface of the flight portion 31 are connected with a smooth curved surface (the groove portion 33a of each zone described later and the wall surface of the flight portion 31 are similarly connected with a smooth curved surface). And since the groove part 32a is formed in the deep groove, even if the resin pellet P of about 70% of the volume of the groove part 32a is supplied, the resin pellet P is packed up to the front side of the groove part 32a located behind the flight part 31. There is almost no cause of shearing heat generation. The space formed on the front side of the groove 32a serves as a passage when sucking gas, moisture, and the like generated from the molten resin M described later. The axial length of the first zone 32 is preferably 7D to 12D (D = the diameter of the screw 15) in order to ensure the supply capability of the resin pellet P. In the present invention, the “deep groove” is a relative depth, and when comparing the groove depth of the first zone 32 and the groove depth of the subsequent zone, the subsequent zone shallows the groove to a compression ratio of 1.2. If it is in the range up to the groove depth, it corresponds to “deep groove”. Accordingly, the groove portion 32a and the groove front portions 33c, 34c from the first zone 32 to the third zone 34 to be described later are formed in “deep grooves”, but if the groove depth is such that almost no shearing heat is generated in the case of starvation supply. It does not exclude the case where the depth gradually decreases or the depth of the groove is changed.

  A second zone 33 is formed in front of the first zone 32. In the groove part 33a of the second zone 33, a groove rear part 33b located in front of the flight part 31 is formed so as to gradually become shallower from the deep groove. Further, the groove front part 33 c located behind the flight part 31 is formed in a deep groove following the first zone 32. A third zone 34 is formed in front of the second zone 33. In the groove portion 34 a of the third zone 34, the groove depth of the groove rear portion 34 b is the same as the groove depth of the general screw metering zone, and the resin pellet P is the inner hole portion 12 a of the heating cylinder 12. It is formed in a shallow groove enough to generate shear heat. In the present invention, the “shallow groove” is a relative depth. When the groove depth of the groove rear portion 34b of the third zone 34 is compared with the groove depth of a groove portion 36a of the fifth zone 36 described later, If it is in the range up to the groove depth where the groove is deepened so that the compression ratio becomes 1.2 toward the zone 36, it corresponds to the “shallow groove”. Accordingly, the groove rear portions 34b and 35b from the third zone 34 to the fourth zone 35 to be described later are formed as “shallow grooves”. However, if the groove depth causes shearing heat generation even in the case of starvation supply, the depth is gradually increased. It does not exclude things that become shallower or that change depth.

  As an example, the compression ratio between the groove portion 32a (deep groove) of the first zone 32 and the groove rear portion 34b (shallow groove) of the third zone 34 is set to about 1.8 to 2.4. The groove depth of the groove front part 34 c of the groove part 34 a of the third zone 34 is formed in a deep groove following the first zone 32 and the second zone 33. Therefore, when sucking in gas or moisture generated from the molten resin M, which will be described later, the groove front portion 34c of the third zone 34 is a deep groove and has a role as a passage that has a certain cross-sectional area. Fulfill.

  FIG. 3 shows an enlarged cross-sectional view of the groove portion 34a of the third zone 34 as representative of each zone. In the second zone 33 to the fourth zone 35, the groove rear portion 34b and the like are grooves from the top front end 31a of the flight portion 31. It refers to a portion up to the intermediate position 34d of the connecting portion formed from an inclined surface or a curved surface between the bottom surface portion of the rear portion 34b and the bottom surface portion of the groove front portion 34c. Further, the groove front part 34c and the like extend from the top rear end 31b of the flight part 31 to the intermediate position 34d of the connecting part formed from an inclined surface or a curved surface between the bottom surface part of the groove front part 34c and the flat part of the groove rear part 34b. Refers to the part. Accordingly, the boundary between the groove rear portion 34 b and the groove front portion 34 c is formed in a spiral shape substantially parallel to the flight portion 31. In the present embodiment, the widths of the groove rear portion 34b and the groove front portion 34c and the like are equal to each other by 1/2 in each zone of the screw 15. However, the ratio of the groove rear portion 34b or the like in the entire width of the groove portion 34a or the like may be 30 to 70%. Further, the widths of the groove rear portions 33b, 34b, and 35b from the second zone 33 to the later-described fourth zone 35 may be widened within the above range.

