Plastic bottle embryo heating device and heating method based on dual wavelengths

Abstract

The invention discloses a plastic bottle preform heating device based on dual wavelengths. The heating device comprises a first laser, a second laser, a first galvanometer and a second galvanometer, the first laser is used for emitting far infrared laser with the wavelength of 2.2-12 microns, and the second laser is used for emitting near infrared laser with the wavelength of 0.8-2 microns; the first galvanometer and the second galvanometer are respectively configured on light emitting paths of the first laser and the second laser; the first laser and the second laser emit light simultaneously; laser emitted by the first laser device and the second laser device is projected onto the plastic bottle blank after being deflected and scanned by the first galvanometer and the second galvanometer respectively, so that the surface and the interior of the plastic bottle blank are heated respectively. Through the synergistic effect of laser with two wavelengths, the heating time of the plastic bottle blank is shortened, and the production efficiency is improved; the surface of the plastic bottle blank is heated through the first laser, the interior of the plastic bottle blank is heated through the second laser, and therefore it is ensured that the plastic bottle blank is evenly heated.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic preforms, and particularly to a heating device and a heating method for plastic preforms based on dual wavelengths. Background Art

[0002] In the field of plastic bottle production, the applications of polyethylene terephthalate (PET), polypropylene (PP), etc. are very extensive, and the heating of these materials is a key step in many manufacturing processes. Traditional plastic preform heating methods, such as lamp tube heating, hot air heating, etc., have many drawbacks. When using lamp tube heating, the heat transfer efficiency is relatively low, resulting in a long heating time, large energy consumption, and it is difficult to ensure heating uniformity, easily causing local overheating or insufficient heating of the plastic preform, thereby affecting the quality stability of the finished plastic bottle, and problems such as uneven bottle wall thickness and inconsistent strength occur. Although hot air heating can improve heating uniformity to a certain extent, the energy loss is large during the transmission of hot air, the improvement of heating efficiency is limited, and the equipment structure is complex and the maintenance cost is high.

[0003] With the continuous development of laser technology, laser heating has gradually been applied to the field of transparent plastic preform heating due to its advantages such as concentrated energy, fast heating speed, and easy control. Currently, there are already some technologies using near-infrared lasers of a certain wavelength to heat plastic preforms. However, when using a single-wavelength laser to heat transparent plastics, the following challenges are often faced:

[0004] 1. The heating efficiency of a single-wavelength laser is relatively low, especially for transparent plastics, and the material of transparent plastics has limited absorption of certain wavelengths.

[0005] 2. The heating uniformity is poor, which may lead to inconsistent temperatures on the surface and inside of the plastic material.

[0006] 3. The heating time is relatively long, affecting production efficiency.

[0007] Therefore, how to make full use of the advantages of lasers and improve the heating efficiency of transparent plastics has become an urgent problem to be solved currently. Summary of the Invention

[0008] To overcome the deficiencies of the above-mentioned prior art, the present invention provides a heating device and a heating method for plastic preforms based on dual wavelengths to solve at least one of the above-mentioned technical problems.

[0009] According to one aspect of the specification of the present invention, there is provided a heating device for a plastic preform based on dual wavelengths. The heating device includes a first laser, a second laser, a first galvanometer, and a second galvanometer. The first galvanometer and the second galvanometer are respectively arranged on the light output paths of the first laser and the second laser; the first laser is used to emit far-infrared laser with a wavelength in the range of 2.2 - 12 microns, and the second laser is used to emit near-infrared laser with a wavelength in the range of 0.8 - 2 microns; the first laser and the second laser emit light simultaneously; wherein, the far-infrared laser emitted by the first laser is deflected and scanned by the first galvanometer to heat the surface of the plastic preform, and the near-infrared laser emitted by the second laser is deflected and scanned by the second galvanometer to heat the inside of the plastic preform.

[0010] Further, the first galvanometer is coated with an anti-reflection film corresponding to the laser wavelength of the first laser, and the second galvanometer is coated with an anti-reflection film corresponding to the laser wavelength of the second laser.

