A high-precision plastic sheet molding equipment

Abstract

This invention relates to the field of injection molding equipment technology, specifically providing a high-precision plastic sheet molding equipment, including a mold body and a flow-blocking assembly. The mold body contains an inlet area, a manifold area, a flow-blocking area, a relaxation area, and a molding area arranged sequentially along the melt flow direction. The flow-blocking assembly includes a flow-blocking strip, a flow-blocking rod, a seal, and a pre-tightening unit. The flow-blocking strip is laterally positioned within the flow-blocking area inside the mold body. This invention incorporates a flow-blocking rod that rotates circumferentially around its axis by a preset angle. This circumferential rotation alters the surface of the flow-blocking rod exposed within the flow-blocking area, changing its scouring surface. This results in different circumferential surfaces of the flow-blocking rod in contact with the melt during two consecutive production operations, preventing continuous scouring of localized surfaces and thus avoiding a sharp decrease in adjustment accuracy. This extends the service life of the flow-blocking rod.

Description

Technical Field

[0001] This invention relates to the field of injection molding equipment technology, and in particular to a high-precision plastic sheet molding equipment. Background Technology

[0002] Plastic sheets are a relatively thick type of sheet material. Their processing and molding process is the same as that of sheet materials. The resin raw materials and the required additives are mixed evenly according to the formula and then fed into an extruder for heating, melting and plasticizing. The molten material is extruded into a flat sheet blank through a T-shaped extrusion die. Then, it is pressed to the target thickness and pre-shaped by multiple sets of calendering rollers. It then enters a cooling and shaping device to fully cool and solidify. Finally, it is fed out at a uniform speed by a traction device and cut into sheet-shaped finished products of specified dimensions by a fixed-length cutting device.

[0003] The T-type extrusion die head mainly consists of a die body, a transverse distribution channel (such as a coat hanger type or a T-type manifold area type), upper and lower die lips, and a flow-blocking bar.

[0004] In use, the melt enters the die head from the extruder, is first diverted laterally through the transverse distribution channel, so that the melt is evenly distributed along the width direction of the die head, and then extruded from the gap between the upper and lower die lips to form a wide and thin plastic sheet blank.

[0005] The flow-restricting rod is inserted into the flow-restricting zone of the mold body to adjust the flow rate of the melt in the flow-restricting zone, thereby achieving the purpose of coarsely adjusting the width of the plastic sheet. Since the melt inevitably contains a certain amount of impurity particles (such as calcium carbonate, talc, glass fiber, etc.), these impurity particles will slide past the flow-restricting rod when passing through the flow-restricting zone, causing tiny surface defects (such as scratches or dents) on the flow-restricting rod. As the working time of the flow-restricting rod accumulates, the surface defects of the flow-restricting rod will continue to worsen, the scratches will become more obvious, and the dents will become deeper. This will cause the adjustment accuracy of the flow-restricting rod to drop sharply, resulting in a shorter service life of the flow-restricting rod. Summary of the Invention

[0006] Therefore, it is necessary to provide a high-precision plastic sheet molding equipment to address the problems existing in current plastic sheet molding equipment, and to solve the problem of the short service life of the flow-blocking bars in existing plastic sheet molding equipment.

[0007] The above objectives are achieved through the following technical solutions: A high-precision plastic sheet molding equipment includes: The mold body has an inlet area, a manifold area, a flow obstruction area, a relaxation area, and a molding area arranged sequentially along the flow direction of the melt. The flow-blocking assembly includes a flow-blocking strip, a flow-blocking rod, a seal, and a pre-tightening unit. The flow-blocking strip is laterally arranged in the flow-blocking area inside the mold body. A notch is opened at the lower part of the flow-blocking strip. The notch extends laterally through the flow-blocking strip and downwards into the flow-blocking area. The flow-blocking rod is embedded in the notch. The seal is connected between the flow-blocking rod and the notch. The preload unit has a preloaded state and a non-preloaded state; In the pre-tightened state, the flow-blocking rod and the sealing element are connected in a sealed manner with a preset sealing force; In the non-pre-tightened state, the flow-restricting bar can rotate circumferentially around its axis.

