Infrared heating lamp and method for coating reflective layer on lamp tube

Abstract

The present invention discloses an infrared heating lamp and a method for coating a reflective layer on a lamp tube. The infrared heating lamp comprises a transparent glass tube, an infrared heating wire disposed within the glass tube, and insulating and sealed ceramic heads disposed at both ends of the glass tube. The insulating and sealed ceramic heads are provided with conductive leads electrically connected to the infrared heating wire. A ceramic coating is provided on the upper portion of the inner surface of the glass tube, and a gold coating is provided on the surface of the ceramic coating. The method for coating the reflective layer comprises two steps: the first step is to spray a layer of ceramic coating on the inner wall of the infrared heating tube; the second step is to spray four layers of gold coating on the surface of the ceramic coating. Using such an infrared lamp tube can significantly reduce the shedding of the gold coating and increase its service life.

Description

Technical Field

[0001] The present invention relates to the field of infrared heating technology, in particular to an infrared heating lamp and a method for coating a reflective layer on a lamp tube. Background Art

[0002] 3D printing, which utilizes thermoplastics, polymer blends, and composite materials, is a promising technology for rapidly constructing objects through melt fabrication. However, it has not achieved widespread adoption, significantly impacted by its technical limitations. This melt fabrication technology is significantly limited in the three-dimensional quadrant. During the printing process, the strength across successive layers can be significantly lower than the corresponding in-plane strength. This is primarily due to poor adhesion between printed layers, caused by the lower layers being below the surface transition temperature before the next layer is deposited. Adding infrared heat pipes to the front of the printing device can preheat the printed layers, raising their surface temperature before depositing new material, thereby enhancing the vertical bond strength between layers.

[0003] To address this issue, infrared heating lamps are now available on the market for preheating printed layers. These infrared heating lamps utilize cylindrical quartz glass tubes, mounted horizontally above the printing surface. The inner wall of the upper portion of the quartz glass tube is coated with one or two layers of gold to reflect and focus the infrared light. However, since the inner surface temperature of the infrared heating tube is relatively high during operation, typically between 80 and 100 degrees Celsius, the gold coating tends to fall off when it sublimates and evaporates. This results in the infrared heating lamp's service life being far less than its theoretical lifespan, requiring frequent replacement of the tube and increasing customer costs. Summary of the Invention

[0004] In view of this, one of the objects of the present invention is to provide an infrared heating lamp that can significantly reduce the shedding of the gold coating and has a long service life.

[0005] A second object of the present invention is to provide a method for coating a reflective layer on the lamp tube of the infrared heating lamp.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] An infrared heating lamp includes a transparent glass tube, an infrared heating wire arranged in the glass tube, and insulating sealed porcelain heads arranged at both ends of the glass tube. The insulating sealed porcelain heads are provided with conductive leads electrically connected to the infrared heating wire. The upper part of the inner surface of the glass tube is provided with a ceramic coating, and the surface of the ceramic coating is provided with a gold coating.

[0008] As a further optimization solution of the above technical solution, the number of the gold coating layers is 2-4 layers.

[0009] As a further optimization of the above technical solution, the thickness of the ceramic coating is 0.25-0.33 mm, and the total thickness of all gold coatings is 0.5-10 μm.

[0010] As a further optimization solution of the above technical solution, a molybdenum wire is provided in the middle of the lumen of the glass tube, and the infrared heating wire is a tungsten wire arranged around the molybdenum wire.

[0011] A method for coating a reflective layer on a lamp tube comprises the following steps:

[0012] S1. Spraying a ceramic coating on the inner wall of the infrared heating tube, and then drying the ceramic coating to obtain the ceramic coating with a thickness of 0.25-0.33 mm;

[0013] S2. Spray gold water on the surface of the ceramic coating, then dry the gold water to obtain the first layer of gold coating. Then, make the second, third, and fourth layers of gold coating in the same way as the first layer of gold coating. The thickness of each layer of gold coating is 0.2-0.28 microns.

[0014] As a further optimization of the above technical solution, the time for drying the ceramic coating is 55-60 minutes, and the drying temperature is 710-730 degrees Celsius.

[0015] As a further optimization of the above technical solution, the time for drying the golden water each time is 55-60 minutes, and the drying temperature is 710-730 degrees Celsius.

[0016] The beneficial effects of the present invention are:

[0017] 1. The gold coating on the inner wall of the glass tube can reflect the upward infrared rays downward to the printing surface, improve the heat utilization rate, speed up the heating speed, shorten the time to open and close the infrared heating equipment, reduce the operation time and optimize the heating uniformity of the material.

[0018] 2. The surface of the ceramic coating is rough and has many depressions and holes. When the gold coating is placed on the surface of the ceramic coating, part of the gold coating will be embedded in the depressions and holes of the ceramic coating, which can increase the bonding strength between the two and improve the service life of the gold coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure when an infrared heating lamp is used to preheat the printed layer;

[0020] Figure 2 This is an exploded view of the glass tube;

[0021] Figure 3 is a cross-sectional view of an infrared heating lamp;

[0022] Figure 4 yes Figure 3 Cross-sectional view at line AA. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0024] It should be noted that all directional indications in the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly. In addition, the descriptions of "preferred", "sub-preferred", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "preferred" or "sub-preferred" may explicitly or implicitly include at least one such feature.

