Gas-assisted forming structure for mold
By introducing a gas-assisted molding structure into the injection mold, nitrogen gas is used to blow out the hollow structure in the screw post molding groove at the initial stage of injection, which solves the molding defect at the screw post position and improves the product yield.
Patent Information
- Application Number
- CN202520482299.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-19
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-03-19
AI Technical Summary
Shrinkage occurred on the outer side of the screw post area of the injection molded product, resulting in a molding defect.
A gas-assisted molding structure is adopted, in which nitrogen is blown in at the beginning of the injection process through a gas channel and a gas nozzle to form a hollow structure in the screw post molding groove, thus solving the problem of excessive glue thickness in the screw post.
This effectively solved the product molding defects caused by excessive thickness of the screw post adhesive, and improved the product yield.
Smart Images
Figure CN223834962U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to molds, specifically to injection molds for soft TPU protective sleeves. Background Technology
[0002] In injection-molded products, the screw post is located close to the side wall, resulting in excessive thickness of the glue layer on the side wall. After molding, the outer surface of the area where the screw post is located shrinks, leading to a molding defect. Utility Model Content
[0003] The technical problem solved by this utility model is that the outer side of the screw post of the injection-molded product shrinks, resulting in a product molding defect.
[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a gas-assisted molding structure for molds, including a gas channel and a gas nozzle. The gas channel passes through a rear template and a rear mold core, and extends into a rear mold body insert. The rear mold body insert has a gas nozzle mounting port. The gas nozzle is installed in the gas nozzle mounting port and connected to the exhaust port of the gas channel. A gas groove is formed on the edge of the rear mold body insert. The gas groove connects the screw post forming groove on the rear mold body insert and the gas nozzle mounting port.
[0005] The rear mold core has screw post holes, and the front mold core has a screw post center rod. When the front and rear molds are closed, the screw post center rod fits into the screw post holes and is located in the screw post forming groove. Liquid glue is injected into the cavity formed by the front and rear molds. Air blowing begins in the initial stage after injection. The gas passes through the gas channel and is ejected from the gas nozzle. The gas enters the screw post forming groove through the gas channel and flows along the screw post center rod, causing the glue in the screw post forming groove (where the glue is thickest) to be blown out into a hollow structure, thus solving the product molding defect caused by excessive glue thickness at the screw post.
[0006] Several screw post forming slots are circumferentially distributed around the periphery of the rear mold body insert. There are several gas channels, each equipped with a gas nozzle, and each gas nozzle with a gas nozzle mounting port. Each gas nozzle mounting port connects to several adjacent screw post forming slots via a gas channel. That is, any one of the gas nozzles is responsible for blowing adhesive into the adjacent screw post forming slots via the gas channel. Alternatively, the product may have 9 screw posts, correspondingly 9 screw post forming slots, 3 gas channels, and 3 gas nozzles. In this way, any one gas nozzle is responsible for blowing adhesive into the 3 adjacent screw post forming slots.
[0007] Alternatively, the gas nozzle mounting port is provided with internal threads, and the gas nozzle is screwed into the gas nozzle mounting port and simultaneously fitted onto the exhaust port of the gas channel.
[0008] An air inlet connector is provided on the outer wall of the rear template, and the air inlet connector is installed on the air inlet of the gas channel. The air inlet connector is connected to the air source through a pipeline.
[0009] The gas-assisted molding structure of this invention is applied to the injection mold of soft TPU protective cases.
[0010] This invention utilizes nitrogen-assisted molding, starting with nitrogen blowing at the initial stage of injection molding to create hollow areas in thicker areas of the screw post, thus solving product molding defects caused by excessively thick glue and improving yield. Attached Figure Description
[0011] The present invention will be further described below with reference to the accompanying drawings:
[0012] Figure 1 This is a schematic diagram of the combined structure of the rear template 20, the rear mold core 30, and the rear mold body insert 40.
[0013] Figure 2 for Figure 1 A schematic diagram of the rear mold plate 20, rear mold core 30, and rear mold body insert 40 after transparent treatment;
[0014] Figure 3 This is a schematic diagram of the rear mold body insert 40.