[0008] Furthermore, the sealing element includes a first flexible sealing strip and a first rigid sealing strip. There are two first flexible sealing strips, which are symmetrically arranged on both sides inside the notch groove with the center line in the width direction of the notch groove as the axis of symmetry. There are also two first rigid sealing strips, which correspond one-to-one with the two first flexible sealing strips and are fixedly connected. The two first rigid sealing strips are also in contact with the flow-blocking rod in a surface-contact manner.

[0009] Furthermore, the sealing element also includes two second flexible sealing strips and two second rigid sealing strips. The two second flexible sealing strips and the two second rigid sealing strips are symmetrically arranged on both sides inside the notch groove with the center line in the width direction of the notch groove as the axis of symmetry. The second rigid sealing strip is located below the second flexible sealing strip, and both the second rigid sealing strip and the second flexible sealing strip are in surface contact with the flow-blocking rod.

[0010] Furthermore, the pre-tightening unit includes a push block and a first screw. The push block is located in the notch groove and above the flow-blocking bar. The axis of the first screw is vertical and rotatably connected to the mold body. The first screw is threadedly connected to the push block.

[0011] Furthermore, the lower part of the push block is connected to several rollers, and the rollers are connected to the flow-blocking bar in a line contact manner.

[0012] Furthermore, a second screw is rotatably connected to the mold body. The axis of the second screw is vertical, and the second screw is threadedly connected to the flow barrier.

[0013] Furthermore, the high-precision plastic sheet molding equipment also includes a side sealing assembly, which is used to seal both sides of the mold.

[0014] Furthermore, the side sealing assembly includes an outer sealing plate, an inner sealing plate, and a tightening bolt. The inner sealing plate and the outer sealing plate are arranged at intervals from the inside to the outside and are slidably connected to the mold body. The tightening bolt is threadedly connected to the outer sealing plate and abuts against the inner sealing plate.

[0015] Furthermore, lifting rings are provided at the four corners of the upper surface of the mold.

[0016] Furthermore, a high-precision plastic sheet molding equipment also includes an injection molding machine, the outlet of which is connected to the inlet area of ​​the mold. The beneficial effects of this invention are: 1. This invention incorporates a flow-restricting rod that rotates circumferentially around its axis at a predetermined angle. This circumferential rotation alters the surface of the flow-restricting rod exposed in the flow-restricting zone, thus changing its scouring surface. This results in the circumferentially different surfaces of the flow-restricting rod that come into contact with the melt in two different production operations. In other words, the circumferential rotation of the flow-restricting rod distributes the wear caused by melt scouring across its entire circumference, preventing a sharp decrease in adjustment accuracy due to continuous scouring of a localized area and extending the lifespan of the flow-restricting rod.

[0017] 2. In this invention, because the flow-blocking rod is located at the throttle throat (i.e., the narrowest part) of the flow-blocking zone, the melt is forcibly accelerated at this location, forming a high-shear, high-turbulence flow state. Therefore, compared to the flow-blocking strip, the flow-blocking rod is more easily worn by solid particulate impurities in the melt; that is, the wear of the flow-blocking component by the melt is mainly concentrated on the flow-blocking rod. When the entire circumference of the flow-blocking rod is worn to a certain extent, the flow-blocking rod can be replaced instead of the entire flow-blocking component, thus significantly reducing the replacement cost of consumable parts. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a high-precision plastic sheet molding equipment according to the present invention; Figure 2 for Figure 1 The front view; Figure 3 for Figure 1 Side view; Figure 4 for Figure 3 Sectional view of AA; Figure 5 for Figure 4 A magnified schematic diagram of the structure at point C; Figure 6 for Figure 3 BB section view; Figure 7 for Figure 6 A magnified schematic diagram of the structure at point D; Figure 8 This is a schematic diagram of the mold body in a high-precision plastic sheet molding equipment of the present invention; Figure 9 for Figure 8 EE section view; Figure 10 for Figure 9A magnified schematic diagram of the structure at point F.

