CN115230197A

CN115230197A - Method for preparing polyurethane pultrusion composite material

Info

Publication number: CN115230197A
Application number: CN202110438963.XA
Authority: CN
Inventors: 顾永明; 李志江; 成浩
Original assignee: Covestro Deutschland AG
Current assignee: Covestro Deutschland AG
Priority date: 2021-04-22
Filing date: 2021-04-22
Publication date: 2022-10-25

Abstract

The invention relates to an automatic control method and equipment for preparing a polyurethane pultrusion composite material by using a polyurethane pultrusion process, the polyurethane pultrusion composite material prepared by the method and application thereof.

Description

Method for preparing polyurethane pultrusion composite material

Technical Field

The invention relates to the field of a polyurethane pultrusion process. In particular, the present invention relates to a method and apparatus for preparing a polyurethane pultruded composite using an automated control process.

Background

The traditional pultrusion process mainly adopts an open impregnation mode, namely, fibers, fabrics or felts pass through an impregnation tank with a compression roller or a compression bar, the fibers with resin are gradually extruded by a preformed plate and then enter a heated die, and finally, the fibers are cured and molded. The traditional open type gum dipping method has some problems, such as high VOC volatilization, higher resin waste rate, high finished product porosity and short gelation time, and a resin system is not suitable for the process. The time required for shutdown and product specification replacement is relatively long and the cost is relatively high.

In order to solve the above problems, two types of hermetic glue injection processes have been tried in the industry. One type is a low-pressure glue injection mode, the inside of a glue injection box is generally provided with one or more tapers, glue injection holes of the glue injection box are generally positioned above and below the glue injection box, resin is injected into the glue injection box through a glue injection machine and then is infiltrated into unidirectional fiber yarns, the glue injection box is suitable for pultrusion of full yarns, the other type is a high-pressure glue injection mode, the glue injection holes of the glue injection box are generally positioned above and below the glue injection box, and the glue injection box is suitable for paving layers with porous structures such as felts or fabrics. Resin volume is usually controlled through whether the manual work observes injecting glue box entry and leaks to glue in the above-mentioned impregnating device, often appears continuously exposing glue and wastes resin or because of injecting glue box in the resin volume too little and the bad problem of infiltration. In the actual production process, the pultrusion production speed may change in real time, and if the process parameters are not adjusted in time, resin is easily wasted or infiltration is poor, so that the production is affected.

CN109986810A discloses a centralized feeding device and a composite pultrusion device comprising the same, the centralized feeding device comprises at least one group of centralized feeding components, each group of centralized feeding components is used for providing a material for a pultrusion traction device, and each group of centralized feeding components comprises: the storage barrel is used for storing materials to be transported; the buffer storage barrel is connected with the material storage barrel through a conveying pipeline and used for buffering materials to be injected; a material injection assembly, and the like.

CN209869449U discloses an automatic production equipment for composite material pultrusion section, which comprises: the fiber yarn storage device is used for storing fiber yarns; the fiber yarn guiding device is used for guiding the fiber yarns guided out by the fiber yarn storage device; the pultrusion die device is used for realizing the heating forming of the section; the material injection device is used for injecting materials into the injection material box and/or the pultrusion die; the clamping traction device is used for realizing the clamping traction of the section; the dust collection cutting device is used for realizing dust collection and cutting of the section; and the central control device realizes automatic control of the device.

Despite the above disclosures, there is still a need for improved processes and equipment suitable for the same, which meet the needs of industrial production.

Disclosure of Invention

In one aspect of the present invention, there is provided an automatically controlled method for preparing a polyurethane pultruded composite comprising:

injecting a polyurethane composition into an infiltration box (5) by using an injection system (30) to form a liquid level;

acquiring liquid level information of the polyurethane composition in the infiltration box (5);

transmitting the liquid level information to the glue injection system (30) and/or a control system (40);

and adjusting process parameters according to the liquid level information, wherein the process parameters comprise glue injection speed, glue injection amount, formula, temperature and the like, and the glue injection speed or the glue injection amount is preferably selected. The injection speed refers to the speed of injecting the polyurethane composition, such as 30 grams per minute (g/min). The injection amount refers to the amount, such as volume or weight, of the polyurethane composition injected.

Preferably, the liquid level information includes liquid level information of two or more different positions.

Preferably, the acquisition positions of the liquid level information are an acquisition position 1 (2) and an acquisition position 2 (4), respectively.

Preferably, the infiltration cartridge (5) comprises an inlet (5 a) and an outlet (5 b), the linear distance between the acquisition position 1 (2) and the inlet (5 a) being comprised between 0 and 100mm, and the linear distance between the acquisition position 2 (4) and the inlet (5 a) being comprised between 110 and 300mm, preferably between 120 and 250mm, more preferably between 130 and 200mm.

Preferably, the method further comprises: and pre-storing the corresponding relations between a plurality of historical liquid level information and historical process parameters, and adjusting the process parameters according to the obtained liquid level information and the corresponding relations between the historical liquid level information and the historical process parameters.

Preferably, the infiltration tank (5) has a length of 300 to 800mm, preferably 350 to 700mm, more preferably 400 to 650mm.

Preferably, the level information is acquired by at least one sensor, preferably two sensors.

Preferably, the sensor is selected from the group consisting of a contact sensor, an infrared sensor, an ultrasonic sensor, or a combination thereof.

