阅读说明：本技术 一种高强度耐低温长纤尼龙的生产配方和生产工艺 (Production formula and production process of high-strength low-temperature-resistant long-fiber nylon ) 是由 李春婵 于 2021-07-06 设计创作，主要内容包括：本发明公开了一种高强度耐低温长纤尼龙的生产配方和生产工艺,涉及塑料改性技术领域。一种高强度耐低温长纤尼龙的生产配方,由以下重量份的原料制成：20-30wt％的尼龙66、5-10wt％的尼龙12、20-30wt％的尼龙6、10-20wt％的聚乙烯辛烯共弹性体、25-35wt％的玻璃纤维、1.0-3.0wt％的黑色母、1.0-5.0wt％的润滑剂、1.0-5.0wt％的抗氧化剂和0.1-0.4wt％的反应剂,所述反应剂包括过氧化二异丙苯和马来酸酐。本发明通过在双螺杆挤出机的侧喂料口喂进熔融的混合料A,其能够有效的保护与其共同进入侧喂料口的玻璃纤维,从而使得玻璃纤维具有合适的长度,进而提升产品的性能,从而在应对低温时产品内部的玻璃纤维能够取得较好的增韧效果。(The invention discloses a production formula and a production process of high-strength low-temperature-resistant long-fiber nylon, and relates to the technical field of plastic modification. A production formula of high-strength low-temperature-resistant long-fiber nylon is prepared from the following raw materials in parts by weight: 20-30 wt% of nylon 66, 5-10 wt% of nylon 12, 20-30 wt% of nylon 6, 10-20 wt% of polyethylene octene co-elastomer, 25-35 wt% of glass fiber, 1.0-3.0 wt% of black master, 1.0-5.0 wt% of lubricant, 1.0-5.0 wt% of antioxidant and 0.1-0.4 wt% of reactant, wherein the reactant comprises dicumyl peroxide and maleic anhydride. According to the invention, the molten mixture A is fed into the side feeding port of the double-screw extruder, so that the glass fiber entering the side feeding port together with the mixture A can be effectively protected, the glass fiber has a proper length, the performance of the product is further improved, and the glass fiber in the product can obtain a good toughening effect at low temperature.)

1. The production formula of the high-strength low-temperature-resistant long-fiber nylon is characterized in that: the feed is prepared from the following raw materials in parts by weight: 20-30 wt% of nylon 66, 5-10 wt% of nylon 12, 20-30 wt% of nylon 6, 10-20 wt% of polyethylene octene co-elastomer, 25-35 wt% of glass fiber, 1.0-3.0 wt% of black master, 1.0-5.0 wt% of lubricant, 1.0-5.0 wt% of antioxidant and 0.1-0.4 wt% of reactant, wherein the reactant comprises dicumyl peroxide and maleic anhydride.

2. The production formula of the high-strength low-temperature-resistant long-fiber nylon according to claim 1, wherein the production formula comprises: the glass fiber is a continuous glass fiber with the surface soaked by a coupling agent, and the diameter of the continuous glass fiber is 10-20 microns.

3. The production formula of the high-strength low-temperature-resistant long-fiber nylon according to claim 1, wherein the production formula comprises: the black master batch is a black master batch taking any one of polyethylene, polypropylene or nylon as a carrier.

4. The production formula of the high-strength low-temperature-resistant long-fiber nylon according to claim 3, wherein the production formula comprises the following components: the colorant of the black master batch is carbon black or aniline black.

5. The production formula of the high-strength low-temperature-resistant long-fiber nylon according to claim 1, wherein the production formula comprises: the antioxidant is any one or a mixture of more of antioxidant 1098, antioxidant 1010 and antioxidant 1620.

6. The production formula of the high-strength low-temperature-resistant long-fiber nylon according to claim 1, wherein the production formula comprises: the lubricant is one or a mixture of more of silicone master batch, calcium stearate and zinc stearate.

