On-line adding device for modifying PBT (Polybutylece Terephthalate) melt
By designing an online addition device for PBT melt modification, continuous and uniform mixing of PBT melt and additives was achieved, solving the problems of complicated processes and high costs in the downstream modification process, and improving product quality and production capacity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-11
- Publication Date
- 2026-03-27
AI Technical Summary
Existing PBT production facilities suffer from problems such as cumbersome processes, high costs, uneven mixing, and oxidative degradation during downstream modification, leading to unstable product quality.
An online additive device for PBT melt modification was designed, including a pre-shrinking reactor, a final shrinking reactor, a filter assembly, a metering assembly, a screw extruder, a melt pump, and a mixing assembly. The additive is continuously and uniformly mixed through pipeline connections. The amount of additive is precisely controlled by a PLC controller. The device is equipped with a nitrogen backflushing system, a heat tracing jacket for the heat medium, and a vacuum pump to prevent clogging and oxidation.
It simplifies the modification process, improves product quality consistency and production capacity, reduces production costs, avoids oxidative degradation, and increases yield.
Smart Images
Figure CN224040872U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the polymeric technical field relates to a kind of PBT melt modification online adding device. BACKGROUND
[0002] Polybutylene terephthalate (hereinafter referred to as PBT) is a polyester made of terephthalic acid (hereinafter referred to as PTA) and 1,4-butanediol (hereinafter referred to as BDO) polycondensation, is one of the important thermoplastic polyesters in the five engineering plastics, has outstanding rigidity, strength, good heat resistance, good dimensional stability and chemical resistance. But due to the problems existing in the prior art, the products prepared by using PBT will have low notched impact strength, low flame retardancy, low heat distortion temperature, poor dimensional stability at high temperature, anisotropy and other problems.
[0003] At present, the pure resin produced by PBT production device is sold to downstream manufacturers, and the downstream manufacturers will modify it by adding various additives or mixing with other plastics, according to the different proportions and specifications of the modifiers, different products are manufactured. For example, PBT modified by glass fiber can be used to manufacture electronic parts with high dimensional stability at high temperature.
[0004] However, when the downstream manufacturers modify PBT, the masterbatch needs to be dissolved and mixed again, which has the problems of complicated process and high cost. At the same time, in this process, the residence time of the material is short, and the phenomenon of uneven mixing of additives is easy to occur. In the process of adding additives, oxygen is also easy to enter, degradation phenomenon occurs, finished products are easy to degrade, etc. For example, the literature (Flame-retardant reinforced PBT modification process. Research and development [J], 2011, 1.) uses the process method of masterbatch heating dissolution, mixing, extrusion and granulation to improve PBT. However, this process method not only has high cost, but also has the disadvantages of uneven mixing, oxygen degradation and other disadvantages in the process of masterbatch heating dissolution, mixing again and granulation.
[0005] Therefore, a PBT melt modification online adding device is needed to solve the above problems, which is of great significance. UTILITY MODEL CONTENT
[0006] The utility model aims at solving the problems existing in the prior art, and provides a kind of PBT melt modification online adding device.
[0007] To achieve the above-mentioned purpose, the utility model adopts the following technical solutions:
[0008] The PBT melt modification on-line adding device is characterized in that the PBT production device comprises a pre-shrinking reaction kettle and a final shrinking reaction kettle, the pre-shrinking reaction kettle and the final shrinking reaction kettle are connected through a pipeline I, and the PBT melt modification on-line adding device comprises a feeding hopper, a filtering assembly, a feeding assembly, a metering assembly, a screw extruder, a melt pump and a mixing assembly which are sequentially connected through a pipeline II, wherein each component is a component existing in the prior art.
[0009] The feeding hopper is used for inputting the additive.
[0010] The filtering assembly is used for screening the particle size of the additive and filtering out large particles.
[0011] The metering assembly is used for weighing the additive.
[0012] The feeding assembly is used for controlling the weight of the additive in the metering assembly, so that the additive from the metering assembly to the screw extruder is in a continuous adding state.
[0013] The melt pump is used for pressurization to facilitate delivery into the PBT melt; the pressure in the pipeline I is 0.10-0.40 Mpa, and the injection pressure of the additive is required to be greater than the pressure in the pipeline I, so that normal delivery can be achieved and backflow can be avoided.
[0014] The mixing assembly is arranged on the pipeline I between the pre-shrinking reaction kettle and the final shrinking reaction kettle and is used for uniformly mixing the PBT melt and the additive melt which is melted and extruded by the screw extruder, so as to prevent the additive melt from being extracted under high vacuum of the final shrinking reaction kettle.
[0015] The PBT melt modification on-line adding device of the utility model can make the load of the PBT polymerization device reach 200 tons / day, while the load of the polyester master batch after being dissolved and mixed and then modified is lower than 100 tons / day. The load is lower than 100 tons / day because the prior art is to melt the PBT resin by screw extrusion and then add various additives for melting, and this method needs to melt the PBT resin, so the melting amount is large, and thus the load is limited by the size and rotating speed of the screw extruder.
