Thermoplastic transparent glass fiber composite board, preparation method thereof and production device of composite board

Abstract

The invention provides a thermoplastic transparent glass fiber composite board, a preparation method thereof and a production device of the composite board, and the preparation method of the thermoplastic transparent glass fiber composite board comprises the following steps: moving glass fiber cloth to infiltration equipment, infiltrating the glass fiber cloth into liquid MMA resin through the infiltration equipment, moving to ultrasonic equipment for vibration, and then moving to hot drying equipment for hot drying and curing, so as to obtain a glass fiber infiltrated coiled material; and carrying out hot compress on polycarbonate (PC) on the glass fiber infiltrated coiled material through co-extrusion equipment, and compounding to form a PC layer and a glass fiber infiltrated layer which are sequentially laminated, so as to obtain the thermoplastic transparent glass fiber composite board. The liquid MMA resin is fully filled and infiltrated into the glass fiber cloth through the vibration of the ultrasonic equipment, so that the thermoplastic transparent glass fiber composite board is relatively high in transparency and relatively low in haze; the glass fiber layer and the PC layer are arranged in a stacked mode, and the surface layer is the PC layer, so that the thermoplastic transparent glass fiber composite board is smooth in surface and good in impact resistance and strength.

Description

Technical Field

[0001] The present disclosure relates to the technical field of polymer composite materials, and in particular to a thermoplastic transparent glass fiber composite board and a preparation method thereof, as well as a production device for the composite board. Background Art

[0002] With the rapid development of 3C products, the demand for materials that are thin, light, puncture-resistant, high modulus and have a high-quality appearance is becoming increasingly strong. Traditional single-component materials can no longer meet the requirements of product shells for mobile phones, laptops and wearable products with a thickness of 0.2mm-0.4mm. The shell needs to take into account both appearance and protection of internal electronic devices, especially battery devices, and cannot cause excessive extrusion and puncture. Therefore, the product shell needs to adopt a multi-component transparent reinforced composite material.

[0003] Currently, multi-component transparent reinforced composite materials are made of thermosetting epoxy composites or thermoplastic composites. Thermoplastic composites are produced using a unidirectional tape, resin powder, or film heat lamination process. When manufacturing product housings requiring a transparent texture, thermosetting epoxy composites or thermoplastic composites struggle to achieve high transparency and low haze. Thermosetting epoxy composites also present recycling challenges. During the composite manufacturing process, thermoplastic and thermosetting epoxy resins struggle to penetrate the interior of the woven fiberglass fabric, resulting in a significant cavity and refraction within the material layer, increasing the haze of the transparent reinforced composite material and failing to meet transparency requirements.

[0004] For example, the preparation method of a highly transparent, hydrophobic, and moisture-resistant glass fiber reinforced composite material disclosed in the comparative document CN202310345890.9 comprises the following steps: mixing an organosilicon-modified alicyclic epoxy resin and a bisphenol A epoxy resin to obtain a resin mixture; adding the resin mixture to solvent A, adding a curing agent and an accelerator, and mixing them evenly to obtain an epoxy resin adhesive; impregnating glass fibers with the epoxy resin adhesive, and heat-treating the impregnated glass fibers to obtain the highly transparent, hydrophobic, and moisture-resistant glass fiber reinforced composite material. The composite material of this scheme uses a thermosetting epoxy resin, which has the problem of difficult recycling, and it is difficult for the epoxy resin to completely impregnate the glass fibers, resulting in a large proportion of cavities in the composite material, resulting in a high haze of the composite material, which does not meet the transparency requirements.

[0005] Another example is a transparent weather-resistant glass fiber reinforced thermoplastic composite material and its preparation method disclosed in the comparative document CN202411691372.3. Polyethylene terephthalate and polyethylene isophthalate are dried separately, melt blended, and extruded to prepare a polymer; the polymer and poly(m-phenylenediamine adipamide) are dried and mixed to prepare a mixture, and after adding a compatibilizer, melt blended, compression molded, and prepared into a film; the film and glass fiber material are alternately layered, and then hot-pressed to obtain a transparent weather-resistant glass fiber reinforced thermoplastic composite material. When the film and glass fiber material are alternately layered in this solution, the film cannot penetrate the glass fiber during hot pressing, resulting in a large proportion of cavities in the glass fiber, resulting in a high haze of the composite material and failing to meet the transparency requirements. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a thermoplastic transparent glass fiber composite sheet with high transparency, low haze, smooth surface and good impact resistance, a preparation method thereof, and a production device for the composite sheet.

[0007] The purpose of this disclosure is achieved through the following technical solutions:

[0008] A method for preparing a thermoplastic transparent glass fiber composite plate comprises the following steps:

[0009] Moving the glass fiber cloth to an impregnation device, wherein the glass fiber cloth is impregnated with liquid MMA resin through the impregnation device to obtain an impregnated glass fiber cloth;

[0010] Moving the impregnated glass fiber cloth to an ultrasonic device, wherein the ultrasonic device vibrates the impregnated glass fiber cloth to obtain a reinforced impregnated glass fiber cloth;

[0011] Moving the reinforced impregnated glass fiber cloth to a heat drying device, wherein the heat drying device heat-cures the reinforced impregnated glass fiber cloth to obtain a glass fiber impregnated coil;

[0012] The polycarbonate PC is hot-applied to the glass fiber impregnated coil through a co-extrusion device for compounding, and after compounding, a PC layer and a glass fiber impregnated layer are stacked in sequence to obtain a thermoplastic transparent glass fiber composite board with both upper and lower surface layers being PC layers.

