Production process of expandable polystyrene (EPS) beads

Abstract

The invention relates to the technical field of production of expandable polystyrene (EPS) beads, and discloses a production process of EPS beads, which comprises the following steps: preparing styrene monomer, deionized water, foaming agent, initiator, dispersing agent and stabilizer raw materials, accurately weighing various raw materials according to the production process and product requirements, and uniformly mixing according to a certain ratio to obtain the EPS beads. The preparation method comprises the following steps: sequentially adding the prepared raw materials into a reaction kettle, firstly adding deionized water, then quantitatively adding a styrene monomer, starting a stirrer, then sequentially adding auxiliaries such as an initiator, a dispersing agent and a stabilizer, and continuously stirring and uniformly mixing to carry out polymerization reaction. According to the present invention, the modern expandable polystyrene bead production process mostly adopts the automatic production line, the continuous and stable production can be achieved, the production efficiency is improved, the styrene monomer, the initiator and the foaming agent are simultaneously added into the reaction kettle in the new preparation production process, the production process is simplified, the production links are reduced, and the production cost is reduced. Therefore, the production efficiency is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of expandable polystyrene bead production, and specifically to the production process of expandable polystyrene beads EPS. Background Art

[0002] Expandable polystyrene beads are expandable beads composed of polystyrene and containing 5% - 8% of highly volatile low-boiling-point hydrocarbon blowing agents. Expandable polystyrene beads appear as white or colorless transparent bead-like particles, with excellent and durable heat insulation, unique cushioning and shock resistance, anti-aging property and waterproof property. They have low thermal conductivity, small water absorption, are resistant to impact and vibration, and have excellent dielectric properties. They are used to produce molded polystyrene insulation boards and are widely used in aspects such as roof insulation and building walls. They are the main demand side in the packaging material field, including express packaging and food packaging. Due to its advantages such as light weight, earthquake resistance, anti-drop, heat insulation, sound absorption, heat preservation, self-extinguishing, environmental protection, low cost, and easy construction, EPS foam boards are widely used in the packaging of various products and can also be used in fields such as electronic products and automobile manufacturing. For example, in the field of automobile manufacturing, the EPS beads have a uniform and closed cavity structure inside and can be used as shock-absorbing materials, mainly used for manufacturing automobile seats.

[0003] With the continuous changes in people's lives, the use of expandable polystyrene beads has become more and more common, so the production of expandable polystyrene beads has also become more and more common. However, the traditional production process has low production efficiency and the quality of the products produced is low. Therefore, a new preparation method is now proposed to solve this technical problem. Summary of the Invention

[0004] (I) Technical Problem to be Solved

[0005] In view of the deficiencies of the prior art, the present invention provides a production process of expandable polystyrene beads EPS, which has the advantages of high production efficiency and solves the problem of low production efficiency caused by the traditional preparation process mentioned in the above background art.

[0006] (II) Technical Solution

[0007] To achieve the purpose of improving production efficiency mentioned in the above background art, the present invention provides the following technical solution: A production process of expandable polystyrene beads EPS, comprising the following steps:

[0008] Step 1: Prepare raw materials such as styrene monomer, deionized water, blowing agent, initiator, dispersant, and stabilizer.

[0009] Step 2: Accurately weigh various raw materials according to the production process and product requirements, and mix them evenly according to a certain ratio.

[0010] Step 3: Add the prepared raw materials into the reaction kettle in sequence. First, add deionized water, then quantitatively input styrene monomer, and start the stirrer.

[0011] Step 4: Then add additives such as initiator, dispersant, and stabilizer in sequence, and continue to stir and mix evenly for polymerization reaction.

[0012] Step 5: Then add some dispersant and stabilizer again, and continue the isothermal reaction. After the reaction is completed, cool the material to a suitable temperature, and then discharge the reaction kettle.

[0013] Step 6: Unload the material in the reaction kettle and conduct post-treatment.

[0014] Step 7: Pack the EPS beads after screening and coating according to different specifications, and store them in a cool, ventilated, and dry place, avoiding direct sunlight and high-temperature environment.

[0015] Preferably, according to the production process and product requirements, formulate a detailed raw material formula, use precise weighing equipment, and weigh various raw materials according to the formula requirements, which are specifically divided into raw material preparation, raw material proportioning and mixing, and raw material storage and management.