[0016] As a preferred technical scheme,
[0017] The PBT melt modification on-line adding device as described above, wherein the feeding assembly is a plug valve.
[0018] The PBT melt modification online adding device also comprises a PLC controller; the plug valve and the metering assembly are electrically connected with the PLC controller, the metering assembly sends the measured weight of the additive to the PLC controller, and compares with the set weight range in the PLC controller, when the measured weight of the additive is greater than the set weight range, the PLC controller controls the plug valve to be closed, and when the measured weight of the additive is less than the set weight range, the PLC controller controls the plug valve to be opened.
[0019] The PBT melt modification online adding device also comprises a nitrogen back flushing system arranged on the feeding hopper, which is used for purging the additive in the feeding hopper to prevent the additive from bridging and causing difficult discharging.
[0020] The PBT melt modification online adding device also comprises a loss-in-weight scale as the metering assembly and a static mixer as the mixing assembly.
[0021] The PBT melt modification online adding device also comprises a heat medium heating jacket pipe with a temperature of 220-240 DEG C arranged on the pipeline II between the melt pump and the mixing assembly, which is used for preventing the PBT melt from solidifying, because the PBT melt point is about 240 DEG C and the additive melt point is generally about 120 DEG C, if the heat medium heating jacket pipe is not arranged, the PBT melt will be solidified and the pipeline will be blocked after the PBT melt contacts the additive.
[0022] The PBT melt modification online adding device also comprises a double-screw extruder as the screw extruder.
[0023] The PBT melt modification online adding device also comprises an electric heating system, a cooling water system, an oil pump and a vacuum pump in the screw extruder.
[0024] The electric heating system is an electric heating jacket, which is used for heating and melting the additive;
[0025] The cooling water system comprises a cooling water pump and a cooling water jacket; the cooling water jacket is used for ensuring the temperature stability of each zone of the screw extruder; and the cooling water pump is used for delivering the cooling water to the cooling water jacket.
[0026] The oil pump is used for circulating and cooling the lubricating oil in the reduction gearbox of the screw extruder.
[0027] The vacuum pump is connected with a certain zone of the screw extruder, which is used for extracting oxygen to prevent the thermal oxidative degradation of the additive.
[0028] Beneficial effects:
[0029] (1) The utility model discloses can be modified according to the requirement on -line adding various additives to polyester, avoid the various problems of the modification after the polyester master batch is dissolved and is mixed, greatly simplify the technological process, and can guarantee that the finished product has higher consistency, uniformity, make the product quality is more stable.
[0030] (2) The utility model discloses a PBT melt modification on -line adding device not only is favorable to improving the capacity, can reduce unit production cost, save energy in addition, the device still passes through the operation of the loss -in -weight balance, and the weight of the discharge is accurately controlled, reduces the finished product quality problem of traditional on -line adding device, and improves the rate of superior product. BRIEF DESCRIPTION OF DRAWINGS
[0031] Figure 1 It is the use flow chart of a PBT melt modification on -line adding device of the utility model;
[0032] Figure 2 It is the schematic diagram of a PBT melt modification on -line adding device of the utility model;
[0033] Among them, 11 is feeding hopper, 12 is filter assembly, 13 is feeding assembly, 14 is metering assembly, 15 is screw extruder, 16 is melt pump, 21 is esterification reaction kettle, 22 is pre-shrinkage reaction kettle, 3 is mixing assembly, 4 is final shrinkage reaction kettle. DETAILED DESCRIPTION
[0034] The utility model will be further described below in conjunction with specific implementation. It should be understood that these examples are only used to illustrate the utility model and are not used to limit the scope of the utility model. In addition, it should be understood that after reading the content taught by the utility model, those skilled in the art can make various changes or modifications to the utility model, and these equivalent forms also fall within the scope defined by the claims attached to the present application.
[0035] As shown in Figure 2 The production device of PBT includes pre-shrinkage reaction kettle 22 and final shrinkage reaction kettle 4, and pre-shrinkage reaction kettle 22 and final shrinkage reaction kettle 4 are connected through pipeline I.
[0036] A PBT melt modification on -line adding device, including feeding hopper 11, filter assembly 12, feeding assembly 13, metering assembly 14, screw extruder 15, melt pump 16, mixing assembly 3 and PLC controller that are connected in proper order through pipeline II.
