阅读说明：本技术 一种双向增强pp板材及其制备方法 (Bidirectional reinforced PP (polypropylene) plate and preparation method thereof ) 是由 吕洪香 邢宝刚 段景宽 高建峰 任通 于 2021-07-12 设计创作，主要内容包括：本发明属于结构材料领域,具体涉及一种双向增强pp板材及其制备方法,包括单面热封BOPP薄膜和双面热封薄膜,所述双面热封薄膜为双面热封BOPP薄膜或双面热封CPP薄膜中的一种或两种,所述单面热封BOPP薄膜设置在双面热封薄膜的两侧。本发明制备得到的pp板材能双向增强的同时不容易出现分层,且制备工艺简单透明,制备过程中不需要排气。(The invention belongs to the field of structural materials, and particularly relates to a bidirectional reinforced PP plate and a preparation method thereof. The PP sheet prepared by the invention can be subjected to bidirectional reinforcement, is not easy to delaminate, has a simple and transparent preparation process, and does not need to exhaust in the preparation process.)

1. A two-way enhancement pp panel which characterized in that: the single-sided heat-sealing BOPP film is characterized by comprising a single-sided heat-sealing BOPP film and a double-sided heat-sealing film, wherein the double-sided heat-sealing film is one or two of the double-sided heat-sealing BOPP film or the double-sided heat-sealing CPP film, and the single-sided heat-sealing BOPP film is arranged on two sides of the double-sided heat-sealing film.

2. The bi-directionally reinforced pp sheet of claim 1, wherein: the single-sided heat-seal BOPP film and the double-sided heat-seal film comprise one or more additives, wherein the additives are opacifiers, coloring agents, nucleating agents, slipping agents, antioxidants, antistatic agents, anti-sticking agents or blocking agents.

3. The bi-directionally reinforced pp sheet of claim 1, wherein: the single-sided heat-sealing BOPP film and the double-sided heat-sealing BOPP film comprise one or more of an aluminum-plated film, an antistatic film, a pearlized film, a color film, an ultraviolet-resistant film, a high-barrier film or a printed film.

4. The bi-directionally reinforced pp sheet of claim 1, wherein: the single-sided heat-seal BOPP film and the double-sided heat-seal BOPP film are oriented 4-6 times in the longitudinal direction and 7-10 times in the transverse direction.

5. The bi-directionally reinforced pp sheet of claim 1, wherein: the thickness of the single-sided heat-sealing BOPP film and the double-sided heat-sealing film is 8-100 mu m.

6. The bi-directionally reinforced pp sheet of claim 1, wherein: the raw materials of the single-sided heat-sealing BOPP film and the double-sided heat-sealing film comprise a core layer and a surface layer, wherein the core layer comprises one or more of homo-polypropylene, wire-drawing PP, film PP, aluminizing PP or high-barrier PP; the surface layer comprises a heat sealing material of homo-polypropylene or random copolymerization polypropylene or binary copolymerization, ethylene-propylene copolymerization and propylene-butylene copolymerization or ternary copolymerization, a propylene-based elastomer and random copolymerization polypropylene are mixed for use, or polyethylene and EVA.

7. The bi-directionally reinforced pp sheet of claim 1, wherein: the forming mode comprises multilayer one-time hot press forming by using a mould press, laminating by using a layered calendering roller layer by layer and irradiating and compounding forming by using a near infrared laser.

8. A method of making the bi-directionally reinforced pp sheet of claim 1, wherein: the specific operation steps are as follows:

respectively preparing a single-sided heat-sealing BOPP film and a double-sided heat-sealing film:

the single-sided heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and biaxial stretching, the inner surface layer is made of 77.5-97.5% of polypropylene copolymer, 2.5% of anti-adhesion master batch and 0-20% of elastomer, the core layer consists of 98% of homo-polypropylene and 2% of antistatic agent, and the outer surface layer consists of 97.5% of homo-polypropylene and 2.5% of anti-adhesion master batch;

the double-sided heat-seal film comprises a double-sided heat-seal BOPP film or/and a double-sided heat-seal CPP film, the double-sided heat-seal BOPP film consists of an inner surface layer, a core layer and an outer surface layer, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the inner surface layer consists of 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, the outer surface layer is made of 77.5% -97.5% of polypropylene copolymer, 2.5% of anti-adhesion agent and 20% of elastomer, and the core layer consists of 98% of polypropylene homopolymer and 2% of antistatic agent;

the double-sided heat-sealing CPP film is composed of an inner surface layer, a core layer and an outer surface layer, wherein the inner surface layer, the core layer and the outer surface layer are formed by coextrusion and then tape casting, the inner surface layer and the outer surface layer are made of 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, and the core layer is composed of 98% of polypropylene homopolymer, 1% of antistatic agent and 1% of slipping agent;