[0016] Main raw materials: Styrene monomer, which is the main polymer raw material for producing EPS. Styrene monomer is a colorless transparent liquid with a pungent aromatic smell, flammable, and will cause polymerization at room temperature and under sunlight irradiation. There are also deionized water, foaming agent, initiator, dispersant, and stabilizer.

[0017] Auxiliary raw materials: Also include emulsifier, nucleating agent, reducing agent, plasticizer, and coating agent.

[0018] Raw material proportioning and mixing: According to the production process and product requirements, formulate a detailed raw material formula. The formula needs to clarify the types, dosages, and proportions of various raw materials. Use precise weighing equipment, weigh various raw materials according to the formula requirements, add the weighed raw materials into the mixing container in a certain order, and conduct uniform mixing. During the mixing process, it is necessary to pay attention to controlling conditions such as temperature and stirring speed to ensure uniform mixing of raw materials. And during the raw material preparation and batching process, it is necessary to strictly control the quality and proportion of raw materials.

[0019] Raw material storage and management: Flammable and explosive raw materials need to be stored in a cool, ventilated, and dry place, away from open flames and heat sources. The storage containers need to be well-sealed to prevent raw material leakage and volatilization. Establish a perfect raw material management system to manage the whole process of raw material procurement, storage, use, and waste treatment. Regularly detect and analyze the raw materials to ensure that the raw material quality meets the production requirements.

[0020] Preferably, the raw materials required for the production of expandable polystyrene beads should be mixed evenly according to precise ratios, and quality control of the raw materials, calibration of weighing equipment, and operation specifications should be ensured.

[0021] Quality control of raw materials: During the preparation of raw materials, strict control should be exercised over the quality of the raw materials to ensure that the raw materials used meet the production requirements. For volatile, flammable, or explosive raw materials, corresponding safety measures should be taken, such as storing them in a cool and well-ventilated place and keeping them away from open flames.

[0022] Calibration of weighing equipment: Regularly calibrate and maintain the weighing equipment to ensure its accuracy and stability. Avoid using uncalibrated or damaged weighing equipment to prevent weighing errors.

[0023] Operation specifications: During the preparation and mixing of raw materials, strictly abide by the operating procedures and safety regulations, and wear personal protective equipment such as gloves and goggles to prevent the raw materials from causing harm to the human body.

[0024] Preferably, the prepared raw materials are sequentially added to the reaction kettle, and the stirrer is immediately started, and then other raw materials are added, the reaction conditions are controlled, and the polymerization reaction is carried out.

[0025] Adding other raw materials: While stirring styrene monomer and deionized water, other raw materials such as dispersants and initiators can be gradually added. The addition sequence and dosage of these raw materials need to be strictly controlled according to the formula.

[0026] Controlling reaction conditions: After adding all the raw materials, the reaction conditions such as temperature and pressure need to be controlled. These conditions have an important impact on the effect of the polymerization reaction.

[0027] Carrying out the polymerization reaction: Under appropriate reaction conditions, the styrene monomer will undergo a polymerization reaction under the action of the initiator to form polystyrene beads. The time, temperature, and pressure conditions of the polymerization reaction need to be strictly controlled according to the formula.

[0028] Preferably, in the suspension formed by styrene monomer and deionized water, an initiator is added, then a dispersant is added, and finally a stabilizer is added. After adding all the additives, continue to stir and mix evenly, and the polymerization reaction is divided into reaction condition control, polymerization reaction process, reaction end, and subsequent treatment.

[0029] Adding the initiator: In the suspension formed by styrene monomer and deionized water, an initiator is added. The role of the initiator is to initiate the polymerization reaction of the styrene monomer, convert it into free radicals, and then form polystyrene chains.

