Film blowing machine die head with adjustable film blowing thickness

Abstract

The utility model provides a film blowing machine die head with adjustable film blowing thickness, which relates to the technical field of film blowing machine devices, and comprises a die holder, a die core is fixedly embedded in the center of the die holder, a composite die sleeve is fixedly arranged at the top of the die holder, the composite die sleeve comprises an inner die ring and an outer die ring, the inner die ring is arranged around the die core, a film blowing seam is formed between the inner die ring and the die core, and the outer die ring is arranged around the die core. The outer mold ring is fixedly arranged on the mold base, a plurality of adjusting mechanisms are arranged on the outer mold ring in a surrounding mode, each adjusting mechanism comprises a driving source and a push rod, the driving sources are fixedly arranged on the side wall of the outer mold ring, the push rods are driven by the driving sources to be telescopically arranged on the side wall of the outer mold ring, and the push rods can be telescopically arranged to abut against the outer wall of the inner mold ring and driven by the driving sources to telescopically move. The radial fine adjustment of the inner mold ring is realized by adjusting the inner mold ring, so that the width of a film blowing seam of a corresponding adjusting part is controlled to be consistent, the thickness of a film blown out of the film blowing seam is finally ensured to be uniform, the displacement distance of the push rod can be accurately controlled by the driving source, the hysteresis of the adjusting process is avoided, and rapid and accurate response is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to a film blowing machine device technical field especially relates to a film blowing machine die head of film blowing thickness adjustable. BACKGROUND

[0002] The film blowing machine forms tubular film bubble through screw extrusion after heating and melting of plastic particles, and the film bubble is inflated and stretched by injecting compressed air into the film bubble, and the film is coiled into a thin film after solidification by cooling air ring. As a key component, the internal flow channel design and die gap of the die head directly affect the uniformity of melt flow. By adjusting the die gap, the flow rate and discharge amount of the melt in each region of the gap can be precisely controlled. With the coordination of the blow ratio and the pulling speed, the film thickness fluctuation or film breakage can be avoided, the consistency of the film thickness in the transverse and longitudinal directions is ensured, and the mechanical properties and subsequent processing quality of the film are ensured.

[0003] The adjustment of the die gap is mainly based on the real-time thickness monitoring data of the extruded film, so that the overall thickness can be uniformly controlled, and local fine tuning can be performed for the thickness deviation in different regions of the film. In the existing production process, the gap of each partition of the die head is usually adjusted by manually operating the bolts arranged around the bottom of the die holder. By adjusting the screw-in length of the bolts in the gap, the cross-sectional area of the melt flow channel is changed, so that the material distribution is balanced. However, this mechanical adjustment method depends on the structural precision and the experience of the operator, and it is difficult to realize high-frequency and high-precision dynamic compensation. Especially when dealing with complex thermal expansion effect or raw material property fluctuation, the adjustment process is time-consuming and unstable, which easily leads to an enlarged thickness tolerance and even periodic quality defects, becoming a key bottleneck restricting the production efficiency and quality improvement of the film.

[0004] The Chinese utility model patent with the authorized announcement number CN222407128U proposes a "adjustable film blowing machine flexible die head", which includes a die sleeve, a die head arranged in the middle of the die sleeve, an adjusting ring arranged around the outer wall of the die head, and a plurality of adjusting devices arranged on the die sleeve; the adjusting devices are arranged outside the adjusting ring and distributed along the circumferential direction of the adjusting ring; the adjusting device includes a sleeve pipe arranged horizontally and connected with the die sleeve, a metal pipe arranged in the sleeve pipe, a top rod connected with the metal pipe, and a heating device connected with the metal pipe; the top rod penetrates through the sleeve pipe and abuts against the outer wall of the adjusting ring. The adjustable film blowing machine flexible die head can more efficiently and accurately adjust the die head of the film blowing machine.

[0005] But in the above structure, since the adjusting device drives the top rod to move is realized by metal pipe heating expansion or cooling tightness, but metal pipe heating or cooling all need time response, cooling needs to rely on the air outlet natural heat dissipation, has certain hysteresis, cannot achieve fast response, and the length of metal pipe expansion and temperature is not absolute linear relationship, which leads to the distance of top rod displacement by temperature control may exist error, the adjusting precision is not high. Content of the utility model

[0006] In view of the deficiencies in the prior art, the utility model provides a blown film thickness adjustable blown film machine die, which solves the problems of the prior art, such as metal pipe heating or cooling all needing time response, cooling needing to rely on the air outlet natural heat dissipation, having certain hysteresis, being unable to achieve fast response, and low adjusting precision.