  A fourth zone 35 is formed in front of the third zone 34. In the groove part 35 a of the fourth zone 35, the groove rear part 35 b located in front of the flight part 31 is formed as a shallow groove following the third zone 34. Moreover, the groove front part 35c located behind the flight part 31 is formed so as to gradually become shallower from the deep groove. In this embodiment, the second zone 33 and the fourth zone 35 have the same axial length, and the third zone 34 is 1.5 times longer than the second zone 33. Yes. However, the ratio of the axial length of the third zone 34 to the second zone 33 or the fourth zone 35 is allowed in the range of 100 to 200% as an example. The axial length including the second zone 33 to the fourth zone 35 is desirably 10D to 16D (D = diameter of the screw 15) as an example. Accordingly, the third zone 34 in which the groove rear part 34b is a shallow groove and the groove front part 34c is a deep groove is at least 3.3D to 8.0D (D = diameter of the screw 15) (both rounded to the second decimal place). It is desirable to provide a length. In addition, a fifth zone 36 is formed in front of the fourth zone 35. The fifth zone 36 is formed as a shallow groove whose entire groove portion 36a has a groove depth similar to that of a general screw metering zone.

  Next, a plasticizing method of the plasticizing apparatus 11 of the injection molding machine will be described with reference to FIG. The inside of the heating cylinder 12 including the inside of the feed device 22 is always sucked by a vacuum pump 26 serving as a suction means, and is kept at −90 kPa or more (absolute vacuum pressure of 11.33 kPa or less). And the thermoplastic resin pellet P which is a molding material is supplied from the storage tank which is not shown in figure through the shutter apparatuses 23a and 23b of the feed apparatus 22. FIG. At this time, in the shutter devices 23a and 23b, the two shutters are not opened simultaneously, and the inside of the heating cylinder 12 is always kept in a vacuum state. In the present embodiment, dry pellets are used as the resin pellets P, but undried pellets and recycled materials may be used. Further, the rear zone 18 of the heating cylinder 12 corresponding to the second zone 33 of the screw 15 is set to be high so that the resin pellets P can be melted (which differs depending on the type of resin, but is generally It is set 10-30 ° C. higher than the set temperature of the rear zone of the plasticizer).

  In the plasticizing step (metering step), the feed screw 24 a of the feed device 22 is rotated to send the resin pellet P, and the first zone 32 of the screw 15 rotated in the heating cylinder 12 through the inlet 21. It is supplied to the groove 32a. In the present embodiment, a predetermined amount of resin pellets P controlled to a certain amount are supplied from the feed device 22 according to the rotation of the screw 15 in the heating cylinder 12, and low starvation molding is performed. In the case of low starvation molding, resin pellets P of about 70% of the volume of the groove 32a of the first zone 32 of the screw 15 are supplied, and the upper surface of the flight part 31 of the screw 15 is the resin pellet P when the insertion port 21 is viewed from above. It will not disappear. Therefore, as shown in FIG. 4, in the case of low starvation supply, a gap having a certain width is formed on the rear side of the flight portion 31 of the screw 15 to be rotated. In the plasticizing step, the screw 15 is slowly retracted while receiving back pressure in the heating cylinder 12 as the molten resin is stored in the heating cylinder 12 in front of the screw 15. Therefore, the same portion of the first zone 32 of the screw 15 does not always face the inlet 21. In the case of a high starvation supply as shown in FIG. 5, the resin pellet P is not completely filled in the groove portion 32a on the lower side of the screw 15 so that the bottom surface portion of the groove portion 32a can be seen from above. Is supplied.

  The resin pellet P is sent from the first zone 32 toward the second zone 33 by the rotation of the screw 15. And since the groove rear part 33b of the groove part 33a of the 2nd zone 33 is formed so that it may become shallow from a deep groove gradually, the resin pellet P sent so that it may be pressed against the front surface of the flight part 31 may be a heating cylinder. 12 is pushed into a narrow space between the inner hole portion 12a and the heat of the screw 15 is generated to generate shear heat to become the molten resin M step by step. Further, as described above, since the rear zone 18 of the heating cylinder 12 corresponding to the second zone 33 is set to a higher set temperature, the melting of the resin pellets P is more than the plasticizing method using a normal plasticizing apparatus. Promoted from an early stage. As for that point, FIG. 4 schematically showing a case where the supply of the resin pellets P, which is a molding material, is supplied in a low-starvation state and plasticized using the screw 15 of the plasticizing apparatus 11 of the present embodiment, and the related art. It is obvious from the comparison of FIG. 6 that schematically shows the case of using the technical screw. Or from the comparison of FIG. 5 that schematically shows the case of using the screw 15 of the plasticizing apparatus 11 of the present embodiment and FIG. Is also obvious.