[0030] Add dispersant: Next, add the dispersant. The function of the dispersant is to increase the viscosity of the aqueous phase, increase the resistance to the movement of oil droplets, reduce the number of collisions of oil droplets, and at the same time form a protective layer on the outer surface of the oil droplets to prevent the oil droplets from coalescing and enhance the ability of the particles to protect the colloid;

[0031] Add stabilizer: The function of the stabilizer is to control the foaming process of EPS beads, so that they have a stable expansion and hardening speed, and ensure the accuracy of the shape and size of the beads;

[0032] Continue to stir and mix evenly: After adding all the additives, continue to stir and mix evenly. The purpose of stirring is to fully disperse and mix the styrene monomer, deionized water, initiator, dispersant, and stabilizer raw materials to form a stable suspension, providing favorable conditions for the subsequent polymerization reaction;

[0033] Reaction condition control: After stirring and mixing evenly, start to control the reaction conditions, such as temperature and pressure. The polymerization reaction usually takes place at a certain temperature. The level of temperature has an important impact on the speed of the polymerization reaction and the performance of the product. At the same time, the pressure inside the reaction kettle also needs to be controlled to ensure the smooth progress of the polymerization reaction;

[0034] Polymerization reaction process: Under appropriate reaction conditions, the styrene monomer starts to undergo a polymerization reaction under the action of the initiator. During the polymerization reaction process, the styrene monomer gradually transforms into polystyrene chains to form polystyrene beads. At the same time, the blowing agent penetrates into the beads under the action of heating and pressure, providing conditions for the subsequent foaming process;

[0035] Reaction end and subsequent treatment: When the polymerization reaction reaches the predetermined conversion rate, stop heating and stirring. At this time, the materials in the reaction kettle have been transformed into polystyrene beads containing a blowing agent. Finally, unload the materials from the reaction kettle and carry out subsequent treatments such as washing and drying.

[0036] Preferably, add the dispersant and stabilizer again, determine the addition timing, and continue the constant-temperature reaction, and finally cool the materials.

[0037] Add dispersant and stabilizer again: At a certain stage of the polymerization reaction, usually after the styrene monomer has been partially polymerized to form polystyrene particles of a certain size, add the dispersant and stabilizer again. The choice of this timing depends on the specific production process and formulation requirements. Then, according to the formulation requirements, accurately weigh the required dispersant and stabilizer, and slowly add these additives to the reaction kettle under stirring. During the addition process, pay attention to observing the state of the materials in the reaction kettle to ensure that the additives are evenly dispersed;

[0038] Continue the isothermal reaction: After adding the dispersant and stabilizer, continue to control the temperature and pressure of the reaction kettle within a constant range. Regularly take samples to detect the materials in the reaction kettle, such as conversion rate, particle size, and dispersion index. Adjust the reaction conditions or the dosage of additives according to the detection results to ensure the stable quality of the product. The time of the isothermal reaction depends on the specific production process and formula requirements. Too long or too short reaction time may affect the performance and quality of the product;

[0039] Cooling of materials: When the polymerization reaction is completed, it is necessary to quickly cool the materials to an appropriate temperature. The cooling method can be water cooling, air cooling, or natural cooling, depending on the production equipment and process requirements. The cooling rate needs to be moderate. Too fast or too slow cooling rates may have an adverse impact on the product quality. Too fast cooling rate may cause excessive internal stress in the particles, affecting the mechanical properties of the product, while too slow cooling rate may cause particle adhesion or agglomeration.

[0040] Preferably, the materials in the reaction kettle are unloaded and post-treated, and it is divided into material unloading and post-treatment. During the material unloading and post-treatment processes, it is necessary to strictly comply with the safety operation procedures and wear personal protective equipment, such as gloves, masks, and goggles. During the post-treatment process, it is necessary to strictly detect various quality indicators of the materials, such as particle size distribution, moisture content, and pH value.

[0041] Material unloading: When the polymerization reaction is completed, first, it is necessary to reduce the temperature of the materials in the reaction kettle to an appropriate level to ensure safety during unloading and the stability of the materials, and prepare the unloading equipment, such as screw conveyors and pumps, to ensure a smooth unloading process. Then, open the discharge port of the reaction kettle and use a screw conveyor or pump to unload the materials from the reaction kettle. During the unloading process, keep the equipment running stably to avoid material blockage or leakage. The unloaded materials usually fall into an intermediate tank or a buffer tank for subsequent treatment;

[0042] Post-treatment: Wash the discharged materials with deionized water to remove residual dispersant and suspending agent impurities. During the washing process, the water needs to be changed several times until the washing liquid is clear. If acidic or alkaline detergents are used during the washing process, the materials also need to be neutralized to adjust the pH value of the materials to the neutral range. Dehydrate the washed materials to remove the water in the materials. Common dehydration methods include centrifugal dehydration and filtration dehydration. Dry the dehydrated materials to remove the residual water in the materials. The drying methods include hot air drying and vacuum drying. The drying temperature and time need to be adjusted according to the properties of the materials and process requirements. Screen the dried materials to remove particles that do not meet the particle size requirements. Different screen mesh apertures can be set according to market demand during the screening process to obtain EPS beads of different specifications. Classify the screened materials, store the qualified particles according to specifications, package the classified EPS beads, usually using plastic bags or paper bags for packaging, and store the packaged EPS beads in a dry, ventilated and cool place, avoiding direct sunlight and high temperature environment.

