Production process of scald-proof and heat-resistant PLA straws

Abstract

The present invention relates to the technical field of PLA straws, and more particularly to a process for producing scald-resistant and heat-resistant PLA straws. The process comprises: first, sorting PLA straws to obtain PLA straws to be processed; then, crystallizing a portion of the PLA straws to be processed; simultaneously, sorting another batch of PLA straws to obtain a next batch of PLA straws to be processed; adjusting the crystallization temperature to 40-50°C for 5-8 minutes, then raising it to 80-95°C for 10-20 minutes to obtain crystallized PLA straws; naturally cooling the crystallized PLA straws to room temperature to obtain scald-resistant and heat-resistant PLA straws; and repeating the above steps with the next batch of PLA straws to be processed to obtain the next batch of scald-resistant and heat-resistant PLA straws. PLA straws produced using the production process of this application exhibit excellent heat and scald resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of PLA straws, and in particular to a production process of scald-proof and heat-resistant PLA straws. Background Art

[0002] With the rapid economic growth and social development, people are increasingly focusing on sustainable development. Polylactic acid (PLA), a green, environmentally friendly polymer material, boasts excellent biodegradability. Polylactic acid is synthesized using starch-rich biomass through various methods. It is widely used in various plastic products, nonwovens, and industrial applications.

[0003] Among them, straws made from PLA are not only biodegradable and compatible, but also possess good mechanical properties and water resistance due to its inherent physical and chemical properties. However, due to the heat resistance of polylactic acid (PLA) at 50-60°C, this limited heat resistance limits its large-scale industrial application. PLA straws will severely deform when exposed to water above 60°C.

[0004] With respect to the above-mentioned related technologies, the inventor believes that general PLA straws have poor heat resistance and scalding resistance, and will deform when inserted into hot water or hot beverages. Summary of the Invention

[0005] In order to improve the heat resistance and scalding resistance of PLA straws, the present application provides a production process for scalding and heat-resistant PLA straws.

[0006] This application provides a production process for scald-proof and heat-resistant PLA straws, which adopts the following technical solutions:

[0007] A production process for scald-proof and heat-resistant PLA straws, comprising the following steps:

[0008] S1. sorting a batch of PLA straws to obtain PLA straws to be processed;

[0009] S2. placing the same end of the PLA straws to be processed in a hot environment, while the other end of the PLA straws to be processed is placed in a room temperature environment; at the same time, sorting another batch of PLA straws to obtain the next batch of PLA straws to be processed;

[0010] S3, first adjusting the temperature of the hot environment to 40-50°C and maintaining it for 5-8 minutes, then raising the temperature of the hot environment to 80-95°C and maintaining it for 10-20 minutes to obtain a crystallized PLA straw;

[0011] S4, placing the entire body of the crystallized PLA straw at room temperature and allowing it to cool naturally to room temperature, thereby obtaining a scald-resistant and heat-resistant PLA straw;

[0012] S5. Repeat steps S2, S3, and S4 for the next batch of PLA straws to be processed to obtain the next batch of scald-resistant and heat-resistant PLA straws.

[0013] By adopting the above technical solution, PLA straws are treated for heat resistance and scald resistance through a coordinated process of sorting and high-temperature crystallization, thereby improving their heat resistance and scald resistance. The treatment temperature is first adjusted to 40-50°C in a hot environment and maintained for 5-8 minutes. The PLA straws are then pre-crystallized at a relatively low temperature to improve their thermal stability. The PLA straws are then subjected to high-temperature crystallization at 80-95°C for 10-20 minutes, resulting in PLA straws with even better heat resistance and scald resistance. When only one end of the PLA straws is treated for heat resistance, not only does it impart heat resistance and scald resistance, but it also reduces processing costs and increases profits. Simultaneously, two batches of PLA straws work together: while one batch undergoes high-temperature treatment, the other batch begins sorting. This repeated process facilitates industrial production.

[0014] In a specific possible implementation scheme, the sorting process is as follows: first, the PLA straws are transported sequentially, the axial directions of the PLA straws are adjusted to be consistent during the transport process, and then the PLA straws are placed sequentially.

[0015] By employing this technical solution, PLA straws are transported sequentially, facilitating the adjustment of their axial orientation. This alignment of the PLA straws and their subsequent placement allows for neat alignment, facilitating the simultaneous movement of a batch of PLA straws into the heat treatment environment.

[0016] In a specific feasible embodiment, the steps S1, S2, S3, S4 and S5 are all carried out in a scald-proof and heat-resistant PLA straw production equipment, which includes a straw sorting device, a straw adsorption device and a crystallization treatment water tank. The crystallization treatment water tank is arranged on one side of the straw sorting device, and the straw adsorption device is arranged between the crystallization treatment water tank and the straw sorting device. The straw sorting device includes a storage funnel, a diverter, a conveying device and a support frame. The conveying device is arranged on the ground, the support frame is mounted on the conveying device, the storage funnel is installed on the support frame, the diverter is installed on the inner wall of the storage funnel, and the discharge end of the storage funnel faces the conveying device.

