In-mold transfer printing mold for automobile touch panel

Abstract

The utility model discloses an in-mold transfer printing mold for an automobile touch panel. The in-mold transfer printing mold comprises an upper mold, a lower mold and a mold cavity, a gradient temperature control die cavity structure is arranged in the die cavity, the gradient temperature control die cavity structure comprises a partition temperature control system, the die cavity is divided into a first temperature control area and a second temperature control area, the first temperature control area is located in a central touch area of the die cavity, and the second temperature control area completely surrounds the first temperature control area in the circumferential direction; the dynamic temperature control module comprises a heating rod, a temperature sensor and a spiral cooling water channel, the heating rod and the temperature sensor are embedded into the first temperature control area, and the spiral cooling water channel is embedded into the second temperature control area. The resin and the transfer printing layer are fully combined, the defects of bubbles, deformation, transfer printing pattern fuzziness and the like of products are reduced, and the size precision and mechanical performance of the products are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of in-mold transfer mold, specifically is a kind of in-mold transfer mold of automobile touch panel. BACKGROUND

[0002] With the development of automobile intelligent, touch panel is more and more widely used in automotive trim. In the production process of traditional automobile touch panel, the mold temperature control system is relatively simple, which is difficult to meet the differentiated needs of different areas for temperature.

[0003] In the in-mold transfer process, if the temperature cannot be accurately controlled, it will cause the film to soften unevenly, and the resin and the transfer layer will not be fully combined during injection molding, which will further cause unstable product quality, such as bubbles, deformation, and blurred transfer pattern. In addition, the existing mold cooling process lacks gradient control, which can easily cause the product to generate a large internal stress, affecting the dimensional accuracy and mechanical properties of the product, and also reducing the production efficiency.

[0004] Therefore, it is urgent to develop an in-mold transfer mold for automobile touch panel that can realize partitioned and dynamic temperature control to improve product quality and production efficiency. SUMMARY

[0005] To solve the problems mentioned in the background, the purpose of the utility model is to provide an in-mold transfer mold for automobile touch panel, which realizes accurate control of the temperature of different areas of the mold cavity through a unique gradient temperature control mold cavity structure, improves the molding quality and production efficiency of the automobile touch panel, and reduces product defects.

[0006] The purpose of the utility model can be achieved by the following technical solutions:

[0007] An in-mold transfer mold for automobile touch panel, comprising an upper mold, a lower mold, and a mold cavity; the mold cavity is provided with a gradient temperature control mold cavity structure, which comprises: a partitioned temperature control system: the mold cavity is divided into a first temperature control zone and a second temperature control zone, the first temperature control zone is located in the center touch control area of the mold cavity, and the second temperature control zone completely surrounds the first temperature control zone in the circumferential direction; a dynamic temperature control module: comprising a heating rod and a temperature sensor embedded in the first temperature control zone, and a spiral cooling water channel embedded in the second temperature control zone; a heat insulation layer: provided at the interface between the first temperature control zone and the second temperature control zone, the heat insulation layer is a nano ceramic coating, and its thickness is 50-150 μm.

[0008] Further, the ratio of the projected area of the first temperature control zone to the projected area of the second temperature control zone is 1:1.5-1:3, and the power of the heating rod in the effective working temperature range is 400-600 W / cm 3 , and the equivalent hydraulic diameter of the cooling water channel is 2-5 mm.

[0009] Further, the heating rod of the first temperature control area is an electric resistance heating tube, which is equidistantly distributed in 3-5 groups along the depth direction of the mold cavity, and the temperature sensor is a K-type thermocouple with gold plating packaging, and the arrangement density of the temperature sensor meets 100cm 2 The mold cavity has at least one measuring point.

[0010] Further, the nano ceramic coating material of the heat insulation layer is aluminum oxide (Al2O3), and the thermal conductivity is less than or equal to 1.5 W / (m·K).

[0011] Further, the water inlet and the water outlet of the spiral cooling water channel are respectively connected with an external circulating cooling device, and the external circulating cooling device provides pulsating flow.

[0012] Further, the dynamic temperature control assembly further comprises a control unit, which is configured to independently adjust the power output of the heating rod and the flow parameter of the external circulating cooling device according to the feedback signal of the temperature sensor.

[0013] The beneficial effects of the utility model are as follows:

[0014] 1. The utility model discloses a partition temperature control system and a dynamic temperature control module, which realize accurate control of the temperature of different areas of the mold cavity, make the film soften uniformly, make the resin and the transfer printing layer fully combine, reduce product defects such as bubbles, deformation and fuzzy transfer printing pattern, and improve the size accuracy and mechanical properties of the product.

