Novel mouth mold adjusting device for plastic film blowing unit
By designing a new type of mouth mold adjustment device in a plastic film blowing unit, the thermal expansion fine adjustment device and adjustment mechanism are used to accurately adjust the circumferential local point width of the mouth mold gap of the blow mold, the problem of uneven film thickness is solved and the further development is achieved. High film production uniformity and quality.
Patent Information
- Application Number
- CN202421180241.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-28
- Publication Date
- 2025-02-07
- Estimated Expiration
- 2034-05-28
AI Technical Summary
Traditional plastic film blowing units cannot fine-tune the width of the circumferential local point gap of the blowing mold mouth mold, resulting in uneven film thickness and lack of effective remedial measures.
Design a new type of mouth mold adjustment device, including a support ring, a thermal expansion fine-tuning device and an adjustment mechanism. By dividing the mold ring into multiple arc segments, and setting a thermal expansion fine-tuning device in the circumference of the mold ring, it is realized by using a thermal expansion tube and a heating member. Accurate adjustment of the width of each point of the die gap.
The precise adjustment of the thickness uniformity of the finished film is achieved, and the film thickness can be adjusted in real time during the film blowing operation to improve the uniformity and quality of film production.
Smart Images
Figure CN222431540U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of film blowing equipment, in particular to a novel die adjusting device for a plastic film blowing machine unit. Background Art
[0002] In the production process of the plastic film blowing machine, the width of the die gap of the blow molding mold is the key to affecting the thickness of the film. If there are parts with different widths in the die gap, the material flow rate will be uneven, resulting in uneven film thickness.
[0003] When the molten material enters the blow mold of the plastic film blowing machine, it must only enter from a general feed port, and then gradually expand and distribute in the blow mold and flow into the annular die gap. In the above expansion and distribution process, although people strive to keep the thickness and pressure of the molten material uniform at each point in the circumference of the die gap, in reality, due to the error of mechanical equipment and the limitation of the distribution channel itself, the thickness of the film formed when the molten material is extruded from the die gap is uneven. The traditional blow mold can only adjust the die gap by moving the position of the mold ring as a whole to adjust the thickness of the finished film, but this adjustment method is systematic and global (that is, when the width of a certain point in the circumference increases, other points in the circumference must also increase, and vice versa), and it cannot fine-tune the width of local points in the circumference. Therefore, when the molten material is extruded from the die gap into a film, even if the width of each point in the circumference is uneven, there is a lack of effective remedial measures. Utility Model Content
[0004] The technical problem to be solved by the utility model is to provide a new type of die adjustment device for a plastic film blowing machine unit, which can accurately adjust the width of each point on the circumference of the die gap, thereby accurately adjusting the thickness uniformity of each part of the finished film. The adopted technical solution is as follows:
[0005] A new type of die adjustment device for a plastic film blowing machine unit comprises a die body, a die core and a die ring sleeved on the outer periphery of the lower part of the die core are arranged on the die body, and the gap between the die ring and the lower part of the die core constitutes an annular die gap; it is characterized in that: the new type of die adjustment device also comprises a support ring and a plurality of thermal expansion fine-tuning devices, the support ring is installed on the die body and is located on the outer periphery of the die ring, and the plurality of thermal expansion fine-tuning devices are arranged on the support ring along the circumference of the die ring; the die ring is divided into a plurality of arc segments along its circumference, each thermal expansion fine-tuning device corresponds to each arc segment of the die ring one by one, each thermal expansion fine-tuning device comprises a thermal expansion tube, a heating element and an adjustment mechanism, the thermal expansion tube is arranged along the radial direction of the die ring and is located outside the corresponding arc segment of the die ring, the inner end of the thermal expansion tube is fixedly connected to the corresponding arc segment of the die ring, the adjustment mechanism is installed on the support ring, the adjustment end of the adjustment mechanism is connected to the outer end of the thermal expansion tube, and the heating element is sleeved in the thermal expansion tube.
[0006] In the above-mentioned new die adjustment device, the power-on state of each heating element can be independently controlled. The heating element is used to conduct heat to the thermal expansion tube, so that the thermal expansion tube will expand and contract according to the temperature; the above-mentioned adjustment mechanism is used to adjust the position of the corresponding arc segments of the thermal expansion tube and the die ring in the radial direction of the die ring (i.e., the inward and outward directions), thereby manually adjusting the width of a certain point of the die gap.