  The resin pellet P and the molten resin M are then sent to the third zone 34 as the screw rotates. Since the groove rear portion 34b of the groove portion 34a of the third zone 34 is a shallow groove that is the same as the groove depth of a general screw metering zone and the groove portion 36a of the fifth zone 36, the melting of the resin pellet P further proceeds. To do. At that time, gas and moisture are generated from the molten resin M. However, as is clear from FIG. 4, a gap (passage) having a cross-sectional area of a certain size or more is formed in the groove front portion 34 c together with the unmelted resin pellet P layer. Penetrates the layer of the resin pellet P and passes through the gap (passage), and is easily sucked by the vacuum pump 26 through the inlet 21 and the suction port 27. On the other hand, as is clear from FIG. 6, in the case of low starvation supply using the conventional screw, the resin pellet P clogged in the entire groove of the feed zone is rapidly melted from the latter half of the compression zone to the metalling zone. The position where the gas or the like is generated from the molten resin M is a position far from the inlet, and the gas or the like is not completely removed by being interrupted by the resin pellet P in the feed zone. Then, while the molten resin M contains gas or the like, it is sent to the front of the screw and then injected, thereby reducing the quality of the molded product or attaching impurities to the mold.

  As shown in FIG. 4, the molten resin M and a part of the unmelted resin are then sent to the fourth zone 35 along with the screw rotation. Since the groove rear part 35b of the groove part 35a of the fourth zone 35 is the same shallow groove as the fifth zone 36, the melting of the molten resin M further proceeds. Further, since the groove front part 35c of the groove part 35a of the fourth zone 35 is formed so as to gradually become shallower from the deep groove, an unmelted resin is formed in the groove front part 34c of the third zone 34 in the low starvation supply state. Even when the pellet P remains, further shearing heat is applied, and the resin pellet P is almost completely melted at the groove front portion 35c. Note that the groove front portion 35c of the fourth zone 35 is deeper than the groove rear portion 35b, so that it becomes a passage when the vacuum pump 26 sucks the gas generated from the molten resin M or the like.

  The molten resin M melted in the fourth zone 35 is sent to the fifth zone 36 along with the screw rotation to be further melted and made uniform. The molten resin M passes through the ring valve 29 and is sent and stored in front of the heating cylinder 12 and the screw 15 inside the cylinder head portion 13. In the plasticizing method of the present invention, the plasticizing step is performed with a low back pressure (for example, 0 MPa to 5 MPa). Further, although the rotational speed of the screw 15 varies depending on the screw diameter, it is desirable to perform the plasticizing step within the range of the normal rotational speed or slightly higher. Then, when the screw 15 is retracted to the measurement completion position, the rotation and retraction are stopped, and in some cases, the screw 15 is reversed at that position to complete the plasticizing process. When the mold clamping device side completes preparations such as mold clamping, an injection motor (not shown) of the plasticizing device that also serves as the injection device is actuated to inject the measured molten resin (including the pressure holding step). ) Is performed.

  In the present embodiment, the description has been made mainly on the low hunger supply shown in FIG. However, when the high starvation supply of FIG. 5 is performed, the plasticization time is often prolonged, but since the suction of the gas etc. from the molten resin M is often performed better, the supply is performed depending on the type of resin material, etc. Determine the amount and screw speed. In the present invention, even if the resin pellet P is intermittently supplied without providing the feed screw 24a and high-precision starvation is not performed, the resin pellet P is melted from an early stage, and the groove of the screw 15 Since a spiral space (passage) is formed between the front portions 33 c, 34 c, 35 c and the inner hole portion 12 a of the heating cylinder 12, it is generated from the molten resin M between the second zone 33 and the fifth zone 36. Can be easily sucked in. Moreover, although the vacuum degree demonstrated about the example of -90 kPa or more, what is necessary is just more than the grade which can carry out negative pressure suction of a gas with a blower etc. Further, in parallel with negative pressure suction including vacuum suction, or instead of negative pressure suction, a gas such as nitrogen gas may be injected into the heating cylinder 12 from the middle zone 19 of the heating cylinder 12 or other parts.