7. A production process of high-strength low-temperature-resistant long-fiber nylon is characterized by comprising the following steps: the production steps are as follows:

the method comprises the following steps: sequentially putting nylon 66, nylon 6, nylon 12, black master, a lubricant and an antioxidant into a low-speed stirrer for stirring to obtain a mixture A;

step two: sequentially putting the polyethylene octene co-elastomer and the reactant into a low-speed stirrer for stirring to obtain a mixture B;

step three: putting the mixture A into a double-screw extruder hopper in a double-stage extruder, and putting the mixture B into a single-screw extruder hopper in the double-stage extruder;

step four: after setting relevant production parameters, starting the double-stage extruder, simultaneously adding glass fiber into a side feeding port of the double-screw extruder, and extruding to obtain modified nylon strand C;

step five: immersing the modified nylon strand C into a cooling water tank, and then drawing and granulating through a granulator to obtain a semi-finished product D;

step six: and drying and cooling the semi-finished product D to obtain a finished product.

8. The production process of the high-strength low-temperature-resistant long-fiber nylon according to claim 7, characterized in that: the stirring speed of the mixture A is 60-120r/min, and the stirring time is 30-60 min.

9. The production process of the high-strength low-temperature-resistant long-fiber nylon according to claim 7, characterized in that: the stirring speed of the mixture B is 30-60r/min, and the stirring time is 20-40 min.

10. The production process of the high-strength low-temperature-resistant long-fiber nylon according to claim 7, characterized in that: the length-diameter ratio of the double-screw extruder in the double-stage extruder is 40:1, the double-screw extruder is divided into ten sections with equal length, the side feeding port is arranged at the fifth section, and the discharge port of the single-screw extruder in the double-stage extruder is communicated with the side feeding port of the double-screw extruder.

11. The process for producing a high-strength low-temperature-resistant long-fiber nylon according to claim 10, wherein: the screw combination of the double-screw extruder can control the length of the glass fiber to be 0.2-0.5 mm.

12. The production process of the high-strength low-temperature-resistant long-fiber nylon according to claim 7, characterized in that: when the single-screw extruder is used for production, the temperature range is 180-200 ℃, and the screw rotating speed is 80-120 r/min.

13. The production process of the high-strength low-temperature-resistant long-fiber nylon according to claim 7, characterized in that: when the double-screw extruder is produced, the temperature range is 180-280 ℃, and the screw rotating speed is 500-700 r/min.

Technical Field

The invention relates to the technical field of plastic modification, in particular to a production formula and a production process of high-strength low-temperature-resistant long-fiber nylon.

Background

With the development of light weight in the automobile and electric vehicle industry, more and more plastics are applied to the automobile and the electric vehicle, but because the temperature range span of the automobile and the electric vehicle is large, the high temperature can reach 80 ℃, and the low temperature can be as low as minus 50 ℃, in order to adapt to the development of the automobile industry, high-strength low-temperature-resistant nylon appears on the market, but most of the high-strength low-temperature-resistant nylon on the market still has a space for improving the performance due to partial process defects during production, and therefore, a production formula and a production process of the high-strength low-temperature-resistant long-fiber nylon are provided, so that the product has high strength and good low-temperature-resistant toughness.

Disclosure of Invention

The invention aims to provide a production formula and a production process of high-strength low-temperature-resistant long-fiber nylon, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a production formula of high-strength low-temperature-resistant long-fiber nylon is prepared from the following raw materials in parts by weight: 20-30 wt% of nylon 66, 5-10 wt% of nylon 12, 20-30 wt% of nylon 6, 10-20 wt% of polyethylene octene co-elastomer, 25-35 wt% of glass fiber, 1.0-3.0 wt% of black master, 1.0-5.0 wt% of lubricant, 1.0-5.0 wt% of antioxidant and 0.1-0.4 wt% of reactant, wherein the reactant comprises dicumyl peroxide and maleic anhydride.

Preferably, in the technical scheme, the glass fiber is a continuous glass fiber with the surface thereof wetted by a coupling agent, and the diameter of the continuous glass fiber is 10-20 microns.

Preferably, in the technical scheme, the black master batch is a black master batch taking any one of polyethylene, polypropylene or nylon as a carrier.

Preferably, in the technical scheme, the colorant of the black master batch is carbon black or aniline black.

Preferably, the antioxidant is one or a mixture of more of antioxidant 1098, antioxidant 1010 and antioxidant 1620.

Preferably, in the technical solution, the lubricant is one or a mixture of more of silicone master batch, calcium stearate and zinc stearate.