[0007] According to the embodiment of the utility model, a blown film thickness adjustable blown film machine die, it includes die holder, the die core is fixedly arranged in the center of die holder, the composite die sleeve is fixedly arranged on the top of die holder, the composite die sleeve includes inner die ring and outer die ring, the inner die ring is arranged around the die core, the blow film gap is formed between the inner die ring and the die core, the outer die ring is fixedly arranged on the die holder, a plurality of adjusting mechanisms are arranged around the outer die ring, the adjusting mechanism includes drive source and push rod, the drive source is fixedly arranged on the side wall of the outer die ring, the push rod is telescopically arranged on the side wall of the outer die ring by the drive source, and the push rod can be telescopically arranged on the side wall of the outer die ring.

[0008] The technical principle of the utility model is as follows: when it is needed to adjust the film thickness at a certain place, the drive source corresponding to the place on the outer die ring is started to drive the push rod to telescopically move, when the drive source drives the push rod to move radially inward, the gap between the inner die ring and the die core decreases, that is, the blow film gap decreases to control the film thickness blown out to decrease, and vice versa, when the drive source drives the push rod to move radially outward, the gap between the inner die ring and the die core increases, and the film thickness blown out increases.

[0009] Further, the composite die sleeve further includes a base, the outer die ring is fixedly connected with the top end of the base, and the base is detachably arranged on the die holder.

[0010] Further, the drive source includes a pneumatic cylinder, and the output end of the pneumatic cylinder is fixedly connected with the push rod.

[0011] Further, a fixing seat is fixedly arranged on the top end of the base, a limiting hole is arranged in the middle of the push rod, and the push rod is slidably arranged in the limiting hole.

[0012] Further, the push rod is fixedly provided with a hemispherical head at one end close to the inner mold ring, and the outer wall of the inner mold ring is fixedly provided with a stress boss for embedding and abutting the head.

[0013] Further, a plurality of arc-shaped adjusting pieces are fixedly arranged on the outer wall of the inner mold ring, and a pressing plate is fixedly arranged on the outer wall of the adjusting piece.

[0014] Further, the adjusting pieces are further provided with isolation grooves, and high-temperature-resistant elastic silica gel is filled in the isolation grooves.

[0015] Further, the pressing plate is fixedly connected with a sliding seat at the bottom, and a sliding block is fixedly arranged on the top of the base, and the sliding seat can slide on the sliding block.

[0016] Further, the driving source comprises a servo motor, the output end of the servo motor is rotationally connected with the push rod, the output shaft of the servo motor is fixedly provided with an external thread at the end, and the push rod is provided with an internal thread which is engaged with the external thread.

[0017] Further, the outer mold ring is further fixedly provided with a plurality of infrared thickness gauges at the top for monitoring the width of the film blowing seam.

[0018] Compared with the prior art, the utility model has the advantages that the push rod is driven to move by the driving source, the abutting degree of the push rod and the inner mold ring can be controlled to realize the radial fine adjustment of the local position of the inner mold ring, the film blowing seam width of the corresponding adjusting part is controlled to be uniform, the film thickness blown from the film blowing seam is uniform, the displacement distance of the push rod can be accurately controlled by the driving source, the hysteresis of the adjusting process is avoided, and quick and accurate response is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a schematic view of the overall structure of the embodiment of the utility model.

[0020] Figure 2 It is Figure 1 It is a schematic view of the structure of the composite mold sleeve of the embodiment of the utility model.

[0021] Figure 3 It is a schematic view of the structure of the composite mold sleeve of the embodiment of the utility model.

[0022] Figure 4 It is Figure 3 It is a schematic view of the structure of the composite mold sleeve of the embodiment of the utility model.

[0023] In the above figure: 1, die holder; 2, die core; 21, hanging block; 22, film blowing seam; 3, composite die sleeve; 31, outer die ring; 311, air cylinder; 312, servo motor; 313, push rod; 314, top head; 315, infrared thickness gauge; 316, internal thread; 32, inner die ring; 321, adjusting piece; 322, isolation groove; 323, pressing plate; 324, stress boss; 325, sliding seat; 326, sliding block; 33, base; 331, fixed seat; 332, limiting hole; 34, high-temperature-resistant elastic silica gel. DETAILED DESCRIPTION

[0024] The technical solutions in the utility model are further described below with reference to the drawings and examples.