[0007] Before the film blowing operation is carried out, the corresponding heat expansion tube and the corresponding arc segment of the mold ring are pre-pulled toward the mold core through the adjustment mechanism of each heat expansion fine-tuning device, so that the width of the die gap is close to the maximum critical value of the target film thickness. During the film blowing operation, when it is detected that the thickness of a certain part of the finished film is greater than the thickness required for production, the heating element of the corresponding heat expansion fine-tuning device can be controlled to be powered on for heating, and the heat expansion tube is heated and expanded by heat conduction. Since the outer end of the heat expansion tube is limited by the adjustment mechanism, the heat expansion tube can only expand toward the mold core, so that the heat expansion tube pushes the corresponding arc segment of the mold ring inward to move toward the mold core, reducing the width of the die gap at this point, thereby reducing the thickness of the finished film at that point.
[0008] As a preferred solution of the utility model, the heat expansion tube is a metal tube, and the heating element is a heating rod, so that the metal tube can be heated by the conductive heat of the heating rod to increase its temperature and expand.
[0009] As a further preferred embodiment of the present invention, the thermal expansion tube is a copper tube or an aluminum tube. Since copper and aluminum have excellent thermal conductivity, when the temperature of the heating rod changes, the copper tube or the aluminum tube can more sensitively expand and contract by a certain amplitude, driving the arc segment to move slightly, thereby adjusting the radius of the corresponding arc segment slightly.
[0010] As a preferred solution of the utility model, the inner end of the thermal expansion tube is fixedly connected to the corresponding arc segment of the mold ring through a fixing buckle.
[0011] As a preferred solution of the utility model, the die ring is an annular elastic metal sheet, and the die ring is equally divided into a plurality of arc segments along its circumference, thereby making it possible to more accurately adjust the width of each point on the circumference of the die gap.
[0012] As a preferred solution of the utility model, the adjustment mechanism includes a guide sleeve, an adjustment bolt and an adjustment nut, the guide sleeve is installed on the support ring, the adjustment nut is connected to the outside of the guide sleeve, the adjustment bolt has a straight section and a threaded section, the straight section of the adjustment bolt is in the guide sleeve, the adjustment nut is sleeved on the threaded section of the adjustment bolt, and the inner end of the adjustment bolt is rotatably connected to the outer end of the thermal expansion tube. During adjustment, the adjustment bolt can be rotated in the forward or reverse direction, and the meshing relationship between the screw rod of the adjustment bolt and the adjustment nut can drive the adjustment bolt to move inward or outward along the guide sleeve, thereby driving the thermal expansion tube to move inward or outward, and pre-adjusting the position of the arc section corresponding to the mold ring in the radial direction of the mold ring.
[0013] As another preferred solution of the utility model, the adjustment mechanism includes a guide sleeve, an adjustment nut and an adjustment bolt, the guide sleeve is mounted on the support ring, the adjustment nut can be rotatably mounted on the outer side of the guide sleeve, the adjustment bolt has a spline section and a threaded section, the spline section of the adjustment bolt is in the guide sleeve and cooperates with the guide sleeve spline, the adjustment nut is sleeved on the threaded section of the adjustment bolt, and the inner end of the adjustment bolt is connected to the outer end of the thermal expansion tube. When adjusting, the adjustment nut can be rotated in the forward or reverse direction, and the meshing relationship between the screw of the adjustment bolt and the adjustment nut can be used to drive the screw of the adjustment bolt to move inward or outward along the guide sleeve, thereby driving the thermal expansion tube to move inward or outward, and pre-adjusting the position of the arc section corresponding to the mold ring in the radial direction of the mold ring.
[0014] Compared with the prior art, the utility model has the following advantages:
[0015] This new die adjustment device divides the die ring into multiple arc segments along its circumference, and sets multiple thermal expansion fine-tuning devices on the outer circumference of the die ring. Each thermal expansion fine-tuning device is used to pull the corresponding arc segment of the die ring to achieve fine-tuning, thereby achieving the effect of more accurately adjusting the thickness uniformity of each part of the finished film. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a structural schematic diagram of a novel die adjustment device of a preferred embodiment of the utility model.
[0017] Figure 2 yes Figure 1 A bottom view of each thermal expansion fine-tuning device in the novel die adjustment device is shown.