the preparation method comprises the steps of preparing the single-sided heat-sealed BOPP film and the double-sided heat-sealed BOPP film, wherein the raw materials of the inner surface layer, the core layer and the outer surface layer are fed into different extruders to be plasticized separately, the extrusion temperature of the extruders is 235-250 ℃, and then the plasticized melt is prepared by compounding, sheet casting, longitudinal drawing and transverse drawing;

the preparation method of the double-sided heat-sealing CPP film comprises the steps of feeding raw materials of the inner surface layer, the core layer and the outer surface layer into different extruders for separate plasticization, wherein the extrusion temperature of the extruders is 235-250 ℃, and then preparing a plasticized melt through compounding, sheet casting, tape casting and traction treatment;

selecting the single-sided heat-sealing BOPP film and the double-sided heat-sealing film prepared in the step (1) according to the upper and lower surface layers, and selecting a plurality of layers of double-sided heat-sealing BOPP films as the middle layer to be superposed layer by layer;

or the upper surface layer and the lower surface layer are made of single-sided heat-sealing BOPP films, the middle layer is made of a plurality of layers of double-sided heat-sealing BOPP films and double-sided heat-sealing CPP films which are alternately stacked, and then the materials are heated and compressed on a flat vulcanizing machine to prepare the plate.

9. The method of claim 8, wherein the method further comprises: and (3) heating the vulcanizing press in the step (2) to 180 ℃ at 170 ℃, pressurizing at 5MPa for 5-10min, and maintaining the pressure and naturally cooling to below 70 ℃.

Technical Field

The invention belongs to the field of structural materials, and particularly relates to a bidirectional reinforced pp plate and a preparation method thereof.

Background

The PP sheet material has the advantages of light weight, excellent performance and low price, and is widely used in the industries of automobiles, household appliances and bags. Higher strength, lighter weight, and cheaper panels have been the subject of efforts by material researchers.

At present, PP plates are mostly formed by extrusion, and although the forming process is simple, the defects of the plates can be caused by slight carelessness of process control. If the temperature of the machine head is controlled to be low, the surface of the plate is matt and is easy to crack, and if the temperature of the machine head is controlled to be too high, the material is easy to decompose; in addition, during the cooling and drawing processes of the plate, the plate is easy to deform due to uneven cooling or bend and warp deformation of the plate due to drawing. In addition, the strength of the single PP material extrusion-molded plate is not enough, and the glass fiber and the carbon fiber are mostly adopted for reinforcement, so that the working procedures are increased, the cost is increased, and the reinforced plate is difficult to recycle. The patent mentions that the PP flat wire is used for preparing the plate by lamination, although the method can effectively improve the strength of the plate and realize single material, the method has the defects that the plate can only be unidirectionally oriented and unidirectionally improved in strength, if the flat wires are vertically and crosswise arranged, bidirectional reinforcement can be realized, the process is complex and non-transparent, multiple air exhaust operations are required in the experimental process, and the plate prepared by the method is easy to delaminate.

In view of this, the present invention is proposed.

Disclosure of Invention

The invention aims to provide a bidirectional enhanced pp plate and a preparation method thereof, which realize bidirectional enhancement of the pp plate, are not easy to delaminate, have simple and transparent preparation process, do not need to exhaust in the preparation process, and have the following specific scheme:

the utility model provides a two-way reinforcing pp panel, includes single face heat-seal BOPP film (single face heat-seal biaxially oriented film) and two-sided heat-seal film, two-sided heat-seal film is one or two kinds in two-sided heat-seal BOPP film (two-sided heat-seal biaxially oriented film) or two-sided heat-seal CPP film (two-sided heat-seal curtain coating polypropylene film), single face heat-seal BOPP film sets up the both sides at two-sided heat-seal film.

The single-sided heat-seal BOPP film and the double-sided heat-seal film contain one or more additives, the additives are opacifiers, coloring agents, nucleating agents, slipping agents, antioxidants, antistatic agents, anti-sticking agents or blocking agents, and can be added according to the required performance in a compounding mode, and the adding amount is determined according to the required performance.

The single-sided heat-sealing BOPP film and the double-sided heat-sealing BOPP film comprise one or more of an aluminum-plated film, an antistatic film, a pearlized film, a color film, an ultraviolet-resistant film, a high-barrier film or a printed film, and different types of boards with various performances can be selected according to requirements.