[0025] Reference Figures 1 to 4 An infrared heating lamp includes a transparent glass tube 1, an infrared heating wire 2 arranged in the glass tube 1, and an insulating and sealed porcelain head 3 arranged at both ends of the glass tube 1. The insulating and sealed porcelain head 3 is provided with a conductive lead 4 electrically connected to the infrared heating wire 2. The glass tube 1 is filled with inert gas, and a ceramic coating 5 is provided on the upper part of the inner surface of the glass tube 1. The surface of the ceramic coating 5 is provided with a gold coating 6.

[0026] Preferably, the number of gold coating layers 6 is 2-4. The thickness of the ceramic coating layer 5 is 0.25-0.33 mm, and the total thickness of all gold coating layers 6 is 0.5-10 μm.

[0027] When the infrared heating tube is operating, the gold coating 6 acts as a reflector, redirecting upward-directed infrared rays downward toward the printing surface 9. If the gold coating 6 were applied directly to the surface of the quartz glass, the bonding between the two would be weak, and the gold coating 6 would easily fall off when it sublimates and evaporates. The ceramic coating 5, on the other hand, has a rough surface with many depressions and holes. Applying the gold coating 6 to the surface of the ceramic coating 5 allows portions of the gold coating 6 to embed into the depressions and holes, strengthening the bonding between the two and extending the lifespan of the gold coating 6.

[0028] Furthermore, a molybdenum wire 7 is provided in the middle of the lumen of the glass tube 1, with both ends of the molybdenum wire 7 respectively fixed on two insulating sealing porcelain heads 3, and the infrared heating wire 2 is a tungsten wire provided around the molybdenum wire 7. The molybdenum wire 7 is strong and has a supporting function.

[0029] The gold coating 6 and the ceramic coating 5 together constitute the reflective layer of the glass tube 1. The specific steps of coating the reflective layer on the glass tube 1 are as follows:

[0030] S1, spraying ceramic coating on the inner wall of the infrared heating tube, and then drying the ceramic coating to obtain a ceramic coating 5 with a thickness of 0.25-0.33 mm;

[0031] S2. Spray gold water on the surface of the ceramic coating 5, then dry the gold water to obtain a first layer of gold coating 6. Then, the second, third, and fourth layers of gold coating 6 are made in the same way as the first layer of gold coating 6. The thickness of each layer of gold coating 6 is 0.2-0.28 microns.

[0032] The optimal thickness of each layer of the gold coating 6 is 2.5 microns. The reason why the gold coating 6 is sprayed in four times is that four layers of gold coating 6 can better reflect heat. Because gold is a heavy metal, spraying too thickly in one time will cause dripping. Therefore, the thickness of each layer of gold coating 6 is controlled at 0.2-0.28 microns to avoid dripping. Spraying four times can thicken the coating, which has a better heat insulation and reflection effect, and can also prevent the three layers of gold coating 6 on the inside from sublimating and evaporating and causing falling off.

[0033] The drying time of ceramic paint is 55-60 minutes, and the drying temperature is 710-730 degrees Celsius. The drying time of golden water is 55-60 minutes, and the drying temperature is 710-730 degrees Celsius.

[0034] Test 1, gold coating 6 durability test.

[0035] Example 1, Example 2 and Comparative Example 1 were selected and the durability test of the gold coating 6 was carried out simultaneously. The difference between the three is only in the different reflective structures. The specific differences between the three are shown in the following table.

[0036]

[0037] The test method is as follows: The three infrared heating tubes were operated continuously at rated voltage for 72 hours. The gold coating fragments that fell off were collected. Finally, the power to the infrared heating tubes was turned off. The shedding rate was calculated based on the amount of gold coating fragments and the coating weight. The test results are shown in the table below.

[0038]

[0039]

[0040] As can be seen from the above table: under long-term high-temperature testing, the gold coating 6 in Comparative Example 1 severely sheds, and the printed layer is prone to local uneven heating; the gold coating 6 in Example 2 sheds less, has a better anti-shedding and anti-evaporation effect, and has basically no effect on the printed layer; the gold coating 6 in Example 1 sheds almost nothing, has an excellent anti-shedding and anti-evaporation effect, and has no effect on the printed layer.

[0041] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. All equivalent structural transformations made based on the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. An infrared heating lamp, comprising a transparent glass tube (1), an infrared heating wire (2) arranged in the glass tube (1), and insulating sealed porcelain heads (3) arranged at both ends of the glass tube (1), wherein the insulating sealed porcelain heads (3) are provided with conductive leads (4) electrically connected to the infrared heating wire (2), characterized in that: A ceramic coating (5) is provided on the upper portion of the inner surface of the glass tube (1), and a gold coating (6) is provided on the surface of the ceramic coating (5); The number of the gold coating (6) is 2-4 layers; The thickness of the ceramic coating (5) is 0.25-0.33 mm, and the total thickness of all the gold coatings (6) is 0.5-10 μm; A molybdenum wire (7) is provided in the middle of the lumen of the glass tube (1), and the infrared heating wire (2) is a tungsten wire provided around the molybdenum wire (7); The method for coating a reflective layer on a lamp tube comprises the following steps: S1, spraying a ceramic coating on the inner wall of the infrared heating tube, and then drying the ceramic coating to obtain the ceramic coating (5) with a thickness of 0.25-0.33 mm; S2. Spraying gold water on the surface of the ceramic coating (5), then drying the gold water to obtain a first layer of gold coating (6), and then preparing a second, third, and fourth layer of gold coating (6) in the same manner as the first layer of gold coating (6). The thickness of each layer of gold coating (6) is 0.2-0.28 microns; The drying time of ceramic coating is 55-60 minutes, and the drying temperature is 710-730 degrees Celsius; Each drying time of golden water is 55-60 minutes, and the drying temperature is 710-730 degrees Celsius.

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