[0019] in: 100. Mold body; 110. Upper mold; 120. Lower mold; 130. Locking bolt; 140. Lifting ring; 101. Inlet area; 102. Manifold area; 103. Flow obstruction area; 104. Relaxation area; 105. Forming area; 200, flow-blocking assembly; 210, flow-blocking strip; 211, notch / groove; 220, flow-blocking rod; 221, internal hexagonal hole; 230, seal; 240, preload unit; 250, second screw; 260, nut; 231. First flexible sealing strip; 232. First rigid sealing strip; 233. Second flexible sealing strip; 234. Second rigid sealing strip; 241. Push block; 242. First screw; 243. Roller; 300. Side sealing assembly; 310. Outer sealing plate; 320. Inner sealing plate; 330. Tightening bolt; 400. Injection molding machine. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0021] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0022] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0023] The following reference Figures 1-10 This invention describes a high-precision plastic sheet molding equipment.

[0024] A high-precision plastic sheet molding equipment includes a mold body 100 and a flow-blocking assembly 200. Inside the mold body 100, along the flow direction of the melt, are sequentially arranged an inlet area 101, a manifold area 102, a flow-blocking area 103, a relaxation area 104, and a molding area 105. The flow-blocking assembly 200 includes a flow-blocking strip 210, a flow-blocking rod 220, a seal 230, and a pre-tightening unit 240. The flow-blocking strip 210 is laterally arranged in the flow-blocking area 103 inside the mold body 100. The lower part of the flow-blocking strip 210... A notch 211 is provided, through which the flow-blocking strip 210 is passed laterally and downward to the flow-blocking area 103. The flow-blocking rod 220 is embedded in the notch 211, and the sealing element 230 is connected between the flow-blocking rod 220 and the notch 211. The pre-tightening unit 240 has a pre-tightened state and a non-pre-tightened state. In the pre-tightened state, the flow-blocking rod 220 and the sealing element 230 are sealed together with a preset sealing force. In the non-pre-tightened state, the flow-blocking rod 220 can rotate circumferentially around its axis.

[0025] Before production begins, the pre-tightening unit 240 is in a pre-tightened state, at which point the flow-blocking rod 220 and the seal 230 are sealed together by a preset sealing force. It should be noted that the sealing force should be greater than the melt pressure to prevent the melt from entering the connection between the notch 211 and the seal 230, and between the flow-blocking rod 220 and the seal 230.

[0026] After production begins, the melt enters from the inlet zone 101, passes sequentially through the manifold zone 102, the choke zone 103, and the relaxation zone 104, and is finally extruded from the forming zone 105 to form a plastic preform. When the melt passes through the choke zone 103, the choke strips 210 within the choke zone 103 and the choke rods 220 exposed in the choke zone 103 obstruct the flow of the melt, thereby regulating the melt flow rate through the choke zone 103. This ensures that the melt is evenly distributed within the choke zone 103, preventing the plastic preform extruded from the extrusion zone from exhibiting localized excessive thickness or thinness along its width.

[0027] After production is completed, the pre-tightening unit 240 is switched from the pre-tightened state to the non-pre-tightened state, at which point the sealing force between the flow-restricting rod 220 and the seal 230 disappears. Next, the flow-restricting rod 220 is rotated circumferentially around its axis by a preset angle, ranging from 90° to 180°. This circumferential rotation alters the surface of the flow-restricting rod 220 exposed in the flow-restricting zone 103, thus changing the scouring surface of the flow-restricting rod 220. This results in the circumferentially different surfaces of the flow-restricting rod 220 that come into contact with the melt during the two production operations. In other words, the circumferential rotation of the flow-restricting rod 220 distributes the wear caused by melt scouring across its entire circumference, preventing a sharp decrease in adjustment accuracy due to continuous scouring of a localized area by the melt, thereby extending the service life of the flow-restricting rod 220. Finally, the inlet area 101, manifold area 102, flow obstruction area 103, relaxation area 104 and molding area 105 inside the mold 100 are purged to remove residual slag.