The single-sided heat-seal BOPP film and the double-sided heat-seal BOPP film are oriented 4 to 6 times in the Machine Direction (MD) and 7 to 10 times in the Transverse Direction (TD), and the times of the machine direction orientation and the transverse direction orientation can be selected according to the required thickness and length of the plate.

The thickness of the single-sided heat-sealing BOPP film and the double-sided heat-sealing BOPP film is 8-100 mu m, and the number of layers of the films to be used is determined by the thickness of the plate and the thickness of the selected film.

The raw materials of the single-sided heat-sealing BOPP film and the double-sided heat-sealing film comprise a core layer and a surface layer, wherein the core layer comprises one or more of homo-polypropylene, wire-drawing PP, film PP, aluminizing PP or high-barrier PP; the surface layer comprises a heat sealing material of homo-polypropylene or random copolymerization polypropylene or binary copolymerization, ethylene-propylene copolymerization and propylene-butylene copolymerization or ternary copolymerization, a propylene-based elastomer and random copolymerization polypropylene are mixed for use or polyethylene and EVA, and different raw materials can be selected according to the matching of the single-sided heat sealing BOPP film and the double-sided heat sealing film to be prepared.

The forming mode comprises multilayer one-time hot press forming by using a mould press, laminating by using a layered calendering roller layer by layer and irradiating and compounding forming by using a near infrared laser.

A preparation method of a bidirectional reinforced pp plate comprises the following specific operation steps:

(1) respectively preparing a single-sided heat-sealing BOPP film and a double-sided heat-sealing film:

the single-sided heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and biaxial stretching, the inner surface layer is made of 77.5-97.5% of polypropylene copolymer, 2.5% of anti-adhesion master batch and 0-20% of elastomer, the core layer consists of 98% of homo-polypropylene and 2% of antistatic agent, and the outer surface layer consists of 97.5% of homo-polypropylene and 2.5% of anti-adhesion master batch;

the double-sided heat-seal film comprises a double-sided heat-seal BOPP film or/and a double-sided heat-seal CPP film, the double-sided heat-seal BOPP film consists of an inner surface layer, a core layer and an outer surface layer, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the inner surface layer consists of 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, the outer surface layer is made of 77.5% -97.5% of polypropylene copolymer, 2.5% of anti-adhesion agent and 20% of elastomer, and the core layer consists of 98% of polypropylene homopolymer and 2% of antistatic agent;

the double-sided heat-sealing CPP film is composed of an inner surface layer, a core layer and an outer surface layer, wherein the inner surface layer, the core layer and the outer surface layer are formed by coextrusion and then tape casting, the inner surface layer and the outer surface layer are made of 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, and the core layer is composed of 98% of polypropylene homopolymer, 1% of antistatic agent and 1% of slipping agent;

the preparation method comprises the steps of preparing the single-sided heat-sealed BOPP film and the double-sided heat-sealed BOPP film, wherein the raw materials of the inner surface layer, the core layer and the outer surface layer are fed into different extruders to be plasticized separately, the extrusion temperature of the extruders is 235-250 ℃, and then the plasticized melt is prepared by compounding, sheet casting, longitudinal drawing and transverse drawing;

the preparation method of the double-sided heat-sealing CPP film comprises the steps of feeding raw materials of the inner surface layer, the core layer and the outer surface layer into different extruders for separate plasticization, wherein the extrusion temperature of the extruders is 235-250 ℃, and then preparing a plasticized melt through compounding, sheet casting, tape casting and traction treatment;

(2) selecting the single-sided heat-sealing BOPP film and the double-sided heat-sealing film prepared in the step (1) according to the upper and lower surface layers, and selecting a plurality of layers of double-sided heat-sealing BOPP films as the middle layer to be superposed layer by layer;

or the upper surface layer and the lower surface layer are made of single-sided heat-seal BOPP films, the middle layer is made of a plurality of layers of double-sided heat-seal BOPP films and double-sided heat-seal CPP films which are alternately stacked, the double-sided heat-seal CPP films serve as adhesives between the layers, and then the two layers of double-sided heat-seal CPP films are heated and compressed on a flat vulcanizing machine to prepare the plate.

And (3) heating the vulcanizing press in the step (2) to 180 ℃ at 170 ℃, pressurizing at 5MPa for 5-10min, and maintaining the pressure and naturally cooling to below 70 ℃.

The invention has the following beneficial effects:

the bidirectional reinforced PP sheet prepared by the invention realizes bidirectional reinforcement of the sheet, the transverse tensile strength can reach 150-308MPa, the longitudinal tensile strength can reach 90-160MPa, and the sheet has better tensile property than a common PP sheet.

