KR20190029351A - Method for manufacturing plastic panel reinforced with glass fibers - Google Patents

Abstract

The present invention relates to a method of manufacturing a glass fiber-reinforced plastic panel; a glass fiber-reinforced plastic panel for carrying out the method; and a glass fiber-reinforced plastic panel manufactured by the method. In particular, the method comprises the steps of: (a) introducing a thermoplastic resin into an extruder and melting the same; (b) introducing continuous glass fibers existing in an uncut continuous state into the extruder and mixing the same with the melted thermoplastic resin, thereby forming a mixture containing cut glass fibers and the thermoplastic resin; (c) extruding the mixture of the cut glass fibers and the melted thermoplastic resin inside the extruder, thereby producing a glass fiber-reinforced thermoplastic composite; (d) passing the glass fiber-reinforced thermoplastic composite between rollers, thereby producing an extruded and cooled glass fiber-reinforced thermoplastic composite sheet; and (e) stacking two or more sheets of the glass fiber-reinforced thermoplastic composite sheets on top of each other and press-forming the same. According to the present invention, the glass fiber-reinforced plastic panel which has excellent mechanical properties such as hardness and rigidity can be produced as the glass fibers are evenly distributed within the thermoplastic resin, and thus may be beneficially used as a weight-reducing reinforcing material in the fields relating to building materials, automobiles, aircrafts, wind power, and the like, by using minimal manufacturing facilities in an economical manner with high manufacturing efficiency.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a glass fiber-

The present invention relates to a novel manufacturing method for economically and efficiently manufacturing a glass fiber reinforced plastic panel used as a construction material or the like.

Generally, in the construction of various buildings or constructions, the concrete wall is formed by a method of filling a concrete such as a mold such as a mold having a shape of a wall, that is, a concrete, and then curing. Therefore, the formation of walls starts with the making of molds, which are concrete molds for concrete curing. The most frequently used molds for pouring concrete are wood plywood. The demand for plywood has increased rapidly since the 2011 earthquake Due to the scarcity of Japanese and Korean plywood, a large quantity of low-quality plywood from China and Southeast Asia was shipped to the construction site, which reduced the number of recycles to one-half, resulting in a rapid increase in the amount of closure plates and a rise in waste treatment costs and material costs.

The glass fiber reinforced plastic composite material which is impregnated with glass fiber to increase the tensile strength and the bending strength to thermoplastic resin such as polypropylene (PP) resin capable of 100% recycling to suppress the occurrence of the closure plate is excellent in mechanical properties, Glass fiber reinforced composites, which are currently being used in the industrial field, are impregnated with short fibers having a length of 0.2 to 0.5 mm in a glass fiber reinforced composite material which is currently in commercial use. However, In the case of the material for replacing the building plywood used in the panel form, the composite material of the panel form is impregnated with the glass fiber used as the reinforcing material in the direction of the extrusion, so that the bonding strength of the glass fiber is lowered during use, There is a problem that a tearing phenomenon occurs.

Accordingly, a thermoplastic composite reinforced with non-continuous fibers and a thermoplastic composite reinforced with continuous fibers have been developed to solve the problems of the short fiber reinforced composite material.

Examples of the thermoplastic composite reinforced with the non-continuous fibers include GMT (Glass Mat Thermoplastic) and LFT (Long Fiber Reinforced Thermoplastic).

The Glass Mat Thermoplastic (GMT) is a composite material reinforced with a non-woven glass fiber mat manufactured through a needling process of a thermoplastic resin matrix. For example, a glass fiber mat (PP) in a molten state extruded through a T-die is heated in an oven, impregnated and cooled. The GMT is characterized by a glass fiber mat and a resin layer laminated in several layers and partially unidirectional reinforcement. However, GMT has a limitation in improvement in rigidity, such as the use of a glass fiber mat in a non-woven form due to the characteristics of a process using a press molding method using fluidity. In some cases, in order to improve the stiffness of GMT, it is possible to use a method of laminating reinforcing sheets to GMT at the time of GMT press working to form a product, and then molding them together. In this case, the fluidity of GMT is lowered and molding by press is difficult There is a problem that stacking of the reinforcing material as well as quality is difficult and a peeling phenomenon occurs.