[0025] As Figures 1-4 shown in the utility model embodiment, a film blowing machine die head with adjustable film blowing thickness is provided, which comprises a die holder 1, the center of the die holder 1 is fixedly provided with a die core 2, the die core 2 is detachably installed in the die holder 1, the top of the die core 2 is fixedly provided with a hanging block 21 for hanging the die core 2 when it is detached, there is an annular fluid passage between the die core 2 and the die holder 1, the fluid passage is used for forming a tubular film bubble under the action of compressed air when the film melt is extruded upward, in order to make the thickness of the formed film bubble more uniform in regulation and control, a composite die sleeve 3 is fixedly arranged at the top of the die holder 1, the composite die sleeve 3 comprises an inner die ring 32 and an outer die ring 31, the material of the inner die ring 32 is preferably a high-strength elastic alloy, such as an iron-based, nickel-based or titanium-based high-elasticity alloy, which can be elastically deformed under a controllable thrust, the inner die ring 32 is arranged around the die core 2, a film blowing seam 22 is formed between the inner die ring 32 and the die core 2, the film blowing seam 22 is connected with the fluid passage formed between the die core 2 and the die holder 1, and the initial width of the film blowing seam 22 is kept consistent with the fluid passage as much as possible, the outer die ring 31 is fixedly arranged on the die holder 1, specifically, the outer die ring 31 can be fixedly connected with the die holder 1 through bolts or other fixing modes, in order to further enhance the practicability of the composite die sleeve 3, the composite die sleeve 3 further comprises a base 33, the bottom of the outer die ring 31 is fixedly connected with the top end of the base 33, the base 33 is fixed with the die holder 1 through bolts or other detachable means, so as to facilitate the maintenance and repair of the composite die sleeve 3, or to facilitate the replacement of the inner die ring 32 to change the initial width of the film blowing seam 22, thereby being capable of producing more sizes of films.

[0026] As Figure 1 and Figure 2As shown in the embodiment, a plurality of adjusting mechanisms are arranged around the outer mold ring 31, the adjusting mechanism includes a driving source and a push rod 313, the driving source is fixedly arranged on the side wall of the outer mold ring 31, the push rod 313 is arranged on the side wall of the outer mold ring 31 in a telescopic manner driven by the driving source, the push rod 313 is telescopic to the outer wall of the inner mold ring 32 and abuts against the center of the inner mold ring 32, in order to meet the above effect, the driving source can be arranged as a cylinder 311, an electric cylinder or a hydraulic cylinder and the like which can drive the output end to move linearly, in the embodiment, the driving source is arranged as a cylinder 311, and the output end of the cylinder 311 is fixedly connected with the push rod 313.

[0027] As shown in the embodiment, a plurality of adjusting mechanisms are arranged around the outer mold ring 31, the adjusting mechanism includes a driving source and a push rod 313, the driving source is fixedly arranged on the side wall of the outer mold ring 31, the push rod 313 is arranged on the side wall of the outer mold ring 31 in a telescopic manner driven by the driving source, the push rod 313 is telescopic to the outer wall of the inner mold ring 32 and abuts against the center of the inner mold ring 32, in order to meet the above effect, the driving source can be arranged as a cylinder 311, an electric cylinder or a hydraulic cylinder and the like which can drive the output end to move linearly, in the embodiment, the driving source is arranged as a cylinder 311, and the output end of the cylinder 311 is fixedly connected with the push rod 313. Figure 2

[0028] As shown in the embodiment, a plurality of adjusting mechanisms are arranged around the outer mold ring 31, the adjusting mechanism includes a driving source and a push rod 313, the driving source is fixedly arranged on the side wall of the outer mold ring 31, the push rod 313 is arranged on the side wall of the outer mold ring 31 in a telescopic manner driven by the driving source, the push rod 313 is telescopic to the outer wall of the inner mold ring 32 and abuts against the center of the inner mold ring 32, in order to meet the above effect, the driving source can be arranged as a cylinder 311, an electric cylinder or a hydraulic cylinder and the like which can drive the output end to move linearly, in the embodiment, the driving source is arranged as a cylinder 311, and the output end of the cylinder 311 is fixedly connected with the push rod 313. Figure 2