[0011] Further, the heating device further includes a controller, and the controller is respectively connected to the first laser and the second laser; the controller presets a heating time, and when the heating duration of the plastic preform reaches the set heating time, the controller controls the first laser and the second laser to turn off.

[0012] Further, the heating device further includes an infrared area array camera. The controller is respectively connected to the infrared area array camera, the first galvanometer, and the second galvanometer. The controller adjusts the motion parameters of the first galvanometer and the second galvanometer to achieve the division of each area of the plastic preform; the infrared area array camera monitors the temperature data of each area of the plastic preform in real time and transmits it to the controller.

[0013] Further, the heating device further includes a rotating platform, and the rotating platform clamps the plastic preform and rotates the plastic preform at a preset speed.

[0014] Further, the controller is also connected to the rotating platform; during the heating process of the plastic preform, the controller adjusts the light output power of the first laser and the second laser, the rotation speed of the plastic preform, and the motion parameters of the first galvanometer and the second galvanometer according to the temperature data of each area of the plastic preform, so as to change the laser input intensity, the laser irradiation duration, and the laser irradiation position, and further achieve precise temperature control of different areas of the plastic preform.

[0015] According to one aspect of the specification of the present invention, a heating method for plastic preforms based on dual wavelengths is provided, which is implemented by using the heating device for plastic preforms based on dual wavelengths. The heating method includes: setting the heating parameters of the first laser and the second laser according to the material and target temperature of the plastic preform; wherein, the first laser is used to emit far-infrared laser with a wavelength in the range of 2.2 - 12 microns, and the second laser is used to emit near-infrared laser with a wavelength in the range of 0.8 - 2 microns; the heating parameters include the wavelength and power of the laser; controlling the first laser and the second laser to emit light simultaneously, so that the far-infrared laser emitted by the first laser is deflected and scanned by the first galvanometer to heat the surface of the plastic preform, and the near-infrared laser emitted by the second laser is deflected and scanned by the second galvanometer to heat the inside of the plastic preform.

[0016] Further, before controlling the first laser and the second laser to emit light simultaneously, the heating method further includes: placing the plastic preform on a rotating platform to drive the plastic preform to rotate at a preset speed by the rotating platform.

[0017] Further, the heating method further includes: controlling the motion parameters of the first galvanometer and the second galvanometer by a controller to achieve the division of each area of the plastic preform; real-time monitoring the temperature data of each area of the plastic preform by an infrared area array camera and transmitting it to the controller; wherein, the controller is preset with a target temperature; when the plastic preform reaches the target temperature, controlling the first laser and the second laser to turn off by the controller.

[0018] Further, before the plastic preform reaches the target temperature, the heating method further includes: adjusting the light output power of the first laser and the second laser, the rotation speed of the plastic preform, and the motion parameters of the first galvanometer and the second galvanometer by the controller according to the temperature data of each area of the plastic preform, so as to change the laser input intensity, laser irradiation duration, and laser irradiation position, and further achieve precise control of the temperature of different areas of the plastic preform.

[0019] The above technical solution sets the first laser and the second laser to emit two different wavelengths of laser simultaneously. Through the synergistic effect of the two wavelengths of laser, the heating time of the plastic preform is shortened and the production efficiency is improved; at the same time, the surface of the plastic preform is heated by the first laser, and the inside of the plastic preform is heated by the second laser, so as to ensure uniform heating of the plastic preform. Description of the Drawings

[0020] Figure 1 It is a structural diagram of a heating device for plastic preforms based on dual wavelengths provided in the embodiment of the present invention.

[0021] Figure 2 It is an electrical connection diagram of a heating device for plastic preforms based on dual wavelengths provided in an embodiment of the present invention.

[0022] Figure 3 It is a flowchart of a heating method for plastic preforms based on dual wavelengths provided in an embodiment of the present invention.

[0023] Figure 4 It is a sub - flowchart of a heating method for plastic preforms based on dual wavelengths provided in an embodiment of the present invention.

[0024] Figure 5 It is a curve graph of spectral analysis of PET preforms provided in an embodiment of the present invention.

[0025] Figure 6 It is a data graph of spectral analysis of PET preforms provided in an embodiment of the present invention.