The LFT (Long Fiber Thermoplastic) is a composite material using long fibers (3 mm to 25 mm) and a thermoplastic resin. The LFT-Long Fiber Thermoplastic (LFT-G) is a composite material made of resin and fiber impregnated pellets, -Granules method and a long fiber thermoplastic-direct (LFT-D) method in which carbon fibers are chopped to a desired length and compounded by impregnation with a resin. Comparing and analyzing the mechanical properties of the LFT-G system containing the same amount of fibers and the composite material produced by the LFT-D system, the latter exhibits much higher properties than the former, It is considered that the reason for this is that no compression for re-melting is required for molding the product after being put into the molding machine in the already melted state, and there is no breakage of the fibrous structure appearing in the solid fillet. Therefore, the LFT-D method, which is suitable for the production of structural parts with short molding cycle, is a continuous production system that can compress the composite material by directly impregnating the long fiber and thermoplastic resin and extruding the composite material. And LFT-G, but it has a problem that the initial facility investment cost is very high due to the expensive equipment.

In addition, the LFT-D method adopts a structure that improves the productivity by molding the extruded material directly in a press. However, this type of processing method does not cause a problem in a small product of 1 m or less. However, in the case of a large- The distribution of the glass fibers is not uniform, and a phenomenon occurs in which the glass fibers are bent to one side.

As described above, the material in which fibers such as glass fibers are combined with a thermoplastic resin is widely used. However, the conventional techniques such as the GMT method and the LFT-D method have the above-described technical problems, It is exclusively conducted by some large corporations with high capital.

Korean Patent Publication No. 10-2015-0083676 (Disclosure Date: (July 20, 2015)) Korean Patent Publication No. 10-2016-0054660 (Publication date: May 17, 2016). Korean Patent Publication No. 10-2017-0014074 (Publication date: Feb. 20, 2017).

DISCLOSURE OF THE INVENTION The technical problem to be solved by the present invention is to provide a glass fiber reinforced plastic panel having excellent mechanical properties by minimizing the production of glass fiber reinforced plastic panels by impregnating the glass fiber with a uniform distribution in the thermoplastic resin in view of the problems of the prior art such as GMT method and LFT- The present invention also provides a glass fiber-reinforced plastic panel manufacturing method which can be economically and efficiently manufactured by using a facility, a glass fiber-reinforced plastic panel for implementing the above method, and a glass fiber-reinforced plastic panel manufactured by the above method.

According to an aspect of the present invention, there is provided a thermoplastic resin composition comprising: (a) injecting and melting a thermoplastic resin into an extruder; (b) introducing continuous continuous glass fibers in an uncut continuous state into an extruder and mixing with a molten thermoplastic resin to form a mixture comprising the cut glass fibers and the thermoplastic resin; (c) extruding a mixture of glass fiber and molten thermoplastic resin cut in the extruder to produce a glass fiber-reinforced thermoplastic composite; (d) passing the glass fiber-reinforced thermoplastic composite material through rollers to produce a compressed and cooled glass fiber-reinforced thermoplastic composite sheet; And (e) laminating at least two glass fiber-reinforced thermoplastic composite sheets and press-molding the glass fiber-reinforced thermoplastic composite sheet.

The thermoplastic resin may be a polypropylene (PP), a poly (ethylene), a poly (amide), a poly (ethylene terephthalate), or an acrylonitrile-butadiene-styrene (ABS) A method of manufacturing a fiber reinforced plastic panel is proposed.

Further, in the step (b), a continuous glass fiber is cut into a glass fiber having a length of 10 to 200 mm in the extruder.

Further, it is also possible to produce a thermoplastic composite sheet having a thickness of 25% of the thickness of the glass fiber-reinforced plastic panel finally produced in the step (d), and then, in the step (e) Laminated so that the glass fiber orientations in the sheet are different from each other, and press molding is performed.

The method of manufacturing a glass fiber reinforced plastic panel according to claim 1, wherein the step (e) comprises interposing a non-woven glass fiber mat between the glass fiber-reinforced thermoplastic composite sheets, followed by press molding. I suggest.

According to another aspect of the present invention, there is provided an apparatus for manufacturing a glass fiber-reinforced plastic panel for use in the manufacturing method, comprising: a barrel equipped with a twin screw; A hopper positioned at one side of the barrel and into which the thermoplastic resin is introduced; And a glass fiber supply part including a helical pipe located at one side of the barrel and capable of supplying continuous glass fiber into the barrel; A roller unit for compressing and cooling the thermoplastic composite material extruded through the extruding unit to form a glass fiber-reinforced thermoplastic composite sheet; And a press forming unit for pressing at least two glass fiber reinforced thermoplastic composite sheets formed through the roller unit to form a glass fiber reinforced plastic panel.