Drawings

FIG. 1 is a schematic structural diagram of a bi-directionally reinforced pp sheet according to embodiment 1 of the present invention;

wherein the reference numbers: 1 is a pp plate, 2 is a single-side heat-sealing BOPP film, and 3 is a double-side heat-sealing BOPP film.

Detailed Description

The present invention will be further described with reference to the following specific examples.

Example 1:

(1) respectively preparing a single-sided heat-sealing BOPP film and a double-sided heat-sealing BOPP film:

the single-side heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the material of the inner surface layer consists of 97.5 percent of polypropylene copolymer and 2.5 percent of anti-adhesion master batch, the core layer consists of 98 percent of polypropylene homopolymer and 2 percent of antistatic agent, the antistatic agent is added to avoid the phenomenon that the film discharges in the production and storage processes, and the outer surface layer consists of 97.5 percent of polypropylene homopolymer and 2.5 percent of anti-adhesion master batch;

the double-sided heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, and the inner surface layer and the outer surface layer are made of 97.5 percent of polypropylene copolymer and 2.5 percent of anti-adhesion agent; the core layer consists of 98% of homopolymerized polypropylene and 2% of antistatic agent;

preparing raw materials of the inner surface layer, the core layer and the outer surface layer according to the proportion, feeding the raw materials into different extruders for separate plasticization, wherein the extrusion temperature of the extruders is 235-250 ℃, and then preparing the plasticized melt into a single-sided heat-seal BOPP film and a double-sided heat-seal BOPP film for later use through compounding, sheet casting, longitudinal drawing and transverse drawing, wherein MD is 4 times, and TD is 7 times;

(2) and (2) superposing the single-sided heat-seal BOPP film and the double-sided heat-seal BOPP film prepared in the step (1) on a flat vulcanizing machine layer by layer in sequence according to the selection of the single-sided heat-seal BOPP films on the upper surface layer and the lower surface layer and the selection of the 120 layers of left and right double-sided heat-seal BOPP films on the middle layer to prepare the bidirectional reinforced PP plate by heating and compressing, wherein the specific process comprises the steps of heating a flat vulcanizing agent to 170-plus-material temperature, pressurizing to 5MPa, lasting for 5-10min, keeping the pressure, naturally cooling to below 70 ℃, and determining the tensile strength of the plate according to the tensile property of GB/T1040 plastic.

Example 2:

(1) respectively preparing a single-sided heat-sealing BOPP film and a double-sided heat-sealing BOPP film:

the single-side heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the material of the inner surface layer consists of 77.5 percent of polypropylene copolymer, 20 percent of elastomer and 2.5 percent of anti-adhesion master batch, the core layer consists of 98 percent of polypropylene homopolymer and 2 percent of antistatic agent, the antistatic agent is added to avoid the discharge phenomenon of the film in the production and storage processes, and the outer surface layer consists of 97.5 percent of polypropylene homopolymer and 2.5 percent of anti-adhesion master batch;

the double-sided heat-sealing BOPP film is composed of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the material of the inner surface layer is composed of 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, the core layer is composed of 98% of polypropylene homopolymer and 2% of antistatic agent, and the outer surface layer is composed of 77.5% of polypropylene copolymer, 20% of elastomer and 2.5% of anti-adhesion master batch;

preparing raw materials of the inner surface layer, the core layer and the outer surface layer according to the proportion, feeding the raw materials into different extruders for separate plasticization, wherein the extrusion temperature of the extruders is 235-250 ℃, and then preparing the plasticized melt into a single-sided heat-seal BOPP film and a double-sided heat-seal BOPP film for later use through compounding, sheet casting, longitudinal drawing and transverse drawing, wherein MD is 4 times, and TD is 7 times;

(2) and (2) superposing the single-sided heat-seal BOPP film and the double-sided heat-seal BOPP film prepared in the step (1) on a flat vulcanizing machine layer by layer in sequence according to the selection of the single-sided heat-seal BOPP films on the upper surface layer and the lower surface layer and the selection of the 120 layers of left and right double-sided heat-seal BOPP films on the middle layer to prepare the bidirectional reinforced PP plate by heating and compressing, wherein the specific process comprises the steps of heating a flat vulcanizing agent to 170-plus-material temperature, pressurizing to 5MPa, lasting for 5-10min, keeping the pressure, naturally cooling to below 70 ℃, and determining the tensile strength of the plate according to the tensile property of GB/T1040 plastic.

