Optical special screw capable of improving stability of melt glue

Abstract

The invention relates to an optical special screw capable of improving the stability of molten glue, and belongs to the technical field of optical screws of injection molding machines, the screw is sequentially divided into a feeding section, a compression section and a metering section from feeding to discharging, the bottom diameter of each tooth of the feeding section is consistent, the bottom diameter and the edge width of each tooth of the compression section are gradually changed, and the bottom diameter of each tooth of the metering section is consistent. The whole length of the feeding section, the compression section and the metering section is subjected to fine polishing mirror surface treatment, so that melt glue is stable and uniform, and the problems that the requirement of an optical special screw on the stability of the melt glue is extremely high, and the quality and the stability of the melt glue are affected due to the fact that shearing stress and temperature gradient are possibly generated by a barrier section in the material circulation process are solved. Meanwhile, due to the reasonable segmented design, the possibility of excessive mixing is reduced, and the problem of non-uniform orientation of the materials is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of optical screws for injection molding machines, and in particular relates to a special optical screw for improving the stability of molten glue. Background Art

[0002] In the design of the optical screw for injection molding machines, the screw is usually divided into the feeding section, compression section, metering section, barrier section and mixing section. By dividing the screw into these different functional areas, the flow, melting and plasticization process of the raw materials in the screw can be effectively controlled, thereby improving production efficiency and product quality. The main function of the barrier section is to prevent the molten material from flowing back and ensure that the material has a single forward direction in the screw, while the mixing section is used to enhance the mixing effect of the material, making the entire injection molding process more efficient and stable.

[0003] However, some problems have been found in the use of the optical screw: because it is a special optical screw, the stability of the molten rubber is extremely required in this process. The barrier section may cause shear stress and temperature gradient in the material during the circulation process, thereby affecting the quality and stability of the molten rubber. At the same time, excessive mixing may also cause uneven orientation of the melt and affect the optical properties of the final product. In this regard, an optical screw with improved molten rubber stability is designed. By removing the barrier section and the mixing section and improving the remaining parts, the molten rubber is stable and the melt is uniform. Summary of the invention

[0004] In order to solve the above-mentioned problems existing in the prior art, the present invention provides an optical-specific screw for improving the stability of the molten adhesive, which solves the problem that the optical-specific screw has extremely high requirements for the stability of the molten adhesive, the barrier section may cause shear stress and temperature gradient in the material during the circulation process, thereby affecting the quality and stability of the molten adhesive, and excessive mixing may also cause uneven orientation of the molten material, affecting the optical properties of the final product.

[0005] The purpose of the present invention can be achieved through the following technical solutions: An optical screw for improving the stability of molten adhesive comprises a screw and a spiral sheet arranged on the screw. The screw is divided into a feeding section, a compression section and a metering section in sequence from the feeding direction to the discharging direction. The bottom diameter of each tooth in the feeding section is consistent, the bottom diameter of each tooth and the edge width of the compression section are gradually changed, the bottom diameter of each tooth in the metering section is consistent, and the overall length of the three sections of the feeding section, the compression section and the metering section are subjected to precision polishing and mirror surface treatment to ensure the stability of the molten adhesive and the uniformity of the molten material.

[0006] As a further solution of the present invention, the total length of the screw is 1216 mm, the lengths of the feed section, compression section and metering section are 490 mm, 260 mm and 160 mm respectively, and the 380 mm length along the screw from the feeding direction to the discharging direction from the starting point of the feed section is the long outer diameter tolerance gradient area.

[0007] As a further solution of the present invention, the screw is vacuum quenched as a whole, and tempered after vacuum quenching.

[0008] As a further solution of the present invention, the surface of the screw is provided with a titanium nitride coating, and the titanium nitride coating has a depth of 0.003-0.005, a hardness of HV1800-2200°, and a surface roughness within 0.1-0.2.

[0009] As a further solution of the present invention, the overall length of the screw ensures that the straightness is within 0.02mm-1mm.

[0010] As a further solution of the present invention, the shank of the screw is tempered, and the hardness after tempering is HRC32±2°.

[0011] As a further solution of the present invention, one side of the feed section is a compression section, and the other side of the feed section is a melting section. The lead of the melting section is 8 mm and the width is 2 mm.

[0012] As a further solution of the present invention, the thread width of the metering section is 4 mm, and the thread width of the long outer diameter tolerance gradient area is 6 mm.