[0017] By adopting the above technical solution, PLA straws are sequentially passed through a straw sorting device, a straw adsorption device, and a crystallization treatment tank, achieving the effect of improving the PLA straws' scald resistance and heat resistance. The storage funnel is mounted on a support frame, which improves the stability of the storage funnel. The storage funnel can store a large number of PLA straws, helping to reduce the frequency of adding PLA straws. When the PLA straws pass through the diverter, the diverter can divert the PLA straws and transport them sequentially to the conveyor. The diverter also reduces the problem of PLA straws clogging the storage funnel. The conveyor can place the PLA straws sequentially and transport them to the straw adsorption device, thus completing the sorting process of the PLA straws. The straw adsorption device is located between the crystallization treatment tank and the conveyor device, and can transfer PLA from the conveyor device to the crystallization treatment tank, thereby smoothly performing high-temperature crystallization on the PLA straws.

[0018] In a specific possible implementation scheme, the storage funnel includes a wide mouth mask and a discharge channel, the wide mouth mask is installed on the support frame, one end of the discharge channel is connected to the bottom end of the wide mouth mask, and the other end of the discharge channel faces the conveying device, and the opposite inner walls of the discharge channel are in contact with the PLA straw, and the diverter is installed on the inner wall of the wide mouth mask, and the diverter is located at the bottom end of the wide mouth mask.

[0019] By adopting this technical solution, the storage funnel is composed of two components: a wide housing and a discharge channel. When PLA straws enter the storage funnel, they first pass through the open end of the wide housing through a diverter, which then feeds the PLA straws one by one into the discharge channel. Once in the discharge channel, the PLA straws abut against the inner wall of the discharge channel, allowing them to fall along the channel's inner wall, effectively aligning the PLA straws' axes during transportation.

[0020] In a specific possible implementation scheme, the diverter element includes a rotating shaft, a diverter spacer and a rotating motor. The rotating shaft is arranged in the storage funnel, and the rotating shaft is rotatably connected to the storage funnel. Several of the diverter spacers are installed on the peripheral wall of the rotating shaft. The rotating motor is installed on the storage funnel, and the motor shaft of the rotating motor is coaxially connected to the rotating shaft.

[0021] By adopting the above technical solution, when in use, the rotating motor drives the rotating shaft to rotate, and the rotating shaft simultaneously drives the diverter partition to rotate in the storage funnel. The PLA straws are stuck one by one between two adjacent diverter partitions and fall to the bottom end of the storage funnel, thereby achieving the effect of conveying the PLA straws in sequence and improving the problem of PLA straws being blocked in the storage funnel.

[0022] In a specific possible implementation scheme, the conveying device includes a conveying frame, a conveying belt, a conveying active roller, a conveying driven roller, a conveying motor and a toothed baffle. The conveying active roller and the conveying driven roller are both rotatably connected to the conveying frame, the conveying belt is overlapped on the conveying active roller and the conveying driven roller, several of the toothed baffles are installed on the conveying belt, the conveying motor is fixedly connected to the conveying frame, the motor shaft of the conveying motor is coaxially connected to the conveying active roller, and the support frame is mounted on the conveying frame.

[0023] With this technical solution, when PLA straws fall from the storage hopper onto the conveyor, the conveyor motor drives the active conveyor roller, which activates the conveyor belt. The PLA straws fall one by one between two adjacent toothed baffles on the conveyor belt. The toothed baffles prevent the PLA straws from rolling freely and also confine the PLA straws to a single axial direction, allowing the conveyor belt to transport the PLA straws to the straw suction device.

[0024] In a specific feasible implementation scheme, the straw adsorption device includes a base, a support platform, a lifting adsorption device, a rotating cylinder and a driving member for driving the rotating cylinder to rotate, the rotating cylinder is rotatably connected to the base, the driving member is installed on the base, and the driving member is connected to the rotating cylinder, the lifting adsorption device includes a lifting plate, a hydraulic cylinder, an adsorption member for adsorbing PLA straws and a driving member for driving the adsorption member to rotate, the hydraulic cylinder is installed on the support platform, the support platform is passed through the rotating cylinder, the support platform is fixedly connected to the rotating cylinder, one end of the lifting plate is slidably connected to the rotating cylinder, the other end of the lifting plate is connected to the driving member, the telescopic end of the hydraulic cylinder is fixedly connected to the lifting plate, and the adsorption member is connected to the driving member.