[0026] In the figure: 1. First laser; 2. Second laser; 3. First galvanometer; 4. Second galvanometer; 5. Infrared area array camera; 6. Controller; 7. Rotating platform; 100. Heating device; 200. Plastic preform. Specific embodiments

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a connection that allows mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal communication between two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the horizontal height of the first feature is lower than that of the second feature.

[0031] Please refer to the attached Figure 1 , this embodiment provides a heating device 100 for a plastic preform 200 based on dual wavelengths. The heating device 100 includes a first laser 1, a second laser 2, a first galvanometer 3, and a second galvanometer 4. The first laser 1 and the second laser 2 respectively emit lasers of different wavelengths. The first laser 1 and the second laser 2 emit light simultaneously. The lasers emitted by the first laser 1 and the second laser 2 are respectively deflected and scanned by the first galvanometer 3 and the second galvanometer 4 and then projected onto the plastic preform 200 to achieve heating of the surface and the interior of the plastic preform 200. In this embodiment, the material of the plastic preform 200 includes, but is not limited to, PP material and PET material.

[0032] In this embodiment, the first laser 1 is a high-absorption wavelength laser, such as a far-infrared laser, for emitting far-infrared laser with a wavelength in the range of 2.2 - 12 micrometers, so as to achieve rapid heating of the surface of the plastic preform 200. The second laser 2 is a penetrative wavelength laser, such as a near-infrared laser, for emitting near-infrared laser with a wavelength in the range of 0.8 - 2 micrometers, so as to achieve heating of the interior of the plastic preform 200. It should be noted that there are significant differences in the absorption characteristics of the plastic preform 200 for lasers of different wavelengths. For example, the plastic preform 200 has an absorption rate of nearly 100% for far-infrared laser, so rapid heating of the surface of the plastic preform 200 can be achieved. The absorption rate of near-infrared laser for the plastic preform 200 is between 20% - 70%, and it has a certain penetration ability, so deep heating of the interior of the plastic preform 200 can be achieved.

[0033] The first galvanometer 3 and the second galvanometer 4 are respectively arranged on the light-emitting paths of the first laser 1 and the second laser 2. The first galvanometer 3 and the second galvanometer 4 respectively deflect and scan the laser beams emitted by the first laser 1 and the second laser 2 to change the projection angles and positions of the laser beams emitted by the first laser 1 and the second laser 2, thereby changing the irradiation area and energy distribution of the laser on the plastic bottle preform 200. In this embodiment, the first galvanometer 3 and the second galvanometer 4 are customized galvanometers. The first galvanometer 3 is coated with an antireflection film corresponding to the laser wavelength of the first laser 1. The second galvanometer 4 is coated with an antireflection film corresponding to the laser wavelength of the second laser 2. It can be understood that the antireflection film can effectively reduce the reflection of the laser on the surface of the galvanometer, thereby reducing the energy loss during the laser transmission process and improving the utilization rate of the laser energy.

[0034] Please refer to the attached Figure 2 , the heating device 100 further includes an infrared area array camera 5, a controller 6, and a rotating platform 7. The rotating platform 7 clamps the plastic bottle preform 200 and rotates the plastic bottle preform 200 at a preset speed. The controller 6 is connected to the infrared area array camera 5. The infrared area array camera 5 monitors the temperature data of each area of the plastic bottle preform 200 in real time and transmits it to the controller 6. In this embodiment, according to the shape, size, and process requirements of the plastic bottle preform 200, the plastic bottle preform 200 is divided into multiple areas by the first galvanometer 3 and the second galvanometer 4, and then the temperature data of different areas is detected by the infrared area array camera. In addition, the infrared area array camera 5 can be installed at a position close to the plastic bottle preform 200 or directly in contact with the surface of the plastic bottle preform 200. The present invention does not limit this here.