[0013] The beneficial effects of the present invention are: The screw is divided into a feeding section, a compression section and a metering section in sequence from the feeding direction to the discharging direction. The bottom diameter of each tooth in the feeding section is consistent, the bottom diameter of each tooth and the edge width of the compression section are gradually changed, and the bottom diameter of each tooth in the metering section is consistent. The overall length of the three sections, the feeding section, the compression section and the metering section, is subjected to a fine-polishing mirror treatment to make the molten adhesive stable and the molten material uniform, thus solving the problem that the optical special screw has extremely high requirements for the stability of the molten adhesive. The barrier section may cause shear stress and temperature gradient in the material during the circulation process, thereby affecting the quality and stability of the molten adhesive. At the same time, excessive mixing may also cause uneven orientation of the molten material, affecting the optical properties of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0015] Figure 1 It is a schematic diagram of the structure of each area of ​​a common screw; Figure 2 It is a schematic diagram of the length design of the overall area of ​​a common screw; Figure 3 This is a schematic diagram of the design of a common screw near the mixing section; Figure 4 This is a design schematic diagram of a common screw near the feed section; Figure 5 This is a schematic diagram of the local area design of a common screw; Figure 6 It is a schematic diagram of the structure of each area of ​​the optical screw of the present invention; Figure 7 It is a schematic diagram of the overall length design of the optical screw of the present invention; Figure 8 It is a schematic diagram of the structure of the optical screw rod of the present invention near the metering section; Fig. 9 This is a schematic diagram of the design of the optical screw of the present invention near the feeding section; Fig.10 This is a schematic diagram of the local area design of the optical screw of the present invention.

[0016] Description of main component symbols: In the figure: X, feeding section; Y, compression section; M, metering section; N, barrier section; K, mixing section. DETAILED DESCRIPTION

[0017] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0018] In the design of the optical screw of the injection molding machine, the screw is usually divided into a feed section X, a compression section Y, a metering section M, a barrier section N and a mixing section K. By dividing the screw into these different functional areas, the flow, melting and plasticization process of the raw material in the screw can be effectively controlled, thereby improving production efficiency and product quality. The main function of the barrier section N is to prevent the molten material from flowing back and ensure that the material has a single forward direction in the screw, while the mixing section K is used to enhance the mixing effect of the material, making the entire injection molding process more efficient and stable. However, some problems have been found in the use of the optical screw: Since it is aimed at the optical screw, the stability of the molten glue is extremely high in this process. The barrier section N may cause shear stress and temperature gradient to be generated in the material during the circulation process, thereby affecting the quality and stability of the molten glue. At the same time, excessive mixing may also cause uneven orientation of the molten material, affecting the optical properties of the final product.

[0019] In order to solve the above problems, this embodiment provides an optical screw that improves the stability of the melt. Figure 1 - Fig.10, including a screw and a spiral sheet arranged on the screw, which is divided into a feeding section X, a compression section Y and a metering section M in sequence from the feeding to the discharging direction of the screw, the bottom diameter of each tooth of the feeding section X is consistent, the bottom diameter of each tooth of the compression section Y and the edge width are gradually changed, the bottom diameter of each tooth of the metering section M is consistent, and the overall length of the three sections of the feeding section X, the compression section Y and the metering section M are finely polished and mirror-finished to make the melt stable and the melt uniform; In the segmented spiral structure designed above, the screw is divided into a feed section X, a compression section Y and a metering section M. These three sections each have different functions, which helps to more accurately control the flow and melting process of the material. Among them, the bottom diameter of each tooth in the feed section X is consistent, ensuring that the material can be evenly distributed when entering and reducing shear stress. This design helps the material to remain stable in the initial stage and avoid flow problems caused by uneven feeding. The bottom diameter of each tooth and the edge width of the compression section Y are gradually changed, so that the material is gradually compressed when passing through this section, achieving better melting and mixing. This gradual design helps to reduce shear stress. Shear stress and temperature gradient are reduced to avoid damage to the material during circulation; the bottom diameter of each tooth of the metering section M is consistent to ensure that the material moves forward at a stable flow rate and pressure in the metering section M, providing guarantee for subsequent uniform melt. The entire length of the feeding section X, compression section Y and metering section M is polished and mirror-finished. This treatment can reduce the friction between the material and the screw surface, reduce shear stress, and help maintain a uniform temperature of the melt, avoiding the influence of temperature gradient on the quality of the melt. Through reasonable segmentation design, the possibility of over-mixing is reduced and the problem of uneven material orientation is avoided. Specifically, the feeding section X ensures the uniform distribution of the material, the compression section Y realizes the moderate compression and melting of the material instead of excessive mixing, and the metering section M ensures that the material reaches a uniform melting state before discharging. Through these designs, the optical screw can meet the high requirements for the stability of the molten adhesive, avoid the shear stress and temperature gradient problems that may be caused by the barrier section N, and ensure the uniformity of the molten material and the optical properties of the final product. This screw design optimizes the melting and mixing process of the material, thereby improving the overall quality and stability of the molten adhesive.