A production process of high-strength low-temperature-resistant long-fiber nylon comprises the following production steps:

the method comprises the following steps: sequentially putting nylon 66, nylon 6, nylon 12, black master, a lubricant and an antioxidant into a low-speed stirrer for stirring to obtain a mixture A;

step two: sequentially putting the polyethylene octene co-elastomer and the reactant into a low-speed stirrer for stirring to obtain a mixture B;

step three: putting the mixture A into a double-screw extruder hopper in a double-stage extruder, and putting the mixture B into a single-screw extruder hopper in the double-stage extruder;

step four: after setting relevant production parameters, starting the double-stage extruder, simultaneously adding glass fiber into a side feeding port of the double-screw extruder, and extruding to obtain modified nylon strand C;

step five: immersing the modified nylon strand C into a cooling water tank, and then drawing and granulating through a granulator to obtain a semi-finished product D;

step six: and drying and cooling the semi-finished product D to obtain a finished product.

Furthermore, the stirring speed of the mixture A is 60-120r/min, and the stirring time is 30-60 min.

Furthermore, the stirring speed of the mixture B is 30-60r/min, and the stirring time is 20-40 min.

Furthermore, the double-screw extruder in the double-stage extruder has a length-diameter ratio of 40:1, the double-screw extruder is divided into ten sections with equal length, a side feeding port is arranged at the fifth section, and a discharge port of the single-screw extruder in the double-stage extruder is communicated with the side feeding port of the double-screw extruder.

Further, the screw combination of the twin-screw extruder enables the control of the length of the glass fiber to 0.2 to 0.5 mm.

Furthermore, when the single-screw extruder is produced, the temperature range is 180-.

Furthermore, the temperature range of the twin-screw extruder is 180-280 ℃, and the screw rotating speed is 500-700 r/min.

Compared with the prior art, the invention has the beneficial effects that:

(1) according to the production formula and the production process of the high-strength low-temperature-resistant long-fiber nylon, the production mode of the double-stage extruder can effectively reduce the production energy consumption, and simultaneously, various raw materials can be better dispersed and fused, so that various mechanical and physical properties of the modified nylon can be effectively improved.

(2) According to the production formula and the production process of the high-strength low-temperature-resistant long-fiber nylon, the molten mixture A is fed through the side feeding port of the double-screw extruder, the mixture A can be effectively protected and jointly enter the glass fiber of the side feeding port, so that the glass fiber has proper length, the performance of the product is further improved, and the glass fiber in the product can obtain a good toughening effect when the low temperature is met.

Drawings

FIG. 1 is a graph of a tensile test according to an embodiment of the present invention;

FIG. 2 is a graph of a tensile test of a comparative example of the present invention;

FIG. 3 is a graph of a bend test according to an embodiment of the present invention;

FIG. 4 is a graph of a bending test of a comparative example of the present invention;

FIG. 5 is a heat distortion temperature test chart of the embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that like reference numerals and letters refer to like items in the following figures, and thus, once an item is defined or illustrated in one figure, it will not need to be further discussed or illustrated in detail in the description of the following figure.

Example (b):

the invention provides a technical scheme that: a production formula of high-strength low-temperature-resistant long-fiber nylon is prepared from the following raw materials in parts by weight: 100kg of nylon 66, 20kg of nylon 12, 100kg of nylon 6, 40kg of polyethylene octene co-elastomer, 120kg of glass fiber, 10kg of black master, 10kg of silicone master batch, 8kg of antioxidant, 50g of dicumyl peroxide and 800g of maleic anhydride;

in the technical scheme, the glass fiber is a continuous glass fiber the surface of which is infiltrated by a coupling agent, the diameter of the glass fiber is 15 microns, the glass fiber is an inorganic non-metallic material with excellent performance, the glass fiber has the advantages of good insulativity, strong heat resistance, good corrosion resistance and high mechanical strength, but has the defects of brittleness and poor wear resistance, the glass fiber is prepared by taking six ores of pyrophyllite, quartz sand, limestone, dolomite, colemanite and ascharite as raw materials and carrying out processes of high-temperature melting, wire drawing, yarn winding, weaving and the like, the diameter of a monofilament is several microns to twenty microns, the monofilament is equivalent to 1/20-1/5 of a hair, each bundle of fiber precursor consists of hundreds of even thousands of monofilaments, and the continuous glass fiber infiltrated by the coupling agent can effectively bond the fiber monofilaments into precursor and avoid the bonding among strands in the unwinding process, meanwhile, the intermiscibility and the cohesiveness between the fiber and the resin base material can be effectively improved, so that various mechanical and physical properties of the modified plastic can be greatly improved;

