Mold structure for improving air traps on product surface
By designing a stepped venting channel in the mold, the problem of low venting efficiency in traditional molds is solved, achieving efficient discharge of gas and overflow, and improving product quality and production efficiency.
Patent Information
- Application Number
- CN202521501748.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-17
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-07-17
AI Technical Summary
The traditional mold venting structure is poorly designed, which prevents gas from being discharged efficiently, affecting product quality and performance. It is also difficult to handle overflow, resulting in product appearance defects and increased production costs.
A stepped venting channel was designed, including a primary venting and glue removal channel and a secondary venting and glue removal channel. The primary venting and glue removal channel quickly discharges the gas at the edge of the cavity, while the secondary venting and glue removal channel further discharges residual gas and simultaneously accommodates and discharges excess glue, ensuring that the gas in the cavity is completely discharged.
It improves product surface quality and molding integrity, reduces appearance defects such as missing material, bubbles, and surface depressions, enhances the stability of the injection molding process and product dimensional accuracy, and reduces scrap rate and production costs.
Smart Images
Figure CN224675431U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of mold technology, specifically to a mold structure that improves the surface air trapping of products. Background Technology
[0002] In injection molding, product quality is significantly affected by the mold's venting effect. When the molten metal fills the mold cavity, if the gas already present in the cavity cannot be expelled in time, it will be compressed by the melt, forming trapped gas areas that hinder the smooth and complete filling of the cavity. This not only causes product appearance defects such as insufficient material, bubbles, and surface depressions, but also affects product performance, reduces product strength and reliability, resulting in products that fail to meet usage requirements and increasing scrap rates and production costs.
[0003] To address the problem of trapped air, existing molds often incorporate venting structures to assist in air removal. However, traditional venting structures have certain limitations, such as poorly designed venting channels that cannot efficiently expel gas, or difficulty in handling excess material (overflow) while venting gas, affecting product dimensional accuracy and surface quality.
[0004] Therefore, there is an urgent need for an optimized mold structure that can effectively and efficiently discharge gas from the mold cavity during injection molding by setting up venting channels, while also helping to discharge excess material, ensuring product molding quality and meeting production needs. This mold structure for improving surface gas trapping is developed based on this background. Utility Model Content
[0005] To overcome the shortcomings mentioned above, this utility model aims to provide a technical solution that can solve the above problems.
[0006] A mold structure for improving surface air trapping of a product includes a lower mold core, a lower mold cavity is provided on the lower mold core, and a primary venting and glue removal groove and a secondary venting and glue removal groove corresponding to the lower mold cavity are provided along the parting surface of the lower mold core. The primary venting and glue-removing groove is located on the side close to the lower mold cavity and is connected to the lower mold cavity. The secondary venting and glue-removing groove is located on the side close to the primary venting and glue-removing groove away from the lower mold cavity and close to the edge of the lower mold core, and is connected to the primary venting and glue-removing groove. The cross-sectional dimensions of the secondary exhaust and glue discharge channel are larger than those of the primary exhaust and glue discharge channel.
[0007] As a further embodiment of this utility model: a first direct-connection flow channel section is provided between the primary venting and glue-discharging groove and the lower mold cavity, and a second direct-connection flow channel section is provided between the primary venting and glue-discharging groove and the secondary venting and glue-discharging groove; The first-stage venting and glue-removing channel has a starting end and an ending end at its two ends, respectively. The starting end of the first-stage venting and glue-removing channel is connected to the lower mold cavity through a first direct-connection runner section, and the ending end of the first-stage venting and glue-removing channel is connected to the second-stage venting and glue-removing channel through a second direct-connection runner section.
[0008] As a further embodiment of this utility model: the secondary exhaust and glue discharge channel includes a straight section and a connected bent section; The secondary venting and discharge channel is connected to the second straight flow channel section through a straight section. The bent section of the secondary venting and discharge channel is set to the side away from the second straight flow channel section, and the bending direction of the bent section of the secondary venting and discharge channel is towards the edge of the lower mold core.