[0020] In addition, the self-cleaning function can be added when designing the screw, such as setting a special spiral shape or structure so that the residue on the inner wall of the screw can be cleaned automatically during operation. A quick-install structure can also be designed to quickly disassemble and install the screw to further improve production efficiency. This design can reduce downtime and improve the continuous operation capacity of the equipment.

[0021] In order to ensure the stability of the material during the melting and mixing process and reduce the flow fluctuation caused by uneven melting or poor mixing of the material, in one embodiment, the total length of the screw is 1216 mm, the lengths of the feeding section X, the compression section Y and the metering section M are 490 mm, 260 mm and 160 mm respectively, and the length of 380 mm from the starting point of the feeding section X along the screw from the feeding to the discharging direction is the long outer diameter tolerance gradual change area. First of all, considering the stable flow of the molten plastic, the feeding section X is designed to be longer and 490 mm, in order to allow the material to have enough time to melt and preliminarily mix, so as to ensure that the material has reached a certain melting state before entering the compression section Y, thereby Reduce the pressure fluctuation of the molten plastic in the screw and improve stability. Secondly, 260mm is designed in the compression section Y. Its function is to further compress and evenly mix the material to ensure that the material reaches the required molten state and uniformity before entering the metering section M. Then a shorter 160mm is designed in the metering section M to accurately control the output of the molten plastic, ensure the stability of the material flow, and ensure the consistency of product size and quality. In addition, a 380mm gradient area is designed. The function of this area is to gradually reduce the outer diameter tolerance when the material transitions from the feeding section X to the metering section M, so as to reduce the resistance of the material flow and prevent the material from generating turbulence in the screw, thereby ensuring the smooth flow of the material. Figure 6-Figure 10 As shown; Specifically, the 380mm gradient area is located at the starting point of the feed section X and extends 380mm along the screw toward the discharge direction. By setting a gradient area at the starting point of the feed section X, the material can have a smooth transition when entering the screw, avoiding the impact and damage of the material caused by the sudden change of diameter. In addition, the gradient area helps to reduce the shear force on the material, thereby reducing the thermal decomposition and performance loss of the material. By controlling the flow speed and pressure of the material in the screw, the stability of the melt can be improved, ensuring the uniformity of the material throughout the melting and plasticizing process. At the same time, this design helps to extend the service life of the screw, reduce screw wear, and improve production efficiency. It should be noted that the total screw length of 1216 mm is determined based on the characteristics of the material and production requirements, and the total screw length is designed to meet the stability of the melt; the length of the feed section X of 490 mm is determined by determining that the material needs sufficient melting time in the feed section X to ensure that the material is fully melted before entering the compression section Y; the length of the compression section Y of 260 mm is determined based on the compression characteristics of the material and production efficiency requirements to determine the length of the compression section Y to achieve effective removal of bubbles and impurities; the length of the metering section M of 160 mm is determined based on the requirements of product dimensional accuracy and flow rate to ensure that the material enters the mold at a constant flow rate and pressure; the design of the long outer diameter tolerance gradient area of ​​380 mm is to ensure that the outer diameter of the material gradually decreases before entering the compression section Y, thereby achieving a smooth transition, reducing the friction and shear force of the material in the screw, and improving the stability of the melt.

[0022] It is worth mentioning that the processing method of each position of the screw will directly affect its shape and dimensional accuracy. Different processing methods may lead to different microstructures on the surface of the screw, thereby affecting the fluidity and mixing uniformity of the molten rubber. For example, turning, grinding, milling and other processing methods have different effects on the surface of the screw. At the same time, the surface roughness will affect the contact between the molten rubber and the screw surface. Higher roughness may cause more turbulence in the flow of the molten rubber, affecting the stability of the flow. In addition, the rough surface may also absorb more molten rubber, affecting the overall performance of the molten rubber. In order to overcome these problems and further ensure the good stability of the molten rubber, in one embodiment, the screw is vacuum quenched as a whole, and tempered after vacuum quenching. Vacuum quenching is used because vacuum quenching is a heat treatment process that is carried out in an oxygen-free environment with rapid heating and rapid cooling. It can improve the hardness and wear resistance of the screw and reduce the dimensional changes caused by wear, thereby maintaining the flow stability of the molten rubber. After that, tempering is performed. Tempering can reduce the residual stress generated during the quenching process and improve the toughness and fatigue resistance of the screw, which helps the screw to maintain the stability of shape and size during long-term work. In accordance with the above embodiment, the titanium nitride coating has high hardness and good wear resistance, which can effectively reduce the wear of the screw surface. The coating depth is 0.003-0.005mm, and the hardness is HV1800-2200°, which can ensure that good performance can be maintained under high temperature and high pressure environment. The surface roughness is within 0.1-0.2, which can reduce the adsorption of molten glue on the screw surface and improve the flow stability. The overall length of the screw ensures that the straightness is within 0.02mm-1mm, which helps to ensure the uniformity of the molten glue flow and avoid the flow instability caused by the difference in local resistance. The tempering treatment of the handle can improve its toughness and prevent deformation during assembly and use, thereby maintaining the overall stability of the screw, and the hardness after tempering is HRC32±2°; The determination of the above parameters is based on the study and verification of the influence of different processing parameters on the melting process and results to determine the best processing method, coating parameters and heat treatment conditions. The reason for using these data is that they are optimized to minimize the unstable factors in the melting process and ensure the quality and efficiency of the melting process. In addition to the above parameters, there are some other parameters such as Figure 7-10 In, through Figure 7-10 Compared with the common screw in the prior art Figure 2-Figure 5 This can be seen by comparison.