Example 3:

(1) respectively preparing a single-side heat-sealing BOPP film, a double-side heat-sealing BOPP film and a double-side heat-sealing CPP film:

the single-side heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the material of the inner surface layer consists of 97.5 percent of polypropylene copolymer and 2.5 percent of anti-adhesion master batch, the core layer consists of 98 percent of polypropylene homopolymer and 2 percent of antistatic agent, the antistatic agent is added to avoid the phenomenon that the film discharges in the production and storage processes, and the outer surface layer consists of 97.5 percent of polypropylene homopolymer and 2.5 percent of anti-adhesion master batch;

the double-sided heat-sealing BOPP film is composed of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the materials of the inner surface layer and the outer surface layer are respectively composed of 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, and the core layer is composed of 98% of polypropylene homopolymer and 2% of antistatic agent;

preparing raw materials of the inner surface layer, the core layer and the outer surface layer according to the proportion, feeding the raw materials into different extruders for separate plasticization, wherein the basic temperature of the extruders is 235-250 ℃, and then preparing the plasticized melt into a single-sided heat-seal BOPP film and a double-sided heat-seal BOPP film for later use through compounding, sheet casting, longitudinal drawing and transverse drawing, wherein MD is 4 times, and TD is 7 times;

the double-sided heat-sealing CPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 4 microns, the thickness of the core layer is 12 microns, the thickness of the outer surface layer is 4 microns, the inner surface layer, the core layer and the outer surface layer are formed by coextrusion and then tape casting, and the inner surface layer and the outer surface layer are made of 97.5% of polypropylene copolymer and 2.5% of an anti-adhesion agent; the core layer consists of 98% of homopolymerized polypropylene, 1% of antistatic agent and 1% of slipping agent;

preparing raw materials of the inner surface layer, the core layer and the outer surface layer according to the proportion, feeding the raw materials into different extruders for separate plasticization, wherein the basic temperature of the extruders is 235-250 ℃, and then preparing the plasticized melt into a double-sided heat-sealing CPP film for later use through compounding, sheet casting, tape casting and traction treatment;

(2) and (2) sequentially and alternately stacking the single-sided heat-sealed BOPP film, the double-sided heat-sealed BOPP film and the double-sided heat-sealed CPP film prepared in the step (1) according to the upper surface layer and the lower surface layer, selecting 120 layers of double-sided heat-sealed BOPP films and the double-sided heat-sealed CPP films as the middle layer, using the CPP as an adhesive between the layers, heating and compressing on a flat vulcanizing machine to prepare the bidirectional reinforced PP plate, wherein the specific process comprises the steps of heating a flat vulcanizing agent to 170-plus-material 180 ℃, pressurizing to 5MPa for 5-10min, maintaining the pressure, naturally cooling to below 70 ℃, and referring to the tensile strength of the plate measured by the tensile property of GB/T1040 plastic.

Example 4:

(1) respectively preparing a single-sided heat-sealing BOPP film and a double-sided heat-sealing BOPP film:

the single-side heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 2.0 mu m, the thickness of the core layer is 96 mu m, the thickness of the outer surface layer is 2.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the material of the inner surface layer consists of 97.5 percent of polypropylene copolymer and 2.5 percent of anti-adhesion master batch, the core layer consists of 98 percent of polypropylene homopolymer and 2 percent of antistatic agent, the antistatic agent is added to avoid the phenomenon that the film discharges in the production and storage processes, and the outer surface layer consists of 97.5 percent of polypropylene homopolymer and 2.5 percent of anti-adhesion master batch;

the double-sided heat-sealing BOPP film is composed of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 2.0 mu m, the thickness of the core layer is 96 mu m, the thickness of the outer surface layer is 2.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the materials of the inner surface layer and the outer surface layer are respectively 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, and the core layer is composed of 98% of polypropylene homopolymer and 2% of antistatic agent;

preparing raw materials of the inner surface layer, the core layer and the outer surface layer according to the proportion, feeding the raw materials into different extruders for separate plasticization, wherein the extrusion temperature of the extruders is 235-250 ℃, and then preparing the plasticized melt into a single-sided heat-seal BOPP film and a double-sided heat-seal BOPP film for later use through compounding, sheet casting, longitudinal drawing and transverse drawing, wherein MD is 4 times, and TD is 7 times;

(2) and (2) superposing the single-sided heat-seal BOPP film and the double-sided heat-seal BOPP film prepared in the step (1) on a flat vulcanizing machine layer by layer in sequence according to the selection of the single-sided heat-seal BOPP films on the upper surface layer and the lower surface layer and the selection of the middle layer of 10 layers of left and right double-sided heat-seal BOPP films, heating and compressing the layers on the flat vulcanizing machine to prepare the bidirectional reinforced PP plate, specifically, heating a flat vulcanizing agent to the temperature of 170-plus-material 180 ℃, pressurizing to the pressure of 5MPa, continuing for 5-10min, maintaining the pressure and naturally cooling to the temperature below 70 ℃, and determining the tensile strength of the plate according to the tensile property of GB/T1040 plastic in the national standard.