Preferably, the method for preparing a polyurethane pultruded composite comprising said method for automatic control of the preparation of a polyurethane pultruded composite reduces the amount of polyurethane composition used by more than or equal to 1%, preferably more than or equal to 2%, more preferably more than or equal to 3% compared to a method for preparing a polyurethane pultruded composite not comprising said method for automatic control of the preparation of a polyurethane pultruded composite.

Preferably, the inlet (5 a) and the outlet (5 b) of the infiltration box (5) both comprise cross sections, and the cross-sectional area ratio of the inlet (5 a) to the outlet (5 b) of the infiltration box (5) is 2: 1-8: 1, preferably 3: 1-8: 1. Specifically, assuming that the cross-sectional area of the inlet is Ai and the cross-sectional area of the outlet is Ao, ai: ao is 2: 1 to 8: 1, preferably 3: 1 to 8: 1.

Preferably, the method further comprises the step of acquiring temperature information in the infiltration box (5) and transmitting the temperature information to the glue injection system (30) or the control system (40), wherein the glue injection system (30) or the control system (40) adjusts process parameters, preferably the temperature, according to the temperature information.

Preferably, the method further comprises:

placing at least one release cloth (2a, 2b) and at least one fibre-reinforced material (1) in a infiltration box (5) comprising an inlet (5 a) and an outlet (5 b); wherein the release cloth (2a, 2b) partially covers the fibre reinforcement (1);

impregnating a polyurethane composition with the fiber-reinforced material (1) through the portion of the fiber-reinforced material (1) not covered with the release fabric (2a, 2b);

and (3) drawing the soaked fiber reinforced material (1) and the demolding cloth (2a, 2b) through a mold (7), and curing and molding to obtain the polyurethane pultrusion composite material.

Preferably, the at least one release cloth (2a, 2b) is two release cloths (2a, 2b), the two release cloths (2a, 2b) being respectively placed on two opposite inner sides (5i, 5j) of the infiltration box (5), the fiber reinforcement (1) being located between the two release cloths (2a, 2b).

The release cloth does not cover the fibre reinforcement entirely, but only partially. The polyurethane composition contacts the fiber reinforcement material through the portion not covered with the release fabric and wets the fiber reinforcement material.

Preferably, the at least one release fabric (2a, 2b) is two release fabrics (2a, 2b), the two release fabrics (2a, 2b) being respectively placed on two opposite inner sides (5i, 5j) of the infiltration tank (5), the fiber reinforcement material (1) being located between the two release fabrics (2a, 2b), the glue injection system (30) comprising at least two glue injections (4a, 4b), the two glue injections (4a, 4b) being located on two opposite sides (5m, 5n) of the infiltration tank (5) where no release fabric is placed.

Preferably, the method further comprises mixing the polyurethane composition using an automatic metering mixing device.

Preferably, the polyurethane composition comprises the following components:

component A comprising one or more organic polyisocyanates;

component B, comprising:

b1 One or more organic polyols in an amount of 21 to 60wt.%, preferably 21 to 40 wt.%, based on the total weight of the polyurethane composition in 100 wt.%;

b2 ) one or more compounds having the structure of formula (I) in an amount of from 0 to 35% by weight, preferably from 4.6 to 35% by weight, based on 100w 4% by weight of the total weight of the polyurethane composition

Wherein R is ₁ Selected from hydrogen, methyl or ethyl; r ₂ Selected from the group consisting of alkylene having 2 to 6 carbon atoms, 2-bis (4-phenylene) -propane, 1, 4-bis (methylene) benzene, 1, 3-bis (methylene) benzene, 1, 2-bis (methylene) benzene n is an integer selected from 1 to 6; and

component C, a free radical initiator.

Preferably, the organic polyol has a functionality of from 1.7 to 6, preferably from 1.9 to 4.5, and a hydroxyl number of from 150 to 1100mgKOH/g, preferably from 150 to 550mgKOH/g.

Preferably, the B2) component is selected from: hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, or combinations thereof.

Preferably, the polyurethane composition has a gel time at 25 ℃ of from 10 to 40 minutes, preferably from 15 to 30 minutes, more preferably from 16 to 28 minutes.

Preferably, the fibrous reinforcement (1) is selected from glass fibers, carbon fibers, polyester fibers, natural fibers, aramid fibers, nylon fibers, basalt fibers, boron fibers, silicon carbide fibers, asbestos fibers, metal fibers or combinations thereof.

Preferably, the method further comprises drawing the impregnated fiber reinforcement material (1) through a mold (7), the fiber reinforcement material (1) being passed through the mold (7) at a speed of 0.2-2m/min, preferably 0.2-1.5m/min, the polyurethane composition being injected into the impregnation box (5) from a glue injection system (30) at a speed of 30-2000g/min, preferably 40-1500g/min, more preferably 60-1200 g/min.

The method for automatically controlling the preparation of the polyurethane pultrusion composite material simply, efficiently and objectively realizes the collection, treatment and application of the process information such as the liquid level information, the temperature information and the like of a pultrusion production line, can ensure the good infiltration of the fiber reinforced material, does not waste the raw material of the polyurethane composition, and is economical and environment-friendly.

In addition, the method for preparing the polyurethane pultrusion composite material uses a continuous pultrusion process, the demolding cloth and the fiber reinforced material are drawn to pass through the infiltration box at a certain speed, the polyurethane composition is injected into the infiltration box through the glue injection device to infiltrate the fiber reinforced material, and preferably, the polyurethane composition is partially injected into the fiber reinforced material (1) which is not covered by the demolding cloth and infiltrates the fiber reinforced material (1). Surprisingly, the method of the present invention, which includes the features of the release cloth, the proper glue injection position, the infiltration method, the traction speed, and the speed of injecting the polyurethane composition, not only provides a high quality polyurethane pultruded composite having a satisfactory surface, but also improves the production efficiency and saves the cost.