[0013] In one embodiment, the liquid MMA resin includes methyl methacrylate (MMA) prepolymer and benzoyl peroxide (BPO) as a catalyst.

[0014] In one embodiment, the viscosity of the methyl methacrylate (MMA) prepolymer is 200 mPa·s-1000 mPa·s.

[0015] In one embodiment, the impregnated glass fiber cloth is moved to the ultrasonic device, and the ultrasonic device vibrates the impregnated glass fiber cloth to obtain a reinforced impregnated glass fiber cloth, including the following steps:

[0016] Moving the impregnated glass fiber cloth into the ultrasonic device via a roll-to-roll device;

[0017] The vibration frequency of the ultrasonic device is 16 kHz to 24 kHz, and the vibration time of the ultrasonic device is 30 seconds to 60 seconds, and the impregnated glass fiber cloth is vibrated to obtain a reinforced impregnated glass fiber cloth;

[0018] The reinforced impregnated glass fiber cloth is moved out of the ultrasonic device through the roll-to-roll device.

[0019] In one embodiment, the reinforced impregnated glass fiber cloth is moved to a heat drying device, and the heat drying device heat-cures the reinforced impregnated glass fiber cloth to obtain a glass fiber impregnated coil, comprising the following steps:

[0020] The reinforced impregnated glass fiber cloth is moved from the ultrasonic device to the hot drying device through a roll-to-roll device;

[0021] The temperature of the heat drying equipment is 60-120°C, and the heat drying time is 3-5 minutes. The heat drying equipment heat-dries and solidifies the reinforced impregnated glass fiber cloth to obtain a glass fiber impregnated coiled material;

[0022] The glass fiber impregnated coil is wound by a roll-to-roll device.

[0023] In one embodiment, after the reinforced impregnated glass fiber cloth is moved to a heat drying device, and the heat drying device heat-cures the reinforced impregnated glass fiber cloth to obtain a glass fiber impregnated coil, before the glass fiber impregnated coil is wound, the following steps are further included:

[0024] The glass fiber impregnated coil is cooled.

[0025] In one embodiment, polycarbonate (PC) is laminated to the glass fiber impregnated coil by hot-coating through a co-extrusion device to form a PC layer and a glass fiber impregnated layer stacked in sequence, thereby obtaining a thermoplastic transparent glass fiber composite sheet having both upper and lower surface layers of PC, including the following steps:

[0026] The polycarbonate PC is heated to 220°C-250°C through a co-extrusion device to form a molten polycarbonate PC melt;

[0027] Casting polycarbonate PC melt onto the surfaces of both sides of the glass fiber impregnated coil;

[0028] The glass fiber impregnation layer is stacked and coated with polycarbonate PC melt, and then rolled by a co-extrusion device to form a sequentially stacked PC layer and a glass fiber impregnation layer, thereby obtaining a thermoplastic transparent glass fiber composite board with PC layers on both the upper and lower surfaces.

[0029] A thermoplastic transparent glass fiber composite sheet is prepared by the preparation method of the thermoplastic transparent glass fiber composite sheet described in any of the above embodiments, comprising a plurality of PC layers and a plurality of glass fiber impregnation layers, wherein the PC layers and the glass fiber impregnation layers are stacked in sequence, and each of the glass fiber impregnation layers is covered with a PC layer on both sides.

[0030] In one embodiment, the thickness of the thermoplastic transparent glass fiber composite sheet is greater than 0.3 mm.

[0031] A production device for thermoplastic transparent glass fiber composite board, used to prepare the thermoplastic transparent glass fiber composite board described in any of the above embodiments, including roll-to-roll equipment, impregnation equipment, ultrasonic equipment, heat drying equipment and co-extrusion equipment, the roll-to-roll equipment including a unwinding assembly and a winding assembly, the glass fiber cloth is wound on the unwinding assembly, one end of the glass fiber cloth is sequentially arranged in the impregnation equipment, ultrasonic equipment and heat drying equipment and wound on the winding assembly, the number of the winding assemblies is multiple, the winding assembly is used to unwind and rewind glass fiber impregnated coils, the glass fiber impregnated coils unwound by the winding assembly are set in the co-extrusion equipment, and the co-extrusion equipment is used to composite polycarbonate PC with the glass fiber impregnated coils to prepare the thermoplastic transparent glass fiber composite board.

[0032] Compared with the prior art, the present disclosure has at least the following advantages:

[0033] In the above-mentioned preparation method of thermoplastic transparent glass fiber composite board, the fluidity of liquid MMA resin is good, and the liquid MMA resin can quickly impregnate the glass fiber cloth. The vibration of the ultrasonic equipment accelerates the liquid MMA resin to enter the glass fiber cloth, so that the liquid MMA resin is fully filled in the gaps of the glass fiber cloth, reducing the cavity ratio of the glass fiber impregnated coil, making the glass fiber impregnated coil have higher transparency and lower haze, thereby making the thermoplastic transparent glass fiber composite board composed of the glass fiber impregnated coil and transparent polycarbonate PC have higher transparency and lower haze, thereby making the thermoplastic transparent glass fiber composite board have better light transmittance; the polycarbonate PC melt is cast and coated on the glass fiber impregnated coil for bonding, the liquid MMA resin of the glass fiber layer and the PC layer have higher bonding strength, the glass fiber layer provides rigid support, the PC layer has good toughness, the glass fiber layer and the PC layer are stacked, so that the strength and rigidity of the thermoplastic transparent glass fiber composite board are good, the surface layer of the thermoplastic transparent glass fiber composite board is all PC layer, so that the surface of the thermoplastic transparent glass fiber composite board is smooth and has good impact resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 This is a flow chart of the steps of a method for preparing a thermoplastic transparent glass fiber composite board according to one embodiment;