[0028] It should be noted that, because the flow-restricting bar 220 is located at the throttle throat (i.e., the narrower section) of the flow-restricting zone 103, the melt is forcibly accelerated at this location, resulting in a high-shear, high-turbulence flow state. Therefore, the flow-restricting bar 220 is more easily worn by solid particulate impurities in the melt than the flow-restricting strip 210; that is, the wear of the flow-restricting assembly 200 by the melt is mainly concentrated on the flow-restricting bar 220. When the entire circumferential surface of the flow-restricting bar 220 is worn to a certain extent, the flow-restricting bar 220 can be replaced without replacing the entire flow-restricting assembly 200, thus significantly reducing the replacement cost of consumable parts.

[0029] In a further embodiment, such as Figure 5 and Figure 7 As shown, the sealing element 230 includes a first flexible sealing strip 231 and a first rigid sealing strip 232. There are two first flexible sealing strips 231, which are symmetrically arranged on both sides inside the notch groove 211 with the center line of the width direction of the notch groove 211 as the axis of symmetry. There are two first rigid sealing strips 232, which correspond one-to-one with the two first flexible sealing strips 231 and are fixedly connected. The two first rigid sealing strips 232 are also in contact with the flow-blocking rod 220.

[0030] During pre-tightening, the pre-tightening unit 240 presses the flow-blocking rod 220 downwards, and the flow-blocking rod 220 presses the first rigid sealing strip 232 downwards. Since the first rigid sealing strip 232 is fixedly connected to the first flexible sealing strip 231, and the first flexible sealing strip 231 is located on the side of the first rigid sealing strip 232 away from the flow-blocking rod 220, and the first rigid sealing strip 232 and the flow-blocking rod 220 are connected by an arc surface, the first flexible sealing strip 231 is subjected to an outward extrusion force along the width direction of the notch 211. This extrusion force causes the first flexible sealing strip 231 to deform along the width direction of the notch 211, thereby increasing the sealing force between the first rigid sealing strip 232 and the flow-blocking rod 220. When the pre-tightening unit 240 moves downward to the preset position, the sealing force between the first rigid sealing strip 232 and the flow-blocking rod 220 reaches the preset sealing force. At this time, the pre-tightening unit 240 stops moving downward and the preset sealing force is maintained between the first rigid sealing strip 232 and the flow-blocking rod 220. At this time, the pre-tightening unit 240 is in the pre-tightening state.

[0031] When the pre-tightening needs to be loosened, the pre-tightening unit 240 moves upward to reduce the downward pressure on the flow-blocking rod 220. At this time, the sealing force between the first rigid sealing strip 232 and the flow-blocking rod 220 gradually decreases. When the sealing force between the first rigid sealing strip 232 and the flow-blocking rod 220 decreases to the lower limit of the threshold, the pre-tightening unit 240 switches to the non-pre-tightening state. At this time, the pre-tightening unit 240 is still in contact with the flow-blocking rod 220, but the flow-blocking rod 220 will not exert a downward pressure. At this time, the operator can rotate the flow-blocking rod 220 to change the part of the surface of the flow-blocking rod 220 exposed in the flow-blocking area 103.

[0032] It should be noted that the first rigid sealing strip 232 and the flow-blocking rod 220 are connected in a surface contact manner. This is because, in the case of spherical contact, the downward movement of the flow-blocking rod 220 can apply a compressive force to the first flexible sealing strip 231 in the left-right direction. On the other hand, the surface contact manner can increase the sealing area, improve the sealing performance, and reduce the risk of the melt entering the notch groove 211 compared to the line contact manner.