In another aspect of the present invention, there is provided an apparatus for an automated controlled process for preparing a polyurethane pultruded composite comprising:

a glue injection system (30), a wetting cartridge (5) comprising an inlet (5 a) and an outlet (5 b), and at least one information acquisition device (2, 4).

Preferably, the at least one information acquisition device (2, 4) is at least two information acquisition devices (2, 4), the information acquisition device (2) is arranged on the infiltration box (5) at a linear distance of 0-100mm from the inlet (5 a) of the infiltration box (5), and the information acquisition device (2) is arranged on the infiltration box (5) at a linear distance of 110-300mm, preferably 120-250mm, more preferably 130-200mm from the inlet (5 a) of the infiltration box (5).

Preferably, the device also comprises at least one temperature information acquisition device (6).

Preferably, the system further comprises at least one control system (40) for receiving information, processing information and adjusting industrial parameters.

Preferably, the glue injection system (30) comprises at least two glue injection ports (4a, 4b), said glue injection ports (4a, 4b) being located on opposite sides (5m, 5n,5i, 5j) of the infiltration cassette (5).

Preferably, the infiltration box (5) is a cuboid, and the glue injection openings (4 a,4 b) are positioned at two sides (5m, 5n) of the infiltration box in the direction vertical to the horizontal plane.

In a further aspect of the present invention, there is provided a method of preparing a polyurethane pultruded composite comprising the aforementioned automatically controlled method of the present invention for preparing a polyurethane pultruded composite.

The automatically controlled method for preparing a polyurethane pultruded composite comprises:

and adjusting process parameters according to the liquid level information, and preferably selecting the glue injection amount.

Preferably, the infiltration cartridge (5) comprises an inlet (5 a), the linear distance between the acquisition position 1 (2) and the inlet (5 a) being comprised between 0 and 100mm, and the linear distance between the acquisition position 2 (4) and the inlet (5 a) being comprised between 110 and 300mm, preferably between 120 and 250mm, more preferably between 130 and 200.

Preferably, the automatic control method further includes: and pre-storing the corresponding relations between a plurality of historical liquid level information and historical process parameters, and adjusting the process parameters according to the obtained liquid level information and the corresponding relations between the historical liquid level information and the historical process parameters.

Preferably, the method for preparing the polyurethane pultrusion composite material comprising the automatic control method reduces the using amount of the polyurethane composition by more than or equal to 1 percent, preferably more than or equal to 2 percent and more preferably more than or equal to 3 percent compared with the method for preparing the polyurethane pultrusion composite material not comprising the automatic control method. The automatic control method is the automatic control method for preparing the polyurethane pultrusion composite material.

In yet another aspect of the present invention, there is provided a polyurethane product comprising the polyurethane composite of the present invention.

Preferably, the polyurethane product is selected from: cable trays, door and window curtain wall frames, ladder frames, tent poles or tubes, antiglare panels, flooring, sucker rods, utility poles and crossarms, guardrails, grilles, architectural profiles, container profiles and sheets, bicycle frames, fishing poles, cable cores, insulator mandrels, antenna covers, single or sandwich continuous sheets, or sheets for making turbine fan blade girders.

Through repeated experiments, we have surprisingly found that the method for preparing a polyurethane pultruded composite according to the present invention, including an automatic control method, allows for the economical, simple, and efficient preparation of polyurethane pultruded composites having a satisfactory quality and a satisfactory, non-smooth or rough surface. Particularly for fiber reinforced materials with certain thickness, the method of the invention can realize good infiltration and simultaneously can prepare the polyurethane pultrusion composite material with satisfactory surface property. Can also save raw materials, save manpower and material resources, and is more economic and environment-friendly.

The method for preparing the polyurethane composite material by the polyurethane pultrusion process adopts the polyurethane composition, skillfully designs the glue injection device and the infiltration box which are adapted to the polyurethane composition, and uses a proper method, so that the polyurethane pultruded composite material with excellent quality is prepared, the surface condition of the polyurethane pultruded composite material is improved, raw materials, manpower and material resources are saved, the production efficiency is improved, and the cost is saved.

In addition, the polyurethane composition has longer gel time, and can realize better pultrusion of polyurethane. The polyurethane composite material has excellent physical properties and high glass fiber content.

In addition, the polyurethane composition has shorter curing time and longer gel time, and can be better and more flexibly (for example, the polyurethane composition can be soaked and molded for a longer time) suitable for preparing a polyurethane pultrusion composite material, in particular a large polyurethane pultrusion composite material, such as a profile for preparing a main beam of a fan blade. In particular, the fibrous reinforcement material can be wetted and shaped for a longer period of time at normal temperatures, for example before entering the mould, and can be cured more quickly at high temperatures, for example after entering the mould.

Detailed Description

The following describes specific embodiments for carrying out the present invention.

An automatically controlled process for preparing a polyurethane pultruded composite comprising:

Preferably, the infiltration cartridge (5) comprises an inlet (5 a), the linear distance between the acquisition position 1 (2) and the inlet (5 a) being between 0 and 100mm, and the linear distance between the acquisition position 2 (4) and the inlet (5 a) being between 110 and 300 millimeters (mm), preferably between 120 and 250mm, more preferably between 130 and 200.