[0043] Preferably, the screened EPS beads are classified according to different particle size specifications, select appropriate packaging materials, and put the classified EPS beads into the packaging bags, paying attention to avoiding mutual extrusion and collision between the beads, and ensuring the storage environment, storage method and storage management.

[0044] Storage environment: The warehouse for storing EPS beads should be cool, ventilated and dry, avoiding direct sunlight and high temperature environment. The storage temperature generally does not exceed 20°C, and the humidity is controlled within an appropriate range to prevent EPS beads from absorbing moisture and deteriorating.

[0045] Storage method: EPS beads should be stacked in layers, and wooden boards or pallets can be used to separate each layer for easy handling and ventilation, avoiding direct contact between the beads and the ground to prevent the influence of ground moisture on the beads.

[0046] Storage management: Regularly check the stored EPS beads to ensure that the packaging bags are intact without air leakage or damage. When abnormal situations are found, measures should be taken in time, such as replacing the packaging bags or adjusting the storage environment.

[0047] Compared with the prior art, the present invention provides a production process of expandable polystyrene beads EPS, having the following beneficial effects:

[0048] 1. In the present invention, modern production processes of expandable polystyrene beads mostly adopt automated production lines, which can achieve continuous and stable production, improve production efficiency, and the new preparation production process adds styrene monomer, initiator and foaming agent into the reaction kettle at the same time, simplifies the production process, reduces production links, and thus further improves production efficiency.

[0049] 2. In the present invention, by adjusting process parameters such as dispersant and stirring speed, the particle size of expandable polystyrene beads can be effectively controlled to meet the needs of different customers. By adding additives such as stabilizers and antioxidants in the production process, the thermal stability, antioxidant properties, etc. of the expandable polystyrene beads can be improved, and the service life of the product can be extended.

[0050] 3. In the present invention, by using an environmentally friendly blowing agent and production process, pollutant emissions during production can be reduced to protect the environment. Expandable polystyrene beads can reduce resource waste through recycling and realize the circular utilization of resources, which is in line with the concept of sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic flow diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0053] Please refer to Figure 1 , the production process of expandable polystyrene beads EPS includes the following steps:

[0054] Step 1: Prepare raw materials such as styrene monomer, deionized water, blowing agent, initiator, dispersant, and stabilizer.

[0055] Step 2: Accurately weigh various raw materials according to the production process and product requirements, and mix them evenly according to a certain ratio.

[0056] Step 3: Add the prepared raw materials into the reaction kettle in sequence. First, add deionized water, and then quantitatively add styrene monomer, and start the stirrer.

[0057] Step 4: Then add additives such as initiator, dispersant, and stabilizer in sequence, and continue to stir and mix evenly for polymerization reaction.

[0058] Step 5: Then add some dispersant and stabilizer again, and continue the constant temperature reaction. After the reaction is completed, cool the material to a suitable temperature, and then discharge the reaction kettle.

[0059] Step 6: Unload the material in the reaction kettle and carry out post-treatment.

[0060] Step 7: Pack the sieved and coated EPS beads according to different specifications and store them in a cool, ventilated and dry place, avoiding direct sunlight and high-temperature environment.

[0061] Specifically, as Figure 1 shown, according to the production process and product requirements, formulate a detailed raw material formula, use precise weighing equipment, weigh various raw materials according to the formula requirements, which are specifically divided into raw material preparation, raw material proportioning and mixing, and raw material storage and management.