[0009] As a further embodiment of the present invention: the lower mold core is provided with a plurality of lower mold cavities, and each lower mold cavity is provided with a set of primary venting and glue-discharging grooves and a set of secondary venting and glue-discharging grooves; The secondary venting and glue removal channels of two adjacent lower mold cavities are interconnected.
[0010] As a further embodiment of this utility model: a third direct flow channel section is provided between the secondary venting and glue discharge grooves of two adjacent lower mold cavities, so as to achieve connection through the third direct flow channel section.
[0011] As a further embodiment of this utility model: the third direct flow channel section is connected between the bent sections of the two secondary exhaust and glue discharge channels.
[0012] As a further embodiment of this utility model: the cross-sectional dimensions of the first direct-connection flow channel section, the second direct-connection flow channel section, and the third direct-connection flow channel section are the same, and all are smaller than the cross-sectional dimensions of the primary exhaust and glue discharge groove.
[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: 1) This mold structure forms a stepped venting channel by setting a primary venting and a secondary venting and discharge channel. The primary venting and discharge channel, located near the lower mold cavity, quickly discharges gas from the cavity edge during the initial melt filling stage, preventing gas accumulation on the product surface and the formation of trapped gas defects. The secondary venting and discharge channel has a larger cross-sectional size and is connected to the primary venting and discharge channel, further accommodating and discharging residual gas transported by the primary venting and discharge channel, ensuring complete gas removal from the cavity. This stepped venting design solves the problem of low venting efficiency in traditional venting structures, reduces appearance defects such as material shortages, bubbles, and surface depressions caused by trapped gas, and improves product surface quality and molding integrity.
[0014] 2) The primary and secondary venting and discharge channels simultaneously collect and discharge excess plastic material (overflow) while venting. The primary venting and discharge channel has a smaller cross-sectional size, guiding small amounts of overflow near the product to prevent it from directly affecting the product's dimensions. The secondary venting and discharge channel has a larger cross-sectional size, accommodating excess plastic material transported by the primary channel, achieving graded collection and discharge of overflow. Furthermore, by injecting smaller amounts of plastic material at a time and discharging it through the venting and discharge channels, the melt is ensured to fully fill the mold cavity, preventing dimensional deviations due to insufficient filling, meeting the product's dimensional accuracy requirements, improving the stability of the injection molding process, reducing waste caused by filling issues, and lowering production costs.
[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 yes Figure 1 A magnified structural diagram of point A in the middle.
[0018] The reference numerals and names in the figure are as follows: 1. Lower mold core; 2. Lower mold cavity; 3. Primary venting and drainage channel; 4. Secondary venting and drainage channel; 5. First straight runner section; 6. Second straight runner section; 7. Straight section; 8. Bend section; 9. Third straight runner section. Detailed Implementation
[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0020] Please see Figure 1-2In this embodiment of the utility model, a mold structure for improving air trapping on the product surface is used in injection molding. By planning air venting and glue removal channels, the problem of product defects caused by air trapping in the cavity is solved, and the injection molding yield is improved.
[0021] The mold includes a lower mold core 1, and a lower mold cavity 2 is provided on the lower mold core 1. This lower mold cavity 2 serves as the space for melt filling and molding during injection molding. Along the parting surface of the lower mold core 1, a primary venting and discharge groove 3 and a secondary venting and discharge groove 4 are provided corresponding to the lower mold cavity 2. These two grooves work together to complete the venting and overflow discharge operations.
[0022] The primary venting and discharge channel 3 is located near and connected to the lower mold cavity 2. During injection molding, gas and a small amount of overflow material in the lower mold cavity 2 can first enter the primary venting and discharge channel 3. In order to guide the gas and overflow material to flow in an orderly manner, a first direct-connection runner section 5 is provided between the primary venting and discharge channel 3 and the lower mold cavity 2. The two ends of the primary venting and discharge channel 3 are the starting end and the ending end, respectively. The starting end is connected to the lower mold cavity 2 through the first direct-connection runner section 5, so that the gas and overflow material in the lower mold cavity 2 can be introduced into the primary venting and discharge channel 3 through the first direct-connection runner section 5.