Preferably, the method further comprises: the method comprises the steps of storing a plurality of corresponding relations between historical liquid level information and historical process parameters in advance, and adjusting the process parameters according to the obtained liquid level information and the corresponding relations between the historical liquid level information and the historical process parameters.

Preferably, the liquid level information is acquired by at least one sensor, preferably two sensors.

Preferably, the sensor is selected from a touch sensor, an infrared sensor or an ultrasonic sensor or a combination thereof.

In some embodiments of the present invention, as shown in fig. 6, the automatic control method of the present invention comprises the steps of: the level information in the infiltration tank is measured in step S11. In step S12, it is determined whether the liquid level information meets the requirements based on the conversion relationship. Wherein the conversion relationship is formed based on the liquid level information and historical data of the process parameters. In step S13, the process parameters are adjusted according to the obtained level information. In step S11, for example, the liquid level information of at least two different positions in the infiltration tank is first measured, for example, the liquid level information and the temperature information of a specific position can be measured by using a sensor.

In a preferred embodiment of the present invention, as shown in fig. 7, the glue injection system 30 includes one or more sensors 301, a computing unit 302, and a transmitting unit 303. Wherein the one or more sensors 301 are configured to measure information such as liquid level and temperature on the polyurethane composite production line, for example, the sensor 301 can be specifically utilized to measure liquid level information and/or temperature information at one or more locations within the infiltration tank.

In some embodiments of the present application, as shown in fig. 8, the control system 40 specifically further includes a receiving unit 401 and an adjusting unit 402. Wherein the receiving unit 401 is configured to receive the liquid level information and the adjusting unit 402 is configured to adjust a parameter of the control system 40 according to the liquid level information. The receiving unit 401 can receive the liquid level information reported by the glue injection system 30 and send the liquid level information to the adjusting unit 402, and the adjusting unit 402 adjusts the parameters of the control system 40 according to the liquid level information. In particular, the adjustment unit 402 may send instructions to adjust parameters of the control system 40 based on the difference between the measured liquid level information and the required liquid level information, the instructions being sent to various execution components (not shown) of the control system 40, such that the measured liquid level information is close to, or even equal to, the required liquid level information. For example, if the measured fluid level information is not sufficient for production, the adjustment unit 402 may send instructions to adjust parameters of the control system 40.

In some embodiments of the present application, the parameters that can be adjusted include recipe parameters and process parameters. The formula parameters comprise raw material proportion, and the process parameters comprise one or more of feeding temperature, glue injection speed, glue injection amount and conveyor belt speed. For example, the adjustment unit 402 may send instructions to a precision pump (e.g., piston pump, gear pump) to adjust the amount of material dosed, the composition, or may send instructions to a conveyor motor to adjust the speed.

Preferably, the polyurethane composition comprises the following components:

component A comprising one or more organic polyisocyanates;

component B comprising:

b1 One or more organic polyols in an amount of 21-60wt.%, preferably 21-40 wt.%, based on the total weight of the polyurethane composition in 100 wt.%;

b2 ) one or more compounds having the structure of formula (I) in an amount of from 0 to 35% by weight, preferably from 4.6 to 35% by weight, based on 100% by weight of the total weight of the polyurethane composition

Wherein R1 is selected from hydrogen, methyl or ethyl; r2 is selected from the group consisting of alkylene having 2 to 6 carbon atoms, 2-bis (4-phenylene) -propane, 1, 4-bis (methylene) benzene, 1, 3-bis (methylene) benzene, 1, 2-bis (methylene) benzene; n is an integer selected from 1 to 6; and

component C, a radical initiator.

When used in the present invention, the fibrous reinforcement is not required in shape and size, and may be, for example, continuous fibers, a web formed by bonding, or a fabric.

In some embodiments of the invention, the fibrous reinforcement material is selected from: glass fibers, carbon fibers, polyester fibers, natural fibers, aramid fibers, nylon fibers, basalt fibers, boron fibers, silicon carbide fibers, asbestos fibers, whiskers, metal fibers, or combinations thereof.

Optionally, the organic polyisocyanate may be any aliphatic, cycloaliphatic or aromatic isocyanate known for use in the preparation of polyurethanes. The isocyanates which can be used according to the invention preferably have a functionality of from 2.0 to 3.5, particularly preferably from 2.1 to 2.9. The isocyanate viscosity is preferably from 5 to 700 mPas, particularly preferably from 10 to 300 mPas, determined at 25 ℃ in accordance with DIN 53019-1-3.

When used in the present invention, the organic polyisocyanate includes an isocyanate dimer, trimer, tetramer, pentamer or a combination thereof.

In a preferred embodiment of the present invention, the isocyanate component a is selected from the group consisting of diphenylmethane diisocyanate (MDI), polyphenylmethane polyisocyanate (pMDI), and polymers, prepolymers or combinations thereof.

Blocked isocyanates may also be used as isocyanate component a, which may be prepared by reacting an excess of an organic polyisocyanate or mixtures thereof with a polyol compound. These compounds and their preparation are well known to those of ordinary skill in the art.

The polyurethane composition of the present invention comprises one or more organic polyols B1). The organic polyol is present in an amount of 21 to 60wt.%, based on the total weight of the polyurethane composition in 100 wt.%. The organic polyol may be an organic polyol commonly used in the art for preparing polyurethanes, including, but not limited to: polyether polyols, polyether carbonate polyols, polyester polyols, polycarbonate diols, polymer polyols, vegetable oil-based polyols, or combinations thereof.

The polyether polyols may be prepared by known processes, for example, by reacting an olefin oxide with an initiator in the presence of a catalyst.