[0018] Figure 3 is included Figure 1 The structural schematic diagram of the plastic film blowing unit with a new die adjustment device is shown. DETAILED DESCRIPTION
[0019] like Figure 1 , Figure 2 As shown, the novel die adjustment device 100 for the plastic film blowing machine unit comprises a die body 1, a support ring 2 and a plurality of thermal expansion fine-tuning devices 3. The die body 1 is provided with a die core 11 and a die ring 12 sleeved on the outer periphery of the lower part of the die core 11, and the gap between the die ring 12 and the lower part of the die core 11 constitutes an annular die gap 10; the support ring 2 is mounted on the die body 1 and is located on the outer periphery of the die ring 12, and a plurality of thermal expansion fine-tuning devices 3 are arranged on the support ring 2 along the circumference of the die ring 12; the die ring 12 is an annular elastic metal sheet, and the die ring 12 is equally divided into a plurality of arc segments 121 along its circumference, and each thermal expansion fine-tuning device 3 is provided with a plurality of arc segments 121. The device 3 corresponds one-to-one to each arc segment 121 of the mold ring 12. Each thermal expansion fine-tuning device 3 includes a thermal expansion tube 31, a heating element 32 and an adjustment mechanism 33. The thermal expansion tube 31 is arranged along the radial direction of the mold ring 12 and is located on the outside of the corresponding arc segment 121 of the mold ring 12. The inner end of the thermal expansion tube 31 is fixedly connected to the corresponding arc segment 121 of the mold ring 12 through a fixing buckle 34. The adjustment mechanism 33 is installed on the support ring 2. The adjustment end of the adjustment mechanism 33 is connected to the outer end of the thermal expansion tube 31. The heating element 32 is sleeved in the thermal expansion tube 31. The power-on state of each heating element 32 can be independently controlled.
[0020] In this embodiment, the thermal expansion tube 31 is a copper tube, and the heating element 32 is a heating rod. Thus, the metal tube can be heated by the conductive heat of the heating rod; since copper has excellent thermal conductivity, when the temperature of the heating rod changes, the copper tube can more sensitively expand and contract by a certain amplitude, driving the arc segment 121 to move slightly, thereby adjusting the radius of the corresponding arc segment 121 slightly.
[0021] In this embodiment, the adjustment mechanism 33 includes a guide sleeve 331, an adjustment bolt 332 and an adjustment nut 333. The guide sleeve 331 is installed on the support ring 2, and the adjustment nut 333 is connected to the outer side of the guide sleeve 331. The adjustment bolt 332 has a straight section 3321 and a threaded section 3322. The straight section 3321 of the adjustment bolt 332 is in the guide sleeve 331. The adjustment nut 333 is sleeved on the threaded section 3322 of the adjustment bolt 332. The inner end of the adjustment bolt 332 is rotatably connected to the outer end of the thermal expansion tube 31. When adjusting, the adjustment bolt 332 can be rotated forward or backward, and the meshing relationship between the screw rod of the adjustment bolt 332 and the adjustment nut 333 can drive the adjustment bolt 332 to move inward or outward along the guide sleeve 331, thereby driving the thermal expansion tube 31 to move inward or outward, and pre-adjusting the position of the arc section 121 corresponding to the mold ring 12 in the radial direction of the mold ring 12.
[0022] In this embodiment, the adjustment mechanism 33 includes a guide sleeve 331, an adjustment nut 333 and an adjustment bolt 332. The guide sleeve 331 is mounted on the support ring 2. The adjustment nut 333 can be rotatably mounted on the outer side of the guide sleeve 331. The adjustment bolt 332 has a spline section and a threaded section 3322. The spline section of the adjustment bolt 332 is in the guide sleeve 331 and is splined with the guide sleeve 331. The adjustment nut 333 is sleeved on the threaded section 3322 of the adjustment bolt 332. The inner end of the adjustment bolt 332 is connected to the outer end of the thermal expansion tube 31. When adjusting, the adjustment nut 333 can be rotated forward or backward, and the screw of the adjustment bolt 332 can be driven to move inward or outward along the guide sleeve 331 by utilizing the meshing relationship between the screw of the adjustment bolt 332 and the adjustment nut 333, thereby driving the thermal expansion tube 31 to move inward or outward, and pre-adjusting the position of the arc section 121 corresponding to the mold ring 12 in the radial direction of the mold ring 12 so that it moves toward or away from the mold core.
[0023] The working principle of the plastic film blowing machine unit containing the novel die adjustment device 100 is briefly described below:
[0024] refer to Figure 3The plastic film blowing machine unit includes a frame, a new die adjusting device 100, a herringbone plate 200, two first clamping rollers 300, a guide roller 400, two second clamping rollers 500 and a monitoring device 600 for detecting the size and thickness of the finished film. The new die adjusting device 100, the herringbone plate 200, the two first clamping rollers 300, the guide roller 400, the two second clamping rollers 500 and the monitoring device 600 are all installed on the frame and are arranged in sequence from front to back along the conveying direction of the finished film. During operation, after the film comes out of the die gap 10 of the novel die adjustment device 100, it first passes through the herringbone plate 200 and the two first clamping rollers 300 in sequence, then passes through the tensioning roller and the guide roller 400, and finally passes through the monitoring device 600 driven by the two second clamping rollers 500. The monitoring device 600 detects the size and thickness of the finished film and sends it to the PLC controller, which compares it with the set value to obtain the difference, and then adjusts the die gap 10 of the novel die adjustment device 100 accordingly, and adjusts the thickness of the finished film at various locations to make up for the difference.