[0023] The secondary venting and discharge channel 4 is located on the side of the primary venting and discharge channel 3 away from the lower mold cavity 2 and close to the edge of the lower mold core 1, while also communicating with the primary venting and discharge channel 3. Since the cross-sectional dimensions of the secondary venting and discharge channel 4 are larger than those of the primary venting and discharge channel 3, it can accommodate more gas and overflow, thereby further enhancing the venting and discharge effect. A second direct-connection flow channel section 6 is provided between the primary venting and discharge channel 3 and the secondary venting and discharge channel 4. The end of the primary venting and discharge channel 3 is connected to the secondary venting and discharge channel 4 through this second direct-connection flow channel section 6, so that the gas and overflow passing through the primary venting and discharge channel 3 can flow into the secondary venting and discharge channel 4.
[0024] The secondary venting and discharge channel 4 is composed of a straight section 7 and a bent section 8 connected together. The straight section 7 is connected to the second straight flow channel section 6 and is used to receive the gas and overflow from the primary venting and discharge channel 3. The bent section 8 is located on the side away from the second straight flow channel section 6, and its bending direction is towards the edge of the lower mold core 1, so as to guide the gas to be discharged towards the edge of the lower mold core 1.
[0025] In one embodiment, an upper mold core corresponds to the lower mold core 1. When the upper and lower mold cores 1 are closed, a complete cavity is formed. An evacuation hole is provided on the upper mold core at the position corresponding to the secondary venting and drainage groove 4. When the mold is closed, one end of the evacuation hole is connected to the secondary venting and drainage groove 4, and the other end leads to the outside of the mold. During injection molding, the gas in the secondary venting and drainage groove 4 can be discharged to the outside of the mold through the evacuation hole, avoiding gas stagnation and trapped air. At the same time, overflow material is temporarily stored in the secondary venting and drainage groove 4 and cleaned later when the mold is opened, without affecting the product molding.
[0026] The lower mold core 1 can be provided with several lower mold cavities 2. Each lower mold cavity 2 is independently configured with a set of primary venting and drainage channels 3 and secondary venting and drainage channels 4 to meet the needs of multi-cavity injection molding. Furthermore, the secondary venting and drainage channels 4 of two adjacent lower mold cavities 2 are interconnected. A third direct runner section 9 is provided between them to achieve this connection. Specifically, the third direct runner section 9 connects between the bent sections 8 of two secondary venting and drainage channels 4.
[0027] The cross-sectional dimensions of the first direct-connection runner section 5, the second direct-connection runner section 6, and the third direct-connection runner section 9 are consistent and all smaller than the cross-sectional dimensions of the primary venting and discharge channel 3. This size design allows gas and overflow to first pass through the narrower runner sections and then enter the relatively wider venting and discharge channel. This maintains a certain flow velocity and allows for effective expansion within the venting and discharge channel, thus smoothly discharging gas and overflow. It also rationally allocates the flow space of material and gas within the runner, ensuring the stable progress of the injection molding process and reducing the adverse effects of trapped gas on the product's appearance and performance.
[0028] In summary, this mold structure forms a stepped venting channel by setting a primary venting and glue removal channel 3 and a secondary venting and glue removal channel 4. The primary venting and glue removal channel 3, located close to the lower mold cavity 2, can quickly expel gas from the cavity edge during the initial stage of melt filling, preventing gas from accumulating on the product surface and forming trapped gas defects. The secondary venting and glue removal channel 4 has a larger cross-sectional size and is connected to the primary venting and glue removal channel 3, further receiving and expelling residual gas transported by the primary venting and glue removal channel 3, ensuring complete gas removal from the cavity. This stepped venting design solves the problem of low venting efficiency in traditional venting structures, reduces appearance defects such as material shortages, bubbles, and surface depressions caused by trapped gas, and improves product surface quality and molding integrity.