[0035] Further, the controller 6 is also connected to the rotary platform 7, the first laser 1 and the second laser 2, the first galvanometer 3 and the second galvanometer 4 respectively. During the overheating process of the plastic bottle preform 200, the controller 6 adjusts the rotation speed of the plastic bottle preform 200, the light output power of the first laser 1 and the second laser 2, and the motion parameters of the first galvanometer 3 and the second galvanometer 4 according to the temperature data of each region of the plastic bottle preform 200, so as to change the laser input intensity, the laser irradiation duration, and the laser irradiation position, and further achieve precise control of the temperature of different regions of the plastic bottle preform 200. It can be understood that the light output power of the first laser 1 and the second laser 2 determines the laser input intensity. The higher the light output power, the more energy the laser irradiates on the plastic bottle preform 200. The rotation speed of the plastic bottle preform 200 will affect the laser irradiation duration (i.e., the single-point exposure time). The slower the rotation speed, the longer the time the same position of the plastic bottle preform 200 is irradiated by the laser. The motion parameters of the first galvanometer 3 and the second galvanometer 4 will determine the laser irradiation position on the plastic bottle preform 200. Therefore, by adjusting the rotation speed of the plastic bottle preform 200, the light output power of the first laser 1 and the second laser 2, and the motion parameters of the first galvanometer 3 and the second galvanometer 4, precise control of the temperature of each region of the plastic bottle preform 200 can be achieved.

[0036] Please refer to the attached Figure 3 , the present invention also provides a heating method for a plastic bottle preform 200 based on dual wavelengths, using the heating device 100 described above to heat the plastic bottle preform 200, including the following steps (steps S101 - S109):

[0037] Step S101, place the plastic bottle preform on the rotary platform to drive the plastic bottle preform to rotate self - clockwise at a preset speed through the rotary platform.

[0038] In step S101, the plastic bottle preform 200 is placed on the rotary platform, and the rotary platform drives the plastic bottle preform 200 to rotate self - clockwise at a preset speed through a driving device such as a motor. This is because the laser scanning path of the present invention is linear and needs to cooperate with the self - rotation of the plastic bottle preform 200, so that each part of the plastic bottle preform 200 can be evenly irradiated by the laser, avoiding local overheating or insufficient heating and ensuring the uniformity of heating. In this embodiment, the rotation speed of the plastic bottle preform 200 is 120 rpm. It can be understood that the rotation speed of the plastic bottle preform 200 can be set to any value according to the specific heating requirements of the plastic bottle preform 200 and is not limited herein.

[0039] Step S103, set the heating parameters of the first laser and the second laser according to the material and target temperature of the plastic bottle preform; wherein, the first laser is used to emit far - infrared laser with a wavelength in the range of 2.2 - 12 microns, and the second laser is used to emit near - infrared laser with a wavelength in the range of 0.8 - 2 microns; the heating parameters include the wavelength and power of the laser.

[0040] In step S103, it can be understood that before turning on the first laser 1 and the second laser 2 to heat the plastic preform 200, preparatory work needs to be done. Specifically, according to the material and target temperature of the plastic preform 200, the heating parameters of the first laser 1 and the second laser 2 need to be initially set. The heating parameters include but are not limited to the power, wavelength, and light output mode of the laser. The first laser 1 is used to emit far-infrared laser with a wavelength in the range of 2.2 - 12 microns, and the second laser 2 is used to emit near-infrared laser with a wavelength in the range of 0.8 - 2 microns. For example, for a PET preform (i.e., the plastic preform 200 made of PET material), the wavelength range of the first laser 1 is set to 2.5 - 12 microns, the light output mode is set to pulsed, the power is set to 100w, the wavelength range of the second laser 2 is set to 1.5 - 2 microns, the light output mode is set to continuous light output, and the power is set to 100w.

[0041] It can be understood that plastic preforms of different materials have different absorption characteristics for lasers of different wavelengths. It should be noted that a low absorption rate indicates that the material of the plastic preform 20 has strong laser transmissivity at this wavelength, weak interaction between light and matter, and poor heat conversion rate. While an excessively high absorption rate indicates that the material of the plastic preform 200 has weak laser transmissivity at this wavelength, that is, the laser of this wavelength cannot completely pass through the plastic preform 200 and only interacts with the surface of the plastic preform 200, resulting in too large a temperature difference between the inside and outside of the plastic preform 200 and uneven heating. Therefore, it is necessary to select a laser with a wavelength corresponding to an appropriate absorption rate according to the material of the plastic preform 200.