[0025] By adopting the above technical solution, the lifting plate, hydraulic cylinder, adsorption member, and driving member cooperate with each other to achieve the effect of adsorbing straws and adjusting the height and tilt direction of the straws. When the lifting adsorption device cooperates with the rotating drum and driving member, the driving member drives the rotating drum to rotate, causing the lifting adsorption device to rotate. The lifting adsorption device is first moved above the straws. After the lifting adsorption device adsorbs a batch of PLA straws, the lifting adsorption device and the straws are synchronously moved above the crystallization treatment tank. The height and tilt direction of the straws are then adjusted. The batch of PLA straws can then be inserted into the crystallization treatment tank and subjected to high-temperature crystallization treatment. The next batch of straws begins to be sorted. After a batch of PLA straws undergoes high-temperature crystallization treatment, the lifting adsorption device can immediately move the next batch of PLA straws into the crystallization treatment tank, effectively improving production efficiency.

[0026] In a specific feasible implementation scheme, the adsorption component includes a suction cup, an air suction pipe and an air pump. The air pump is arranged on the lifting plate, the suction cup is connected to the driving component, one end of the air suction pipe is connected to the air pump, and the other end of the air suction pipe is connected to the suction cup. A plurality of air suction holes are provided on the surface of the suction cup, and the air suction holes are connected to the air suction pipe.

[0027] By adopting the above technical solution, when using the device, the suction cup is first placed against the straw. The air pump draws air through the suction pipe, causing the PLA straw to be attached to the cup. The cup and straw are then moved synchronously above the crystallization tank. The actuator is operated to adjust the tilt of the suction cup, allowing the PLA straw to be inserted into the tank for high-temperature crystallization. The hydraulic cylinder is raised and lowered to control the height of the PLA straw inserted into the tank, thereby adjusting the length of the PLA straw for high-temperature crystallization. This ensures that only the portion of the PLA straw used for inserting hot beverages is heat-resistant and scald-resistant, thus reducing the cost of heat-resistant and scald-resistant PLA treatment.

[0028] In a specific feasible implementation scheme, the driving component includes a mounting plate, a mounting shaft, a driving motor, a driving active gear and a driving driven gear. The lifting plate is provided with a groove at the end away from the rotating cylinder. The mounting shaft is fixedly connected to the mounting plate. The mounting plate is inserted into the groove. A rotating hole is provided on the groove wall of the groove. The mounting shaft is passed through the rotating hole. The end of the mounting shaft away from the mounting plate is fixedly connected to the driving driven gear. The driving motor is installed on the lifting plate. The motor shaft of the driving motor is coaxially connected to the driving active gear. The driving active gear is meshed with the driving driven gear, and the adsorption component is bonded to the mounting plate.

[0029] By adopting the above technical solution, the driving motor drives the driving gear to rotate, and then drives the driven gear to rotate, and the mounting shaft, mounting plate and adsorption member rotate synchronously, thereby achieving the effect of adjusting the angle between the mounting plate and the adsorption member, which helps to place the PLA straws into the crystallization treatment water tank or take the PLA straws out of the crystallization treatment water tank, so that the PLA straws can be effectively anti-scalding and heat-resistant.

[0030] In a specific possible implementation scheme, the crystallization treatment water tank includes a water tank, a plurality of heating rods and a plurality of thermometers, wherein the plurality of heating rods are installed on the bottom wall of the water tank, and the plurality of thermometers are installed on the inner wall of the water tank.

[0031] By adopting the above technical solution, the PLA straws are transferred to a water tank, several heating rods heat the water in the water tank, and a thermometer monitors the water temperature in the water tank. The heating rods and thermometer work together to adjust the water temperature in the water tank to the required temperature, which can effectively perform high-temperature crystallization treatment on the PLA straws, effectively improving the scald and heat resistance of the PLA straws.

[0032] In summary, this application includes at least one of the following beneficial technical effects:

[0033] 1. The straw sorting device, straw adsorption device and crystallization treatment water tank equipment work together to effectively improve the scald and heat resistance performance of PLA straws;

[0034] 2. The driving member drives the rotating drum to rotate, thereby driving the lifting and adsorption device to rotate, enabling the lifting and adsorption device to continuously produce anti-scalding and heat-resistant PLA straws, effectively improving production efficiency;

[0035] 3. After the suction cup absorbs the straw, adjust the tilt direction of the suction cup and operate the hydraulic cylinder to adjust the height of the PLA straw inserted into the crystallization treatment tank, thereby adjusting the length of the PLA straw for high-temperature crystallization treatment, which helps to reduce the cost of heat-resistant and scald-proof treatment of PLA. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic diagram of the overall structure of the scald-proof and heat-resistant PLA straw production equipment of Example 1 of the present application.

[0037] Figure 2 Schematic diagram of the structure of the straw sorting device of Example 1 of the present application.

[0038] Figure 3 2 is a cross-sectional view of the straw sorting device of Example 1 of the present application.

[0039] Figure 4 This is an exploded view of the storage funnel of Example 1 of the present application.

[0040] Figure 5 It is a structural schematic diagram of the straw adsorption device of Example 1 of the present application.

[0041] Figure 6 It is a structural schematic diagram of the lifting adsorption device of Example 1 of the present application.

[0042] Figure 7 This is an exploded view of the driving component of Example 1 of the present application.

[0043] Figure 8 It is a structural schematic diagram of the crystallization treatment water tank of Example 1 of the present application.