[0036] Figure 2 This is a partial structural diagram of a production device for a thermoplastic transparent glass fiber composite board according to an embodiment;

[0037] Figure 3 for Figure 2 The schematic diagram of the partial structure of the production device of the thermoplastic transparent glass fiber composite board is shown. DETAILED DESCRIPTION

[0038] To facilitate understanding of the present disclosure, a more comprehensive description of the present disclosure will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present disclosure. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure.

[0039] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. The terms used herein in the specification of this disclosure are intended only to describe specific embodiments and are not intended to limit this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] In order to better understand the technical solutions and beneficial effects of the present disclosure, the present disclosure is further described in detail below with reference to specific embodiments:

[0042] The present application provides a method for preparing a thermoplastic transparent glass fiber composite sheet. The above-mentioned method for preparing a thermoplastic transparent glass fiber composite sheet comprises the following steps: moving a glass fiber cloth to an impregnation device, wherein the glass fiber cloth is impregnated with liquid MMA resin through the impregnation device to obtain an impregnated glass fiber cloth; moving the impregnated glass fiber cloth to an ultrasonic device, wherein the ultrasonic device vibrates the impregnated glass fiber cloth to obtain a reinforced impregnated glass fiber cloth; moving the reinforced impregnated glass fiber cloth to a hot drying device, wherein the hot drying device heat-dries and solidifies the reinforced impregnated glass fiber cloth to obtain a glass fiber impregnated coil; and applying polycarbonate (PC) to the glass fiber impregnated coil through a co-extrusion device for compounding, forming a PC layer and a glass fiber impregnated layer stacked in sequence after compounding, thereby obtaining a thermoplastic transparent glass fiber composite sheet with both upper and lower surface layers being PC layers.

[0043] please Figure 1 Refer to the method for preparing a thermoplastic transparent glass fiber composite sheet according to an embodiment of the present invention, which comprises the following steps:

[0044] S101 moves the glass fiber cloth to an impregnation device, where the glass fiber cloth is impregnated with liquid MMA resin to obtain an impregnated glass fiber cloth. In this embodiment, the liquid MMA resin has a low viscosity and good permeability. The impregnation device can use an impregnation tank, spray, or curtain method to impregnate the glass fiber cloth. The impregnation tank method immerses the glass fiber cloth in a resin tank for impregnation. The spray method atomizes the resin and then sprays it for impregnation. The curtain method forms a continuous curtain of resin that vertically passes through the glass fiber cloth for impregnation.

[0045] S103 moves the impregnated glass fiber cloth to an ultrasonic device, which vibrates the impregnated glass fiber cloth to obtain a reinforced impregnated glass fiber cloth. In this embodiment, when ultrasonic waves propagate through the liquid, they generate tiny bubbles that quickly burst, impacting the surface of the glass fibers and promoting resin penetration into the micropores. The acoustic vibrations also accelerate the diffusion of MMA resin molecules, evenly distributing the resin and ensuring that the liquid MMA resin fully fills the pores of the glass fiber cloth.

[0046] S105 moves the reinforced impregnated fiberglass cloth to a heat drying device, where the heat drying device heat-cures the reinforced impregnated fiberglass cloth to obtain a fiberglass impregnated coil. In this embodiment, the MMA resin is polymerized by a free agent to form a three-dimensional network structure. During the curing process, the resin further wraps around the fibers. After curing, the glass transition temperature of the polymethyl methacrylate (PMMA) is increased, imparting rigidity to the PMMA resin polymer, resulting in improved strength and shear resistance of the fiberglass impregnated coil.

[0047] S107: Polycarbonate PC is heat-applied to the glass fiber impregnated coil through a co-extrusion device for compounding. After compounding, a PC layer and a glass fiber impregnated layer are stacked in sequence to obtain a thermoplastic transparent glass fiber composite sheet, wherein the upper and lower surface layers of the thermoplastic transparent glass fiber composite sheet are both PC layers. In this embodiment, the polycarbonate PC is melted through a co-extrusion device and then heat-applied to the glass fiber impregnated coil. The polycarbonate PC is bonded to the polymethyl methacrylate (PMMA) resin, so that the bonding strength between the polycarbonate PC and the glass fiber impregnated layer is high, the surface of the formed PC layer is smooth, and the transparency of the PC layer and the glass fiber impregnated layer is high, so that the obtained thermoplastic transparent glass fiber composite sheet has low haze and high transparency. The obtained thermoplastic transparent glass fiber composite sheet has a light transmittance greater than 85% and a haze less than 5%.