[0029] The primary venting and discharge channel 3 and the secondary venting and discharge channel 4 simultaneously collect and discharge excess rubber material (overflow) while venting. The primary venting and discharge channel 3 has a smaller cross-sectional size, which guides the small amount of overflow near the product, preventing it from directly affecting the product's dimensions. The secondary venting and discharge channel 4 has a larger cross-sectional size, which can accommodate the excess rubber material conveyed by the primary venting and discharge channel 3, achieving graded collection and discharge of the overflow. At the same time, by injecting smaller amounts of rubber material multiple times and discharging it through the venting and discharge channels, it ensures that the melt fully fills the mold cavity, avoiding dimensional deviations caused by insufficient filling, meeting the product's dimensional accuracy requirements, improving the stability of the injection molding process, reducing waste caused by filling problems, and lowering production costs.
[0030] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.
Claims
1. A mold structure for improving air trapping on the surface of a product, characterized in that, It includes a lower mold core, on which a lower mold cavity is provided, and a primary venting and glue-discharging groove and a secondary venting and glue-discharging groove corresponding to the lower mold cavity are provided along the parting surface of the lower mold core; The primary venting and glue-removing groove is located on the side close to the lower mold cavity and is connected to the lower mold cavity. The secondary venting and glue-removing groove is located on the side close to the primary venting and glue-removing groove away from the lower mold cavity and close to the edge of the lower mold core, and is connected to the primary venting and glue-removing groove. The cross-sectional dimensions of the secondary exhaust and glue discharge channel are larger than those of the primary exhaust and glue discharge channel.
2. The mold structure for improving air trapping on the product surface according to claim 1, characterized in that, A first direct-connection flow channel section is provided between the primary venting and glue-discharging channel and the lower mold cavity, and a second direct-connection flow channel section is provided between the primary venting and glue-discharging channel and the secondary venting and glue-discharging channel. The first-stage venting and glue-removing channel has a starting end and an ending end at its two ends, respectively. The starting end of the first-stage venting and glue-removing channel is connected to the lower mold cavity through a first direct-connection runner section, and the ending end of the first-stage venting and glue-removing channel is connected to the second-stage venting and glue-removing channel through a second direct-connection runner section.
3. The mold structure for improving air trapping on the product surface according to claim 2, characterized in that, The secondary exhaust and glue discharge channel includes a straight section and a connected bent section; The secondary venting and discharge channel is connected to the second straight flow channel section through a straight section. The bent section of the secondary venting and discharge channel is set to the side away from the second straight flow channel section, and the bending direction of the bent section of the secondary venting and discharge channel is towards the edge of the lower mold core.
4. The mold structure for improving air trapping on the product surface according to claim 3, characterized in that, The lower mold core is provided with a plurality of lower mold cavities, and each lower mold cavity is provided with a set of primary venting and glue removal grooves and a set of secondary venting and glue removal grooves. The secondary venting and glue removal channels of two adjacent lower mold cavities are interconnected.
5. The mold structure for improving air trapping on the product surface according to claim 4, characterized in that, A third direct flow channel section is provided between the secondary venting and glue discharge grooves of two adjacent lower mold cavities to achieve connection.
6. The mold structure for improving air trapping on the product surface according to claim 5, characterized in that, The third direct flow channel section is connected between the bent sections of the two secondary exhaust and glue discharge channels.
7. The mold structure for improving air trapping on the product surface according to claim 5, characterized in that, The cross-sectional dimensions of the first direct-connection flow channel section, the second direct-connection flow channel section, and the third direct-connection flow channel section are the same, and all are smaller than the cross-sectional dimensions of the primary exhaust and glue discharge groove.