The polyether carbonate polyols, which can be prepared by addition of carbon dioxide and alkylene oxides onto starters containing active hydrogen using double metal cyanide catalysts, can also be used in the present invention.

The polyester polyol is prepared by reacting dicarboxylic acid or dicarboxylic anhydride with polyhydric alcohol.

Methods for measuring hydroxyl number are well known to the person skilled in the art, for example in Houben Weyl, methoden der Organischen Chemie, vol.XIV/2 Makromolekulare Stoffe, p.17, georg Thieme Verlag; stuttgart 1963. The entire contents of this document are incorporated herein by reference.

When used in the present invention, unless otherwise indicated, the functionality, hydroxyl number of the organic polyol all refer to the average functionality and average hydroxyl number.

Optionally, the polyurethane composition of the invention also comprises one or more compounds B2) having the structure of formula (I)

Wherein R is ₁ Selected from hydrogen, methyl or ethyl; r ₂ Selected from alkylene groups having 2 to 6 carbon atoms; n is an integer selected from 1 to 6.

In the preferred embodiment of the inventionIn, R ₂ Selected from the group consisting of ethylene, propylene, butylene, pentylene, 1-methyl-1, 2-ethylene, 2-methyl-1, 2-ethylene, 1-ethyl-1, 2-ethylene, 2-ethyl-1, 2-ethylene, 1-methyl-1, 3-propylene, 2-methyl-1, 3-propylene, 3-methyl-1, 3-propylene, 1-ethyl-1, 3-propylene, 2-ethyl-1, 3-propylene, 3-ethyl-1, 3-propylene, 1-methyl-1, 4-butylene, 2-methyl-1, 4-butylene, 3-methyl-1, 4-butylene and 4-methyl-1, 4-butylene, 2-bis (4-phenylene) -propane, 1, 4-dimethylene benzene, 1, 3-dimethylene benzene, 1, 2-dimethylene benzene.

Preferably, B1) is selected from organic polyols, wherein the organic polyols are selected from organic polyols having a functionality of from 1.7 to 6, preferably from 1.9 to 4.5, and a hydroxyl number of from 150 to 1100mgKOH/g, preferably from 150 to 550mgKOH/g.

In a preferred embodiment of the invention, said B2) component is selected from: hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, or combinations thereof.

The compounds of formula (1) can be prepared by methods customary in the art, for example by (meth) acrylic anhydride or (meth) acrylic acid, (meth) acryloyl halide compounds with HO- (R) ₂ O) _n -H is prepared by esterification reactions, the preparation methods of which are well known to the skilled person, for example, the instructions in chapter three of the handbook of polyurethane raw materials and auxiliaries (liu yi jun, published 4/1/2005), chapter two of the polyurethane elastomers (liu gay jun, published 8/2012), and CN 104974502A, the entire contents of the aforementioned documents being incorporated herein by reference.

Preferably, the polyurethane composition of the present invention further comprises a C radical reaction initiator. The free radical initiator used in the present invention may be added to either the polyol component or the isocyanate component or both components. Specifically, t-butyl peroxyisopropylcarbonate, t-butyl peroxy-3, 5-trimethylhexanoate, methyl ethyl ketone peroxide, cumene hydroperoxide, etc. may be mentioned. Preferably, the free radical reaction initiator of the present invention is present in an amount of 0.1 to 8wt.%, based on 100wt.% of the total weight of the polyurethane composition of the present invention. In addition, an accelerator, such as a cobalt compound or an amine compound, may be present.

Optionally, the polyurethane composition may further comprise a catalyst for catalyzing the reaction of isocyanate groups (NCO) with hydroxyl groups (OH). Suitable catalysts for the polyurethane reaction are preferably, but not limited to, amine catalysts, organometallic catalysts, or mixtures thereof. Preferably, the catalyst is used in an amount of 0.001 to 10wt.%, based on 100wt.% of the total weight of the polyurethane composition of the present invention.

In the embodiment of the present invention, in the addition polymerization reaction of the isocyanate group and the hydroxyl group, the isocyanate group may be an isocyanate group contained in the organic polyisocyanate (component a), an isocyanate group contained in an intermediate product of the reaction of the organic polyisocyanate (component a) with the organic polyol (B1) component) or B2) component, and the hydroxyl group may be a hydroxyl group contained in the organic polyol (B1) component) or B2) component, or a hydroxyl group contained in an intermediate product of the reaction of the organic polyisocyanate (component a) with the organic polyol (B1) component) or B2) component.

In the embodiment of the present invention, the radical polymerization is an addition polymerization of the ethylenic bonds, wherein the ethylenic bonds may be those contained in the B2) component, or those contained in the intermediate product of the reaction of the B2) component with the organic polyisocyanate.

In the present example, the polyurethane addition polymerization (i.e., the addition polymerization of isocyanate groups and hydroxyl groups) is carried out simultaneously with the radical polymerization. As known to those skilled in the art, suitable reaction conditions can be selected so that the polyurethane addition polymerization reaction and the free radical polymerization reaction are carried out in sequence, but the polyurethane matrix prepared in the way is different from the polyurethane resin matrix prepared by simultaneously carrying out the polyurethane addition polymerization reaction and the free radical polymerization reaction, so that the mechanical properties and the manufacturability of the prepared polyurethane composite material are different.

Optionally, the polyurethane composition may further comprise auxiliaries or additives.

