Preparation and application of a chemical information substance diffusion core

Abstract

This invention discloses the preparation and application of a chemical information substance volatile core, relating to the field of agricultural pest control. It employs an integrated blow-fill-seal equipment, which automatically executes the following steps in a closed environment: a polymer material is melted and extruded into a tube preform using an extruder; the tube preform is then subjected to low-temperature blow molding in a blow molding die with active cooling to form a cavity; liquid chemical information substance is filled into the cavity using a filling mandrel with independent cooling and a metering pump; the cavity is then vacuum-sealed using a sealing head mold; and the volatile core is cooled and demolded, and output by a conveyor belt. The preparation and application of this chemical information substance volatile core, through a process of first rapidly cooling and forming a carrier cavity, and then filling it in situ at low temperature, fundamentally cuts off any contact path between the pheromone and the high-temperature processing stage.

Description

Technical Field

[0001] This invention relates to agricultural pest control technology, specifically to the preparation and application of a chemical information substance volatile core. Background Technology

[0002] Chemical pheromones, especially insect sex pheromones, have enormous potential for industrial application as a highly specific and environmentally friendly behavioral regulation tool in integrated pest management. However, their core components are typically esters, alcohols, or aldehydes, which exhibit significant thermal instability and high volatility. This characteristic makes them highly susceptible to chemical decomposition or physical loss during traditional processing and carrier loading, ultimately leading to a substantial reduction in their biological activity, constituting the primary technical bottleneck restricting their widespread adoption.

[0003] Currently, the mainstream production technologies for chemical pheromone carriers mainly follow two technical routes, but both have inherent defects: The stepwise carrier post-loading process involves first manufacturing a carrier with a specific shape (such as a rubber stopper, capillary, or polymer matrix), and then loading pheromones onto it through secondary operations such as soaking, spraying, or injection. This method is cumbersome, inefficient, and difficult to automate for continuous production. More importantly, during the post-loading process, the pheromones are completely exposed to the environment, leading to uncontrollable losses due to volatilization, oxidation, or hydrolysis. At the same time, the uniformity and precision of loading are difficult to guarantee, resulting in significant differences in release rates between different batches and even within the same batch, leading to unstable field effects. Summary of the Invention

[0004] The purpose of this invention is to provide a preparation and application of a chemical information substance volatile core, in order to solve the problems of the stepwise carrier post-loading process in the prior art, which is complicated and inefficient, and the pheromone is easily exposed and lost during the secondary loading process, resulting in uneven load and ultimately poor product performance stability.

[0005] To achieve the above objectives, the present invention provides the following technical solution: preparation and application of a chemical information substance volatile core, which employs an integrated blow-fill-seal equipment to automatically execute the following steps in a closed environment: melting and extruding polymer materials into a tube preform using an extruder; performing low-temperature blow molding on the tube preform in a blow molding mold with active cooling to form a preform cavity; filling the cavity with liquid chemical information substance using a filling mandrel with independent cooling and a metering pump; vacuum heat-sealing the cavity after filling using a sealing head mold; cooling and demolding to obtain the volatile core, which is then output by a conveyor belt.

[0006] Furthermore, the surface temperature of the cavity of the blow molding die is maintained at 5-25°C.

[0007] Furthermore, the filling port temperature of the filling mandrel is maintained at 10-20°C.

[0008] Furthermore, the polymer material is selected from one of ethylene-vinyl acetate copolymer, polyethylene, polypropylene, polylactic acid, or polyhydroxyalkanoate.

[0009] Furthermore, the chemical information substance is a mixture of one or more compounds such as alcohols, esters, aldehydes, and ketones, including one or more types such as sex pheromones, tracer pheromones, alarm pheromones, and altruistic pheromones.

[0010] Furthermore, the vacuum heat-sealing step is performed under a vacuum of -0.05 MPa to -0.1 MPa.

[0011] A chemical information substance volatile core prepared by the method described above.

[0012] The application of the described chemical information substance volatile core in agricultural pest monitoring or green control.