[0037] Feeding hopper 11 is used to input additive;
[0038] Nitrogen back flushing system is arranged on feeding hopper 11, and nitrogen back flushing system is used to purge the additive in feeding hopper 11;
[0039] The filtering assembly 12 is used for screening the particle size of the additive;
[0040] The metering assembly 14 is a loss-in-weight scale, which is used for weighing the additive;
[0041] The feeding assembly 13 is a plug valve; the plug valve and the metering assembly 14 are electrically connected with the PLC controller respectively, the metering assembly 14 sends the measured value of the weight of the additive to the PLC controller, and compares the measured value with the set weight range in the PLC controller; when the measured weight of the additive is greater than the set weight range, the PLC controller controls the plug valve to be closed; when the measured weight of the additive is less than the set weight range, the PLC controller controls the plug valve to be opened;
[0042] The screw extruder 15 is a double-screw extruder 15, which comprises an electric heating system, a cooling water system, an oil pump and a vacuum pump;
[0043] The electric heating system is an electric heating jacket, which is used for heating and melting the additive;
[0044] The cooling water system comprises a cooling water pump and a cooling water jacket; the cooling water jacket is used for ensuring the temperature stability of each zone of the screw extruder 15; and the cooling water pump is used for delivering cooling water to the cooling water jacket;
[0045] The oil pump is used for circulating and cooling the lubricating oil in the reduction gearbox of the screw extruder 15;
[0046] The vacuum pump is connected with a zone of the screw extruder 15, which is used for extracting oxygen to prevent the thermal oxidative degradation of the additive;
[0047] The melt pump 16 is used for pressurization;
[0048] The mixing assembly 3 is a static mixer, which is arranged on the pipeline I between the pre-shrinking reaction kettle 22 and the final-shrinking reaction kettle 4, and is used for uniformly mixing the PBT melt and the additive melt which is melted and extruded by the screw extruder 15;
[0049] A heat medium heating jacket pipe with a temperature of 220-240℃ is arranged on the pipeline II between the melt pump 16 and the mixing assembly 3.
[0050] The use process of the above device is as follows: Figure 1 、 Figure 2As shown, first, according to certain proportion, various additives are put into the feeding hopper 11 through the additive feeding port, then the additives are transported to the filtering assembly 12 through the pipeline II to screen the particles with too large particle size, and the screened additives are transported to the feeding assembly 13 through the pipeline II, then the feeding assembly 13 is transported to the double screw extruder 15 through the pipeline II to melt and extrude to obtain the additive melt, the amount of the additives transported to the double screw extruder 15 is measured by the metering assembly 14 during the transportation, finally, the additive melt is transported to the mixing assembly 3 through the pipeline II by using the melt pump 16; at the same time, according to certain proportion, PTA and BDO are configured and then added to the esterification reaction kettle 21 to perform esterification reaction, the product after the reaction is continuously transported to the pre-shrinking reaction kettle 22, the reacted prepolymer is added to the mixing assembly 3 through the pipeline I to be uniformly mixed with the additive melt transported through the pipeline II according to the proportion, then it is transported to the final shrinking reaction kettle 4 through the pipeline I to perform reaction, the product after the reaction is cut and packaged, and the modified PBT is obtained.
Claims
1. A PBT melt modification on-line adding device, the production device of PBT comprising a pre-shrinking reaction kettle and a final shrinking reaction kettle, the pre-shrinking reaction kettle and the final shrinking reaction kettle being connected through a pipeline I, characterized in that, The PBT melt modification on-line adding device comprises a feeding hopper, a filtering assembly, a feeding assembly, a metering assembly, a screw extruder, a melt pump and a mixing assembly connected in sequence through pipeline II; The feeding hopper is used for inputting the additive; The filtering assembly is used for screening the particle size of the additive; The metering assembly is used for weighing the additive; The feeding assembly is used for controlling the weight of the additive in the metering assembly; The melt pump is used for pressurization; The mixing assembly is arranged on the pipeline I between a pre-shrinking reaction kettle and a final-shrinking reaction kettle, and is used for uniformly mixing the PBT melt and the additive melt extruded by the screw extruder.
2. The on-line PBT melt modification additive device according to claim 1, characterized in that, The feeding assembly is a plug valve.
3. The on-line PBT melt modification additive device according to claim 2, characterized in that, The PBT melt modification on-line adding device further comprises a PLC controller; the plug valve and the metering assembly are electrically connected with the PLC controller; the metering assembly sends the measured weight of the additive to the PLC controller and compares the measured weight with a set weight range in the PLC controller; when the measured weight of the additive is greater than the set weight range, the PLC controller controls the plug valve to be closed; when the measured weight of the additive is less than the set weight range, the PLC controller controls the plug valve to be opened.
4. The on-line PBT melt modification additive device according to claim 2, wherein A nitrogen back flushing system is arranged on the feeding hopper, and is used for purging the additive in the feeding hopper.
5. The on-line PBT melt modification additive device according to claim 1, wherein The metering assembly is a loss-in-weight scale; and the mixing assembly is a static mixer.
6. The on-line PBT melt modification additive device according to claim 1, wherein A heat medium heating jacket pipe with a temperature of 220-240 DEG C is arranged on the pipeline II between the melt pump and the mixing assembly.
7. The on-line PBT melt modification additive device according to claim 1, wherein The screw extruder is a double-screw extruder.