[0023] In order to further improve the quality and stability of the melt, in one embodiment, one side of the feed section X is the compression section Y, and the other side of the feed section X is the melting section. The lead of the melting section is 8 mm, the width is 2 mm, the thread width of the metering section M is 4 mm, and the thread width of the long outer diameter tolerance gradual change area is 6 mm. Among them, the compression section Y of the feed section X helps the material to be initially compressed before entering the melting section, which can increase the density of the material and create more favorable conditions for subsequent melting and mixing. The lead of the melting section is 8 mm, and the width is 2 mm, which helps the material to achieve more uniform melting during the flow process in the screw, ensuring that the material reaches a better melting state before entering the metering section M. The thread width of the metering section M is 4 mm. This design helps to ensure that the material is in a better state before entering the metering section M. Precise metering is performed during the delivery process to ensure stable material output and quality. The long outer diameter tolerance gradient area has a thread width of 6mm. This design helps to reduce resistance when the material flows in the screw, optimizes flow performance, and reduces bubbles and fluctuations in the melting process. In addition, in order to solve the quality and stability of the melt, by optimizing the design of the melting section and metering section M of the screw, bubbles and fluctuations in the material during the melting process can be reduced, thereby improving the transparency and stability of the melt, and improving the uniformity of the melt. Through precise metering and optimized mixing, it is ensured that the material is fully mixed in the screw, thereby improving the uniformity of the melt. Through the design of this screw, the temperature of the melt can be better controlled to prevent overheating or insufficient material and ensure the quality of the melt.

[0024] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An optical screw for improving melt stability, comprising a screw and a spiral sheet arranged on the screw, characterized in that: The screw is divided into a feeding section, a compression section and a metering section in sequence from the feeding direction to the discharging direction. The bottom diameter of each tooth in the feeding section is consistent, the bottom diameter of each tooth and the edge width of the compression section are gradually changed, and the bottom diameter of each tooth in the metering section is consistent. The overall length of the feeding section, the compression section and the metering section is subjected to precision polishing and mirror finishing to ensure stable molten glue and uniform molten material.

2. The optical screw for improving melt stability according to claim 1, characterized in that: The total length of the screw is 1216 mm, the lengths of the feed section, compression section and metering section are 490 mm, 260 mm and 160 mm respectively, and the 380 mm length from the starting point of the feed section along the screw from the feeding to the discharging direction is the long outer diameter tolerance gradient area.

3. The optical screw for improving melt stability according to claim 1, characterized in that: The screw rod is vacuum quenched as a whole, and is tempered after vacuum quenching.

4. The optical screw for improving melt stability according to claim 1, characterized in that: The surface of the screw is provided with a titanium nitride coating, and the depth of the titanium nitride coating is 0.003-0.005, the hardness is HV1800-2200°, and the surface roughness is within 0.1-0.

2.

5. The optical screw for improving melt stability according to claim 1, characterized in that: The overall length of the screw ensures that the straightness is within 0.02mm-1mm.

6. The optical screw for improving melt stability according to claim 1, characterized in that: The shank of the screw is tempered, and the hardness after tempering is HRC32±2°.

7. The optical screw for improving melt stability according to claim 1, characterized in that: One side of the feeding section is a compression section, and the other side of the feeding section is a melting section. The lead of the melting section is 8 mm and the width is 2 mm.

8. The optical screw for improving melt stability according to claim 2, characterized in that: The thread width of the metering section is 4 mm, and the thread width of the long outer diameter tolerance gradient area is 6 mm.

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