in the technical scheme, the black master batch is nigrosine which takes polyethylene as a carrier, the nigrosine is a black dye which is directly generated on cotton fabrics and is insoluble in common solvents, the nigrosine has strong tinting strength, low dispersion energy, very strong light absorption performance and very good color stability, and the nigrosine is an organic dye, so that the nigrosine has strong cohesiveness and is not easy to decolor in plastics, and meanwhile, the pigment can also produce an extinction effect, so the nigrosine is suitable for being used as a pigment of modified nylon in the technical scheme;

in the technical scheme, the antioxidant is a mixture of an antioxidant 1098 and an antioxidant 1010 with a mass ratio of 1:1, wherein the antioxidant 1098 is N, N' -bis- (3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine with a chemical name of non-discoloration, non-pollution, thermal oxidation resistance and extraction resistance, is mainly used in polymers such as polyamide, polyolefin, polystyrene, ABS resin, acetal resin, polyurethane and rubber, and can be matched with a phosphorus-containing auxiliary antioxidant to improve the oxidation resistance, the antioxidant 1010 is tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] with a chemical name of white crystalline powder and stable chemical properties, and belongs to phenolic antioxidants, the polymer material has the advantages of small volatility, good extraction resistance, high thermal stability and long lasting effect, and can effectively prevent thermal oxidation degradation of the polymer material in a long-term aging process, so that the color change resistance of the polymer material under a high-temperature processing condition is improved, in the case, the antioxidant 1010 and the antioxidant 1098 are compounded at the same time, so that a certain synergistic effect is generated, the oxidation resistance of the polymer material is further improved, and the technical effect that 1+1 is larger than 2 is generated.

A production process of high-strength low-temperature-resistant long-fiber nylon comprises the following production steps:

the method comprises the following steps: sequentially putting 100kg of nylon 66, 100kg of nylon 6, 20kg of nylon 12, 10kg of black master batch, 10kg of silicone master batch and 8kg of antioxidant into a low-speed stirrer for stirring, wherein the stirring speed is 100r/min, and the stirring time is 50min to obtain a mixture A;

step two: sequentially putting 40kg of polyethylene octene co-elastomer, 50g of dicumyl peroxide and 800g of maleic anhydride into a low-speed stirrer for stirring, wherein the stirring speed is set to be 40r/min, and the stirring time is to obtain a mixture B;

step three: putting the mixture A into a double-screw extruder hopper in a double-stage extruder, putting the mixture B into a single-screw extruder hopper in the double-stage extruder, wherein the double-screw extruder in the embodiment adopts a double-screw extruder with the screw diameter of 65mm, the length-diameter ratio of the double-screw extruder is 40:1, the double-screw extruder is divided into ten sections with equal length, a side feeding port is arranged in a fifth section, the temperature from the first section to the tenth section is sequentially set to be 180 ℃, 200 ℃, 240 ℃, 260 ℃, 220 ℃, 260 ℃ and 270 ℃, the head temperature of the double-screw extruder is set to be 280 ℃, the temperature setting of the gradient type can effectively prevent the materials from melting in advance to generate slipping, and further the mixture A in the double-screw extruder hopper from bridging, and simultaneously, the low temperature setting of the fifth section can effectively prevent the mixture A from flowing excessively and overflowing from the side feeding port, the screw rotation speed of the twin-screw extruder at the time of production was set to 600r/min, and the screw combinations of the twin-screw extruder in this example were 56/56, 80/80, 80/80, 72/72, 64/64, 56/56, 44/44, 56/5/45, 66/7/60, 80/80, 64/64, 56/56, 56/56, 45/5/45, 66/7/60, 56/56, 44/44, 44/44, 66/10/30, 56/8/45, 36 reverse, 56/56, 80/80, 72/72, 64/64, 56/5/45, 66/7/60, 80/80, 72/72, 56/8/90, 44/44, a, 45/5/45, 66/10/60, 36, 72/72, 80/80, 80/80, 72/72, 64/64, 56/56, 44/44 and 44/44, the screw combination can effectively control the length of the glass fiber within 0.2-0.5mm, thereby playing the role of the glass fiber to the maximum and improving various physical and mechanical properties of the modified nylon in the embodiment, the single screw extruder adopts a single screw extruder with the screw diameter of 90mm, the length-diameter ratio of the single screw extruder is 28:1, the single screw extruder is divided into four sections with equal length, the temperature from the first section to the fourth section is sequentially set to be 180 ℃, 190 ℃, 200 ℃ and 200 ℃ during production, the temperature of an extruder head is set to be 190 ℃, the screw rotating speed of the single screw extruder is set to be 100r/min, in the embodiment, a discharge port of the single screw extruder is communicated with a side double screw feeding port of the extruder, the production mode of the double-step extruder is adopted, so that the energy consumption of production can be effectively reduced, and meanwhile, various raw materials can be better fused, so that various mechanical and physical properties of the modified nylon can be effectively improved, the produced product can be suitable for low-temperature severe environment, meanwhile, the molten mixture A is secondarily added into the side feeding port, the glass fiber entering the side feeding port together with the side feeding port can be effectively protected, the glass fiber has proper length, and the performance of the product is improved;