[0033] It is understandable that when the pre-tightening unit 240 no longer applies downward pressure to the flow-blocking bar 220, the first flexible sealing strip 231 cannot fully elastically return to its initial shape. Therefore, there will still be a certain sealing force between the first rigid sealing strip 232 and the flow-blocking bar 220. This sealing force is the lower threshold.

[0034] In a further embodiment, such as Figure 5 and Figure 7As shown, the sealing element 230 also includes two second flexible sealing strips 233 and two second rigid sealing strips 234. The two second flexible sealing strips 233 and the two second rigid sealing strips 234 are symmetrically arranged on both sides inside the notch groove 211 with the center line of the width direction of the notch groove 211 as the axis of symmetry. The second rigid sealing strip 234 is located below the second flexible sealing strip 233. The second rigid sealing strip 234 and the second flexible sealing strip 233 are both in surface contact with the flow-blocking rod 220.

[0035] During pre-tightening, the pre-tightening unit 240 presses the flow-blocking rod 220 downwards, and the flow-blocking rod 220 presses the first rigid sealing strip 232 downwards. Since the second flexible sealing strip 233 is located below the first rigid sealing strip 232, the second flexible sealing strip 233 is compressed and deformed. At this time, the sealing force between the second flexible sealing strip 233 and the flow-blocking rod 220 increases, thereby improving the sealing performance between the second flexible sealing strip 233 and the flow-blocking rod 220. At the same time, the second rigid sealing strip 234 is also subjected to downward compressive force. Since the second rigid sealing strip 234 and the flow-blocking rod 220 are in surface contact, and as the flow-blocking rod 220 moves downwards, the second rigid sealing strip 234 is also subjected to outward compressive force along the width direction of the notch 211. Therefore, the positions of the notch 211 of the flow-blocking strip 210 will move away from each other along the width direction of the notch 211. This helps to increase the positive pressure between the flow-blocking strip 210 and the mold body 100, thereby improving the sealing performance between the flow-blocking strip 210 and the mold body 100.

[0036] After the pre-tightening unit 240 is switched to the non-pre-tightening state, the operator rotates the flow-blocking rod 220. Since the flow-blocking rod 220 is in contact with the second rigid sealing strip 234, the second rigid sealing strip 234 is equivalent to a "scraper". As the flow-blocking rod 220 is rotated, the slag adhering to the surface of the flow-blocking rod 220 can be scraped off, so as to prevent the slag from entering the connection between the second rigid sealing strip 234, the second flexible sealing strip 233, and the first rigid sealing strip 232 and the flow-blocking rod 220, and avoid the problem of reduced sealing between the second rigid sealing strip 234, the second flexible sealing strip 233, and the first rigid sealing strip 232 and the flow-blocking rod 220.

[0037] It should be noted that if the cleaning method of flushing out the slag from the previous batch of melt material through the next batch of melt material is adopted, the slag will be closer to the molding area 105 after the second rigid sealing strip 232 scrapes off the slag, making it easier to discharge the residual slag from the mold body 100.

[0038] In a further embodiment, such as Figure 7As shown, the pre-tightening unit 240 includes a push block 241 and a first screw 242. The push block 241 is disposed in the notch groove 211 and is located above the flow-blocking bar 220. The axis of the first screw 242 is vertical and is rotatably connected to the mold body 100. The first screw 242 is threadedly connected to the push block 241.

[0039] During pre-tightening, the first screw 242 rotates circumferentially. Since the first screw 242 is threadedly connected to the push block 241, and the push block 241 is slidably connected within the notch 211, the push block 241 moves downwards under pressure. At this time, the compressive force between the push block 241 and the flow-blocking rod 220 increases. After overcoming the sealing force between the flow-blocking rod 220 and the first rigid sealing strip 232, the second flexible sealing strip 233, and the second rigid sealing strip 234, the flow-blocking rod 220 is pushed downwards, causing the sealing force between the first rigid sealing strip 232, the second flexible sealing strip 233, and the second rigid sealing strip 234 and the flow-blocking rod 220 to gradually increase until the sealing force reaches the preset sealing force. When it is necessary to loosen the pre-tightening, the first screw 242 simply rotates in the opposite direction; further details are omitted.