[0044] Description of reference numerals:

[0045] 1. Straw sorting device; 11. Storage funnel; 111. Wide mask; 1111. Axis hole; 112. Feeding channel; 12. Diverter; 121. Rotating shaft; 122. Diverter spacer; 123. Rotating motor; 13. Conveying device; 131. Conveying rack; 132. Conveying belt; 133. Conveying active roller; 134. Conveying driven roller; 135. Conveying motor; 136. Toothed baffle; 137. Roller hole; 14. Support frame; 141. Frame; 2. Straw adsorption device; 21. Base; 211. Base column; 212. Bottom platform; 213. Driving platform; 22. Support platform; 23. Lifting adsorption device; 231. Lifting plate; 2311. Bump; 2312. Flat 2313, placing plate; 2314, groove; 2315, rotating hole; 232, hydraulic cylinder; 233, adsorption part; 2331, suction cup; 2332, suction pipe; 2333, air pump; 2334, suction hole; 234, driving part; 2341, mounting plate; 2342, mounting shaft; 2343, driving motor; 2344, driving driving gear; 2345, driving driven gear; 2346, horizontal plate; 2347, vertical plate; 24, rotating cylinder; 241, slide; 25, driving part; 251, driving motor; 252, driving driving gear; 253, driving driven gear; 3, crystallization treatment water tank; 31, water tank; 32, heating rod; 33, thermometer. DETAILED DESCRIPTION

[0046] The following is combined with Figure 1-8 , preparation examples, embodiments and comparative examples are used to further describe this application in detail.

[0047] In the description of the patent of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the patent of 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 understood as a limitation on the patent of the present invention.

[0048] Preparation Example

[0049] This preparation example discloses a PLA straw.

[0050] The PLA straws of this preparation example use the following components in parts by weight: 60 kg of REVODE190 type PLA, 3 kg of D070 type PDLA, 17 kg of TH801T type PBAT, 20 kg of talc, 0.5 kg of polycarbodiimide and 0.5 kg of glycidyl methacrylate.

[0051] A preparation process for PLA straws comprises the following steps: placing PLA, PDLA, PBAT, talc, polycarbodiimide, and glycidyl methacrylate into a high-speed mixer, mixing and stirring at a speed of 3500 r / min, transferring the mixture to an internal mixer after uniform stirring for internal mixing, conveying the mixture to a feeder, and then feeding the mixture from the feeder into a twin-screw extruder for granulation to obtain pellets, the temperature of the extruder being 190°C; and extruding the pellets into PLA straws through a straw extruder.

[0052] Example

[0053] The PLA straws in the examples and comparative examples of the present application are all PLA straws prepared in the preparation example.

[0054] The following description will be given using Example 1 as an example.

[0055] Example 1

[0056] This embodiment provides a scald-proof and heat-resistant PLA straw production equipment, referring to Figure 1 The scald-proof and heat-resistant PLA straw production equipment includes a straw sorting device 1, a straw adsorption device 2 and a crystallization treatment water tank 3. The straw sorting device 1 is arranged on the right side of the straw adsorption device 2, and the crystallization treatment water tank 3 is arranged on the left side of the straw adsorption device 2.

[0057] Reference Figure 2 and Figure 3 The straw sorting device 1 includes a storage funnel 11, a diverter 12, a conveying device 13 and a support frame 14.

[0058] The conveyor 13 comprises a conveyor frame 131, a conveyor belt 132, a driving conveyor roller 133, a driven conveyor roller 134, a conveyor motor 135, and a toothed baffle 136. The conveyor frame 131 is a steel frame structure placed on the ground. It is provided with roller holes 137. The driving conveyor roller 133 and the driven conveyor roller 134 are inserted into the roller holes 137 and abut against the hole walls. The driving conveyor roller 133 and the driven conveyor roller 134 are mounted on the conveyor frame 131 and are parallel to each other. The conveyor motor 135 is riveted to the conveyor frame 131, and its motor shaft is coaxially connected to the driving conveyor roller 133. The conveyor belt 132 is an annular synchronous belt. The conveyor active roller 133 and the conveyor driven roller 134 are both inserted into the conveyor belt 132. The conveyor belt 132 is overlapped on the outer peripheral walls of the conveyor active roller 133 and the conveyor driven roller 134. Several toothed baffles 136 are bonded to the conveyor belt 132.

[0059] The support frame 14 includes two frames 141 . Both frames 141 are welded to the conveying frame 131 . The storage hopper 11 is located between the two frames 141 . The outer wall of the storage hopper 11 is welded to the frames 141 .

[0060] The storage funnel 11 includes a wide mouth mask 111 and a discharge channel 112. The bottom end of the wide mouth mask 111 and the top end of the discharge channel 112 are integrally connected. The discharge channel 112 is located between the two frames 141. The outer wall of the discharge channel 112 is welded to the frame 141, and the bottom end of the discharge channel 112 faces downward toward the conveyor belt 132.

