A method for injection molding a toy light pipe
By controlling the injection speed and pressure in stages and optimizing the gate design, the problems of flow lines and air bubbles in the injection molding process of toy light guide tubes were solved, achieving high-quality injection molding results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YINGDE BEST TOP TOYS CO LTD
- Filing Date
- 2023-10-11
- Publication Date
- 2026-06-23
AI Technical Summary
In traditional injection molding of toy light guide tubes, it is difficult to control the flow trajectory of the adhesive, resulting in flow lines and bubbles in the molded product, which affects the performance.
The injection process is divided into five stages. The injection speed and pressure are adjusted, and the position of the injection port is optimized to make the glue flow more evenly and avoid the generation of bubbles and flow lines.
By optimizing the injection process and the design of the gating gate, the injection-molded toy light guide tubes are virtually free of flow marks and bubbles, thus improving product quality.
Smart Images
Figure CN117245876B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of injection molding technology, and more specifically, relates to an injection molding method for a toy light guide tube. Background Technology
[0002] In toys, transparent parts are often combined with light sources to create a beautiful atmosphere and enhance aesthetics. These transparent parts are often designed in irregular shapes for aesthetic purposes and are usually manufactured using injection molding.
[0003] This application mainly relates to the injection molding process of toy light guide tubes, which are a type of transparent component. The toy light guide tube includes a base, a first branch, and a second branch. The base, the first branch, and the second branch are constructed in a Y-shape, wherein the length of the first branch is less than the length of the second branch.
[0004] In traditional injection molding, the sprue of the mold cavity is usually aligned with the base. Due to the special shape of the toy light guide tube, it is difficult to control the flow trajectory of the glue in the mold cavity during injection. The time difference of the glue reaching different positions is large, which is not conducive to the expulsion of gas. The injection molded product will have problems such as flow lines and bubbles. For toy light guide tubes, these will affect the subsequent use effect. Summary of the Invention
[0005] The main objective of this invention is to provide an injection molding method for toy light guide tubes, which aims to avoid flow lines and bubbles in the injection-molded toy light guide tubes.
[0006] According to a first aspect of the present invention, an injection molding method for a toy light guide tube is provided, comprising a mold, wherein the mold has a cavity, the cavity has a gating gate, and glue is injected into the cavity through the gating gate, and pressure holding and cooling are performed after injection, wherein the injection is divided into injection stage one, injection stage two, injection stage three, injection stage four and injection stage five.
[0007] The injection speed of the first injection stage is the highest; the injection speed of the third injection stage is higher than that of the second and fourth injection stages; and the injection speed of the fifth injection stage is the lowest.
[0008] The injection pressure of the first injection stage is lower than that of the second injection stage, and the injection pressure of the second injection stage is lower than that of the third injection stage.
[0009] In the above-mentioned injection molding method for toy light guide tubes, the injection pressure of the fourth injection stage is greater than that of the first injection stage, and the injection pressure of the fourth injection stage is less than that of the second injection stage.
[0010] The injection pressure of the fifth injection stage is the same as that of the fourth injection stage.
[0011] In the above-mentioned injection molding method for toy light guide tubes, the injection pressure of the injection section is 130-140 bar;
[0012] The injection pressure of the second injection stage is 145-155 bar;
[0013] The injection pressure of the three injection stages is 182-190 bar;
[0014] The injection pressure of the four injection stages is 135-145 bar.
[0015] In the above-mentioned injection molding method for toy light guide tubes, the injection speed of the injection section is 107-120 ml / s;
[0016] The injection speed of the second injection stage is 33.5–47 ml / s;
[0017] The injection speed of the three injection stages is 67-78 ml / s;
[0018] The injection speed of the four injection stages is 11-15 ml / s;
[0019] The injection speed of the five injection stages is 2.5 to 6.5 ml / s.
[0020] In the above-mentioned injection molding method for toy light guide tubes, the nozzle temperature is 185-235℃ during injection.
[0021] In the above-mentioned injection molding method for toy light guide tubes, the injection time is called the injection time, the holding time is called the holding time, and the cooling time is called the cooling time.
[0022] The injection time is 9-13 seconds; the cooling time is 10-13 seconds; and the sum of the injection time, holding time, and cooling time is no more than 32 seconds.
[0023] In the above-described injection molding method for toy light guide tubes, the pouring port is connected to the cavity used to form the second branch of the toy light guide tube.
[0024] One of the above-described technical solutions of the present invention has at least one of the following advantages or beneficial effects:
[0025] This invention optimizes the injection process by dividing it into five stages. The first stage involves a high injection speed to rapidly inject most of the adhesive into the mold cavity. The second stage allows for a lower injection speed, buffering the adhesive and expelling air bubbles. The third stage replenishes the adhesive, filling the entire cavity while increasing the injection pressure to stabilize the adhesive and prevent flow lines. The fourth and fifth stages transition to the holding pressure process, maintaining high injection pressure to stabilize the adhesive within the cavity and further prevent flow lines. Based on this injection process, the molded product is virtually free of flow lines and air bubbles.