[0042] Furthermore, the specific implementation of selecting a laser with a wavelength corresponding to an appropriate absorption rate according to the material of the plastic preform 200 is as follows: The absorption spectrum of the plastic preform 200 at different wavelengths can be measured by a spectrophotometer (the results are as shown in the appendix Figures 5 - 6 shown. It should be noted that the PET spectral absorption rate relationship diagram shown in the appendix Figures 4 - 5 is not used to limit the scope of the present invention), determine its absorption peak wavelength range, and select a laser wavelength that matches the absorption peak wavelength, so as to maximize the absorption efficiency of the plastic preform 200 for laser energy and improve the heating effect. In addition, when determining the wavelength of the laser, it is also necessary to consider whether there are mature industrial lasers in the corresponding optimal band, and determine the wavelength of the laser by comprehensively considering both the absorption rate and the laser.

[0043] Step S105, control the first laser and the second laser to emit light simultaneously, so that the far-infrared laser emitted by the first laser is deflected and scanned by the first galvanometer to heat the surface of the plastic preform, and the near-infrared laser emitted by the second laser is deflected and scanned by the second galvanometer to heat the inside of the plastic preform.

[0044] In step S105, the first laser 1 and the second laser 2 emit light simultaneously. The first laser 1 rapidly heats the surface of the plastic preform 200, and the second laser 2 heats the inside of the plastic preform 200, making the temperature of the surface and the inside of the plastic preform 200 consistent, ensuring the heating uniformity of the plastic preform 200, and thus avoiding quality problems such as uneven wall thickness and inconsistent strength of the bottle body caused by local overheating or insufficient heating of the plastic preform 200. Please refer to the attached Figure 4 , and the following will further introduce step S105 (including steps S1051 - S1055).

[0045] In step S1051, the controller controls the motion parameters of the first galvanometer and the second galvanometer to achieve the division of each area of the plastic preform. It can be understood that since the present invention needs to precisely control the temperature of each area of the plastic preform 200. Therefore, before turning on the first laser 1 and the second laser 2, it is also necessary to set the motion parameters of the first galvanometer 3 and the second galvanometer 4 according to the size of the plastic preform 200, so as to achieve the division of each area of the plastic preform 200. Among them, the motion parameters include but are not limited to the scanning range, scanning speed, and deflection angle range of the first galvanometer 3 and the second galvanometer 4. It can be understood that plastic preforms 200 of different sizes have different surface areas and shapes. Setting the galvanometer motion parameters according to the size of the plastic preform 200 can make the laser scan the surface of the plastic preform along a specific path and speed, ensure that each area receives uniform laser energy, avoid local overheating or insufficient heating, and thus improve the consistency of product quality. At the same time, reasonably setting the galvanometer motion parameters can optimize the laser scanning path, reduce unnecessary idle strokes and repeated scanning areas, save production time and energy consumption. Finally, it also avoids the laser irradiating areas outside the plastic preform 200, causing damage to surrounding equipment, and ensures the safety and stability of the production process.

[0046] In step S1053, the infrared area array camera monitors the temperature data of each area of the plastic preform in real time and transmits it to the controller. In this embodiment, the infrared area array camera 5 monitors the temperature data of each area of the plastic preform 200 in real time, and these temperature data are transmitted to the controller 6 in real time, thus providing a basis for the subsequent adjustment of the controller 6.

[0047] Step S1055: When the plastic preform reaches the target temperature, the first laser and the second laser are controlled to turn off by the controller. In this embodiment, the heating of a PET preform is taken as an example for illustration. There are four states of the PET preform. When at room temperature, the PET preform is in a glass state. It transforms from the glass state to a rubber state at 76°. It reaches the target blow molding state at 100°. Crystallization starts at 128°, and 160° is the crystallization transformation point temperature. It starts to change from a solid state to a liquid state at 246°. The goal of this embodiment is to heat the PET preform to the target blow molding state, that is, when the temperature of the PET preform reaches 110° (i.e., the target temperature), the first laser 1 and the second laser 2 are turned off. In another feasible embodiment, the controller 6 presets a heating time. When the heating duration of the plastic preform 200 reaches the set heating time, the controller 6 controls the first laser 1 and the second laser 2 to turn off.