[0061] Reference Figure 4 The diverter 12 is provided at the bottom end of the wide mouth cover 111. The diverter 12 includes a rotating shaft 121, a diverter spacer 122, and a rotating motor 123. The rotating shaft 121 is located inside the wide mouth cover 111. The wide mouth cover 111 is provided with an axial hole 1111, and the rotating shaft 121 is passed through the axial hole 1111. There are a plurality of diverter spacers 122, and the plurality of diverter spacers 122 are evenly bonded to the peripheral wall of the rotating shaft 121 along the circumference of the rotating shaft 121. The minimum distance between the edge of the diverter spacer 122 and the side wall of the wide mouth cover 111 is less than the diameter of the straw. The rotating motor 123 is riveted to the outer wall of the wide mouth cover 111, and the motor shaft of the rotating motor 123 is coaxially connected to the rotating shaft 121.

[0062] Reference Figure 5The straw suction device 2 includes a base 21, a support platform 22, a lifting suction device 23, a rotating cylinder 24, and a driving member 25. The base 21 includes a base column 211, a bottom platform 212, and a driving platform 213. The bottom platform 212 is placed on the ground, the base column 211 is welded to the bottom platform 212, and the driving platform 213 is integrally connected to the base column 211. The driving platform 213 is located above the bottom platform 212. The rotating cylinder 24 is sleeved on the base column 211, and the inner circumferential wall of the rotating cylinder 24 abuts against the base column 211. The support platform 22 is integrally connected to the outer wall of the rotating cylinder 24. The support platform 22 is located above the driving platform 213.

[0063] The driving member 25 includes a driving motor 251, a driving gear 252, and a driven gear 253. The driven gear 253 is coaxially connected to the rotating cylinder 24. The driving motor 251 is welded to the driving platform 213. The driving gear 252 is coaxially connected to the motor shaft of the driving motor 251. The driving gear 252 and the driven gear 253 are meshed.

[0064] There are two lifting adsorption devices 23 , both of which are mounted on the support platform 22 . The rotating cylinder 24 is located between the two lifting adsorption devices 23 , and the lifting adsorption devices 23 are connected to the rotating cylinder 24 .

[0065] Reference Figure 5 and Figure 6 The lifting adsorption device 23 includes a lifting plate 231, a hydraulic cylinder 232, an adsorption member 233 and a driving member 234. The hydraulic cylinder 232 is riveted on the support platform 22, and the hydraulic cylinder 232 is arranged in a vertical direction with the telescopic end of the hydraulic cylinder 232 facing upward.

[0066] The lifting plate 231 includes a protrusion 2311, a balancing plate 2312, and a placement plate 2313. The protrusion 2311 and the balancing plate 2312 are integrally connected. A vertically extending chute 241 is provided on the sidewall of the rotating cylinder 24. The chute 241 is a T-shaped slot, and the protrusion 2311 is a T-shaped block. The protrusion 2311 is inserted into the chute 241 and abuts against the groove wall of the chute 241. The telescopic end of the hydraulic cylinder 232 is riveted to the balancing plate 2312. The side of the balancing plate 2312 away from the protrusion 2311 is welded to the placement plate 2313.

[0067] Reference Figure 6 and Figure 7 The driving component 234 is located at the end of the balance plate 2312 away from the protrusion 2311. The driving component 234 includes a mounting plate 2341, a mounting shaft 2342, a driving motor 2343, a driving active gear 2344 and a driving driven gear 2345. The driving motor 2343 is riveted to the placement plate 2313, and the driving active gear 2344 is coaxially connected to the motor shaft of the driving motor 2343.

[0068] The mounting plate 2341 includes a horizontal plate 2346 and a vertical plate 2347, the mounting shaft 2342 is integrally connected to the vertical plate 2347, a groove 2314 is provided on the end of the balance plate 2312 away from the protrusion 2311, and a rotating hole 2315 is provided on the groove wall of the groove 2314, the vertical plate 2347 is inserted into the groove 2314, the vertical plate 2347 is in contact with the inner wall of the groove 2314, the mounting shaft 2342 is passed through the rotating hole 2315, and the end of the mounting shaft 2342 on the same side as the placement plate 2313 is welded to the driving driven gear 253, and the driving driving gear 2344 is meshed with the driving driven gear 2345.

[0069] The suction member 233 includes a suction cup 2331, an air suction pipe 2332, and an air pump 2333. The air pump 2333 is riveted to the balance plate 2312. One end of the air suction pipe 2332 is connected to the air inlet of the air pump 2333, and the other end of the air suction pipe 2332 is connected to the suction cup 2331. The surface of the suction cup 2331 is sticky and elastic. The suction cup 2331 is bonded to the horizontal plate 2346. The surface of the suction cup 2331 facing away from the horizontal plate 2346 is provided with an air suction hole 2334, which is connected to the air suction pipe 2332.