[0029] As shown in the embodiment, a plurality of adjusting mechanisms are arranged around the outer mold ring 31, the adjusting mechanism includes a driving source and a push rod 313, the driving source is fixedly arranged on the side wall of the outer mold ring 31, the push rod 313 is arranged on the side wall of the outer mold ring 31 in a telescopic manner driven by the driving source, the push rod 313 is telescopic to the outer wall of the inner mold ring 32 and abuts against the center of the inner mold ring 32, in order to meet the above effect, the driving source can be arranged as a cylinder 311, an electric cylinder or a hydraulic cylinder and the like which can drive the output end to move linearly, in the embodiment, the driving source is arranged as a cylinder 311, and the output end of the cylinder 311 is fixedly connected with the push rod 313. Figure 2

[0030] As shown in the embodiment, a plurality of adjusting mechanisms are arranged around the outer mold ring 31, the adjusting mechanism includes a driving source and a push rod 313, the driving source is fixedly arranged on the side wall of the outer mold ring 31, the push rod 313 is arranged on the side wall of the outer mold ring 31 in a telescopic manner driven by the driving source, the push rod 313 is telescopic to the outer wall of the inner mold ring 32 and abuts against the center of the inner mold ring 32, in order to meet the above effect, the driving source can be arranged as a cylinder 311, an electric cylinder or a hydraulic cylinder and the like which can drive the output end to move linearly, in the embodiment, the driving source is arranged as a cylinder 311, and the output end of the cylinder 311 is fixedly connected with the push rod 313. Figure 2 ​​​As shown, in the embodiment, the bottom of the pressing plate 323 is fixedly connected with a sliding seat 325, the top of the base 33 is fixedly provided with a sliding block 326, the sliding seat 325 can slide on the sliding block 326, and the sliding seat 325 and the sliding block 326 provide radial limiting for the pressing plate 323, so that the push rod 313 cannot deviate during abutting against the stress boss 324, and the force transmitted by the push rod 313 can stably act on the adjusting sheet 321.

[0031] As shown in the drawings, Figure 1 and Figure 2 As shown, in the embodiment, the top end of the outer mold ring 31 is also fixedly provided with a plurality of infrared thickness gauges 315, which are used for monitoring the width of the film blowing seam 22, and a PLC can be arranged, after the infrared thickness gauges 315 transmit data to the PLC in real time, the PLC calculates the displacement amount required by each adjusting sheet 321 to compensate, then controls the air cylinder 311 to drive the push rod 313 to push the adjusting sheet 321 to move radially, and through the pre-set hard limiting of the PLC, it is ensured that the film blowing seam 22 still retains a minimum safety gap when the adjusting sheet 321 moves to the maximum displacement, so as to avoid direct contact between the film blowing seam 22 and the mold core 2, causing the air cylinder 311 to be overloaded or other components to be damaged, thereby realizing intelligent and high-precision dynamic regulation and control of the film blowing thickness.

[0032] The technical principle of the utility model is as follows: when the infrared thickness gauge 315 monitors that the thickness of the film blown out from the film blowing seam 22 is inconsistent at some position or needs to be actively adjusted, the corresponding air cylinder 311 on the outer mold ring 31 is started to drive the push rod 313 to extend and retract, when the air cylinder 311 drives the push rod 313 to move radially inward, the gap between the inner mold ring 32 and the mold core 2 decreases, that is, the film blowing seam 22 decreases, thereby controlling the thickness of the film blown out to decrease; on the contrary, when the air cylinder 311 drives the push rod 313 to move radially outward, the gap between the inner mold ring 32 and the mold core 2 increases, and the thickness of the film blown out increases.

[0033] By adopting the air cylinder 311 to drive the push rod 313 to extend and retract, the top head 314 at the end of the push rod 313 can form point contact with the spherical groove and transmit pressure sensitive and accurate to the adjusting sheet 321, and the adjusting sheet 321 drives the corresponding elastic inner mold ring 32 to move radially, and finally converts into the change of the width of the film blowing seam 22, thereby realizing accurate regulation and control of the film thickness, the abutting degree of the push rod 313 and the inner mold ring 32 is controlled to realize radial fine adjustment of the local position of the inner mold ring 32, the width of the film blowing seam 22 at the corresponding adjusting position is controlled to be consistent, and finally the thickness of the film blown out from the film blowing seam 22 is ensured to be uniform, the air cylinder 311 can accurately control the displacement distance of the push rod 313, and the hysteresis of the adjusting process is avoided, so that rapid and accurate response is achieved.