Example 5:

(1) respectively preparing a single-sided heat-sealing BOPP film and a double-sided heat-sealing BOPP film:

the single-side heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the material of the inner surface layer consists of 97.5 percent of polypropylene copolymer and 2.5 percent of anti-adhesion master batch, the core layer consists of 98 percent of polypropylene homopolymer and 2 percent of antistatic agent, the antistatic agent is added to avoid the phenomenon that the film discharges in the production and storage processes, and the outer surface layer consists of 97.5 percent of polypropylene homopolymer and 2.5 percent of anti-adhesion master batch;

the double-sided heat-sealing BOPP film is composed of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the materials of the inner surface layer and the outer surface layer are respectively 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, and the core layer is composed of 98% of polypropylene homopolymer and 2% of antistatic agent;

preparing raw materials of the inner surface layer, the core layer and the outer surface layer according to the proportion, feeding the raw materials into different extruders for separate plasticization, wherein the extrusion temperature of the extruders is 235-250 ℃, and then preparing the plasticized melt into a single-sided heat-seal BOPP film and a double-sided heat-seal BOPP film for later use through compounding, sheet casting, longitudinal drawing and transverse drawing, wherein MD is 4 times, and TD is 10 times;

(2) and (2) superposing the single-sided heat-seal BOPP film and the double-sided heat-seal BOPP film prepared in the step (1) on a flat vulcanizing machine layer by layer in sequence according to the selection of the single-sided heat-seal BOPP films on the upper surface layer and the lower surface layer and the selection of the 120 layers of left and right double-sided heat-seal BOPP films on the middle layer to prepare the bidirectional reinforced PP plate by heating and compressing, wherein the specific process comprises the steps of heating a flat vulcanizing agent to 170-plus-material temperature, pressurizing to 5MPa, lasting for 5-10min, keeping the pressure, naturally cooling to below 70 ℃, and determining the tensile strength of the plate according to the tensile property of GB/T1040 plastic.

Example 6:

(1) respectively preparing a single-sided heat-sealing BOPP film and a double-sided heat-sealing BOPP film:

the single-side heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 2.0 mu m, the thickness of the core layer is 96 mu m, the thickness of the outer surface layer is 2.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the material of the inner surface layer consists of 97.5 percent of polypropylene copolymer and 2.5 percent of anti-adhesion master batch, the core layer consists of 98 percent of polypropylene homopolymer and 2 percent of antistatic agent, the antistatic agent is added to avoid the phenomenon that the film discharges in the production and storage processes, and the outer surface layer consists of 97.5 percent of polypropylene homopolymer and 2.5 percent of anti-adhesion master batch;

the double-sided heat-sealing BOPP film is composed of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 2.0 mu m, the thickness of the core layer is 96 mu m, the thickness of the outer surface layer is 2.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the materials of the inner surface layer and the outer surface layer are respectively 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, and the core layer is composed of 98% of polypropylene homopolymer and 2% of antistatic agent;

preparing raw materials of the inner surface layer, the core layer and the outer surface layer according to the proportion, feeding the raw materials into different extruders for separate plasticization, wherein the extrusion temperature of the extruders is 235-250 ℃, and then preparing the plasticized melt into a single-sided heat-seal BOPP film and a double-sided heat-seal BOPP film for later use through compounding, sheet casting, longitudinal drawing and transverse drawing, wherein MD is 4 times, and TD is 10 times;

(2) and (2) superposing the single-sided heat-seal BOPP film and the double-sided heat-seal BOPP film prepared in the step (1) on a flat vulcanizing machine layer by layer in sequence according to the selection of the single-sided heat-seal BOPP films on the upper surface layer and the lower surface layer and the selection of the middle layer of 10 layers of left and right double-sided heat-seal BOPP films, heating and compressing the layers on the flat vulcanizing machine to prepare the bidirectional reinforced PP plate, specifically, heating a flat vulcanizing agent to the temperature of 170-plus-material 180 ℃, pressurizing to the pressure of 5MPa, continuing for 5-10min, maintaining the pressure and naturally cooling to the temperature below 70 ℃, and determining the tensile strength of the plate according to the tensile property of GB/T1040 plastic in the national standard.