[0070] Reference Figure 8 The crystallization treatment water tank 3 includes a water tank 31, a heating rod 32 and a thermometer 33. The water tank 31 is placed on the ground, several heating rods 32 are evenly placed on the bottom wall of the water tank 31, and several thermometers 33 are evenly fixed on the side wall of the water tank 31.

[0071] The operating principle of the scald-resistant and heat-resistant PLA straw production equipment provided in this embodiment is as follows: Several PLA straws are placed into a wide housing 111. The rotating motor 123 and the conveying motor 135 are activated. The rotating motor 123 drives the rotating shaft 121 to rotate, and the diverter septum 122 rotates synchronously with the rotating shaft 121. The PLA straws pass through the diverter septum 122 one by one through the discharge channel 112 and fall between two adjacent toothed baffles 136 on the conveyor belt 132. The conveying motor 135 then drives the active conveyor roller 133 to rotate, which in turn drives the driven conveyor roller 134 and the conveyor belt 132 to rotate, thereby placing the fallen PLA straws in order. Once a batch of PLA straws has been arranged on the conveyor belt 132, the rotating motor 123 and the conveying motor 135 are turned off.

[0072] The drive motor 251, hydraulic cylinder 232, and rotating motor 2343 are activated. The telescopic end of the hydraulic cylinder 232 is moved downward, causing the lifting plate 231 to move downward. When the suction cup 2331 contacts the PLA straws, the hydraulic cylinder 232 is closed. The air pump 2333 is activated, causing the suction cup 2331 to hold the straws. The telescopic end of the hydraulic cylinder 232 is then moved upward, causing the straws to move upward. The hydraulic cylinder 232 is then closed. The drive motor 251 is activated, driving the driving gear 252 to rotate, which in turn drives the driven gear 253 and the rotating drum 24 to rotate synchronously. The straws rotate from above the conveyor belt 132 to above the water tank 31. The other, unused lifting plate 231 rotates from above the water tank 31 to above the conveyor belt 132. The drive motor 251 is then turned off. The rotating motor 123 and conveying motor 135 are then activated to sort the next batch of straws.

[0073] The driving motor 2343 is started, and the driving motor 2343 drives the driving gear 2344 to rotate, and the driven gear 2345, the mounting shaft 2342 and the mounting plate 2341 to rotate synchronously. When the straw axis is in the vertical direction, the driving motor 2343 is turned off.

[0074] The hydraulic cylinder 232 is started again to shorten, the straw moves downward, and after the lower end of the straw is inserted into the water in the water tank 31, the hydraulic cylinder 232 is closed. The water is heated by the heating rod 32, and the thermometer 33 detects the water temperature in the water tank 31, and the straw begins to undergo high-temperature crystallization treatment.

[0075] When the straws have completed the high-temperature crystallization process, the hydraulic cylinder 232 and the rotating motor 2343 are activated, causing the lifting plate 231 to move upward, removing the straws from the water tank 31. The mounting plate 2341 is then rotated back to a horizontal position, and the hydraulic cylinder 232 and the rotating motor 2343 are deactivated. The air pump 2333 is then turned off, collecting the processed PLA straws. The driving motor 251 is then activated, placing the next batch of straws into the water tank 31 for high-temperature crystallization.

[0076] This embodiment provides a production process for scald-proof and heat-resistant PLA straws, comprising the following steps:

[0077] First, the diverter 12 sequentially transports the PLA straws in the wide mask 111 to the discharge channel 112 , and then the PLA straws fall from the discharge channel 112 onto the conveyor belt 132 . The PLA straws are sequentially arranged along the same axial direction on the conveyor belt 132 to obtain PLA straws to be processed.

[0078] Next, straw suction device 2 picks up the PLA straws to be processed. These straws are then transferred to the top of water tank 31. The lower ends of the PLA straws are then inserted into the water in tank 31, leaving the upper ends of the PLA straws at room temperature. Simultaneously, straw suction device 2 sorts another batch of PLA straws, generating the next batch of PLA straws to be processed, ready for heat treatment.

[0079] The temperature of the water in the water tank 31 was adjusted to 45° C. and maintained for 8 minutes, and then the water temperature was raised to 80° C. and maintained for 15 minutes to obtain the first batch of crystallized PLA straws.

[0080] The first batch of crystallized PLA straws was then removed from the straw adsorption device 2 and allowed to cool naturally at room temperature for 12 hours to obtain heat-resistant and scald-resistant PLA straws. The above steps were repeated for the next batch of PLA straws to be processed to obtain the next batch of heat-resistant and scald-resistant PLA straws.

[0081] Example 2

[0082] The difference between Example 2 and Example 1 is that the water temperature in the water tank 31 is adjusted to 40° C. and maintained for 5 minutes; then the water temperature is raised to 95° C. and maintained for 10 minutes.

[0083] Example 3

[0084] The difference between Example 3 and Example 1 is that the water temperature in the water tank 31 is adjusted to 50° C. and maintained for 8 minutes; then the water temperature is raised to 90° C. and maintained for 20 minutes.