The internal mold release agent which can be used in the present invention includes any conventional mold release agent used for producing polyurethanes, and examples thereof include long-chain carboxylic acids, particularly fatty acids such as stearic acid, amines of long-chain carboxylic acids such as stearamide, fatty acid esters, metal salts of long-chain carboxylic acids such as zinc stearate, or polysiloxanes.

Examples of flame retardants that can be used in the present invention include triaryl phosphate, trialkyl phosphate, triaryl or trialkyl phosphate with halogen, melamine resins, halogenated paraffins, red phosphorus, or combinations thereof.

Other adjuvants useful in the present invention include water scavengers such as molecular sieves; defoamers, such as polydimethylsiloxane; coupling agents, such as monoepoxyethane or organic amine functional trialkoxysilane or combinations thereof. Coupling agents are particularly preferred for improving the adhesion of the resin matrix to the fibrous reinforcement. Finely particulate fillers, such as clays and fumed silicas, are commonly used as thixotropic agents.

The radical reaction inhibitor which can be used in the present invention includes polymerization inhibitors and retarders and the like, such as some phenols, quinone compounds or hindered amine compounds, examples of which include methylhydroquinone, p-methoxyphenol, benzoquinone, polymethine pyridine derivatives, low valent copper ions and the like.

Through repeated experiments, the method for preparing the polyurethane pultrusion composite material can control the production process simply and efficiently, so that the polyurethane pultrusion composite material with the required rough surface and the satisfactory quality can be prepared better. The method is suitable for the method, and the glue injection device and the infiltration box which are specially designed can better infiltrate the fiber reinforced material, particularly the fiber infiltration material with certain thickness in shorter time.

In addition, the polyurethane composition has shorter curing time and longer gel time, can be better and more flexibly (for example, can be soaked and molded for a longer time) and is suitable for preparing a polyurethane pultrusion composite material, in particular a large polyurethane pultrusion composite material. In particular, the fibrous reinforcement material can be wetted and shaped for a longer period of time at normal temperatures, for example before entering the mould, and can be cured more quickly at high temperatures, for example after entering the mould.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. To the extent that the definitions of terms used in this specification conflict with meanings commonly understood by those skilled in the art to which this invention pertains, the definitions set forth herein control.

The present invention is illustrated by the following examples, but it should be understood that the scope of the present invention is not limited to these examples.

Drawings

The invention is illustrated in the following description with reference to the accompanying drawings:

FIG. 1 shows a schematic view of the die and process flow shown in the method of producing a polyurethane pultruded composite according to a preferred embodiment of the present invention, wherein: the production process comprises the following steps of 1-fiber reinforced material, 2-1# liquid level sensor or information acquisition position 1, 3-yarn guide plate, 4-2# liquid level sensor or information acquisition position 2, 5-infiltration box, 6-temperature sensor, 7-mold, 8-section bar/polyurethane pultrusion composite material and 9-clamping device.

Fig. 2 is a relative position diagram of the preferred infiltration box and glue injection device/and demolding cloth of the invention, wherein: 2a,2 b-release cloths (in order to avoid the figure being too complex, the fiber reinforced material which should be between the two release cloths is not drawn), 30-glue injection equipment/system, 4a,4 b-glue injection opening, 5 denotes an infiltration box, 5a denotes an infiltration box inlet, 5b denotes an infiltration box outlet, 5m,5n denotes two opposite sides (5 i and 5j are two opposite sides up and down, shown in fig. 3) of the infiltration box (5), and X denotes the perpendicular distance between the glue injection system (30) and the infiltration box inlet (5 a) in the pultrusion direction.

FIG. 3 shows a front view of a preferred infiltration cassette of the present invention, wherein 5i and 5j respectively show the top and bottom opposite sides of the infiltration cassette.

FIG. 4 is a cross-sectional view of a preferred infiltration cartridge of the present invention, where 5 denotes the infiltration cartridge, 5a denotes the infiltration cartridge inlet, and 5b denotes the infiltration cartridge outlet.

Fig. 5 is an automatic control flowchart 200 in the preferred embodiment of the present invention, in which 22 denotes a glue injection machine, 201 denotes-glue injection (↓), 202 denotes + glue injection (↓), 203 denotes fixed frequency glue injection, 1# denotes a

sensor

1,2# denotes a sensor 2, y denotes yes, and N denotes no.

Fig. 6 illustrates the steps of the automatic control method according to the preferred embodiment of the present invention.

Fig. 7 shows a glue injection system according to a preferred embodiment of the present invention.

Fig. 8 is a control system shown in a preferred embodiment of the present invention.

Examples

The performance parameter test in the examples of the present application shows:

functionality, means according to the industry formula: functionality = hydroxyl value (mw) value measured per 56100; wherein the molecular weight is determined by GPC high performance liquid chromatography;

isocyanate index, which means a value calculated by the following formula:

the NCO content, which is the content of NCO groups in the system, is determined by GB/T12009.4-2016.

Pultrusion rate/degree, i.e. the speed at which the migrating fibrous reinforcement passes through the die, is the length of pultruded fibrous reinforcement passing through the die per minute, i.e. the length of the product produced per minute; the specific test method comprises the following steps: the length of the pultruded fibre reinforcement material measured using a speed sensor or stopwatch plus a ruler divided by the time used is the length of passage through the die per unit time, i.e. the rate/degree of pultrusion.

The curing time refers to the time from the beginning of mixing the A component and the B component of the reaction system to curing.