[0015] 2. The rapid heating characteristics of the electric resistance heating tube and the high-efficiency cooling capacity of the spiral cooling water channel are matched with gradient cooling control, the period of in-mold transfer printing is shortened, and the production efficiency is improved. DRAWINGS

[0016] The utility model will be further described below in combination with the drawings.

[0017] Figure 1 It is the overall structure schematic diagram of the utility model;

[0018] Figure 2 It is the lower mold structure schematic diagram in the utility model;

[0019] Figure 3 It is the mold cavity structure sectional view in the utility model;

[0020] Figure 4 It is the lower mold structure sectional view in the utility model;

[0021] Figure 5 It is the principle block diagram in the utility model,

[0022] In the drawing:

[0023] 1, upper die; 2, lower die; 3, mold cavity; 4, first temperature control zone; 5, second temperature control zone; 6, heating rod; 7, temperature sensor; 8, spiral cooling water channel; 9, heat insulation layer; 10, control unit; 11, circulating cooling device. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0025] In the description of the utility model, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "periphery" and the like indicate the orientation or positional relationship, which are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the components or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0026] As shown in the drawings, Figures 1-5 An automobile touch panel in-mold transfer mold mainly comprises an upper die 1, a lower die 2 and a mold cavity 3. The mold cavity 3 is provided with a gradient temperature control mold cavity 3 structure, which is composed of a partition temperature control system, a dynamic temperature control module and a heat insulation layer 9.

[0027] Partition temperature control system: the mold cavity 3 is divided into a first temperature control zone 4 and a second temperature control zone 5. The first temperature control zone 4 is located in the center touch area of the mold cavity 3, which directly affects the function realization of the touch panel, so the accurate control of temperature is very important. The second temperature control zone 5 completely surrounds the first temperature control zone 4 in the circumferential direction, which plays a role in auxiliary control of temperature and protection of product forming quality during injection molding and cooling.

[0028] Dynamic temperature control module:

[0029] First temperature control zone 4: embedded with independent heating rod 6 and temperature sensor 7, the heating rod 6 is integrated in the mold insert. The heating rod 6 adopts a resistance type heating pipe, and the power is 400-600W / cm 3 in the effective working temperature interval, which is equally distributed in 3-5 groups along the depth direction of the mold cavity 3. The resistance type heating pipe 6 can quickly convert electrical energy into heat energy, realize rapid heating of the first temperature control zone 4, and promote the softening of the printed PET film. The temperature sensor 7 is a gold-plated K-type thermocouple, and the sensor arrangement density meets every 100cm 2The area of the mold cavity 3 has at least one measuring point, which can accurately monitor the temperature change of the first temperature control area 4 and feed the data back to the control unit 10.

[0030] The second temperature control area 5 is embedded with a spiral cooling water channel 8 with an equivalent hydraulic diameter of 2-5mm. The water inlet and outlet of the spiral cooling water channel 8 are respectively connected to the external circulating cooling device 11, which provides pulsating flow and helps to improve cooling efficiency and quickly remove the heat of the second temperature control area 5.

[0031] The heat insulation layer 9 is a nano ceramic coating with a thickness of 50-150μm, which is arranged at the interface between the first temperature control area 4 and the second temperature control area 5. The material of the heat insulation layer 9 is aluminum oxide (Al2O3) with a thermal conductivity coefficient ≤1.5W / (m·K), which can effectively block the heat transfer from the first temperature control area 4 to the second temperature control area 5, maintain the temperature difference between the two temperature control areas, and avoid temperature interference.

[0032] In addition, the dynamic temperature control assembly also includes a control unit 10, which independently adjusts the power output of the heating rod 6 and the flow parameter of the cooling water channel according to the feedback signal of the temperature sensor 7, to realize accurate and dynamic control of the temperature of the mold cavity 3. At the same time, the ratio of the projected area of the first temperature control area 4 to the projected area of the second temperature control area 5 is 1:1.5-1:3, which helps to optimize the temperature control effect of the mold and improve the forming quality of the product.

[0033] Workflow:

[0034] Preheating stage

[0035] The printed PET film (thickness 0.2mm) is sent into the mold cavity 3 and fixed by vacuum suction (the vacuum suction device is the original structure of the transfer mold), and the resistance heating tube 6 embedded in the first temperature control area 4 starts to operate. The first temperature control area 4 is located in the center touch area of the mold cavity 3, and under the output of the heating rod, the first temperature control area 4 quickly heats up to the set temperature of 100℃, which promotes the softening of the film. At the same time, the temperature change is monitored in real time, and the data is fed back to the control unit 10. The control unit 10 adjusts the power of the heating rod according to the feedback signal to effectively prevent temperature overshoot. In addition, the nano ceramic coating heat insulation layer 9 at the interface between the first temperature control area 4 and the second temperature control area 5 can effectively block the heat transfer to the second temperature control area 5, so that the temperature of the periphery of the second temperature control area 5 is maintained at 80℃.