[0048] In the above-mentioned preparation method of thermoplastic transparent glass fiber composite board, the fluidity of liquid MMA resin is good, and the liquid MMA resin can quickly impregnate the glass fiber cloth. The vibration of the ultrasonic equipment accelerates the liquid MMA resin to enter the glass fiber cloth, so that the liquid MMA resin is fully filled in the gaps of the glass fiber cloth, reducing the cavity ratio of the glass fiber impregnated coil, making the glass fiber impregnated coil have higher transparency and lower haze, thereby making the thermoplastic transparent glass fiber composite board composed of the glass fiber impregnated coil and transparent polycarbonate PC have higher transparency and lower haze, thereby making the thermoplastic transparent glass fiber composite board have better light transmittance; the polycarbonate PC melt is cast and coated on the glass fiber impregnated coil for bonding, the liquid MMA resin of the glass fiber layer and the PC layer have higher bonding strength, the glass fiber layer provides rigid support, the PC layer has good toughness, the glass fiber layer and the PC layer are stacked, so that the strength and rigidity of the thermoplastic transparent glass fiber composite board are good, the surface layer of the thermoplastic transparent glass fiber composite board is all PC layer, so that the surface of the thermoplastic transparent glass fiber composite board is smooth and has good impact resistance.

[0049] In one embodiment, the liquid MMA resin comprises a methyl methacrylate (MMA) prepolymer and a benzoyl peroxide (BPO) catalyst. In this embodiment, the methyl methacrylate (MMA) prepolymer is an intermediate formed through a partial polymerization reaction. The excellent fluidity of the methyl methacrylate (MMA) prepolymer allows the MMA resin prepolymer to penetrate deeply into the pores within the glass fiber. After curing, the MMA resin prepolymer forms a mechanically locked structure with the glass fiber, thereby improving the rigidity and strength of the glass fiber-impregnated coil. The benzoyl peroxide (BPO) catalyst promotes the free radical polymerization of the MMA resin prepolymer through thermal initiation, resulting in a highly transparent polymethyl methacrylate (PMMA) resin formed from the MMA resin prepolymer.

[0050] In one embodiment, the viscosity of the methyl methacrylate MMA prepolymer is 200mPa·s-1000mPa·s. In this embodiment, the molecular chain of the low molecular weight methyl methacrylate MMA prepolymer is short, the intermolecular force is weak, the monomer content is high, and the viscosity is low. The molecular chain of the high molecular weight methyl methacrylate MMA prepolymer is long, the intermolecular friction is increased, and the viscosity is high. The viscosity of the methyl methacrylate MMA prepolymer is controlled by adjusting the molecular weight of the methyl methacrylate MMA prepolymer. It can be understood that when the molecular weight of the methyl methacrylate MMA prepolymer is greater than 1000mPa·s, the wetting effect of the methyl methacrylate MMA prepolymer on the glass fiber cloth decreases, and the transparency of the methyl methacrylate MMA prepolymer after curing of the glass fiber cloth decreases. When the MMA resin When the viscosity is less than 200 mPa·s, the methyl methacrylate MMA prepolymer has excellent permeability to the glass fiber cloth, but the methyl methacrylate MMA prepolymer is easy to drip from the glass fiber cloth, thereby affecting the distribution uniformity of the methyl methacrylate MMA prepolymer on the glass fiber cloth; the viscosity of the methyl methacrylate MMA prepolymer is 200 mPa·s-1000 mPa·s, which reduces the problems of the methyl methacrylate MMA prepolymer on the glass fiber cloth, makes the methyl methacrylate MMA prepolymer have a better wetting effect on the glass fiber cloth, and thus makes the methyl methacrylate MMA prepolymer have a higher transparency after curing on the glass fiber cloth.

[0051] In one embodiment, the method further includes the following steps before moving the glass fiber cloth to the impregnation device:

[0052] A vinyl coupling agent is sprayed on the surface of the glass fiber cloth and then dried at 80°C-100°C for 15-30 minutes. In this embodiment, the vinyl group undergoes free radical copolymerization with the double bonds in the MMA resin to form chemical bonds. The vinyl group's binding strength with the MMA resin is stronger than that of a silane coupling agent, thereby improving the interfacial bonding between the glass fiber and the MMA resin and enhancing the wettability of the glass fiber cloth with the MMA resin prepolymer.

[0053] In one embodiment, the impregnated glass fiber cloth is moved to the ultrasonic device, and the ultrasonic device vibrates the impregnated glass fiber cloth to obtain a reinforced impregnated glass fiber cloth, including the following steps:

[0054] Moving the impregnated glass fiber cloth into the ultrasonic device via a roll-to-roll device;

[0055] The vibration frequency of the ultrasonic device is 16 kHz to 24 kHz, and the vibration time of the ultrasonic device is 30 seconds to 60 seconds, and the impregnated glass fiber cloth is vibrated to obtain a reinforced impregnated glass fiber cloth;

[0056] The reinforced impregnated glass fiber cloth is moved out of the ultrasonic device through the roll-to-roll device.

[0057] In this embodiment, ultrasonic vibration improves the resin's impregnation of glass fiber through cavitation effect and acoustic streaming effect. The vibration frequency is 16kHZ-24kHZ. High-frequency ultrasonic waves are coordinated with low-viscosity methyl methacrylate (MMA) prepolymer to achieve deep impregnation. Ultrasonic waves destroy the surface tension of the resin, thereby obtaining a uniformly impregnated reinforced glass fiber cloth.

[0058] Furthermore, when the ultrasonic device vibrates the impregnated glass fiber cloth, if the viscosity of the liquid MMA is low, the ultrasonic wave-induced acoustic cavitation effect causes bubbles to rapidly contract and expand under the action of the acoustic pressure, resulting in localized differential heat generation. The heated benzoyl peroxide (BPO) catalyst triggers premature polymerization of the MMA, affecting the impregnation of the glass fiber cloth with the MMA resin prepolymer. Therefore, it is necessary to reduce the effect of ultrasonic wave-induced acoustic cavitation on the MMA resin temperature rise. When vibrating the impregnated glass fiber cloth, the ultrasonic device uses a pulsed ultrasonic mode, operating for 2-4 seconds with a 1-2 second pause, and a duty cycle of 20%-50%.