[0085] Comparative Example

[0086] Comparative Example 1

[0087] This comparative example provides a straw. The difference between comparative example 1 and example 1 is that the straw in comparative example 1 is the PLA straw of the preparation example.

[0088] Comparative Example 2

[0089] This comparative example provides a straw. The difference between Comparative Example 2 and Example 1 is that: in Comparative Example 2, the entire tube body of the straw is placed in a water tank, the water temperature in the water tank is adjusted to 50°C and maintained for 8 minutes; then the water temperature is raised to 90°C and maintained for 20 minutes for high-temperature crystallization treatment.

[0090] High temperature crystallization treatment.

[0091] Comparative Example 3

[0092] This comparative example provides a straw. The difference between Comparative Example 3 and Example 1 is that the water temperature in the water tank is directly raised to 80° C. and maintained for 15 minutes to obtain the first batch of crystallized PLA straws.

[0093] Performance testing

[0094] The following tests were conducted on the PLA straws provided in Examples 1-3 and Comparative Examples 1-3 of the present application. Specific test data are shown in Table 1.

[0095] Scald and heat resistance testing: The PLA straws provided in Examples 1-3 and Comparative Examples 1-3 were tested for melting enthalpy, cold crystallization enthalpy, and fully crystallized melting enthalpy in accordance with GB / T 19466.3-2004 Plastics - Differential Scanning Calorimetry - Part 3: Determination of Melting and Crystallization Temperatures and Enthalpies. The total enthalpy method was used to calculate the degree of crystallinity. The higher the degree of crystallinity, the better the scald and heat resistance of the PLA straws. The calculation formula is as follows:

[0096]

[0097] Among them, ΔHm and ΔHc represent the melting enthalpy and cold crystallization enthalpy of PLA straw respectively, ΔHm 0 Represents the melting enthalpy of complete crystallization of PLA straw.

[0098] Table 1

[0099]

[0100] It can be seen from the crystallinity of Examples 1-3 that Examples 1-3 can all obtain PLA straws with good scald resistance and heat resistance under the production equipment and production process conditions in this application, among which Example 3 is a more preferred example.

[0101] Compared with Example 3, the crystallinity and heat resistance of the crystallized end of the straw in Comparative Example 1 are both lower. In Comparative Example 1, the PLA straw is not subjected to anti-scalding and heat-resistant treatment, indicating that the production equipment and production process conditions in this application can effectively improve the anti-scalding and heat-resistant performance of the PLA straw.

[0102] Compared with Example 3, the crystallinity and heat resistance of the crystallized end of the straw in Comparative Example 2 after high-temperature crystallization of the entire straw are similar to those in Example 3. However, Comparative Example 2 is more costly than Comparative Example 3. This shows that using the production equipment and production process of this application, the PLA straw with scalding and heat resistance at only one end prepared not only has excellent scalding and heat resistance properties, but also reduces production costs.

[0103] Compared with Example 3, Comparative Example 3 did not undergo pre-crystallization treatment, and the crystallinity of Comparative Example 3 was lower than that of Example 3, which shows that the production process in this application can effectively improve the anti-scalding and heat-resistant performance of PLA straws.