[0040] Furthermore, there are multiple pre-tightening units 240, which are arranged at intervals along the length of the flow-blocking strip 210.

[0041] When tightening or loosening the pre-tightening, the operator shall rotate each first screw 242 sequentially from one end of the flow barrier 210 to the other along the length of the flow barrier 210, and each first screw 242 shall rotate a maximum of two turns each time, in order to prevent the flow barrier 220 from bending excessively along its axial direction.

[0042] In a further embodiment, such as Figure 7 As shown, the lower part of the push block 241 is connected to several rollers 243, and the rollers 243 are connected to the flow-blocking rod 220 in a line contact manner.

[0043] The roller 243 serves two purposes. First, it reduces the contact area between the push block 241 and the flow-blocking rod 220, thereby reducing the friction between them when the flow-blocking rod 220 rotates. Second, by setting the roller 243, the contact between the roller 243 and the flow-blocking rod 220 becomes line contact. Under the constraint of this line contact, rotating the first screw 242 effectively prevents the push block 241 from slightly deflecting relative to the flow-blocking rod 220.

[0044] In a further embodiment, such as Figure 5As shown, a second screw 250 is rotatably connected to the mold body 100. The axis of the second screw 250 is vertical, and the second screw 250 is threadedly connected to the flow-blocking strip 210. Specifically, a nut 260 is fixedly embedded in the upper part of the flow-blocking strip 210, and the second screw 250 is threadedly connected to the nut 260.

[0045] When it is necessary to adjust the flow-blocking area of ​​the flow-blocking strip 210 in the flow-blocking zone 103, rotate the second screw 250. Driven by the second screw 250, the nut 260 moves along its axis. Since the nut 260 is fixed on the upper part of the flow-blocking strip 210, the nut 260 and the flow-blocking strip 210 move together along the axis of the nut 260, which changes the flow-blocking area of ​​the flow-blocking strip 210 in the flow-blocking zone 103.

[0046] Furthermore, there are multiple second screws 250 and multiple nuts 260. The multiple second screws 250 and multiple screws are arranged at intervals along the length direction of the flow-blocking strip 210, and the multiple second screws 250 and multiple first screws 242 are arranged alternately along the length direction of the flow-blocking strip 210.

[0047] When adjusting the overall flow-blocking area of ​​the flow-blocking strip 210 in the flow-blocking zone 103, the operator can rotate each of the first screws 242 sequentially from one end of the flow-blocking strip 210 to the other along the length of the flow-blocking strip 210.

[0048] In a further embodiment, such as Figure 9 and Figure 10 As shown, the high-precision plastic sheet molding equipment also includes a side sealing assembly 300, which is used to seal both sides of the mold body 100.

[0049] When it is necessary to purge the inside of the mold body 100, the side sealing assembly 300 is removed from the mold body 100. At this time, the two ends of the manifold area 102, the flow obstruction area 103, the relaxation area 104 and the forming area 105 are connected in the width direction, and the inside can be purged to remove the slag inside.

[0050] In a further embodiment, such as Figure 9 and Figure 10 As shown, the side sealing assembly 300 includes an outer sealing plate 310, an inner sealing plate 320, and a tightening bolt 330. The inner sealing plate 320 and the outer sealing plate 310 are arranged at intervals from the inside to the outside and are slidably connected to the mold body 100. The tightening bolt 330 is threadedly connected to the outer sealing plate 310 and abuts against the inner sealing plate 320.