step four: after related production parameters of the single-screw extruder and the double-screw extruder in the double-stage extruder are set in sequence according to the third step, starting the equipment, simultaneously adding glass fiber into a side feeding port of the double-screw extruder, and extruding to obtain modified nylon strand C;

step five: immersing the modified nylon strand C into a cooling water tank, and then dragging and granulating through a granulator to obtain a semi-finished product D, wherein the particle diameter of the semi-finished product D is required to be ensured to be between 10 and 20mm, so that the semi-finished product D is convenient to dissipate heat and store subsequently;

step six: and drying and cooling the semi-finished product D to obtain a finished product.

Comparative example:

the raw materials are mixed together during mixing and added into a blanking hopper of the double-screw extruder, and the other steps are the same as the embodiment.

And (3) comparison test:

the products in the examples and the comparative examples are injected into test sample strips which accord with GB test standards by adopting a 80T sea injection molding machine and a mold, the test sample strips are pretreated according to the GB test standards and are subjected to low temperature, the standard environmental standards of GB/T2918-1998 plastic sample strip state adjustment and test, the 1 st part immersion method, the liquid pycnometer method and the titration method for measuring GB/T1033.1-2008 non-foam plastic density, the 2 nd part for measuring GB/T1040.2-2006 plastic tensile property, the test conditions of molding and extrusion plastic, the first part for measuring GB/T1043.1-2008 plastic simple beam impact property, the non-instrumented impact test, the 1 st part for measuring GB/T1634.1-2004 plastic load deformation temperature, the general test method, the test standards for measuring GB/T9341-2008 plastic bending property and the like are respectively adopted, the products of examples and comparative examples were tested for density, tensile properties, simple beam notched impact, heat distortion temperature and flexural properties, respectively.

And (3) testing the density:

the density of the test sample strips of the examples and the comparative examples is respectively tested by using the density test sample strip pretreated for 24 hours at normal temperature according to the Standard environmental Standard for Conditioning and testing the State of GB/T2918-1998 Plastic sample strip according to the hydrometer bottle method in the part 1 immersion method, hydrometer bottle method and titration method for measuring the density of non-foamed plastics of GB/T1033.1-2008, and the test steps are as follows:

weighing a dried empty specific gravity bottle, loading a proper amount of sample strips in the specific gravity bottle, weighing, soaking the sample strips in an impregnating solution, putting the specific gravity bottle in a dryer, vacuumizing to expel air in the specific gravity bottle, stopping vacuumizing, filling the specific gravity bottle with the impregnating solution, putting the specific gravity bottle in a constant-temperature liquid bath at 23 ℃ and 0.5 ℃ for constant temperature, accurately filling the impregnating solution to the limit capable of being accommodated by the capacity of the specific gravity bottle, wiping the specific gravity bottle, and weighing the specific gravity bottle containing the sample strips and the impregnating solution;

the pycnometer is emptied, cleaned and dried, filled with boiled distilled water or deionized water, then the air is removed by the above method, and the quality of the pycnometer and the contents is weighed at the testing temperature.