[0059] It can be understood that, compared with the continuous ultrasound mode, the temperature rise of the acoustic cavitation effect induced in the methyl methacrylate (MMA) prepolymer using the pulsed ultrasound mode is lower, which prevents the temperature rise from inducing the self-polymerization reaction of the methyl methacrylate (MMA) prepolymer. At the same time, the pulsed ultrasound mode can reduce the damage to the impregnated glass fiber cloth.

[0060] Furthermore, in the process of ultrasonic vibration of the impregnated glass fiber cloth by the ultrasonic device, by controlling the working time of the pulse ultrasonic mode of the ultrasonic device and controlling the duty cycle of the ultrasonic wave, the impregnation of the glass fiber cloth can be improved and the damage to the glass fiber cloth can be reduced, including the following steps:

[0061] When the viscosity of the methyl methacrylate (MMA) prepolymer is less than 500 mPa·s, the pulse ultrasonic mode operates for 2 seconds, and the ultrasonic foil device has a duty cycle of 20%-30%. When the viscosity of the methyl methacrylate (MMA) prepolymer is greater than 500 mPa·s, the pulse ultrasonic mode operates for 3-4 seconds, and the ultrasonic foil device has a duty cycle of 30%-50%. In this embodiment, when the viscosity of the methyl methacrylate (MMA) prepolymer is greater than 500 mPa·s, increasing the duty cycle of the ultrasonic foil device improves the wetting effect of the methyl methacrylate (MMA) prepolymer on the glass fiber cloth, thereby reducing the proportion of cavities in the reinforced impregnated glass fiber cloth and improving the transparency of the glass fiber impregnated coil. When the viscosity of the methyl methacrylate (MMA) prepolymer is less than 500 mPa·s, the resin has high fluidity, allowing ultrasonic energy to be easily transmitted to the micropores of the glass fiber cloth. Reducing the duty cycle reduces energy input, thereby minimizing damage to the glass fiber cloth.

[0062] Furthermore, when the viscosity of the methyl methacrylate (MMA) prepolymer is greater than 500 mPa·s and the glass fiber cloth is high-density, the duty cycle of the ultrasonic device output is controlled to be 40%-50%. When the glass fiber cloth is low-density, the duty cycle of the ultrasonic device output is controlled to be 20%-30%. In this embodiment, when the glass fiber cloth is high-density woven, the high duty cycle increases the cavitation impact force of the ultrasonic wave, allowing the methyl methacrylate (MMA) prepolymer to fully penetrate the high-density woven cloth. When the glass fiber cloth is low-density, MMA easily penetrates the low-density glass fiber cloth. When the ultrasonic duty cycle is reduced, the methyl methacrylate (MMA) prepolymer maintains its penetration into the glass fiber cloth, reducing damage to the low-density glass fiber cloth caused by the ultrasonic wave.

[0063] In one embodiment, the reinforced impregnated glass fiber cloth is heat-cured by an ultrasonic device and a heat-drying device to obtain a glass fiber impregnated coil, comprising the following steps:

[0064] The reinforced impregnated fiberglass cloth is moved from the ultrasonic equipment to the hot drying equipment through a roll-to-roll device;

[0065] The temperature of the heat drying equipment is 60° C.-120° C., and the heat drying time is 3 min-5 min. The heat drying equipment heat-dries the reinforced impregnated glass fiber cloth to obtain a glass fiber impregnated coil;

[0066] The glass fiber impregnated coil is wound.

[0067] In this embodiment, the ultrasonically treated reinforced impregnated glass fiber cloth is converted into a glass fiber impregnated coil by heat curing. When the heat curing temperature rises to above 60°C, the benzoyl peroxide (BPO) catalyst is heated to initiate MMA free radical polymerization to form a cross-linked network, and the MMA resin is polymerized to form polymethyl methacrylate (PMMA). When the heat curing temperature is less than 120°C, thermal degradation of the MMA resin is prevented. The heat curing time is greater than 3 minutes, which ensures the curing of the MMA resin on the glass fiber cloth and avoids curing shrinkage caused by insufficient curing. The heat curing time is less than 5 minutes, which reduces the strength attenuation of the glass fiber caused by excessive heating, making the heat curing process time-consuming, thereby improving production efficiency.

[0068] In one embodiment, after the heat drying equipment heat-dries the reinforced impregnated glass fiber cloth to obtain the glass fiber impregnated coil, and before the glass fiber impregnated coil is wound, the following steps are further included:

[0069] The glass fiber impregnated coil is cooled for 15-25 minutes. In this embodiment, the curing shrinkage of polymethyl methacrylate (PMMA) formed by polymerization of MMA resin generates internal stress. The temperature difference between the high-temperature glass fiber impregnated coil and the room temperature environment generates thermal gradient stress. By cooling the glass fiber impregnated coil, the internal stress is released, the residual stress and deformation are reduced, and the size and performance of the glass fiber impregnated coil are stabilized.

[0070] Furthermore, after the MMA resin is polymerized to form polymethyl methacrylate (PMMA), it is necessary to eliminate internal stress, stabilize the polymer structure, and perform step-by-step cooling during the static cooling process:

[0071] The cured and heated glass fiber impregnated coil is purged in the first stage by vertical laminar flow, with the air flow temperature at 80-100°C and the purging time at 2-5 minutes.