[0025] Before the film blowing operation is performed, the novel die adjustment device 100 first pre-pulls the corresponding heat expansion tube 31 and the corresponding arc segment 121 of the die ring 12 toward the die core 11 through the adjustment mechanism 33 of each heat expansion fine adjustment device 3, so that the width of the die gap 10 is close to the maximum critical value of the target film thickness. During the film blowing operation, when the monitoring device 600 detects that the thickness of a certain part of the finished film is greater than the thickness required for production, the PLC controller controls the corresponding heating element 32 of the heat expansion fine adjustment device 3 to be powered on for heating, and conducts heat to the heat expansion tube 31 to make it heat up and expand. Since the outer end of the heat expansion tube 31 is limited by the adjustment mechanism 33, the heat expansion tube 31 can only expand toward the die core 11, so that the heat expansion tube 31 pushes the corresponding arc segment 121 of the die ring 12 inward to move toward the die core 11, reducing the width of the die gap 10 at this point, thereby reducing the thickness of the finished film at that point.
[0026] In addition, it should be noted that the names of the various parts of the specific embodiments described in this specification may be different, and any equivalent or simple changes made based on the structure, features and principles described in the utility model patent concept are included in the protection scope of the utility model patent. The technical personnel of the technical field to which the utility model belongs can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, they should all fall within the protection scope of the utility model.
Claims
1. A novel die adjustment device for a plastic film blowing machine unit, comprising a die body, a die core and a die ring sleeved on the periphery of the lower part of the die core, and a gap between the die ring and the lower part of the die core forming an annular die gap; characterized in that: The novel die adjustment device also includes a support ring and a plurality of thermal expansion fine-adjustment devices. The support ring is installed on the die body and is located on the outer circumference of the die ring. The plurality of thermal expansion fine-adjustment devices are arranged on the support ring along the circumference of the die ring. The die ring is divided into a plurality of arc segments along its circumference. Each thermal expansion fine-adjustment device corresponds one-to-one to each arc segment of the die ring. Each thermal expansion fine-adjustment device includes a thermal expansion tube, a heating element and an adjustment mechanism. The thermal expansion tube is arranged along the radial direction of the die ring and is located outside the corresponding arc segment of the die ring. The inner end of the thermal expansion tube is fixedly connected to the corresponding arc segment of the die ring. The adjustment mechanism is installed on the support ring. The adjustment end of the adjustment mechanism is connected to the outer end of the thermal expansion tube. The heating element is sleeved in the thermal expansion tube.
2. The novel die adjustment device for a plastic film blowing machine according to claim 1, characterized in that: The thermal expansion tube is a metal tube, and the heating element is a heating rod.
3. The novel die adjustment device for a plastic film blowing machine according to claim 2, characterized in that: The thermal expansion tube is a copper tube or an aluminum tube.
4. The novel die adjustment device for a plastic film blowing machine according to claim 1, characterized in that: The inner end of the heat expansion tube is fixedly connected to the corresponding arc segment of the mold ring through a fixing buckle.
5. The novel die adjustment device for a plastic film blowing machine according to claim 1, characterized in that: The mold ring is an annular elastic metal sheet, and the mold ring is equally divided into a plurality of arc segments along its circumference.
6. A novel die adjustment device for a plastic film blowing machine according to any one of claims 1 to 5, characterized in that: The adjustment mechanism includes a guide sleeve, an adjustment bolt and an adjustment nut. The guide sleeve is installed on the support ring. The adjustment nut is connected to the outside of the guide sleeve. The adjustment bolt has a straight section and a threaded section. The straight section of the adjustment bolt is in the guide sleeve. The adjustment nut is sleeved on the threaded section of the adjustment bolt. The inner end of the adjustment bolt is rotatably connected to the outer end of the thermal expansion tube.
7. A novel die adjustment device for a plastic film blowing machine according to any one of claims 1 to 5, characterized in that: The adjustment mechanism includes a guide sleeve, an adjustment nut and an adjustment bolt. The guide sleeve is installed on the support ring. The adjustment nut can be rotatably installed on the outer side of the guide sleeve. The adjustment bolt has a spline section and a threaded section. The spline section of the adjustment bolt is in the guide sleeve and cooperates with the guide sleeve spline. The adjustment nut is sleeved on the threaded section of the adjustment bolt, and the inner end of the adjustment bolt is connected to the outer end of the thermal expansion tube.