In addition, the present invention proposes a glass fiber reinforced plastic panel for construction manufactured by the above manufacturing method from another aspect of the invention.

According to the method for producing a glass fiber-reinforced plastic panel according to the present invention, glass fibers are uniformly distributed in a thermoplastic resin and are excellent in mechanical properties such as strength and rigidity, and can be usefully used as lightweight reinforcements in construction materials, automobiles, Glass fiber-reinforced plastic panels can be manufactured economically and with high production efficiency using a minimum production facility.

1 is a process flow diagram of a method of manufacturing a glass fiber-reinforced plastic panel according to the present invention.
2 (a) to 2 (c) are a perspective view, a side view, and a plan view, respectively, of an example of the extruded portion included in the apparatus for manufacturing a glass fiber-reinforced plastic panel according to the present invention.
3 is a perspective view of an example of twin screws mounted on an extruder included in a glass fiber reinforced plastic panel manufacturing apparatus according to the present invention.
4 is a perspective view of an extruded part including a barrel section having twin screws, as an example of an extruded part included in an apparatus for manufacturing a glass fiber-reinforced plastic panel according to the present invention.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Embodiments in accordance with the concepts of the present invention can make various changes and have various forms, so that specific embodiments are illustrated in the drawings and described in detail in this specification or application. It should be understood, however, that the embodiments according to the concepts of the present invention are not intended to be limited to any particular mode of disclosure, but rather all variations, equivalents, and alternatives falling within the spirit and scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises ", or" having ", or the like, specify that there is a stated feature, number, step, operation, , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

Hereinafter, the present invention will be described in detail.

As shown in FIG. 1, the method for manufacturing a glass fiber-reinforced plastic panel according to the present invention comprises the steps of: (a) injecting a thermoplastic resin into an extruder and melting it; (b) introducing continuous continuous glass fibers in an uncut continuous state into an extruder and mixing with a molten thermoplastic resin to form a mixture comprising the cut glass fibers and the thermoplastic resin; (c) extruding a mixture of glass fiber and molten thermoplastic resin cut in the extruder to produce a glass fiber-reinforced thermoplastic composite; (d) passing the glass fiber-reinforced thermoplastic composite material through rollers to produce a compressed and cooled glass fiber-reinforced thermoplastic composite sheet; And (e) laminating at least two glass fiber-reinforced thermoplastic composite sheets, followed by press molding.

The step (a) is performed by heating the thermoplastic resin to an appropriate temperature in consideration of the melting point of each thermoplastic resin as a process of melting the resin so as to be suitable for extruding the thermoplastic resin into the extruder.

As the thermoplastic resin, it is preferable to use PP (polypropylene) as the thermoplastic resin. However, the present invention is not limited thereto, and any one of PA (polyacetate), poly (ethylene terephthalate), PA (polyamide) and ABS (acrylonitrile-butadiene-styrene) may be used.

In the step (b), the string type continuous glass fiber which is in a continuous state which is not cut is put into the extruder and mixed with the thermoplastic resin melted in the previous step. In the course of this step, Is cut into a glass fiber having a length of 200 mm or less, more preferably 10 to 200 mm by a screw of an extruder, and the transferred glass fiber is mixed with a thermoplastic resin to form a mixture to be provided in an extrusion molding step .

It is preferable that the mixture of the cut continuous glass fiber and the thermoplastic resin is composed of 20 to 40% by weight of glass fiber and 60 to 80% by weight of thermoplastic resin. If less than 20% by weight of glass fiber is added, The strength required for the panel can not be secured. If it is added in an amount exceeding 40% by weight, the glass fiber is not impregnated into the thermoplastic resin properly, so that even if the material is plasticized, the flowability is lowered, .

 Next, the step (c) is a step of producing a glass fiber-reinforced thermoplastic composite by extruding a mixture of the glass fiber cut and the melted thermoplastic resin in the extruder, wherein the molten thermoplastic resin and the cut continuous glass fiber impregnated therewith While pressing the glass fiber reinforced thermoplastic composite material.