[0048] In addition, during the heating process of the plastic preform 200, the controller 6 can also adjust the light output power of the first laser 1 and the second laser 2, the rotation speed of the plastic preform 200, and the movement parameters of the first galvanometer 3 and the second galvanometer 4 according to the temperature data of each region of the plastic preform 200, so as to change the laser input intensity, the laser irradiation duration, and the laser irradiation position, and further achieve precise control of the temperature of different regions of the plastic preform. It can be understood that when the temperatures of each region of the plastic preform 200 are inconsistent, by adjusting the temperatures of each region of the plastic preform 200, the temperatures of each region of the plastic preform 200 are made consistent, thus ensuring the stability and uniformity of the heating process of the plastic preform 200. The following will be described in conjunction with Examples 1-3 (it should be noted that Examples 1-3 are only examples and do not limit the scope of the present invention).

[0049] Example 1: When the temperature of a certain region of the plastic preform 200 is relatively low, the controller 6 increases the light output power of the first laser 1 and the second laser 2 in this region, so that more laser energy acts on this region, thereby increasing the temperature of this region; conversely, when the temperature of a certain region of the plastic preform 200 is relatively high, the controller 6 reduces the light output power of the first laser 1 and the second laser 2 in this region, reducing the laser energy acting on this region, thereby reducing the temperature of this region.

[0050] Example 2: When the temperature of a certain region of the plastic preform 200 is relatively high, the rotation speed of the plastic preform 200 can be appropriately increased, so that the time for this region to receive laser irradiation per unit time is shortened, thereby reducing the absorbed heat and lowering the temperature; for the region with a relatively low temperature, the rotation speed of the plastic preform 200 can be appropriately reduced, allowing this region to have more time to receive laser irradiation, increasing the heat absorption, and raising the temperature.

[0051] Example 3: For areas with lower temperatures, the galvanometer scanner is controlled by the controller 6 to make the laser scan these areas more, increasing the energy input; while for areas with higher temperatures, the number of laser scans in these areas is reduced or the scan time is shortened, reducing the energy input.

[0052] In addition, through experiments, it is known that when using the first laser 1 alone to heat the PET preform and monitoring through the infrared area array camera 5, when the temperature reaches 110 °C, the time taken is 62 s. When using the second laser 2 alone to heat the PET preform and monitoring through the infrared area array camera 5, when the temperature reaches 110 °C, the time taken is 20 s. When using the first laser 1 and the second laser 2 simultaneously to heat the PET preform, the time taken is 6 s. It can be understood that in this embodiment, lasers with two wavelengths are used in cooperation to heat the plastic preform 200. This cooperative effect can achieve the effect of "1 + 1 > 2". Compared with a single-wavelength laser, it can complete the heating task in a shorter time, reduce the total energy consumption, and improve the production efficiency. In addition, in some other feasible embodiments, a single laser or a combination of multiple lasers (more than two) can be used to heat the plastic preform 200 to reach the target blow molding temperature to meet the matching of blow molding machines with different production capacities.

[0053] In this embodiment, the plastic preform 200 can be transported using a step-by-step transmission line body or an encoder-compatible continuously operating conveying device, which is not limited herein.

[0054] In this embodiment, a laser light source with a wavelength range of 1450 - 2500 nanometers is selected to heat the transparent preform. Preferably, the wavelength range of the laser light source is between 1550 - 2500 nanometers. In addition, in some other feasible embodiments, a laser light source with a wavelength range of 700 - 2500 nanometers can be selected to heat the colored preform.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A heating device for plastic bottle preforms based on dual wavelengths, characterized in that, The heating device includes a first laser, a second laser, a first galvanometer, and a second galvanometer. The first galvanometer and the second galvanometer are respectively arranged on the light output paths of the first laser and the second laser. The first laser is used to emit far-infrared laser with a wavelength in the range of 2.2 - 12 microns, and the second laser is used to emit near-infrared laser with a wavelength in the range of 0.8 - 2 microns. The first laser and the second laser emit light simultaneously. Among them, the far-infrared laser emitted by the first laser is deflected and scanned by the first galvanometer to heat the surface of the plastic bottle preform, and the near-infrared laser emitted by the second laser is deflected and scanned by the second galvanometer to heat the inside of the plastic bottle preform.