[0062] Through the above technical solution, the main raw materials: styrene monomer, which is the main polymer raw material for producing EPS. Styrene monomer is a colorless transparent liquid with a pungent aromatic smell, flammable, and will cause polymerization at room temperature and under sunlight irradiation. There are also deionized water, blowing agent, initiator, dispersant and stabilizer;

[0063] Auxiliary raw materials: also include emulsifier, nucleating agent, reducing agent, plasticizer, coating agent;

[0064] Raw material proportioning and mixing: According to the production process and product requirements, formulate a detailed raw material formula. The formula needs to clarify the types, dosages and proportions of various raw materials. Use precise weighing equipment to weigh various raw materials according to the formula requirements, add the weighed raw materials into the mixing container in a certain order, and carry out uniform mixing. During the mixing process, it is necessary to pay attention to controlling conditions such as temperature and stirring speed to ensure uniform mixing of raw materials. And during the raw material preparation and batching process, it is necessary to strictly control the quality and proportion of raw materials;

[0065] Raw material storage and management: Flammable and explosive raw materials need to be stored in a cool, ventilated and dry place, away from open flames and heat sources. The storage containers need to be well-sealed to prevent raw material leakage and volatilization. Establish a perfect raw material management system to manage the whole process of raw material procurement, storage, use and waste treatment, and regularly detect and analyze raw materials to ensure that the raw material quality meets the production requirements.

[0066] Specifically, as Figure 1 shown, ensure that the raw materials required for the production of expandable polystyrene beads can be mixed evenly according to precise proportions, and ensure raw material quality control, weighing equipment calibration and operation specifications.

[0067] Through the above technical solution, raw material quality control: During the raw material preparation process, strictly check the quality of raw materials to ensure that the used raw materials meet the production requirements. For volatile or flammable and explosive raw materials, take corresponding safety measures, such as storing in a cool and ventilated place and away from open flames;

[0068] Calibration of weighing equipment: Regularly calibrate and maintain the weighing equipment to ensure its accuracy and stability. Avoid using uncalibrated or damaged weighing equipment to prevent weighing errors.

[0069] Operation specifications: During the raw material preparation and mixing process, strictly comply with the operating procedures and safety regulations, and wear personal protective equipment such as gloves and goggles to prevent harm to the human body caused by raw materials.

[0070] Specifically, as Figure 1 shown, add the prepared raw materials to the reaction kettle in sequence, immediately start the stirrer, and then add other raw materials, control the reaction conditions, and carry out the polymerization reaction.

[0071] Through the above technical solution, adding other raw materials: While stirring styrene monomer and deionized water, other raw materials such as dispersant and initiator can be gradually added. The addition sequence and dosage of these raw materials need to be strictly controlled according to the formula.

[0072] Controlling reaction conditions: After adding all the raw materials, the reaction conditions such as temperature and pressure need to be controlled. These conditions have an important impact on the effect of the polymerization reaction.

[0073] Carrying out the polymerization reaction: Under appropriate reaction conditions, styrene monomer will undergo a polymerization reaction under the action of an initiator to form polystyrene beads. The time, temperature, and pressure conditions of the polymerization reaction need to be strictly controlled according to the formula.

[0074] Specifically, as Figure 1 shown, in the suspension formed by styrene monomer and deionized water, add the initiator, then add the dispersant, and finally add the stabilizer. After adding all the additives, continue to stir and mix evenly. The polymerization reaction is divided into reaction condition control, polymerization reaction process, reaction end, and subsequent treatment.

[0075] Through the above technical solution, adding the initiator: In the suspension formed by styrene monomer and deionized water, add the initiator. The role of the initiator is to initiate the polymerization reaction of styrene monomer, convert it into free radicals, and then form polystyrene chains.

[0076] Adding the dispersant: Then add the dispersant. The role of the dispersant is to increase the viscosity of the aqueous phase, increase the resistance of oil droplets to movement, reduce the number of oil droplet collisions, and at the same time form a protective layer on the outer surface of the oil droplets to prevent oil droplet coalescence and enhance the colloid protection ability of the particles.

[0077] Adding the stabilizer: The role of the stabilizer is to control the foaming process of EPS beads, make it have a stable expansion and hardening speed, and ensure the accuracy of the shape and size of the beads.