  Next, FIG. 8 demonstrates the screw 41 of another embodiment corresponding to Claim 4 of this invention. Since the shape of the plasticizing device 11 and the heating cylinder 12 in which the screw 41 is disposed is substantially the same as that of the plasticizing device 11 of FIG. 1 described above, the same parts are referred to by the same reference numerals and description thereof is omitted. Further, the screw 41 and the screw 15 described above are the same in that the first zone 32, the second zone 33, the third zone 34, the fourth zone 35, and the fifth zone 36 are formed in this order from the rear side. Therefore, the same part uses the same number and abbreviate | omits description. In the screw 41, an open zone 42 is provided between the third zone 34 and the fourth zone 35. As shown in FIG. 8, the groove portion 42a of the open zone 42 is formed such that the groove rear portion 42b is once deeper than the shallow groove and deeper than the shallow groove. The groove rear portion 42b is again formed as a shallow groove. The groove front part 42c of the groove part 42a is continuously formed as a deep groove. The groove front part 42 c may be formed so as to gradually become shallower from the deep groove, and may be connected to the groove front part 35 c of the fourth zone 35.

  In the screw 41 shown in FIG. 8, the melted material melted by the groove rear part 34 b of the third zone 34 is once pressure-released at the part where the groove depth of the groove rear part 42 b of the release zone 42 is deep. As a result, the release of gas or the like from the molten resin M in the open zone 42 can be further promoted.

  The present invention is not limited to the embodiments described above, and various modifications can be added and implemented without departing from the spirit of the invention.

  The molding material used in the plasticizing apparatus of the present invention is not limited to various resin materials, metal materials, organic materials other than resins, inorganic materials, and the like. In addition, the screw of the plasticizing apparatus of the present invention is an in-line type injection molding machine in which the screw also moves forward and backward, as well as a pre-plastic (registered trademark) type that combines a plasticizing apparatus and an injection plunger. Used in injection devices, extruders, kneading devices, etc. Therefore, the screw in the heating cylinder only needs to rotate at least.

11 Plasticizing equipment

12 Heating cylinder

12a Inner hole

15,41 screw

22 Feed device

26 Vacuum pump (suction means)

31 Flight Department

32 Zone 1

33 Zone 2

34 Zone 3

35 Zone 4

36 Zone 5

32a, 33a, 34a, 35a, 36a, 42a Groove

33b, 34b, 35b, 42b Groove rear

33c, 34c, 35c, 42c groove front

42 Open Zone

Claims (5)

In the screw of the plasticizing apparatus in which the flight part and the groove part are formed and provided at least rotatably in the heating cylinder,
From the rear to the front of the screw,
A first zone in which the entire groove is formed in a deep groove;
A second zone in which the rear portion of the groove is formed so as to gradually become shallower from the deep groove and the front portion of the groove is continuously formed in the deep groove;
A third zone in which the rear portion of the groove is formed as a shallow groove and the front portion of the groove is continuously formed as a deep groove;
A fourth zone formed such that the rear portion of the groove is continuously formed into a shallow groove and the front portion of the groove gradually becomes shallower from the deep groove;
A screw for a plasticizing apparatus, comprising a fifth zone in which the entire groove is formed as a shallow groove. The screw of the plasticizing apparatus according to claim 1, wherein the shallow groove at the front part of the groove and the rear part of the groove has a depth at which the molding material generates shear heat between the inner hole part of the heating cylinder. . The screw of the plasticizing apparatus according to claim 1 or 2, wherein a ratio of the rear portion of the groove in the entire groove portion is 30 to 70%. Between the third zone and the fourth zone, the rear portion of the groove is once formed from the shallow groove to a depth that is deeper than the shallow groove and not more than the deep groove and is formed again as the shallow groove, and the front portion of the groove continues from the deep groove or the deep groove. The screw of the plasticizing apparatus according to any one of claims 1 to 3, further comprising an open zone formed so as to gradually become shallower. While the screw of the plasticizing apparatus according to any one of claims 1 to 4 is disposed in the heating cylinder,
The plasticizing apparatus, wherein the inside of the heating cylinder is sucked from the rear side of the heating cylinder including the inlet.