The gel time is a time until the components A and B in the reaction system start to be mixed until the viscosity reaches a certain value (for example, about 10000 mPa.s). The gel time of the present invention is measured using a gel tester. The specific test method comprises the steps of uniformly mixing the component A and the component B, placing the mixture into a gel tester, and recording the time from pressing a start button until the gel tester stops working as the gel time. The gel tester used in the invention is selected from Shanghai Senlan scientific instruments Co, ltd (model GT-STHP-220from Shanghai SINO-LAB Instrument Co, ltd.)

Raw material sources and descriptions

TABLE 1 raw materials List

Raw materials/Equipment name	Specification/brand	Suppliers of goods
			Isocyanates	Desmodur1511L	Costron polymer (China) Co.,Ltd.
Polyol composition	Baydur 18BD209	Costron polymer (China) Co.,Ltd.
			Internal mold release agent	Baydur 18BD101	Costron polymer (China) Co.,Ltd.
Glass fiber roving	PS 4100-2400Tex	Owens Corning composites (China) Co.,Ltd.
			Pultrusion device	Crawler-type pultrusion machine for composite material	Nanjing Noaltai composite Equipment Co Ltd
Glue injection machine	Hydraulic Mini Link System	Magnum Venus Products
			Sensor with a sensor element	T32 intelligent flat membrane pressure transmitter	Beijing Linuo Tian Cheng science and technology Limited
Demoulding cloth	Nylon 66 release fabric 105g/m2	Southern chemical fiber

Example 1:

the production process of glass fiber reinforced polyurethane pultruded profiles/sheets with release cloth is exemplified by the production of 3 millimeter (mm) by 100mm flat panels. In addition, in the embodiment, the cross-sectional area ratio of the inlet and the outlet of the infiltration box is 7: 1; the vertical distance between the glue injection system (30) and the infiltration box inlet (5 a) in the pultrusion direction is 50mm; the width of the glue injection runner is 10mm, the diameter of the runner hole is 2mm, the length of the runner hole is 200mm, and the length of the gap is 50mm.

The glue injection system (30), the infiltration box (5), the mold (7) and the like are assembled and fixed on a pultrusion platform, the 1# liquid level sensor (2) is installed at a position 20mm away from an inlet of the glue injection box, the 2# liquid level sensor (4) is installed at a position 150mm away from the inlet of the glue injection box, and then the glue injection box and the mold are assembled according to a drawing and fixed on the pultrusion platform. The method comprises the steps of leading 220 bundles of glass fibers (1) out of a creel, simultaneously leading two pieces of demolding cloth (2a, 2b) out of the creel, leading the demolding cloth and the glass fibers (1) to sequentially pass through a yarn guide plate/preforming plate (3), a wetting box (5) and a mold (7), then leading the demolding cloth to be pulled forwards by a traction device to enable the glass fibers to be completely pulled down, wherein the demolding cloth 1 (2 a) is close to the upper side (5 i) of the wetting box (5), and the demolding cloth 2 (2 b) is close to the lower side (5 j) of the wetting box. And (3) starting a heating device of the mold (7), and sequentially controlling the mold temperature from an inlet to an outlet as follows: 80C/180/190C, starting a glue injection machine after the temperature is stabilized, and enabling the glue injection machine to inject a component A (Desmodur 1511L) and a component B (100 parts of Baydur 18BD209, 4 parts of Baydur18BD 101) according to the weight ratio of 100:116 are continuously pumped to the static mixing head and injected into the glue-injection box, at which point the level sensor begins to operate:

1) When the No. 1 liquid level sensor (2) detects resin, the sensor sends out an instruction for reducing the glue injection frequency;

2) The No. 1 liquid level sensor (2) cannot detect the liquid level, and meanwhile, when the No. 2 liquid level sensor (4) detects the liquid level, the sensor sends a stable glue injection frequency instruction;

3) When the No. 2 liquid level sensor (4) cannot detect the liquid level, the sensor sends out an instruction for improving the glue injection frequency;

when the production speed is changed, the 1# liquid level sensor (2) and/or the 2# liquid level sensor (4) work synchronously with the glue injection system (30) to maintain stable resin supply:

1) When the No. 1 liquid level sensor (2) detects the liquid level, the liquid level is in a high liquid level, and the sensor sends out an instruction for reducing the glue injection speed;

2) When the No. 2 liquid level sensor (4) cannot detect the liquid level, the liquid level is in a low liquid level, and the sensor sends an instruction for increasing the glue injection speed;

as the preferred scheme can install temperature sensor (6) on the injecting glue box, temperature sensor real-time recording injecting glue box export department material temperature, signal injecting glue system (30)/control system (40) simultaneously to guarantee product quality:

1) When the temperature sensor (6) detects a higher temperature, the sensor informs the glue injection machine to start the resin cooling device so as to reduce the material temperature, and simultaneously informs the pultrusion line to increase the speed and reduce the resin retention;

2) When the temperature sensor detects a lower temperature, the sensor informs the glue injection machine to start the resin heating device so as to reduce the viscosity of the resin and improve the wettability of the resin.

After the resin is mixed by a mixing head, the resin is injected into a glue injection runner from glue injection ports (4 a,4 b) at two sides (5 m,5 n) of a soaking box (5), the resin is uniformly injected into the soaking box through a plurality of runner holes on the resin runner and is fully injected (the average glue injection speed is 110 g/min), so that the glass fiber (1) and the demolding cloth (2a, 2b) are fully soaked, and the glue injection pressure in the soaking box (5) is controlled to be 0.1-15 bar. The glass fiber (1) and the demoulding cloth (2a, 2b) soaked by the soaking box (5) are continuously pulled through the mould (7) by a traction device 8 at the speed of 0.5m/min, the plate is smooth without dry yarns after being discharged from the mould, and when the polyurethane pultrusion composite material/section bar is prepared by metal knocking at the position 1 m away from the mould, the sound is crisp, and the soaking and curing are good.