[0026] Meanwhile, the gating gate of the cavity was optimized, connecting the gating gate to the position of the second branch of the cavity used to form the light guide tube of the toy. This changed the flow speed and direction of the glue, resulting in a shorter flow path for the glue, shorter filling time, and more uniform pressure during injection, which can avoid the generation of air bubbles and air streaks. Attached Figure Description
[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments;
[0028] Figure 1 This is a schematic diagram of the structure of the toy light guide tube of the present invention;
[0029] Figure 2 This is a schematic diagram of the pouring gate in Embodiment 1 of the present invention;
[0030] Figure 3 This is a schematic diagram of the pouring gate of Comparative Example 3 of the present invention. Detailed Implementation
[0031] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0032] Reference Figure 1 The product to be injection molded in this application is a toy light guide tube, made of transparent MABS material, and its specific shape is as follows: Figure 1 As shown, it includes a base portion a, a first branch portion b, and a second branch portion c. The base portion a, the first branch portion b, and the second branch portion c are constructed in a Y-shape, wherein the length of the first branch portion b is less than the length of the second branch portion c.
[0033] Example 1
[0034] A method for injection molding a toy light guide tube includes a mold, a cavity in the mold, a sprue 100 in the cavity, injection of glue into the cavity through the sprue 100, pressure holding and cooling after injection, and the injection is divided into injection stage one, injection stage two, injection stage three, injection stage four and injection stage five.
[0035] The injection speed of the injection stage is relatively fast, mainly to quickly inject most of the glue into the cavity to prevent air marks and flow marks from forming when the glue is cold.
[0036] The injection speed in the second stage of injection can be lower, while the injection pressure can be increased slightly to allow the adhesive to be buffered and to expel air bubbles.
[0037] The third stage of injection involves replenishing the adhesive to fill the entire cavity. At the same time, the injection pressure is increased and maintained at the maximum pressure to make the adhesive more stable and avoid flow marks.
[0038] The fourth and fifth injection stages are used to transition to the holding pressure process. A high injection pressure needs to be maintained to stabilize the glue in the cavity and prevent flow marks. In addition, the fourth and fifth injection stages will also inject glue, but at a decreasing speed, which can be used for final replenishment. Then, the product in the mold cavity is cooled and formed through the mold's cooling cycle. Based on this injection process, the injection molded product will basically not have flow marks or bubbles.
[0039] In this embodiment, the injection speed of the first injection stage is the highest; the injection speed of the third injection stage is higher than that of the second and fourth injection stages; the injection speed of the second injection stage is higher than that of the fourth injection stage; and the injection speed of the fifth injection stage is the lowest.
[0040] Specifically, the injection speed for stage 1 is 107–120 ml / s; for stage 2 it is 33.5–47 ml / s; for stage 3 it is 67–78 ml / s; for stage 4 it is 11–15 ml / s; and for stage 5 it is 2.5–6.5 ml / s.
[0041] As a specific implementation of this embodiment, the injection speed of the first injection stage is 114 ml / s; the injection speed of the second injection stage is 40 ml / s; the injection speed of the third injection stage is 74 ml / s; the injection speed of the fourth injection stage is 13.4 ml / s; and the injection speed of the fifth injection stage is 5.4 ml / s.
[0042] In this embodiment, the injection pressure of the first injection stage is lower than that of the second injection stage, and the injection pressure of the second injection stage is lower than that of the third injection stage; the injection pressure of the fourth injection stage is higher than that of the first injection stage, the injection pressure of the fourth injection stage is lower than that of the second injection stage, and the injection pressure of the fifth injection stage is the same as that of the fourth injection stage.
[0043] Specifically, the injection pressure in the first stage of injection is 130–140 bar; the injection pressure in the second stage is 145–155 bar; the injection pressure in the third stage is 182–190 bar; and the injection pressure in the fourth stage is 135–145 bar.
[0044] As a specific implementation of this embodiment, the injection pressure of the first injection stage is 135 bar; the injection pressure of the second injection stage is 150 bar; the injection pressure of the third injection stage is 185 bar; the injection pressure of the fourth injection stage is 140 bar; and the injection pressure of the fifth injection stage is 140 bar.
[0045] In this embodiment, the nozzle temperature is 185–235°C during injection.
[0046] Reference Figure 2 In this embodiment, the pouring port 100 of the cavity is optimized and connected to the position of the second branch c of the cavity used to form the toy light guide tube. This changes the flow speed and flow direction of the adhesive, so that the adhesive does not have an excessively long flow path, the time for the adhesive to fill the cavity is shorter, and the pressure during injection is more uniform, which can avoid the generation of air bubbles and air lines.