[0051] During installation, the outer sealing plate 310 and the inner sealing plate 320 are slidably connected to the mold body 100. Then, the tightening bolt 330 is rotated to tighten the inner sealing plate 320 against the side wall of the mold body 100 with the target preload. At this time, the inner sealing plate 320 forms a sealing barrier at both ends of the width direction of the manifold area 102, the flow obstruction area 103, the relaxation area 104, and the forming area 105.

[0052] After production is completed, loosen the pre-tightening of the bolts and pull out the inner sealing plate 320 and the outer sealing plate 310 from the mold body 100. At this time, the end of the flow-blocking rod 220 is exposed. The operator can then rotate the flow-blocking rod 220 so that it rotates circumferentially by a certain angle, and then blow the inside of the manifold area 102, the flow-blocking area 103, the relaxation area 104 and the molding area 105.

[0053] It should also be noted that after the side sealing assembly 300 is installed, the inner sealing plate 320 is also pressed against both ends of the flow-blocking rod 220, forming a rotation limit on the flow-blocking rod 220, so that the flow-blocking rod 220 is kept in the current position.

[0054] Furthermore, such as Figure 10 As shown, one end of the flow-blocking rod 220 is provided with an internal hexagonal hole 221 so as to connect with an internal hexagonal wrench to drive the flow-blocking rod 220 to rotate circumferentially.

[0055] In a further embodiment, such as Figure 4 As shown, lifting rings 140 are provided at the four corners of the upper surface of the mold body 100.

[0056] The purpose of setting the lifting ring 140 is to facilitate the lifting of the mold 100.

[0057] In a further embodiment, such as Figure 4 As shown, the mold body 100 includes an upper mold 110, a lower mold 120 and a locking bolt 130, which locks the upper mold 110 and the lower mold 120 together.

[0058] In a further embodiment, such as Figure 1 As shown, a high-precision plastic sheet molding equipment also includes an injection molding machine 400, the outlet of which is connected to the inlet area 101 of the mold body 100, for feeding the melt into the inlet area 101.

[0059] The specific working process of the high-precision plastic sheet molding equipment provided by the present invention will be described in conjunction with the above embodiments: Before production begins, the side sealing assembly 300 is installed. The outer sealing plate 310 and the inner sealing plate 320 are slidably installed on both sides of the mold body 100. The tightening bolt 330 is rotated to make the inner sealing plate 320 press against the side wall of the mold body 100, forming a seal at both ends of the width direction of each area inside the mold body 100. At the same time, the inner sealing plate 320 presses against both ends of the flow-blocking rod 220 to form a rotation limit. Then, the first screws 242 are rotated sequentially along the length of the flow-blocking strip 210, causing the push block 241 to press the flow-blocking rod 220 downward. During the downward movement of the flow-blocking rod 220, the first flexible sealing strip 231 and the second flexible sealing strip 233 are deformed under pressure. The first rigid sealing strip 232 and the flow-blocking rod 220 reach the preset sealing force. The second rigid sealing strip 234 increases the positive pressure between the flow-blocking strip 210 and the mold body 100, and the pre-tightening unit 240 is in the pre-tightened state. If it is necessary to adjust the flow-blocking area, the second screw 250 is rotated to move the flow-blocking strip 210 up and down.

[0060] During the production process, the injection molding machine 400 delivers the melt into the inlet area 101 of the mold body 100. The melt flows sequentially through the manifold area 102, the choke zone 103, the relaxation zone 104, and the molding zone 105. In the choke zone 103, the choke bar 210 and the choke rod 220 exposed in the choke zone 103 obstruct the flow of the melt, regulate the melt flow rate, and ensure uniform distribution. Finally, the melt is extruded from the molding zone 105 to form a plastic preform.