Example 7:

(1) respectively preparing a single-sided heat-sealing BOPP film and a double-sided heat-sealing BOPP film:

the single-side heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the material of the inner surface layer consists of 97.5 percent of polypropylene copolymer and 2.5 percent of anti-adhesion master batch, the core layer consists of 98 percent of polypropylene homopolymer and 2 percent of antistatic agent, the antistatic agent is added to avoid the phenomenon that the film discharges in the production and storage processes, and the outer surface layer consists of 97.5 percent of polypropylene homopolymer and 2.5 percent of anti-adhesion master batch;

the double-sided heat-sealing BOPP film is composed of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the materials of the inner surface layer and the outer surface layer are respectively 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, and the core layer is composed of 98% of polypropylene homopolymer and 2% of antistatic agent;

preparing raw materials of the inner surface layer, the core layer and the outer surface layer according to the proportion, feeding the raw materials into different extruders for separate plasticization, wherein the extrusion temperature of the extruders is 235-250 ℃, and then preparing the plasticized melt into a single-side heat-seal BOPP film and a double-side heat-seal BOPP film for later use through compounding, sheet casting, longitudinal drawing and transverse drawing, wherein MD is 6 times, and TD is 7 times.

(2) And (2) superposing the single-sided heat-seal BOPP film and the double-sided heat-seal BOPP film prepared in the step (1) on a flat vulcanizing machine layer by layer in sequence according to the selection of the single-sided heat-seal BOPP films on the upper surface layer and the lower surface layer and the selection of the 120 layers of left and right double-sided heat-seal BOPP films on the middle layer to prepare the bidirectional reinforced PP plate by heating and compressing, wherein the specific process comprises the steps of heating a flat vulcanizing agent to 170-plus-material temperature, pressurizing to 5MPa, lasting for 5-10min, keeping the pressure, naturally cooling to below 70 ℃, and determining the tensile strength of the plate according to the tensile property of GB/T1040 plastic.

Example 8:

(1) respectively preparing a single-sided heat-sealing BOPP film and a double-sided heat-sealing BOPP film:

the single-side heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 2.0 mu m, the thickness of the core layer is 96 mu m, the thickness of the outer surface layer is 2.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the material of the inner surface layer consists of 97.5 percent of polypropylene copolymer and 2.5 percent of anti-adhesion master batch, the core layer consists of 98 percent of polypropylene homopolymer and 2 percent of antistatic agent, the antistatic agent is added to avoid the phenomenon that the film discharges in the production and storage processes, and the outer surface layer consists of 97.5 percent of polypropylene homopolymer and 2.5 percent of anti-adhesion master batch;

the double-sided heat-sealing BOPP film is composed of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 2.0 mu m, the thickness of the core layer is 96 mu m, the thickness of the outer surface layer is 2.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the materials of the inner surface layer and the outer surface layer are respectively 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, and the core layer is composed of 98% of polypropylene homopolymer and 2% of antistatic agent;

preparing raw materials of the inner surface layer, the core layer and the outer surface layer according to the proportion, feeding the raw materials into different extruders for separate plasticization, wherein the extrusion temperature of the extruders is 235-250 ℃, and then preparing the plasticized melt into a single-sided heat-seal BOPP film and a double-sided heat-seal BOPP film for later use through compounding, sheet casting, longitudinal drawing and transverse drawing, wherein MD is 6 times, and TD is 7 times;

(2) and (2) superposing the single-sided heat-seal BOPP film and the double-sided heat-seal BOPP film prepared in the step (1) on a flat vulcanizing machine layer by layer in sequence according to the selection of the single-sided heat-seal BOPP films on the upper surface layer and the lower surface layer and the selection of the middle layer of 10 layers of left and right double-sided heat-seal BOPP films, heating and compressing the layers on the flat vulcanizing machine to prepare the bidirectional reinforced PP plate, specifically, heating a flat vulcanizing agent to the temperature of 170-plus-material 180 ℃, pressurizing to the pressure of 5MPa, continuing for 5-10min, maintaining the pressure and naturally cooling to the temperature below 70 ℃, and determining the tensile strength of the plate according to the tensile property of GB/T1040 plastic in the national standard.

Example 9:

(1) respectively preparing a single-sided heat-sealing BOPP film and a double-sided heat-sealing BOPP film:

the single-side heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the material of the inner surface layer consists of 97.5 percent of polypropylene copolymer and 2.5 percent of anti-adhesion master batch, the core layer consists of 98 percent of polypropylene homopolymer and 2 percent of antistatic agent, the antistatic agent is added to avoid the phenomenon that the film discharges in the production and storage processes, and the outer surface layer consists of 97.5 percent of polypropylene homopolymer and 2.5 percent of anti-adhesion master batch;

the double-sided heat-sealing BOPP film is composed of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 1.0 mu m, the thickness of the core layer is 6 mu m, the thickness of the outer surface layer is 1.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the materials of the inner surface layer and the outer surface layer are respectively 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, and the core layer is composed of 98% of polypropylene homopolymer and 2% of antistatic agent;

preparing raw materials of the inner surface layer, the core layer and the outer surface layer according to the proportion, feeding the raw materials into different extruders for separate plasticization, wherein the extrusion temperature of the extruders is 235-250 ℃, and then preparing the plasticized melt into a single-sided heat-seal BOPP film and a double-sided heat-seal BOPP film for later use through compounding, sheet casting, longitudinal drawing and transverse drawing, wherein MD is 6 times, and TD is 10 times;