In the step (d), the glass fiber-reinforced thermoplastic composite material formed by the extrusion molding is cooled, and at the same time, a glass fiber-reinforced thermoplastic material having a bulged state by extrusion And then performing roller molding on the composite material to produce a compressed and cooled glass fiber-reinforced thermoplastic composite sheet.

The existing LFT-D method adopts a method to increase the productivity by molding the extruded material directly in the press. Such a method does not cause any problems in small products having a length of less than 1 m, but in the case of large- The distribution of the glass fibers is not uniform, and a phenomenon occurs in which the glass fibers are bent to one side. In this step, the extruded composite material is molded so that the impregnated glass fiber and the thermoplastic resin can be uniformly distributed using a roller, and molded in an area of 95% of the product area to be compression molded, It is preferable that at least four sheets are compressed in the press forming step of step (e) to be described later to produce one product.

Finally, in the step (e), two or more glass fiber-reinforced thermoplastic composite sheets are laminated and press-molded to obtain a glass fiber-reinforced plastic panel.

In this step, more than two sheets, more preferably four sheets or more, are laminated so that the orientation of the glass fiber can take various forms such as a cross, a lattice, an X-letter and a rhombus. This is very important when the distribution direction affects the strength of the product. Even if no separate composition or reinforcing agent is included, the stiffness can be increased by 30% or more simply by arranging the arrangement of the glass fibers in a cross or lattice shape as described above.

As an example of this step, four or more glass fiber-reinforced thermoplastic composite sheets in which the glass fiber arrangement is uniformly distributed in the lengthwise direction are heated in an electric oven heated to a temperature of 180 to 200 ° C, The sheet is laminated on a metal mold so that it can be arranged in the cross or lattice direction, press molded at a pressure of 2,000 tons and cooled to obtain a glass fiber reinforced plastic panel.

Further, in this step, in order to further improve the strength and rigidity of the glass fiber reinforced plastic panel, a glass fiber reinforced plastic panel can be manufactured by interposing an intermediate layer between the glass fiber reinforced thermoplastic composite sheets, if necessary, have. At this time, the intermediate layer is preferably a non-woven glass fiber mat.

The panel obtained in this step may be used directly as a product such as a construction material, but it may be used after finishing through a finishing process such as cutting a surface protruding glass fiber if necessary.

Hereinafter, an apparatus for manufacturing a glass fiber-reinforced plastic panel for implementing the above manufacturing method will be described.

The glass fiber reinforced plastic panel manufacturing apparatus comprises: a barrel equipped with a twin screw; A hopper positioned at one side of the barrel and into which the thermoplastic resin is introduced; And a glass fiber supply part including a helical pipe located at one side of the barrel and capable of supplying continuous glass fiber into the barrel; A roller unit for compressing and cooling the thermoplastic composite material extruded through the extruding unit to form a glass fiber-reinforced thermoplastic composite sheet; And a press forming unit for pressing at least two glass fiber reinforced thermoplastic composite sheets formed through the roller unit to form a glass fiber reinforced plastic panel.

Wherein the extrusion portion comprises: a barrel equipped with a twin screw; A hopper positioned at one side of the barrel and into which the thermoplastic resin is introduced; And a fiberglass feeder located at one side of the barrel and including a helical pipe for supplying continuous glass fibers into the barrel.

As shown in FIGS. 2 to 4, the extruding portion is provided with a twin screw in the barrel and rotated by a rotating shaft, a hopper for feeding the extruded material to one side of the barrel, and a continuous glass fiber- And a glass fiber supply portion.

The thermoplastic resin is taken through the hopper and the string type continuous glass fiber is taken in the pipe of the glass fiber feeding part installed in the 1220 mm barrel section (the molten thermoplastic resin flows backward toward the glass fiber inlet, ) And mixed and conveyed by the rotation of the screw inside the extruder barrel to be extruded.

The overall length of the extruder barrel may be 4000 mm, the metering zone may be 1600 mm, and the head zone may be 1000 mm. In order to control the temperature inside the extruded part, a controller is installed so that the temperature of the heater installed in the heater section can be developed and controlled so that the temperature can be freely adjusted so that the resin does not boil. For reference, an extruder having a barrel length of 4 m usually controls the heater by dividing it into four sections for cost problems, but it is preferable to separately control the heaters by dividing the section into 12 or more sections to improve the extrusion quality.