[0047] In this embodiment, the injection time is the injection time, the holding time is the holding time, and the cooling time is the cooling time.
[0048] The injection time is 9–13 seconds; the cooling time is 10–13 seconds; the total of the injection time, holding time, and cooling time shall not exceed 32 seconds.
[0049] As a specific implementation of this embodiment, the injection time is 11s, the holding time is 7s, the cooling time is 12s, and the entire cycle only takes 30s. The time required to complete the injection molding is shorter, and the injection quality is also better.
[0050] Comparative Example 1
[0051] It is basically the same as Example 1, except that the injection process is different:
[0052] The injection speed of the first stage is 127 ml / s; the injection speed of the second stage is 54 ml / s; the injection speed of the third stage is 80 ml / s; the injection speed of the fourth stage is 16 ml / s; and the injection speed of the fifth stage is 8 ml / s.
[0053] The injection pressure in the first stage of injection is 120 bar; the injection pressure in the second stage is 135 bar; the injection pressure in the third stage is 180 bar; the injection pressure in the fourth stage is 155 bar; and the injection pressure in the fifth stage is 60 bar.
[0054] The injection time is 11s, the holding time is 7s, and the cooling time is 12s.
[0055] Products injection molded using this injection process still exhibit flow lines and air bubbles.
[0056] Comparative Example 2
[0057] It is basically the same as Example 1, except that the injection process is different:
[0058] The injection speed of the first stage is 127 ml / s; the injection speed of the second stage is 54 ml / s; the injection speed of the third stage is 80 ml / s; the injection speed of the fourth stage is 16 ml / s; and the injection speed of the fifth stage is 8 ml / s.
[0059] The injection pressure in the first stage of injection is 120 bar; the injection pressure in the second stage is 135 bar; the injection pressure in the third stage is 180 bar; the injection pressure in the fourth stage is 155 bar; and the injection pressure in the fifth stage is 60 bar.
[0060] The injection time is 15s, the holding time is 27s, and the cooling time is 18s.
[0061] Products injection molded using this injection process still exhibit flow lines and bubbles, but the number of flow lines and bubbles is less than in Comparative Example 1.
[0062] Comparative Example 3
[0063] Reference Figure 3 It is basically the same as Example 1, except that the position of the pouring port 100 of the cavity is different, so that the pouring port 100 is connected to the position of the base part a of the cavity used to form the toy light guide tube.
[0064] The injection-molded product still has flow lines and bubbles, and most of the bubbles appear on the second branch c of the toy's light guide tube.
[0065] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
Claims
1. An injection molding method for a toy light guide tube, the toy light guide tube comprising a base, a first branch, and a second branch, wherein the base, the first branch, and the second branch are configured in a Y-shape, wherein, The length of the first branch is less than the length of the second branch; The invention includes a mold, which has a cavity and a gating gate. Glue is injected into the cavity through the gating gate, and pressure holding and cooling are performed after injection. The invention is characterized in that the injection is divided into five stages: injection stage one, injection stage two, injection stage three, injection stage four, and injection stage five. The injection speed of the first injection stage is the highest; the injection speed of the third injection stage is higher than that of the second and fourth injection stages; and the injection speed of the fifth injection stage is the lowest. The injection pressure of the first injection stage is lower than that of the second injection stage, and the injection pressure of the second injection stage is lower than that of the third injection stage; the injection pressure of the fourth injection stage is higher than that of the first injection stage, and the injection pressure of the fourth injection stage is lower than that of the second injection stage; the injection pressure of the fifth injection stage is the same as that of the fourth injection stage. The injection time is the injection time, the holding time is the holding time, and the cooling time is the cooling time. The injection time is 9-13 seconds; the cooling time is 10-13 seconds; the sum of the injection time, holding time, and cooling time is no more than 32 seconds. The pouring port is connected to the position of the cavity used to form the second branch of the toy light guide tube.
2. The injection molding method for the toy light guide tube according to claim 1, characterized in that, The injection pressure of the injection section is 130~140 bar; The injection pressure of the second injection stage is 145~155 bar; The injection pressure of the three injection stages is 182~190 bar; The injection pressure of the four injection stages is 135~145 bar.
3. The injection molding method for the toy light guide tube according to claim 1, characterized in that, The injection speed of the injection section is 107~120 ml / s; The injection speed of the second injection stage is 33.5~47ml / s; The injection speed of the three injection stages is 67~78 ml / s; The injection speed of the four injection stages is 11~15 ml / s; The injection speed of the five injection stages is 2.5~6.5 ml / s.
4. The injection molding method for the toy light guide tube according to claim 1, characterized in that, During injection, the nozzle temperature is 185~235℃.