[0061] After production is completed, the first screws 242 are rotated in opposite directions along the length of the flow-blocking bar 210, causing the push block 241 to move upwards, and the pre-tightening unit 240 switches to the non-pre-tightened state. The tightening bolts 330 are loosened, and the inner sealing plate 320 and outer sealing plate 310 are removed, releasing the rotation limit on the flow-blocking bar 220. The flow-blocking bar 220 is rotated 90°–180°. During this process, the second rigid sealing strip 234 scrapes off the slag adhering to the surface of the flow-blocking bar 220, and simultaneously distributes the wear caused by melt scouring across the entire circumference of the flow-blocking bar 220. Finally, the interior areas of the mold body 100 are purged to remove residual slag. After cleaning, the next round of production can begin.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A high-precision plastic sheet molding equipment, characterized in that, include: The mold body has an inlet area, a manifold area, a flow obstruction area, a relaxation area, and a molding area arranged sequentially along the flow direction of the melt. The flow-blocking assembly includes a flow-blocking strip, a flow-blocking rod, a seal, and a pre-tightening unit. The flow-blocking strip is laterally arranged in the flow-blocking area inside the mold body. A notch is opened at the lower part of the flow-blocking strip. The notch extends laterally through the flow-blocking strip and downwards into the flow-blocking area. The flow-blocking rod is embedded in the notch. The seal is connected between the flow-blocking rod and the notch. The preload unit has a preloaded state and a non-preloaded state; In the pre-tightened state, the flow-blocking rod and the sealing element are connected in a sealed manner with a preset sealing force; In the non-pre-tightened state, the flow-restricting bar can rotate circumferentially around its axis.

2. The high-precision plastic sheet molding equipment according to claim 1, characterized in that, The sealing element includes a first flexible sealing strip and a first rigid sealing strip. There are two first flexible sealing strips, which are symmetrically arranged on both sides inside the notch groove with the center line in the width direction of the notch groove as the axis of symmetry. There are also two first rigid sealing strips, which correspond one-to-one with the two first flexible sealing strips and are fixedly connected. The two first rigid sealing strips are also in contact with the flow-blocking rod in a surface-contact manner.

3. The high-precision plastic sheet molding equipment according to claim 2, characterized in that, The sealing element also includes two second flexible sealing strips and two second rigid sealing strips. The two second flexible sealing strips and the two second rigid sealing strips are symmetrically arranged on both sides inside the notch groove with the center line in the width direction of the notch groove as the axis of symmetry. The second rigid sealing strip is located below the second flexible sealing strip. Both the second rigid sealing strip and the second flexible sealing strip are in surface contact with the flow-blocking rod.

4. A high-precision plastic sheet molding equipment according to any one of claims 1-3, characterized in that, The pre-tightening unit includes a push block and a first screw. The push block is located in the notch groove and above the flow-blocking bar. The axis of the first screw is vertical and rotatably connected to the mold body. The first screw is threadedly connected to the push block.

5. The high-precision plastic sheet molding equipment according to claim 4, characterized in that, The lower part of the push block has several rollers that are rolled together, and the rollers are rolled together with the flow-blocking bar in a line contact manner.

6. The high-precision plastic sheet molding equipment according to claim 5, characterized in that, A second screw is rotatably connected to the mold body. The axis of the second screw is vertical, and the second screw is threadedly connected to the flow barrier.

7. The high-precision plastic sheet molding equipment according to claim 6, characterized in that, The high-precision plastic sheet molding equipment also includes a side sealing assembly, which is used to seal both sides of the mold.

8. The high-precision plastic sheet forming equipment according to claim 7, characterized in that, The side sealing assembly includes an outer sealing plate, an inner sealing plate, and a tightening bolt. The inner and outer sealing plates are arranged at intervals from the inside to the outside and are slidably connected to the mold body. The tightening bolt is threadedly connected to the outer sealing plate and abuts against the inner sealing plate.

9. The high-precision plastic sheet molding equipment according to claim 1, characterized in that, The upper surface of the mold has lifting rings at the four corners.

10. A high-precision plastic sheet forming equipment according to claim 1, characterized in that, It also includes an injection molding machine, whose outlet is connected to the mold's inlet area.

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