[0072] The glass fiber impregnated coil is purged in the second stage by vertical laminar flow, the air flow temperature is 60-80°C, and the purging time is 5-10 minutes;

[0073] The glass fiber impregnated coil is purged in the second stage by vertical laminar flow, the air flow temperature is 40° C.-60° C., and the purging time is 5 min-10 min.

[0074] In this embodiment, during the first stage of blowing, the vertical laminar flow passes through the air in a unidirectional and uniform manner in the vertical direction, avoiding temperature unevenness caused by lateral turbulence, thereby releasing the residual stress of the glass fiber impregnated coil; during the second stage of blowing, the stress is further released to prevent uneven surface shrinkage caused by rapid cooling; during the third stage of blowing, the temperature of the glass fiber impregnated coil is brought close to room temperature, eliminating the influence of heat on subsequent winding; the stress can be gradually released through three-stage stepped cooling to avoid deformation of the glass fiber impregnated coil caused by residual stress caused by sudden cooling, thereby reducing the residual stress and warping of the glass fiber impregnated coil, and improving the performance stability of the glass fiber impregnated coil.

[0075] In one embodiment, polycarbonate (PC) is laminated to the glass fiber impregnated coil by hot-coating through a co-extrusion device to form a PC layer and a glass fiber impregnated layer stacked in sequence, thereby obtaining a thermoplastic transparent glass fiber composite sheet having both upper and lower surface layers of PC, including the following steps:

[0076] The polycarbonate PC is heated to 220°C-250°C through a co-extrusion device to form a molten polycarbonate PC melt;

[0077] Casting polycarbonate PC melt onto the surfaces of both sides of the glass fiber impregnated coil;

[0078] The glass fiber impregnation layer is stacked and coated with polycarbonate PC melt, and then rolled by a co-extrusion device to form a sequentially stacked PC layer and a glass fiber impregnation layer, thereby obtaining a thermoplastic transparent glass fiber composite board with PC layers on both the upper and lower surfaces.

[0079] In this embodiment, the polycarbonate PC melt is coated on the glass fiber impregnated coil and quickly cooled to form. When the high-temperature polycarbonate PC melt comes into contact with the polymethyl methacrylate (PMMA) resin of the glass fiber impregnated coil, the molecular chain segments on the surface of the polymethyl methacrylate (PMMA) are activated, which promotes the penetration of the polycarbonate PC melt and the polymethyl methacrylate (PMMA) resin, so that the PC layer and the glass fiber impregnated layer have better bonding. After rolling, the thermoplastic transparent glass fiber composite board has higher flatness; the PC layer completely wraps the glass fiber impregnated layer, and the transparency of the PC layer and the glass fiber impregnated layer is higher, so that the thermoplastic transparent glass fiber composite board has higher transparency and lower haze.

[0080] Furthermore, in one embodiment, the glass fiber impregnated coil layer is preheated at a temperature of 60°C to 90°C. In this embodiment, the preheating temperature is less than 90°C to reduce deformation of the glass fiber impregnated coil due to premature softening of the polymethyl methacrylate (PMMA). By preheating the glass fiber impregnated coil layer, the bonding strength between the polycarbonate (PC) melt and the polymethyl methacrylate (PMMA) of the glass fiber impregnated coil layer is increased, and the internal stress generated by the temperature difference between the glass fiber impregnated coil layer and the PC layer is reduced, thereby improving the flatness of the thermoplastic transparent glass fiber composite sheet.

[0081] like Figure 3 As shown, the present application also provides a thermoplastic transparent glass fiber composite sheet, which is prepared by the preparation method of the thermoplastic transparent glass fiber composite sheet described in any of the above embodiments, including a plurality of PC layers 600 and a plurality of glass fiber impregnation layers 700, wherein the PC layers 600 and the glass fiber impregnation layers 700 are stacked in sequence, and each of the glass fiber impregnation layers 700 is covered with a PC layer 600 on both sides.

[0082] In this embodiment, in the thermoplastic transparent glass fiber composite sheet, each glass fiber impregnation layer 700 is completely wrapped by the PC layer 600 on both sides, and the surface layer of the thermoplastic transparent glass fiber composite sheet is the PC layer 600. The PC layer 600 has good transparency. The PC layer 600 improves the impact resistance, so that the surface of the thermoplastic transparent glass fiber composite sheet is smooth and has good impact resistance. The glass fiber impregnation layer 700 includes glass fiber cloth and impregnated and cured polymethyl methacrylate PMMA resin. The polymethyl methacrylate PMMA resin gives the material rigidity and improves the strength of the thermoplastic transparent glass fiber composite sheet. The glass fiber impregnation layer 700 has a small cavity ratio and a high transparency, and the thermoplastic transparent glass fiber composite sheet has a large light transmittance. Specifically, the cavity ratio of the glass fiber impregnation layer 700 is less than 2%, and the obtained thermoplastic transparent glass fiber composite sheet has a light transmittance greater than 85% and a haze less than 5%.