[0036] Injection stage

[0037] When the preheating stage is completed, the molten resin is injected into the mold cavity 3. In the high-temperature and high-pressure environment, the molten resin is fully combined with the transfer layer. At this time, the second temperature control area 5 is stable by controlling the temperature, and the resin is filled completely in the mold cavity 3. The second temperature control area 5 completely surrounds the first temperature control area 4 in the circumferential direction, and ensures that the entire injection molding process is stable.

[0038] Gradient cooling stage

[0039] After the injection molding is completed, the gradient cooling stage is entered. The spiral cooling water channel 8 inlet in the second temperature control area 5 is connected to the external circulating cooling device 11, and the device provides a pulsating flow with a frequency of 2Hz, which quickly leads out the heat outside the periphery of the second temperature control area 5. At the same time, the control unit 10 reduces the heating pipe power according to the feedback of the first temperature control area 4 temperature sensor 7, and synchronously reduces the heating pipe power, so as to realize the slow cooling of the first temperature control area 4 and release the central shrinkage stress. The heat insulation layer 9 continuously maintains the temperature difference between the first and second temperature control areas 5≥20℃, avoids the temperature interference between the two areas, and guarantees the stability of the product cooling process.

[0040] Demolding stage

[0041] After the gradient cooling stage is completed, the ejector mechanism (the ejector mechanism is the original structure of the transfer mold) of the mold starts to work, and the formed automobile touch panel is ejected out, and the entire in-mold transfer process is completed.

[0042] In the description of the specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the utility model. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0043] The basic principles, main features and advantages of the utility model are shown and described above. It should be understood by those skilled in the art that the utility model is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the utility model. Without departing from the spirit and scope of the utility model, the utility model can also have various changes and improvements, and these changes and improvements all fall within the scope of the utility model claimed.

Claims

1. An automotive touch panel in-mold transfer mold characterized by, The mould cavity (3) is provided with a gradient temperature control mould cavity (3) structure, comprising: The mould cavity (3) is divided into a first temperature control zone (4) and a second temperature control zone (5), the first temperature control zone (4) is located in the center touch control area of the mould cavity (3), and the second temperature control zone (5) completely surrounds the first temperature control zone (4) in the circumferential direction; The dynamic temperature control module comprises a heating rod (6) and a temperature sensor (7) embedded in the first temperature control zone (4), and a spiral cooling water channel (8) embedded in the second temperature control zone (5); The heat insulation layer (9) is provided on the interface between the first temperature control zone (4) and the second temperature control zone (5), and the heat insulation layer (9) is a nano ceramic coating. The nano ceramic coating material of the heat insulation layer (9) is aluminum oxide, and the thermal conductivity coefficient is less than or equal to 1.5 W / (m·K).

2. The automotive touch panel in-mold transfer mold according to claim 1, characterized by, The ratio of the projection area of the first temperature control area (4) to the projection area of the second temperature control area (5) is 1:1.5-1:3, and the power of the heating rod (6) in the effective working temperature range is 400-600 W / cm 3 The equivalent hydraulic diameter of the cooling water channel is 2-5 mm.

3. The automotive touch panel in-mold transfer mold according to claim 1, characterized by, The heating rod (6) of the first temperature control area (4) is a resistance heating tube, which is equally distributed in 3-5 groups along the depth direction of the mold cavity (3). The temperature sensor (7) is a gold-plated K-type thermocouple. The arrangement density of the temperature sensor (7) meets the requirement of one sensor per 100 cm 2 The area of the mold cavity (3) is at least one measuring point.

4. The automotive touch panel in-mold transfer mold according to claim 1, characterized by, The water inlet and the water outlet of the spiral cooling water channel (8) are respectively connected with an external circulating cooling device (11), and the external circulating cooling device (11) provides pulsating flow.

5. The automotive touch panel in-mold transfer mold according to claim 1, characterized by, The dynamic temperature control module further comprises a control unit (10), and the control unit (10) is configured to independently adjust the power output of the heating rod (6) and the flow parameter of the external circulating cooling device (11) according to the feedback signal of the temperature sensor (7).

6. The automotive touch panel in-mold transfer mold according to claim 1, characterized by, ​

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