[0078] Continue to stir and mix evenly: After adding all the additives, continue to stir and mix evenly. The purpose of stirring is to fully disperse and mix the styrene monomer, deionized water, initiator, dispersant, and stabilizer raw materials to form a stable suspension, which provides favorable conditions for the subsequent polymerization reaction;

[0079] Reaction condition control: After stirring and mixing evenly, start to control the reaction conditions, such as temperature and pressure. The polymerization reaction is usually carried out at a certain temperature. The temperature has an important influence on the speed of the polymerization reaction and the performance of the product. At the same time, it is also necessary to control the pressure in the reactor to ensure the smooth progress of the polymerization reaction;

[0080] Polymerization process: Under appropriate reaction conditions, styrene monomer begins to polymerize under the action of initiator. During the polymerization process, styrene monomer gradually transforms into polystyrene chain to form polystyrene beads. At the same time, the blowing agent penetrates into the beads under the action of heating and pressure, providing conditions for the subsequent foaming process.

[0081] End of reaction and subsequent treatment: When the polymerization reaction reaches the predetermined conversion rate, stop heating and stirring. At this time, the material in the reactor has been converted into polystyrene beads containing foaming agent. Finally, the material is unloaded from the reactor and subjected to subsequent treatment, such as washing and drying.

[0082] Specifically, Figure 1 As shown, the dispersant and stabilizer are added again, the timing of addition is determined, and the constant temperature reaction is continued, and finally the material is cooled.

[0083] Through the above technical solution, the dispersant and stabilizer are added again: when the polymerization reaction reaches a certain stage, usually after the styrene monomer has been partially polymerized to form polystyrene particles of a certain size, the dispersant and stabilizer are added again. The timing depends on the specific production process and formulation requirements. Then, according to the formulation requirements, the required dispersant and stabilizer are accurately weighed, and these additives are slowly added to the reactor under stirring. During the addition process, attention should be paid to observing the state of the materials in the reactor to ensure that the additives are evenly dispersed.

[0084] Continue constant temperature reaction: After adding dispersant and stabilizer, continue to control the temperature and pressure of the reactor within a constant range, regularly sample and test the materials in the reactor, such as conversion rate, particle size, and dispersibility index, and adjust the reaction conditions or the amount of additives according to the test results to ensure stable product quality. The time of constant temperature reaction depends on the specific production process and formula requirements. Too long or too short a reaction time may affect the performance and quality of the product;

[0085] Material Cooling: After the polymerization reaction is completed, the material needs to be quickly cooled to an appropriate temperature. The cooling methods can include water cooling, air cooling, or natural cooling, depending on the production equipment and process requirements. The cooling rate needs to be moderate. Too fast or too slow a cooling rate may have an adverse impact on the product quality. An overly fast cooling rate may cause excessive internal stress in the particles, affecting the mechanical properties of the product, while an overly slow cooling rate may lead to particle adhesion or caking.

[0086] Specifically, as Figure 1 shown, the material in the reaction kettle is unloaded and post-treated, which is divided into material unloading and post-treatment. During the material unloading and post-treatment processes, safety operating procedures must be strictly adhered to, and personal protective equipment such as gloves, masks, and goggles should be worn. During the post-treatment process, strict detection of various quality indicators of the material is required, such as particle size distribution, moisture content, and pH value.

[0087] Through the above technical solution, Material Unloading: After the polymerization reaction is completed, first, the temperature of the material in the reaction kettle needs to be reduced to an appropriate level to ensure safety during unloading and the stability of the material, and the unloading equipment such as screw conveyors and pumps should be prepared to ensure a smooth unloading process. Then, open the discharge port of the reaction kettle, and use a screw conveyor or pump to unload the material from the reaction kettle. During the unloading process, the stable operation of the equipment should be maintained to avoid material blockage or leakage. The unloaded material usually falls into an intermediate tank or buffer tank for subsequent processing;

[0088] Post-treatment: Wash the unloaded material with deionized water to remove residual dispersant and suspending agent impurities. During the washing process, the water needs to be changed several times until the washing liquid is clear. If acidic or alkaline detergents are used during the washing process, the material also needs to be neutralized to adjust the pH value of the material to the neutral range. Dehydrate the washed material to remove the moisture in the material. Common dehydration methods include centrifugal dehydration and filtration dehydration. Dry the dehydrated material to remove the residual moisture in the material. Drying methods include hot air drying and vacuum drying. The drying temperature and time need to be adjusted according to the properties of the material and process requirements. Screen the dried material to remove particles that do not meet the particle size requirements. Different screen mesh apertures can be set according to market demand during the screening process to obtain EPS beads of different specifications. Classify the screened material, store the qualified particles according to specifications, package the classified EPS beads, usually using plastic bags or paper bags for packaging, and store the packaged EPS beads in a dry, ventilated, and cool place, avoiding direct sunlight and high-temperature environments.