[0104] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A production process for scald-proof and heat-resistant PLA straws, comprising the following steps: S1. sorting a batch of PLA straws to obtain PLA straws to be processed; S2. placing the same end of the PLA straws to be processed in a hot environment, while the other end of the PLA straws to be processed is placed in a room temperature environment; at the same time, sorting another batch of PLA straws to obtain the next batch of PLA straws to be processed; S3, first adjusting the temperature of the hot environment to 40-50°C and maintaining it for 5-8 minutes, then raising the temperature of the hot environment to 80-95°C and maintaining it for 10-20 minutes to obtain a crystallized PLA straw; S4, placing the entire body of the crystallized PLA straw at room temperature and allowing it to cool naturally to room temperature, thereby obtaining a scald-resistant and heat-resistant PLA straw; S5, repeating steps S2, S3 and S4 for the next batch of PLA straws to be processed to obtain the next batch of scalding and heat-resistant PLA straws; the steps S1, S2, S3, S4 and S5 are all carried out in a scalding and heat-resistant PLA straw production device, the scalding and heat-resistant PLA straw production device comprising a straw sorting device (1), a straw adsorption device (2) and a crystallization treatment water tank (3), wherein the crystallization treatment water tank (3) is arranged on one side of the straw sorting device (1), and the straw adsorption device (2) is arranged on the crystallization treatment water tank (3). and the straw sorting device (1), the straw sorting device (1) comprising a storage funnel (11), a diverter (12), a conveying device (13) and a support frame (14), the conveying device (13) being arranged on the ground, the support frame (14) being mounted on the conveying device (13), the storage funnel (11) being mounted on the support frame (14), the diverter (12) being mounted on the inner wall of the storage funnel (11), and the discharge end of the storage funnel (11) being directed toward the conveying device (13); The straw adsorption device (2) comprises a base (21), a support platform (22), a lifting adsorption device (23), a rotating cylinder (24) and a driving member (25) for driving the rotating cylinder (24) to rotate, wherein the rotating cylinder (24) is rotatably connected to the base (21), the driving member (25) is mounted on the base (21), and the driving member (25) is connected to the rotating cylinder (24), and the lifting adsorption device (23) comprises a lifting plate (231), a hydraulic cylinder (232), an adsorption member (233) for adsorbing PLA straws and a driving member (234) for driving the adsorption member (235). 3) a rotating driving member (234), wherein the hydraulic cylinder (232) is mounted on the supporting platform (22), the supporting platform (22) is provided on the rotating cylinder (24), the supporting platform (22) is fixedly connected to the rotating cylinder (24), one end of the lifting plate (231) is slidably connected to the rotating cylinder (24), the other end of the lifting plate (231) is connected to the driving member (234), the telescopic end of the hydraulic cylinder (232) is fixedly connected to the lifting plate (231), and the adsorption member (233) is connected to the driving member (234); The adsorption component (233) includes a suction cup (2331), an air suction pipe (2332) and an air pump (2333), wherein the air pump (2333) is arranged on the lifting plate (231), the suction cup (2331) is connected to the driving component (234), one end of the air suction pipe (2332) is connected to the air pump (2333), and the other end of the air suction pipe (2332) is connected to the suction cup (2331), and a plurality of air suction holes (2334) are provided on the surface of the suction cup (2331), and the air suction holes (2334) are connected to the air suction pipe (2332); The driving member (234) includes a mounting plate (2341), a mounting shaft (2342), a driving motor (2343), a driving active gear (2344) and a driving driven gear (2345). A groove (2314) is provided at one end of the lifting plate (231) away from the rotating cylinder (24). The mounting shaft (2342) is fixedly connected to the mounting plate (2341). The mounting plate (2341) is inserted into the groove (2314). A rotating hole (2315) is provided on the groove wall of the groove (2314). The mounting shaft (2342) is passed through the rotating hole (2315), and the end of the mounting shaft (2342) away from the mounting plate (2341) is fixedly connected to the driving driven gear (2345), and the driving motor (2343) is installed on the lifting plate (231), and the motor shaft of the driving motor (2343) is coaxially connected to the driving active gear (2344), and the driving active gear (2344) is meshed with the driving driven gear (2345), and the adsorption member (233) is bonded to the mounting plate (2341).

2. The production process of a scald-proof and heat-resistant PLA straw according to claim 1, characterized in that: The sorting process is as follows: first, the PLA straws are transported in sequence, the axial directions of the PLA straws are adjusted to be consistent during the transport process, and then the PLA straws are placed in sequence.

3. The production process of a scald-proof and heat-resistant PLA straw according to claim 1, characterized in that: The storage funnel (11) comprises a wide mouth (111) and a feeding channel (112), wherein the wide mouth (111) is mounted on the support frame (14), one end of the feeding channel (112) is connected to the bottom end of the wide mouth (111), and the other end of the feeding channel (112) faces the conveying device (13), and the opposite inner walls of the feeding channel (112) are in contact with the PLA straw, and the diverter (12) is mounted on the inner wall of the wide mouth (111), and the diverter (12) is located at the bottom end of the wide mouth (111).

4. The production process of a scald-proof and heat-resistant PLA straw according to claim 3, characterized in that: The diverter (12) comprises a rotating shaft (121), a diverter spacer (122) and a rotating motor (123); the rotating shaft (121) is arranged in the storage funnel (11); the rotating shaft (121) is rotatably connected to the storage funnel (11); a plurality of the diverter spacers (122) are mounted on the peripheral wall of the rotating shaft (121); the rotating motor (123) is mounted on the storage funnel (11); and the motor shaft of the rotating motor (123) is coaxially connected to the rotating shaft (121).

5. The production process of a scald-proof and heat-resistant PLA straw according to claim 3, characterized in that: The conveying device (13) comprises a conveying frame (131), a conveying belt (132), a conveying active roller (133), a conveying driven roller (134), a conveying motor (135) and a toothed baffle (136); the conveying active roller (133) and the conveying driven roller (134) are both rotatably connected to the conveying frame (131); the conveying belt (132) is overlapped on the conveying active roller (133) and the conveying driven roller (134); a plurality of toothed baffles (136) are installed on the conveying belt (132); the conveying motor (135) is fixedly connected to the conveying frame (131); the motor shaft of the conveying motor (135) is coaxially connected to the conveying active roller (133); and the supporting frame (14) is mounted on the conveying frame (131).

6. The production process of a scald-proof and heat-resistant PLA straw according to claim 1, characterized in that: The crystallization treatment water tank (3) comprises a water tank (31), a plurality of heating rods (32) and a plurality of thermometers (33), wherein the plurality of heating rods (32) are mounted on the bottom wall of the water tank (31), and the plurality of thermometers (33) are mounted on the inner wall of the water tank (31).

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