2. The heating device for plastic preforms based on dual wavelengths according to claim 1, wherein The first galvanometer is coated with an anti-reflection film corresponding to the laser wavelength of the first laser, and the second galvanometer is coated with an anti-reflection film corresponding to the laser wavelength of the second laser.

3. The heating device for plastic bottle preforms based on dual wavelengths according to claim 1, wherein The heating device further includes a controller, which is respectively connected to the first laser and the second laser. The controller is preset with a heating time. When the heating duration of the plastic bottle preform reaches the set heating time, the controller controls the first laser and the second laser to turn off.

4. The heating device for plastic preforms based on dual wavelengths according to claim 3, characterized in that, The heating device further includes an infrared array camera. The controller is respectively connected to the infrared array camera, the first galvanometer, and the second galvanometer. The controller adjusts the motion parameters of the first galvanometer and the second galvanometer to achieve the division of each area of the plastic bottle preform. The infrared array camera monitors the temperature data of each area of the plastic bottle preform in real time and transmits it to the controller.

5. The heating device for plastic bottle preforms based on dual wavelengths according to claim 4, wherein The heating device further includes a rotating platform, which clamps the plastic bottle preform and makes the plastic bottle preform rotate at a preset speed.

6. The heating device for plastic preforms based on dual wavelengths according to claim 5, wherein, The controller is also connected to the rotating platform. During the heating process of the plastic bottle preform, the controller adjusts the light output power of the first laser and the second laser, the rotation speed of the plastic bottle preform, and the motion parameters of the first galvanometer and the second galvanometer according to the temperature data of each area of the plastic bottle preform, so as to change the laser input intensity, laser irradiation duration, and laser irradiation position, and further achieve precise control of the temperature of different areas of the plastic bottle preform.

7. A heating method for plastic bottle preforms based on dual wavelengths, characterized in that, The heating method is implemented by using the heating device for plastic bottle preforms based on dual wavelengths according to any one of claims 1 - 6, and includes: Setting the heating parameters of the first laser and the second laser according to the material and target temperature of the plastic bottle preform. Among them, the first laser is used to emit far-infrared laser with a wavelength in the range of 2.2 - 12 microns, and the second laser is used to emit near-infrared laser with a wavelength in the range of 0.8 - 2 microns. The heating parameters include the wavelength and power of the laser. Controlling the first laser and the second laser to emit light simultaneously, so that the far-infrared laser emitted by the first laser is deflected and scanned by the first galvanometer to heat the surface of the plastic bottle preform, and the near-infrared laser emitted by the second laser is deflected and scanned by the second galvanometer to heat the inside of the plastic bottle preform.

8. The heating device for plastic bottle preforms based on dual wavelengths according to claim 7, characterized in that, Before controlling the first laser and the second laser to emit light simultaneously, the heating method further includes: Placing the plastic bottle preform on a rotating platform to drive the plastic bottle preform to rotate self - at a preset speed through the rotating platform.

9. The heating method of a plastic bottle preform based on dual wavelengths according to claim 7, characterized in that, The heating method further includes: Controlling the motion parameters of the first galvanometer and the second galvanometer through a controller to achieve the division of each area of the plastic bottle preform; Real - time monitoring the temperature data of each area of the plastic bottle preform through an infrared area array camera and transmitting it to the controller; When the plastic bottle preform reaches the target temperature, controlling the first laser and the second laser to turn off through the controller.

10. The heating method of a plastic preform based on dual wavelengths according to claim 9, wherein, Before the plastic bottle preform reaches the target temperature, the heating method further includes: Adjusting the light output power of the first laser and the second laser, the rotation speed of the plastic bottle preform, and the motion parameters of the first galvanometer and the second galvanometer by the controller according to the temperature data of each area of the plastic bottle preform, so as to change the laser input intensity, laser irradiation duration, and laser irradiation position, and further achieve precise control of the temperature of different areas of the plastic bottle preform.

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