[0083] In one embodiment, the thickness of the thermoplastic transparent glass fiber composite sheet is greater than 0.3 mm. In this embodiment, the PC layer 600 and the glass fiber layer thermoplastic transparent glass fiber composite sheet are relatively thin, having good transparency and impact resistance, making the thermoplastic transparent glass fiber composite sheet suitable for mobile phone, laptop computer, and wearable product casings, and can balance the appearance and protection of internal electronic components. The alternating stacking of the PC layer 600 and the glass fiber impregnation layer 700, by controlling the number of layers of the PC layer 600 and the glass fiber impregnation layer 700, can produce thermoplastic transparent glass fiber composite sheets of different thicknesses, making the thermoplastic transparent glass fiber composite sheet suitable for different product structures.

[0084] Furthermore, in one embodiment, the glass fiber impregnation layer 700 has a thickness of less than 1.5 mm. The glass fiber impregnation layer 700 provides structural support. A too thick glass fiber impregnation layer 700 affects transparency. A thinner glass fiber impregnation layer 700 improves transparency, resulting in a thinner thermoplastic transparent glass fiber composite sheet formed by combining the glass fiber impregnation layer 700 with the PC layer 600.

[0085] In one embodiment, the thermoplastic transparent glass fiber composite sheet has a thickness of 0.3 mm to 0.5 mm, and a flexural modulus of 3.5 GPa to 5 GPa. In this embodiment, the thermoplastic transparent glass fiber composite sheet is provided with rigidity by the glass fiber impregnation layer 700, and the PC layer 600 provides impact resistance and toughness. The thermoplastic transparent glass fiber composite sheet has a flexural modulus of 3.5 GPa to 5 GPa at a thickness of 0.3 mm to 0.5 mm, making the thermoplastic transparent glass fiber composite sheet lightweight and highly rigid, making it more suitable for use in mobile phone, laptop computer, and wearable product casings.

[0086] like Figure 2 and Figure 3As shown, the present application also provides a device for thermoplastic transparent glass fiber composite board, a production device for thermoplastic transparent glass fiber composite board, used to prepare the thermoplastic transparent glass fiber composite board described in any of the above embodiments, including a roll-to-roll device 100, an impregnation device 200, an ultrasonic device 300, a heat drying device 400 and a co-extrusion device 500, the roll-to-roll device 100 includes a unwinding component 110 and a winding component 120, the glass fiber cloth is wound on the unwinding component 110, one end of the glass fiber cloth is sequentially arranged in the impregnation device 200, the ultrasonic device 300 and the heat drying device 400 and wound on the winding component 120, the number of the winding components 120 is multiple, the winding component 120 is used to unwind and rewind glass fiber impregnated coils, the glass fiber impregnated coils unwound by the winding component 120 are arranged in the co-extrusion device 500, and the co-extrusion device 500 is used to composite polycarbonate PC with the glass fiber impregnated coils to prepare the thermoplastic transparent glass fiber composite board. In this embodiment, the unwinding assembly 110 unwinds and unrolls the glass fiber cloth, the impregnation device 200 impregnates the glass fiber cloth to a preliminary impregnation state, the ultrasonic device 300 vibrates the glass fiber cloth to promote the penetration and impregnation of the glass fiber bundles by the resin, thereby obtaining a reinforced impregnated glass fiber cloth, the drying device 400 heat-cures the reinforced impregnated glass fiber cloth to obtain a glass fiber impregnated coil, and the winding assembly 120 is used to wind the treated glass fiber impregnated coil. In the coextrusion device 500, the glass fiber impregnated coil is compounded with polycarbonate (PC) under heat and pressure to form a thermoplastic transparent glass fiber composite sheet. The ultrasonic device 300 improves the bonding of the liquid MMA resin and the glass fiber cloth to obtain a thermoplastic transparent glass fiber composite sheet with a low cavity ratio and high light transmittance. The thermoplastic transparent glass fiber composite sheet has the glass fiber impregnated coil as the core layer and the PC layer 600 as the surface layer, resulting in a smooth surface, good impact resistance, and high strength.

[0087] Compared with the prior art, the present disclosure has at least the following advantages:

[0088] In the above-mentioned preparation method of thermoplastic transparent glass fiber composite board, the fluidity of liquid MMA resin is good, and the liquid MMA resin can quickly impregnate the glass fiber cloth. The vibration of the ultrasonic equipment accelerates the liquid MMA resin to enter the glass fiber cloth, so that the liquid MMA resin is fully filled in the gaps of the glass fiber cloth, reducing the cavity ratio of the glass fiber impregnated coil, making the glass fiber impregnated coil have higher transparency and lower haze, thereby making the thermoplastic transparent glass fiber composite board composed of the glass fiber impregnated coil and transparent polycarbonate PC have higher transparency and lower haze, thereby making the thermoplastic transparent glass fiber composite board have better light transmittance; the polycarbonate PC melt is cast and coated on the glass fiber impregnated coil for bonding, the liquid MMA resin of the glass fiber layer and the PC layer have higher bonding strength, the glass fiber layer provides rigid support, the PC layer has good toughness, the glass fiber layer and the PC layer are stacked, so that the strength and rigidity of the thermoplastic transparent glass fiber composite board are good, the surface layer of the thermoplastic transparent glass fiber composite board is all PC layer, so that the surface of the thermoplastic transparent glass fiber composite board is smooth and has good impact resistance.

[0089] The above-described embodiments merely represent several implementation methods of the present disclosure. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the scope of the present disclosure, all of which fall within the scope of protection of the present disclosure. Therefore, the scope of protection of the disclosed patent shall be determined by the appended claims.