When a large extruder having a barrel having a diameter of 200 mm or more is used, it is difficult to impregnate the glass fiber with a glass fiber length of 50 mm or more, and the strength and flexural rigidity are lowered as the glass fiber is shortened. And the glass fiber directly fed into the continuous fiber form is cut into glass fibers having various lengths of 10 to 200 mm in length in the extrusion portion and then impregnated to increase the impregnation efficiency. The volume reduction is compensated using a twin screw.

The extrusion screw is designed so that the glass fiber can be automatically cut into various shapes irregularly with a length of 10 to 200 mm automatically in the extruder at the same time with the mixing of the thermoplastic resin and the uncut glass fiber, It is preferable to reduce the tolerance of the extrusion screw as much as possible. For example, it is preferable that the extrusion screw is 3.3 mm or less.

In the present invention, each of the above-mentioned two screws has a problem that the glass fiber is formed more than twice as long as in the prior art so that the impregnation can not be performed well. Therefore, in the final stage of the screw, The screw is usually 1000 mm long, twice the size of the extruder screw.

The roller portion is passed through a plurality of rollers at a high temperature (about 200 DEG C) to be extruded through an extrusion portion, cooled to a predetermined temperature, and formed into a sheet-like composite material having a desired thickness.

The press forming section presses a glass fiber-reinforced thermoplastic composite sheet laminated on two or more sheets in a mold at a high temperature and a high pressure to form a glass fiber reinforced plastic panel.

According to the method for producing a glass fiber reinforced plastic panel according to the present invention as described above in detail, the glass fiber is uniformly distributed in the thermoplastic resin and is excellent in mechanical properties such as strength and rigidity and is useful as a lightweight reinforcement in construction materials, automobiles, Fiberglass reinforced plastic panels that can be used in a wide variety of applications can be manufactured economically and with high production efficiency by using a minimum production facility.

Claims (7)

(a) injecting and melting a thermoplastic resin into an extruder;
(b) introducing continuous continuous glass fibers in an uncut continuous state into an extruder and mixing with a molten thermoplastic resin to form a mixture comprising the cut glass fibers and the thermoplastic resin;
(c) extruding a mixture of glass fiber and molten thermoplastic resin cut in the extruder to produce a glass fiber-reinforced thermoplastic composite;
(d) passing the glass fiber-reinforced thermoplastic composite material through rollers to produce a compressed and cooled glass fiber-reinforced thermoplastic composite sheet; And
(e) laminating at least two glass fiber-reinforced thermoplastic composite sheets and press-molding the glass fiber-reinforced thermoplastic composite sheets. The method according to claim 1,
Wherein the thermoplastic resin is a glass fiber reinforced thermoplastic resin which is a polypropylene (PP), a poly-ethylene (PE), a poly-amide (PA), a poly-ethylene-terephthalate (PET), or an acrylonitrile-butadiene- Method of manufacturing a plastic panel. The method according to claim 1,
Wherein the continuous glass fibers in the step (b) are cut into glass fibers having a length of 10 to 200 mm while forming a mixture with the melted thermoplastic resin in the extruder. The method according to claim 1,
After producing a thermoplastic composite sheet having a thickness of 25% of the thickness of the glass fiber-reinforced plastic panel finally produced in the step (d)
Wherein the four thermoplastic composite sheets are laminated in such a manner that the glass fiber orientations in the respective sheets are different from each other in the step (e), and press molding is performed. The method according to claim 1,
Wherein the step (e) comprises interposing a non-woven glass fiber mat between the glass fiber-reinforced thermoplastic composite sheets, and press-molding the glass fiber-reinforced thermoplastic composite sheet. A glass fiber reinforced plastic panel manufacturing apparatus used in the manufacturing method according to any one of claims 1 to 5,
Barrel with twin screw; A hopper positioned at one side of the barrel and into which a thermoplastic resin is injected; And a glass fiber supply part including a helical pipe located at one side of the barrel and capable of supplying continuous glass fiber into the barrel;
A roller unit for compressing and cooling the thermoplastic composite material extruded through the extrusion unit to form a glass fiber-reinforced thermoplastic composite sheet; And
And a press forming section for pressing at least two glass fiber reinforced thermoplastic composite sheets formed through the roller section to form a glass fiber reinforced plastic panel. A glass fiber reinforced plastic panel for construction produced by the method of any one of claims 1 to 5.

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