[0089] Specifically, as Figure 1As shown, the sieved EPS beads are classified according to different particle size specifications, and appropriate packaging materials are selected. The classified EPS beads are put into packaging bags, taking care to avoid mutual extrusion and collision between the beads, and ensuring the storage environment, storage method, and storage management.

[0090] Through the above technical solution, for the storage environment: the warehouse for storing EPS beads should be cool, ventilated, and dry, avoiding direct sunlight and high-temperature environments. The storage temperature generally does not exceed 20°C, and the humidity is controlled within an appropriate range to prevent the EPS beads from absorbing moisture and deteriorating.

[0091] For the storage method: the EPS beads should be stacked in layers, and each layer can be separated by wooden boards or pallets for easy handling and ventilation, avoiding direct contact between the beads and the ground to prevent the influence of ground moisture on the beads.

[0092] For the storage management: regularly check the stored EPS beads to ensure that the packaging bags are intact without air leakage or damage. When abnormal situations are found, measures should be taken in a timely manner, such as replacing the packaging bags or adjusting the storage environment.

[0093] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. The production process of expandable polystyrene beads EPS, characterized in that, It includes the following steps: Step 1: Prepare raw materials including styrene monomer, deionized water, foaming agent, initiator, dispersant, and stabilizer; Step 2: Accurately weigh various raw materials according to the production process and product requirements, and mix them evenly according to a certain ratio; Step 3: Add the prepared raw materials into the reaction kettle in sequence. First, add deionized water, then quantitatively add styrene monomer, and start the stirrer; Step 4: Then add auxiliaries such as initiator, dispersant, and stabilizer in sequence, and continue to stir and mix evenly for polymerization reaction; Step 5: Then add some dispersant and stabilizer again, continue the isothermal reaction. After the reaction is completed, cool the material to an appropriate temperature, and then discharge the reaction kettle; Step 6: Unload the material in the reaction kettle and carry out post-treatment; Step 7: Package the EPS beads after screening and coating according to different specifications, and store them in a cool, ventilated, and dry place, avoiding direct sunlight and high-temperature environment.

2. The production process of expandable polystyrene beads EPS according to claim 1, characterized in that: According to the production process and product requirements, formulate a detailed raw material formula, use accurate weighing equipment, and weigh various raw materials according to the formula requirements, which is specifically divided into raw material preparation, raw material ratio and mixing, and raw material storage and management.

3. The production process of expandable polystyrene beads EPS according to claim 1, characterized in that: Ensure that the raw materials required for the production of expandable polystyrene beads can be mixed evenly according to accurate ratios, and ensure raw material quality control, weighing equipment calibration, and operation specifications.

4. The production process of expandable polystyrene beads EPS according to claim 1, characterized in that: Add the prepared raw materials into the reaction kettle in sequence, immediately start the stirrer, and then add other raw materials, control the reaction conditions, and carry out the polymerization reaction.

5. The production process of expandable polystyrene beads EPS according to claim 1, characterized in that: In the suspension formed by styrene monomer and deionized water, add the initiator, then add the dispersant, and finally add the stabilizer. After adding all the auxiliaries, continue to stir and mix evenly, and the polymerization reaction is divided into reaction condition control, polymerization reaction process, reaction end and subsequent treatment.

6. The production process of expandable polystyrene beads EPS according to claim 1, characterized in that: Add the dispersant and stabilizer again, determine the addition time, continue the isothermal reaction, and finally cool the material.

7. The production process of expandable polystyrene beads EPS according to claim 1, characterized in that: Unload the material in the reaction kettle and carry out post-treatment, which is divided into material unloading and post-treatment. During the material unloading and post-treatment processes, safety operation procedures need to be strictly observed, and personal protective equipment such as gloves, masks, and goggles should be worn. During the post-treatment process, strict detection of various quality indicators of the material is required, such as particle size distribution, moisture content, and pH value.

8. The production process of expandable polystyrene beads EPS according to claim 1, characterized in that: The screened EPS beads are classified according to different particle size specifications, select appropriate packaging materials, and pack the classified EPS beads into packaging bags, paying attention to avoiding mutual extrusion and collision between the beads, and ensuring the storage environment, storage method, and storage management.

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