[0013] Compared with existing technologies, the preparation and application of a chemical information substance volatile core provided by the present invention have the following beneficial effects: By rapidly cooling the molded carrier cavity first and then filling it in situ at low temperature, the process fundamentally cuts off any contact path between the pheromone and the high-temperature processing. The dual active cooling system of the blow molding mold and the filling mandrel ensures that the pheromone is at a safe temperature. When the volatile core is produced using the method of this invention, the thermal decomposition and volatilization loss rate of the pheromone active ingredients loaded therein is much lower than that of traditional soaking methods or some microencapsulation processes that require heating reactions, thereby maximizing the preservation of the initial biological activity of the pheromone. This marks the first time a highly automated, continuous blow-fill-seal production line has been introduced into the field of pheromone carrier manufacturing, transforming the traditional multi-step, intermittent production mode into a continuous assembly line operation based on a single piece of equipment and started with a single button. From resin granules to the final sealed product, the entire process is completed automatically within tens of seconds, without the need for manual transfer or intermediate processing. Each product is manufactured under almost identical process parameters, thus ensuring a high degree of consistency and reliability in key performance aspects such as drug loading and release rate among different batches of products, laying a solid foundation for stable and predictable field effects. Because the pheromone is injected and immediately sealed when the carrier polymer has just undergone blow molding and before the molecular chain segments have fully crystallized and frozen, it can diffuse, adsorb, and even slightly swell in the micropores and amorphous regions of the carrier wall material more quickly and uniformly by utilizing the residual thermal motion of the molecular chains. This in-situ loading and synchronous shaping mechanism allows the pheromone and the carrier material to form a more ideal binding state at the interface; This method has a simple process flow, does not require the use of organic solvents, avoids complex solvent recovery or post-processing issues, and also eliminates corresponding safety and environmental hazards. The high reliability, low maintenance requirements and large-scale production capacity of the blow-fill-seal equipment have significantly reduced the unit production cost of pheromone evaporation cores. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0015] Figure 1 This is a schematic diagram of the process flow of the improved blow-fill-seal integrated equipment used in the chemical information substance volatile core preparation method provided in the embodiments of the present invention during one working cycle.

[0016] Explanation of reference numerals in the attached figures: 1. Extruder; 2. Tube preform; 3. Blow mold; 4. Filling mandrel; 5. Metering pump; 6. Sealing head mold; 7. Volatilization core; 8. Conveyor belt. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0018] As attached Figure 1 As shown:

[0019] Example: This invention provides a method for preparing a chemical information substance volatile core, which uses an integrated blow-fill-seal equipment to automatically execute the following steps in a closed environment: a polymer material is melted and extruded into a tube preform 2 through an extruder 1; the tube preform 2 is blow-molded at low temperature in a blow molding die 3 with active cooling to form a preform cavity; liquid chemical information substance is filled into the cavity through a filling mandrel 4 with independent cooling and a metering pump 5; the cavity after filling is vacuum heat-sealed through a sealing head mold 6; the volatile core 7 is obtained by cooling and demolding and is output by a conveyor belt 8.

[0020] The surface temperature of the cavity of blow mold 3 is maintained at 5-25℃.

[0021] The filling port temperature of filling mandrel 4 is maintained at 10-20℃.

[0022] Chemical information substances are mixtures of one or more compounds such as alcohols, esters, aldehydes, and ketones, including one or more of sex pheromones, tracer pheromones, and alarm pheromones.

[0023] The chemical information substance is an insect sex pheromone, which is one or more mixtures of esters, alcohols or aldehydes.

[0024] The vacuum heat-sealing step is performed under a vacuum of -0.05 MPa to -0.1 MPa.

[0025] A chemical information substance volatile core 7 prepared by the above method.

[0026] Application of chemical information substance volatile core 7 in agricultural pest monitoring or green control.

[0027] This embodiment details how to prepare a highly efficient pheromone-dispersing core for controlling the pear fruit moth, and systematically evaluates its thermal stability and sustained-release performance.

[0028] 1. Raw materials and pretreatment Carrier material: Ethylene-vinyl acetate copolymer (EVA) resin particles are selected as the carrier substrate, with a vinyl acetate (VA) monomer content of 28%. This content of EVA material combines good flexibility, elasticity, and excellent compatibility with pheromone components, which is beneficial for the uniform adsorption and gradual release of active substances. Before use, the EVA particles are placed in a 50℃ circulating air drying oven for 4 hours to thoroughly remove moisture from the raw material and prevent the formation of bubbles or degradation during processing.

[0029] Chemical pheromone: (Z)-8-dodecenol acetate, a key pheromone component of the pear fruit moth. To meet the requirements of high-precision filling, it is dissolved in high-purity n-hexane to prepare a 10% (w / w) filling solution. This solvent has good compatibility with the pheromone and is easily volatilized in trace amounts through the carrier wall material after sealing, without affecting the sustained release of the pheromone.

[0030] 2. Equipment configuration and process parameters A commercially available blow-fill-seal integrated machine was used. The core modifications included: integrating a high-precision circulating water cooling temperature control system into the blow mold 3; and replacing the standard filling head with a custom-designed filling mandrel 4 that integrates a Peltier semiconductor cooling module.