The density of the sample at 23 ℃ is as follows when the immersion liquid is water in the test:

Ρ_s＝m_s*Ρ_l/(m₁-m₂)

wherein p_sThe density of the sample at 23 ℃ is given in grams per cubic centimeter (g/cm)³)；

m_sIs the apparent mass of the sample in grams (g);

m₁the apparent mass of liquid required to fill a empty specific gravity bottle is given in grams (g);

m₂the apparent mass of the liquid required to fill a sample-filled pycnometer is in grams (g);

Ρ_lis the density of the impregnation solution at 23 ℃ in grams per cubic centimeter (g/cm)³)。

At least three sample bars should be measured for each sample, the average value of the three tests is calculated, the result is retained to the third position after the decimal point, and the detection result is shown in table 1:

table 1 units: g/cm³

Density test	1	2	3	Mean value of
					Examples	1.353	1.355	1.352	1.353
Comparative example	1.352	1.353	1.352	1.352

And (3) tensile test:

tensile strength and tensile modulus of test specimens of examples and comparative examples were respectively tested according to GB/T1040.2-2006 test conditions for tensile Properties of plastics, part 2 of test for molded and extruded plastics, of tensile test specimens pretreated at room temperature for 24 hours according to GB/T2918-1998 Standard environmental standards for Condition and test of specimens of plastics, the test procedures being as follows:

measuring the width b and the thickness h within 5mm from each end of a standard distance in the middle of each spline, wherein the width b is accurate to 0.1mm, the thickness h is accurate to 0.02mm, recording the maximum value and the minimum value of the width and the thickness of each spline, and ensuring that the arithmetic mean value of the width and the thickness of each spline is calculated within the tolerance range of the corresponding material standard so as to be used for other calculation;

the bar is placed in the fixture, the long axis of the bar is aligned with the axis of the tester, and when the fixture is used to center the pin, the bar is tightened slightly before tightening the fixture, and then the fixture is clamped smoothly and firmly to prevent slippage of the bar, and then the test is performed.

The tensile strength of the alloy is calculated by the formula:

σ＝F/A

wherein σ is tensile stress in megapascals (MPa);

f is the corresponding load measured in cattle (N);

a is the original cross-sectional area of the sample strip in square millimeters (mm)²)。

The tensile modulus calculation formula is as follows:

E_t＝(σ₂-σ₁)/(ε₂-ε₁)

wherein E_tTensile modulus of elasticity in megapascals (MPa);

σ₁is a strain value epsilon₁Stress measured at 0.0005 in megapascals (MPa);

σ₂is a strain value epsilon₁Stress measured in megapascals (MPa) at 0.0025.

The tensile strength and tensile modulus of 5 tensile bars of the examples and comparative examples were measured, and the results are shown in tables 2 and 3, and the test curves are shown in fig. 1 and 2:

table 2 units: MPa of

Tensile strength	1	2	3	4	5	Mean value of
							Examples	144	143	142	142	143	143
Comparative example	119	119	120	121	121	120

Table 3 units: MPa of

Tensile modulus	1	2	3	4	5	Mean value of
							Examples	9420	9120	9053	8738	9191	9104
Comparative example	7652	7584	7325	7716	7524	7560

Bending test:

bending strength and flexural modulus of test specimens of examples and comparative examples were respectively tested according to GB/T9341-2008 determination of bending property of plastics by bending test specimens subjected to 24-hour normal temperature pretreatment according to GB/T2918-1998 Standard environmental standards for Conditioning and testing Plastic specimens, and the test procedures were as follows:

measuring the width b of the middle part of the sample to be accurate to 0.1 mm; the thickness h is accurate to 0.01mm, the average value h of the thicknesses of a group of samples is calculated, the samples with the thicknesses exceeding 2% of the average thickness tolerance are removed and replaced by randomly selected samples, the size of the samples for measuring the bending performance is measured at room temperature, the span is adjusted according to the formula L ═ 16 +/-1) x average value h, and the adjusted span is measured and is accurate to 0.5%;

before the test, the sample is not stressed excessively, in order to avoid the bending of the initial part of a stress-strain curve, prestress is required to be applied, the test speed is set according to the specification of the standard of a tested material, if no relevant standard exists, the bending strain rate is enabled to be as close to 1%/min as possible, the test speed given by the test is 2mm/min, the sample is symmetrically placed on two supports, force is applied to the center of a span, and an automatic recording device is applied to the test to record the force applied and the corresponding deflection in the test process, so that a complete stress-strain curve graph 3 and a complete stress-strain curve graph shown in fig. 4 are obtained.