Before the prepared polyurethane pultrusion composite material/profile is further processed and used, the demolding cloth is removed, and the polyurethane pultrusion composite material/profile with the surface condition meeting the requirement can be obtained.

The polyurethane pultruded composites produced 100 m.multidot.3 mm.multidot.100 mm were recorded as consuming 13kg of the polyurethane composition.

Comparative example 1

The same density, 100m 3 mm 100mm, was obtained as the same polyurethane pultruded composite, recording the amount of polyurethane composition consumed as 13.5kg, following the same procedure and procedure as in example 1, except that no automatic control was added.

From the experimental results, the automatic control method is very suitable for the pultrusion process, can accurately and objectively control the injection time and speed of the raw materials in the pultrusion production process, can save raw materials, manpower and material resources, reduce the cost and is beneficial to commercialization of related products while preparing the polyurethane pultrusion composite material with good infiltration and solidification.

In addition, the polyurethane composition of the invention has shorter curing time and longer gel time, can be better and more flexible (for example, can be soaked and molded for a longer time) and is suitable for the preparation of polyurethane products, in particular large polyurethane products.

Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.

Claims

1. An automatically controlled process for preparing a polyurethane pultruded composite comprising:

injecting a polyurethane composition into a soaking box (5) by using an injection device (30) to form a liquid level;

transmitting the liquid level information to the glue injection device (30) and/or a control system (40);

and adjusting process parameters according to the liquid level information.

2. The method of claim 1, wherein the fluid level information comprises fluid level information for two or more different locations.

3. Method according to claim 2, characterized in that the acquisition positions of the level information are acquisition position 1 (2) and acquisition position 2 (4), respectively, and that the infiltration cartridge (5) comprises an inlet (5 a), the linear distance between the acquisition position 1 (2) and the inlet (5 a) being 0-100mm, and the linear distance between the acquisition position 2 (4) and the inlet (5 a) being 110-300mm, preferably 120-250mm, more preferably 130-200mm.

4. A method according to any of claims 1-3, characterized in that the method further comprises:

the method comprises the steps of storing a plurality of corresponding relations between historical liquid level information and historical process parameters in advance, and adjusting the process parameters according to the obtained liquid level information and the corresponding relations between the historical liquid level information and the historical process parameters.

5. A method according to any of claims 1-3, wherein the level information is acquired by at least one sensor, preferably two sensors.

6. A method according to any one of claims 1-3, characterized in that the method further comprises acquiring temperature information in the infiltration tank (5) and transmitting the temperature information to the glue injection device (30) or the control system (40), the glue injection device (30) or the control system (40) adjusting process parameters, preferably the glue injection temperature, based on the temperature information.

7. A method according to any of claims 1-3, characterized in that the method further comprises:

placing at least one release fabric (2a, 2b) and at least one fibrous reinforcement material (1) in a infiltration tank (5); wherein the release cloth (2a, 2b) partially covers the fibre reinforcement (1);

partially impregnating a polyurethane composition with the fiber-reinforced material (1) via the fiber-reinforced material (1) not covered with the release fabric (2a, 2b);

8. The method as claimed in claim 9, wherein said at least one release cloth (2a, 2b) is two release cloths (2a, 2b), said two release cloths (2a, 2b) being placed respectively on two opposite inner sides (5i, 5j) of the infiltration tank (5), said fibrous reinforcement (1) being placed between the two release cloths (2a, 2b).

9. A method according to any of claims 1-3, characterized in that the method further comprises drawing the impregnated fibrous reinforcement material (1) through a mould (7), the speed of the fibrous reinforcement material (1) through the mould (7) being 0.2-2m/min, preferably 0.2-1.5m/min, and the polyurethane composition being injected into the impregnation box (5) at a speed of 30-2000g/min, preferably 40-1500g/min, more preferably 60-1200 g/min.

10. An apparatus for use in the automatically controlled process for the preparation of a polyurethane pultruded composite according to any of the claims 1 to 9, comprising:

a glue injection device (30), a wetting cartridge (5) comprising an inlet (5 a) and an outlet (5 b), and an information acquisition device (2, 4).

11. The device according to claim 10, characterized in that the information acquisition means (2, 4) are two information acquisition means (2, 4), the information acquisition means (1) (2) being located on the infiltration tank (5) at a linear distance of 0-100mm from the inlet (5 a) of the infiltration tank (5), the information acquisition means (2) (4) being located on the infiltration tank (5) at a linear distance of 110-300mm, preferably 120-250mm, more preferably 130-200mm from the inlet (5 a) of the infiltration tank (5).

12. A device according to claim 11, characterized in that the information acquisition means (2, 4) are two sensors.

13. A method of preparing a polyurethane composite comprising an automatically controlled process for preparing a polyurethane pultruded composite according to any of the claims 1 to 9.

14. The method according to claim 13, wherein the amount of polyurethane composition used in the method for the preparation of a pultruded composite of polyurethane comprising said automatically controlled method is reduced by more than or equal to 1%, preferably more than or equal to 2%, more preferably more than or equal to 3% compared to the method for the preparation of a pultruded composite of polyurethane not comprising said automatically controlled method.

15. A computer-readable storage medium having instructions stored therein, which when executed by a processor, cause the processor to perform the method of any one of claims 1-9.