[0015] Explanation of symbols in the diagram:
[0016] 10. Gas passage; 11. Gas nozzle; 12. Air inlet connector;
[0017] 20. Post-template;
[0018] 30. Rear mold core; 31. Screw post hole;
[0019] 40. Rear mold body insert; 41. Gas nozzle mounting port; 42. Gas channel; 43. Screw post forming groove. Detailed Implementation
[0020] Combination Figures 1 to 3 A gas-assisted molding structure for molds, applied to injection molds for soft TPU protective sleeves, includes a gas channel 10 and a gas nozzle 11. The gas channel passes through a rear mold platen 20 and a rear mold core 30, and extends into a rear mold body insert 40. The rear mold body insert has a gas nozzle mounting port 41, in which the gas nozzle is installed and connected to the exhaust port of the gas channel. A gas groove 42 is formed on the edge of the rear mold body insert, which connects to a screw post forming groove 43 on the rear mold body insert and the gas nozzle mounting port.
[0021] Several screw post forming grooves 43 are circumferentially distributed around the periphery of the rear mold body insert 40. Several gas channels 10 are provided, each equipped with a gas nozzle 11, and each gas nozzle with a gas nozzle mounting port 41. Each gas nozzle mounting port connects to several adjacent screw post forming grooves 43 via a gas groove 42. The product has nine screw posts, correspondingly nine screw post forming grooves, three gas channels, and three gas nozzles. Thus, each gas nozzle is responsible for blowing the adhesive into the three adjacent screw post forming grooves.
[0022] The gas nozzle mounting port 41 is provided with an internal thread, and the gas nozzle 11 is screwed into the gas nozzle mounting port and simultaneously fitted onto the exhaust port of the gas channel 10.
[0023] An air inlet connector 12 is provided on the outer side wall of the rear template 20, and the air inlet connector is installed on the air inlet of the gas channel 10. The gas in the gas channel 10 is nitrogen.
[0024] The rear mold core 30 has screw post holes 31, and the front mold core (not shown in the attached drawing) has a screw post center rod. When the front mold core and the rear mold core 20 are closed, the screw post center rod fits into the screw post holes 31, and at the same time, the screw post center rod is located in the screw post forming groove 43. Liquid glue is injected into the cavity formed by the front mold core and the rear mold core 20. Air blowing begins in the early stage after glue injection. The gas is ejected from the gas nozzle 11 after passing through the gas channel 10. The gas enters the screw post forming groove 43 through the gas groove 42 and flows along the screw post center rod, causing the glue in the screw post forming groove (the thickest part of the glue) to blow out a hollow structure, thereby solving the product molding defect caused by excessive glue thickness in the screw post.
[0025] The above description is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of this utility model. The content of this specification should not be construed as a limitation of this utility model.
Claims
1. A gas-assisted molding structure for a mold, comprising a gas channel (10) and a gas nozzle (11), characterized in that: The gas channel passes through the rear template (20) and the rear mold core (30), and extends into the rear mold body insert (40). The rear mold body insert has a gas nozzle mounting port (41). The gas nozzle is installed in the gas nozzle mounting port and connected to the exhaust port of the gas channel. A gas groove (42) is opened on the edge of the rear mold body insert. The gas groove connects the screw post forming groove (43) on the rear mold body insert and the gas nozzle mounting port.
2. The gas-assisted molding structure for molds as described in claim 1, characterized in that: Several screw stud forming grooves (43) are circumferentially distributed around the outer periphery of the rear mold body insert (40). There are several gas channels (10), each gas channel is equipped with a gas nozzle (11), each gas nozzle is equipped with a gas nozzle mounting port (41), and each gas nozzle mounting port is connected to several adjacent screw stud forming grooves (43) through a gas channel (42).
3. The gas-assisted molding structure for molds as described in claim 1, characterized in that: The gas nozzle mounting port (41) is provided with an internal thread, and the gas nozzle (11) is screwed into the gas nozzle mounting port and simultaneously fitted onto the exhaust port of the gas passage (10).
4. The gas-assisted molding structure for molds as described in claim 1, characterized in that: An air inlet connector (12) is provided on the outer side wall of the rear template (20), and the air inlet connector is installed on the air inlet of the gas channel (10).
5. The gas-assisted molding structure for molds as described in claim 1, characterized in that: The gas in the gas channel (10) is nitrogen.
6. The gas-assisted molding structure for molds as described in claim 1, characterized in that: The gas-assisted molding structure is used in the injection mold of soft TPU protective cases.