(2) and (2) superposing the single-sided heat-seal BOPP film and the double-sided heat-seal BOPP film prepared in the step (1) on a flat vulcanizing machine layer by layer in sequence according to the selection of the single-sided heat-seal BOPP films on the upper surface layer and the lower surface layer and the selection of the 120 layers of left and right double-sided heat-seal BOPP films on the middle layer to prepare the bidirectional reinforced PP plate by heating and compressing, wherein the specific process comprises the steps of heating a flat vulcanizing agent to 170-plus-material temperature, pressurizing to 5MPa, lasting for 5-10min, keeping the pressure, naturally cooling to below 70 ℃, and determining the tensile strength of the plate according to the tensile property of GB/T1040 plastic.

Example 10:

(1) respectively preparing a single-sided heat-sealing BOPP film and a double-sided heat-sealing BOPP film:

the single-side heat-sealing BOPP film consists of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 2.0 mu m, the thickness of the core layer is 96 mu m, the thickness of the outer surface layer is 2.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the material of the inner surface layer consists of 97.5 percent of polypropylene copolymer and 2.5 percent of anti-adhesion master batch, the core layer consists of 98 percent of polypropylene homopolymer and 2 percent of antistatic agent, the antistatic agent is added to avoid the phenomenon that the film discharges in the production and storage processes, and the outer surface layer consists of 97.5 percent of polypropylene homopolymer and 2.5 percent of anti-adhesion master batch;

the double-sided heat-sealing BOPP film is composed of an inner surface layer, a core layer and an outer surface layer, wherein the thickness of the inner surface layer is 2.0 mu m, the thickness of the core layer is 96 mu m, the thickness of the outer surface layer is 2.0 mu m, the inner surface layer, the core layer and the outer surface layer are formed by co-extrusion and then biaxial stretching, the materials of the inner surface layer and the outer surface layer are respectively 97.5% of polypropylene copolymer and 2.5% of anti-adhesion agent, and the core layer is composed of 98% of polypropylene homopolymer and 2% of antistatic agent;

preparing raw materials of the inner surface layer, the core layer and the outer surface layer according to the proportion, feeding the raw materials into different extruders for separate plasticization, wherein the extrusion temperature of the extruders is 235-250 ℃, and then preparing the plasticized melt into a single-sided heat-seal BOPP film and a double-sided heat-seal BOPP film for later use through compounding, sheet casting, longitudinal drawing and transverse drawing, wherein MD is 6 times, and TD is 10 times;

(2) and (2) superposing the single-sided heat-seal BOPP film and the double-sided heat-seal BOPP film prepared in the step (1) on a flat vulcanizing machine layer by layer in sequence according to the selection of the single-sided heat-seal BOPP films on the upper surface layer and the lower surface layer and the selection of the middle layer of 10 layers of left and right double-sided heat-seal BOPP films, heating and compressing the layers on the flat vulcanizing machine to prepare the bidirectional reinforced PP plate, specifically, heating a flat vulcanizing agent to the temperature of 170-plus-material 180 ℃, pressurizing to the pressure of 5MPa, continuing for 5-10min, maintaining the pressure and naturally cooling to the temperature below 70 ℃, and determining the tensile strength of the plate according to the tensile property of GB/T1040 plastic in the national standard.

The results of the performance tests on the two-way reinforced pp sheets prepared in examples 1-10 are shown in table 1:

TABLE 1

The PP plate prepared by the invention has the characteristics of low density, impact resistance, high tensile strength, high bending strength, high impact strength of the notch of the simply supported beam, good toughness and strong load resistance, and can be completely recycled. Therefore, the material can be designed into a transparent plate, an antistatic plate, a pearly-lustre plate, a metal luster plate and the like, and can also be widely applied to structural materials needing high strength and light weight, such as cases, safety helmets, automobile roofs, automobile bottom guard plates and the like.

The above description is provided for the purpose of describing the preferred embodiments of the present invention in more detail, and it should not be construed that the embodiments of the present invention are limited to the description above, and it will be apparent to those skilled in the art that the present invention can be implemented in many different forms without departing from the spirit and scope of the present invention.