Claims

1. A method for preparing a thermoplastic transparent glass fiber composite sheet, characterized in that: The steps include: Moving the glass fiber cloth to an impregnation device, wherein the glass fiber cloth is impregnated with liquid MMA resin through the impregnation device to obtain an impregnated glass fiber cloth; Moving the impregnated glass fiber cloth to an ultrasonic device, wherein the ultrasonic device vibrates the impregnated glass fiber cloth to obtain a reinforced impregnated glass fiber cloth; Moving the reinforced impregnated glass fiber cloth to a heat drying device, wherein the heat drying device heat-cures the reinforced impregnated glass fiber cloth to obtain a glass fiber impregnated coil; The polycarbonate PC is hot-applied to the glass fiber impregnated coil through a co-extrusion device for compounding, and after compounding, a PC layer and a glass fiber impregnated layer are stacked in sequence to obtain a thermoplastic transparent glass fiber composite board with both upper and lower surface layers being PC layers.

2. The method for preparing a thermoplastic transparent glass fiber composite sheet according to claim 1, characterized in that: The liquid MMA resin comprises methyl methacrylate (MMA) prepolymer and catalyst benzoyl peroxide (BPO).

3. The method for preparing a thermoplastic transparent glass fiber composite sheet according to claim 2, wherein: The viscosity of the methyl methacrylate (MMA) prepolymer is 200 mPa·s to 1000 mPa·s.

4. The method for preparing a thermoplastic transparent glass fiber composite sheet according to claim 1, wherein: The impregnated glass fiber cloth is moved to the ultrasonic device, and the ultrasonic device vibrates the impregnated glass fiber cloth to obtain a reinforced impregnated glass fiber cloth, comprising the following steps: Moving the impregnated glass fiber cloth into the ultrasonic device via a roll-to-roll device; The vibration frequency of the ultrasonic device is 16 kHz to 24 kHz, and the vibration time of the ultrasonic device is 30 seconds to 60 seconds, and the impregnated glass fiber cloth is vibrated to obtain a reinforced impregnated glass fiber cloth; The reinforced impregnated glass fiber cloth is moved out of the ultrasonic device through the roll-to-roll device.

5. The method for preparing a thermoplastic transparent glass fiber composite sheet according to claim 1, wherein: The reinforced impregnated glass fiber cloth is moved to a heat drying device, and the heat drying device heat-cures the reinforced impregnated glass fiber cloth to obtain a glass fiber impregnated coil, including the following steps: The reinforced impregnated glass fiber cloth is moved from the ultrasonic device to the hot drying device through a roll-to-roll device; The temperature of the heat drying equipment is 60-120°C, and the heat drying time is 3-5 minutes. The heat drying equipment heat-dries and solidifies the reinforced impregnated glass fiber cloth to obtain a glass fiber impregnated coiled material; The glass fiber impregnated coil is wound by a roll-to-roll device.

6. The method for preparing a thermoplastic transparent glass fiber composite sheet according to claim 5, characterized in that: The reinforced impregnated glass fiber cloth is moved to a heat drying device, and the heat drying device heat-cures the reinforced impregnated glass fiber cloth to obtain a glass fiber impregnated coil. Before the glass fiber impregnated coil is wound, the following steps are further included: The glass fiber impregnated coil is cooled.

7. The method for preparing a thermoplastic transparent glass fiber composite sheet according to claim 1, characterized in that: The polycarbonate PC is heat-applied to the glass fiber impregnated coil through a co-extrusion device for compounding, and after compounding, a PC layer and a glass fiber impregnated layer are stacked in sequence to obtain a thermoplastic transparent glass fiber composite sheet with both upper and lower surface layers being PC layers, including the following steps: The polycarbonate PC is heated to 220°C-250°C through a co-extrusion device to form a molten polycarbonate PC melt; Casting polycarbonate PC melt onto the surfaces of both sides of the glass fiber impregnated coil; The glass fiber impregnation layer is stacked and coated with polycarbonate PC melt, and then rolled by a co-extrusion device to form a sequentially stacked PC layer and a glass fiber impregnation layer, thereby obtaining a thermoplastic transparent glass fiber composite board with PC layers on both the upper and lower surfaces.

8. A thermoplastic transparent glass fiber composite sheet, characterized in that: The thermoplastic transparent glass fiber composite sheet is prepared by the preparation method of any one of claims 1 to 7, comprising a plurality of PC layers and a plurality of glass fiber impregnation layers, wherein the PC layers and the glass fiber impregnation layers are stacked in sequence, and each of the glass fiber impregnation layers is covered with a PC layer on both sides.

9. The thermoplastic transparent glass fiber composite sheet according to claim 8, characterized in that: The thickness of the thermoplastic transparent glass fiber composite board is greater than 0.3 mm.

10. A production device for thermoplastic transparent glass fiber composite board, characterized in that: Used to prepare the thermoplastic transparent glass fiber composite board material described in claim 9, comprising a roll-to-roll device, an impregnation device, an ultrasonic device, a heat drying device and a co-extrusion device, the roll-to-roll device comprises a unwinding component and a winding component, the glass fiber cloth is wound on the unwinding component, one end of the glass fiber cloth is sequentially arranged on the impregnation device, the ultrasonic device and the heat drying device and wound on the winding component, the number of the winding components is multiple, the winding component is used to unwind and rewind the glass fiber impregnated coil, the glass fiber impregnated coil unwound by the winding component is set in the co-extrusion device, and the co-extrusion device is used to composite polycarbonate PC with the glass fiber impregnated coil to prepare the thermoplastic transparent glass fiber composite board material.

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