[0031] Extruder 1: The temperature settings for each zone are as follows: feed section 150℃, melting section 165℃, homogenization section and die head 170℃. This temperature profile ensures that the EVA is fully plasticized and flows stably, forming a uniform preform 2.

[0032] Blow mold 3: The cooling system is set to a constant temperature of 10℃ and is monitored in real time by thermocouples to ensure that the working temperature of the mold cavity surface is stable in the low temperature range of 10-15℃.

[0033] Filling mandrel 4 and metering pump 5: The cooling end temperature of filling mandrel 4 is set to 5℃. The connected high-precision micro-metering pump 5 is calibrated, with a single filling volume error of less than ±0.5%.

[0034] Sealing head mold 6: Heat sealing temperature set to 180℃, vacuum degree set to -0.08 MPa, pressure holding time 0.5 seconds.

[0035] Conveyor belt 8: Speed ​​adjustment is set to match the production cycle to ensure orderly output of volatile core 7.

[0036] 3. Preparation process flow Plasticizing and extruding: The dried EVA granules are added to the hopper of extruder 1. The equipment is started, and the molten EVA is continuously extruded through the annular die to form a transparent tube preform 2 with a diameter of about 8 mm and a wall thickness of about 1.2 mm.

[0037] Cryogenic blow molding: The tube preform 2 descends vertically to the center of the open blow mold 3. The mold quickly closes and clamps the tube preform. Subsequently, clean compressed air at a temperature of 10°C, treated by a sterile filter, is injected into the tube preform, inflating it and completely adhering it to the inner wall of the low-temperature mold, instantly forming a cylindrical hollow carrier preform with a diameter of 3.0 mm and a length of 20.0 mm.

[0038] Precision filling at room temperature: After the blowing stops, the filling mandrel 4, with a constant temperature of 5°C, immediately descends and precisely positions itself at the opening of the embryo's neck. The metering pump 5 starts simultaneously, injecting 2.0 μL of the above-mentioned pheromone solution (equivalent to loading 200 μg of pure pheromone) into the embryo cavity through the mandrel.

[0039] Vacuum heat-sealing: The filling mandrel 4 is quickly retracted the moment filling is completed. The sealing head mold 6 immediately closes, and the neck of the preform is instantly heat-pressed under a vacuum of -0.08MPa. This process completes the sealing while the internal air is exhausted under vacuum, forming a bubble-free, completely sealed volatile core 7.

[0040] Cooling and Output: After the mold remains closed for 3 seconds to cool, it opens, and the formed and sealed volatile core 7 is automatically ejected by the ejector pin and falls smoothly onto the conveyor belt 8, where it is sent into the collection container, completing one production cycle. The equipment then begins the next cycle, achieving continuous production.

[0041] 4. Performance Testing and Comparative Analysis To objectively and quantitatively evaluate the advantages of this invention, a traditional "post-soaking" process was set up as a control.

[0042] Control group preparation: Using the same batch of EVA raw materials, solid cylinders of the same size were made by injection molding, and then immersed in a high concentration of pheromone solution until swelling equilibrium (48 hours). After removing and drying the surface, the traditional process volatile core was obtained.

[0043] Accelerated thermal stability test: 30 pheromone cores prepared according to this invention and 30 cores from the control group were taken and sealed in glass bottles. These were then placed in a constant temperature drying oven at 60℃ for accelerated aging testing to simulate high-temperature storage or transportation environments. Samples were taken on days 0, 3, and 7, and the residual pheromone rate in the samples was quantitatively determined using gas chromatography-mass spectrometry (GC-MS).

[0044] Results: After 7 days, the average retention rate of pheromones in the volatile core of this invention was as high as 95.2% ± 1.5%. In contrast, the average retention rate of the control group product was only 78.5% ± 3.2%, because a large amount of pheromones remained attached to the surface of the carrier after soaking and were more easily lost due to volatilization at high temperatures. The data conclusively prove that the "low-temperature molding-room-temperature filling" process of this invention provides fundamental protection for heat-sensitive pheromones.

[0045] Slow-release performance simulation experiment: Two sets of newly prepared volatile cores were placed in a constant temperature wind tunnel experimental chamber at 30℃, and the air flow in the field was simulated with a constant wind speed of 0.5 m / s. Samples were randomly selected periodically (on days 0, 15, 30, 60, 90, and 120), and the residual amount of pheromones inside was determined by solvent extraction combined with GC analysis. The cumulative release rate was calculated and the release kinetic curve was plotted.