The bending strength of the steel plate is calculated according to the formula:

σ_f＝3FL/(2bh²)

wherein sigma_fBending stress in megapascals (MPa);

f is the applied force in newtons (N);

l is span in millimeters (mm);

b is the sample width in millimeters (mm);

h is the specimen thickness in millimeters (mm).

The formula for calculating the flexural modulus is as follows:

E_f＝(σ_f2-σ_f1)/(ε_f2-ε_f1)

wherein E_fFlexural modulus in megapascals (MPa);

σ_f1the deflection is s₁Bending stress in megapascals (MPa);

σ_f2the deflection is s₂The bending stress in MPa is expressed.

The bending strength and the bending modulus of the test pieces of 5 pieces of the example and the comparative example were measured, and the results are shown in tables 3 and 4, and the test curves are shown in fig. 3 and 4:

table 3 units: MPa of

Bending strength	1	2	3	4	5	Mean value of
							Examples	225	227	232	226	227	227
Comparative example	184	187	186	187	188	187

Table 4 units: MPa of

Flexural modulus	1	2	3	4	5	Mean value of
							Examples	7336	7193	7192	7226	7251	7240
Comparative example	6803	6803	6586	6941	7071	6841

Impact test of the simply supported beam notch:

according to the test standard of non-instrumented impact test, the notch impact of the normal-temperature simple-supported beam and the notch impact of the low-temperature simple-supported beam of the embodiment and the comparative example are respectively tested according to the standard environmental standard of GB/T2918-1998 plastic sample condition regulation and test, wherein the standard environmental standard of GB/T2918-1998 plastic sample condition regulation and test is subjected to normal-temperature pretreatment for 24 hours and low-temperature treatment for minus 40 ℃ for 24 hours, and the notch impact sample of the simple-supported beam of the comparative example and the notch impact of the low-temperature simple-supported beam of the comparative example are respectively tested according to the test standard of GB/T1043.1-2008 plastic simple-supported beam, wherein the test steps are as follows:

the thickness h and the width b of the middle part of each sample are measured to be 0.02mm, and for notch samples, the residual width b is carefully measured to be 0.02 mm;

confirming whether the pendulum impact tester reaches the specified impact speed, whether the absorbed energy is within the range of 10-80% of the nominal energy, if more than one pendulum meets the requirement, using the pendulum with the maximum energy, and measuring the friction loss and correcting the absorbed energy according to the specification of GB/T21189-2007;

lifting the pendulum bob to a specified height, placing the sample on a tester support, enabling the punching blade to be opposite to the punching center of the sample, carefully placing the notch sample, enabling the center of the notch to be just positioned on the punching plane, releasing the pendulum bob, recording the punching energy absorbed by the sample and correcting the friction loss of the sample.

The calculation formula of the impact strength of the simply supported beam notch is as follows:

a_cn＝E_c/(h*b_N)*10³

wherein a is_cnThe impact strength of the sample simply supported beam is a notch sample, the notch is A, B or C type, and the unit is kilojoule per square meter (kJ/m)²)

E_cThe energy absorbed in joules (J) for the failure of the corrected specimen;

h is the sample thickness in millimeters (mm);

b_Nthe remaining width of the sample is in millimeters (mm).

Taking 20 simple support beam notch impact sample bars of the products of the examples and the comparative examples, dividing the samples into two groups, respectively carrying out normal-temperature pretreatment and low-temperature pretreatment, and testing the normal-temperature simple support beam notch impact performance and the low-temperature simple support beam notch impact performance, wherein the low-temperature simple support beam notch impact is required to be tested within 30s after the test sample bars are taken out during testing, and the detection results are shown in table 5:

table 5 units: kJ/m²

Heat distortion temperature:

the test specimens for heat distortion temperature after 24-hour room temperature pretreatment according to GB/T2918-1998 Standard environmental standards for Conditioning and testing of Plastic specimens for Heat distortion temperature test the heat distortion of the examples and comparative examples were respectively tested according to GB/T1634.1-2004 part 1 of the measurement of deformation temperature under load for plastics, general test method, and the test results are shown in Table 6:

table 6 units: c

Density test	1	2	3	Mean value of
					Examples	204.1	204.1	204.1	204.1
Comparative example	205.3	205.3	205.3	205.3

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.