[0034] As shown in the drawings, Figure 3 and Figure 4As shown, according to another embodiment of the utility model embodiment, the drive source can also be a servo motor 312, the output end of the servo motor 312 is rotatably connected with the push rod 313, the output shaft end of the servo motor 312 is fixedly provided with external thread, the push rod 313 is provided with internal thread 316 that is mutually engaged with the external thread, at this time the section of the push rod 313 and the limiting hole 332 are preferably set as rectangle, the push rod 313 section is slightly smaller than the limiting hole 332, so that when the output shaft of the servo motor 312 and the push rod 313 relatively engage rotation, the push rod 313 cannot follow rotation due to the limitation of the limiting hole 332, thereby can only be radially translated in the limiting hole 332, it needs to be noted that the internal thread 316 and the external thread of servo motor 312 output shaft preferably use self-locking tooth type, to ensure that when the push rod 313 is not rotated, it can be locked.

[0035] Based on the above further improvement, compared with the cylinder 311, the servo motor 312 can realize closed-loop control of position, speed and torque, has higher control precision, and usually can achieve accurate positioning of about 0.01mm, and the servo motor 312 has higher transmission efficiency, can realize faster linear motion speed, thereby further realizing accurate regulation of film thickness.

[0036] Finally, it is explained that the above embodiments are only used to illustrate the technical scheme of the utility model and not to limit, although the utility model is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical scheme of the utility model can be modified or replaced, without departing from the purpose and scope of the technical scheme of the utility model, which should be covered in the scope of the claims of the utility model.

Claims

1. A blown film machine die head with adjustable film thickness, comprising a die base (1), wherein a die core (2) is fixedly embedded in the center of the die base (1), and a composite die sleeve (3) is fixedly disposed on the top of the die base (1), characterized in that: The composite mold sleeve (3) includes an inner mold ring (32) and an outer mold ring (31). The inner mold ring (32) is arranged around the mold core (2). A blown film slit (22) is formed between the inner mold ring (32) and the mold core (2). The outer mold ring (31) is fixedly arranged on the mold base (1). Several adjustment mechanisms are arranged around the outer mold ring (31). The adjustment mechanism includes a drive source and a push rod (313). The drive source is fixedly arranged on the side wall of the outer mold ring (31). The push rod (313) is driven by the drive source and is extended and retracted on the side wall of the outer mold ring (31). The push rod (313) can extend and retract to abut against the outer wall of the inner mold ring (32).

2. The blown film die head with adjustable film thickness as described in claim 1, characterized in that: The composite mold sleeve (3) also includes a base (33), the outer mold ring (31) is fixedly connected to the top of the base (33), and the base (33) is detachably mounted on the mold base (1).

3. The blown film die head with adjustable film thickness as described in claim 2, characterized in that: The drive source includes a cylinder (311), the output end of which is fixedly connected to the push rod (313).

4. The blown film thickness adjustable die head as described in claim 3, characterized in that: The base (33) is fixedly provided with a fixed seat (331) at the top, and the push rod (313) is provided with a limiting hole (332) in the middle, and the push rod (313) is slidably disposed in the limiting hole (332).

5. The blown film thickness adjustable die head as described in claim 4, characterized in that: The push rod (313) is fixedly provided with a hemispherical top (314) at one end near the inner mold ring (32), and the outer wall of the inner mold ring (32) is fixedly provided with a force-bearing boss (324) for the top (314) to be inserted into and abut against.

6. The blown film thickness adjustable die head as described in claim 5, characterized in that: A number of arc-shaped adjustment plates (321) are fixedly arranged around the outer wall of the inner mold ring (32), and a pressure plate (323) is fixedly arranged on the outer wall of the adjustment plate (321). The force-bearing boss (324) is fixedly connected to the outer wall of the pressure plate (323).

7. The blown film thickness adjustable die head as described in claim 6, characterized in that: An isolation groove (322) is also provided between the adjustment plates (321), and the isolation groove (322) is filled with high temperature resistant elastic silicone (34).

8. The blown film thickness adjustable die head as described in claim 6, characterized in that: The bottom of the pressure plate (323) is fixedly connected to a sliding seat (325), and the top of the base (33) is fixedly provided with a slider (326). The sliding seat (325) can slide on the slider (326).

9. The blown film thickness adjustable die head as described in claim 1, characterized in that: The drive source includes a servo motor (312), the output end of which is rotatably connected to the push rod (313). The output shaft end of the servo motor (312) is fixedly provided with an external thread, and the push rod (313) is provided with an internal thread (316) that meshes with the external thread.

10. The blown film thickness adjustable die head as described in claim 1, characterized in that: Several infrared thickness gauges (315) are also fixedly arranged around the top of the outer mold ring (31) to monitor the width of the blown film slit (22).

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