[0046] Results: The volatile core of this invention exhibits an ideal sustained-release mode with near-zero order of release and a smooth release curve. Its effective release period (the time required for the release amount to reach 80% of the total loading) was calculated to be 120 ± 5 days. The control group product, however, exhibited a typical two-phase release: a burst release of up to 35% in the initial stage (first 15 days), followed by a sharp decline in the release rate, with an effective release period of only 85 ± 7 days. This confirms that the "in-situ loading" process of this invention can form a more uniform and deeper drug distribution within the carrier, thereby achieving a longer-lasting and more stable controlled-release effect.

[0047] Example 2: Preparation of an environmentally degradable cotton bollworm sex pheromone volatile core This embodiment demonstrates the flexibility of the present invention in applying biodegradable materials to prepare an environmentally friendly pheromone volatile core.

[0048] Carrier material: Biodegradable polylactic acid (PLA) resin is selected. PLA has different processing characteristics than EVA and is more sensitive to temperature and moisture.

[0049] Chemical information substances: A multi-component mixture of cotton bollworm sex pheromones is used.

[0050] Key process adjustments: Raw material processing: PLA granules are vacuum dried at 80℃ for more than 6 hours to ensure that the moisture content is less than 0.02%.

[0051] Extruder 1 parameters: Temperature settings increased to: 165℃ for the feed section, 175℃ for the melting section, and 180℃ for the homogenization section and die, to cope with the higher melt viscosity of PLA.

[0052] Environmental control: The humidity of the production environment is controlled below 30% to prevent PLA from undergoing hydrolytic degradation during processing.

[0053] Blow mold 3 temperature: The cooling temperature is set at 15-20℃ to suit the crystallization characteristics of PLA.

[0054] The equipment was operated according to the adjusted parameters, and the process steps were completely consistent with those in Example 1. The extruder 1 plasticized PLA to form a tube preform 2, which was then shaped in a low-temperature blow molding die 3. Pheromones were filled through a cooled filling mandrel 4 and a metering pump 5, and the tube was vacuum-sealed by a sealing head mold 6 to finally obtain a PLA volatile core 7, which was output by a conveyor belt 8.

[0055] Continuous production of biodegradable volatile cores has been successfully achieved. The resulting product not only inherits all the advantages of the process of this invention (high efficiency, low temperature, and high activity retention), but also adds the added value of environmental biodegradability. Preliminary field trials show that after completing its expected pest control life cycle (approximately 90-120 days), the volatile core gradually decomposes under the action of soil microorganisms, eventually converting into carbon dioxide and water, avoiding the residue problems caused by traditional plastic carriers, and meeting the requirements of sustainable agriculture development.

[0056] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a chemical information substance volatile core, characterized in that, Using an integrated blow-fill-seal equipment, the following steps are automatically executed in a closed environment: a polymer material is melted and extruded into a tube preform (2) through an extruder (1); the tube preform (2) is blow-molded at low temperature in a blow mold (3) with active cooling to form a preform cavity; liquid chemical information substance is filled into the cavity through a filling mandrel (4) with independent cooling and a metering pump (5); the cavity after filling is vacuum heat-sealed through a sealing head mold (6); the volatile core (7) is obtained by cooling and demolding and is output by a conveyor belt (8).

2. The method for preparing a chemical information substance volatile core according to claim 1, characterized in that, The surface temperature of the cavity of the blow molding die (3) is maintained at 5-25℃.

3. The method for preparing a chemical information substance volatile core according to claim 1, characterized in that, The filling port temperature of the filling mandrel (4) is maintained at 10-20℃.

4. The method for preparing a chemical information substance volatile core according to claim 1, characterized in that, The polymer material is selected from one of ethylene-vinyl acetate copolymer, polyethylene, polypropylene, polylactic acid, or polyhydroxyalkanoate.

5. The method for preparing a chemical information substance volatile core according to claim 1, characterized in that, The chemical information substance is a mixture of one or more compounds such as alcohols, esters, aldehydes, and ketones, including one or more types of sex pheromones, tracer pheromones, alarm pheromones, and altruistic pheromones.

6. The method for preparing a chemical information substance volatile core according to claim 1, characterized in that, The vacuum heat-sealing step is performed under a vacuum of -0.05 MPa to -0.1 MPa.

7. A chemical information substance volatile core (7) prepared by the method of any one of claims 1 to 6.

8. The application of the chemical information substance volatile core (7) as described in claim 7 in agricultural pest monitoring or green control.

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