Bio-based polypropylene composite material, preparation method of vehicle door interior decorative plate structure, vehicle door interior decorative plate structure and vehicle

Abstract

The invention discloses a bio-based polypropylene composite material, a preparation method of a vehicle door interior decorative plate structure, the vehicle door interior decorative plate structure and a vehicle, and relates to the technical field of vehicles, and the bio-based polypropylene composite material comprises, by mass, 38-42 parts of bio-based polypropylene; 35 to 40 parts by mass of homo-polypropylene; 7-10 parts by mass of a toughening agent; 2-3 parts by mass of a reinforcing agent; 10-20 parts by mass of a filler; 3-5 parts by mass of a compatilizer; and 0.3 to 0.5 part by mass of a lubricant. According to the technical scheme provided by the invention, the density of the decorative plate body can be reduced under the condition that the strength and the rigidity are ensured, namely, the weight of the decorative plate body is reduced, so that the carbon emission of the decorative plate body can be reduced while the light weight of the decorative plate body is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a bio-based polypropylene composite material, a preparation method of a car door interior trim panel structure, a car door interior trim panel structure and a vehicle. BACKGROUND

[0002] The car door interior trim panel structure is one of the car doors, which is installed on the car door in the vehicle space to play the functions of decoration and handrail installation. In order to ensure the lightweight of the vehicle body, the car door interior trim panel is required to be light enough, so that the car door interior trim panel made of plastic material in the prior art reduces the cost and weight of the car door interior trim panel. However, the rigidity and strength of the car door interior trim panel structure made of plastic material on the market are generally insufficient. SUMMARY

[0003] The main purpose of the present application is to provide a bio-based polypropylene composite material, a preparation method of a car door interior trim panel structure, a structure and a vehicle, which aims to reduce the weight of the car door interior trim panel structure while meeting the strength and rigidity of the car door interior trim panel structure.

[0004] To achieve the above purpose, the bio-based polypropylene composite material provided by the present application comprises:

[0005] Bio-based polypropylene 38-42 parts by mass;

[0006] Homopolymer polypropylene 35-40 parts by mass;

[0007] Toughening agent 7-10 parts by mass;

[0008] Reinforcing agent 2-3 parts by mass;

[0009] Filler 10-20 parts by mass;

[0010] Compatibility agent 3-5 parts by mass; and

[0011] Lubricant 0.3-0.5 parts by mass.

[0012] In an embodiment, the bio-based polypropylene composite material further comprises 0.1-0.3 parts by mass of a scratch aid; and / or

[0013] The bio-based polypropylene composite material further comprises 0.3-1 parts by mass of a light stabilizer; and / or

[0014] The bio-based polypropylene composite material further comprises 0.3-1 parts by mass of an antioxidant.

[0015] In an embodiment, the reinforcing agent is selected from nano-sized mica; and / or

[0016] The filler is selected from wheat straw fiber; and / or

[0017] the compatibilizer is selected from maleic anhydride grafted polypropylene; and / or

[0018] the light stabilizer is selected from ultraviolet light absorbers; and / or

[0019] the antioxidant is selected from hindered amines and phosphites; and / or

[0020] the lubricant is selected from one or both of zinc stearate and calcium stearate; and / or

[0021] the scratch aid is selected from organosilicones; and / or

[0022] the toughening agent is selected from POE.

[0023] In an embodiment, the biobased polypropylene, the homopolymer polypropylene, the toughening agent, the reinforcing agent, the filler, the compatibilizer, the light stabilizer, the antioxidant, the lubricant, and the scratch aid are mixed in a high-speed mixer according to the above mass fractions, and then the mixture is added to an extruder for plasticizing and mixing, and after sufficient mixing, the mixture is extruded and granulated to obtain the product raw material.

[0024] In an embodiment, when the extrusion granulation is performed, the temperature of the extruder ranges from 170°C to 250°C; and / or

[0025] When the extruder is used for plasticizing and mixing, the rotation speed of the extruder ranges from 280 r / min to 320 r / min; and / or

[0026] When the mixture is added to the extruder, the rotation speed of the extruder ranges from 28 r / min to 32 r / min; and / or

[0027] After the extruder is used for extrusion and granulation, the granules obtained by extrusion are subjected to drying treatment, the drying temperature ranges from 80°C to 100°C, and the time ranges from 3 h to 4 h.

[0028] The application further provides a preparation method of the vehicle door interior trim panel structure, which is injection molded by using the biobased polypropylene composite material.

[0029] In an embodiment, the preparation method comprises:

[0030] The biobased polypropylene composite material is extruded and granulated and dried to obtain the product raw material;

[0031] The product raw material is added to an injection molding machine, and injection molding is performed at a temperature of 210°C to 230°C to obtain the vehicle door interior trim panel structure.

[0032] In an embodiment, in the injection molding at a temperature of 210-230 DEG C, the rotation speed of the screw of the injection molding machine ranges between 40 r / min and 45 r / min; and / or

[0033] In the injection molding at a temperature of 210-230 DEG C, the injection pressure ranges between 120 bar and 120 bar; and / or

[0034] In the injection molding at a temperature of 210-230 DEG C, the holding pressure ranges between 35 bar and 45 bar; and / or

[0035] In the injection molding at a temperature of 210-230 DEG C, the temperature of the injection material ranges between 200 DEG C and 230 DEG C when the injection material is extruded by the screw of the injection molding machine.

[0036] The application further provides a vehicle door inner trim panel structure, which comprises a trim panel body prepared by the above method.

[0037] In an embodiment, the trim panel body is provided with a plurality of pouring heads, which decrease in diameter in a direction away from the trim panel body.

[0038] In an embodiment, the outer periphery of the trim panel body is provided with a flange structure, and a reinforcing rib is arranged between the flange structure and the trim panel body; and / or

[0039] The wall thickness of the trim panel body ranges between 2.5 mm and 3 mm; and / or

[0040] The trim panel body is provided with a transverse reinforcing rib, a longitudinal reinforcing rib and an annular reinforcing rib, and the transverse reinforcing rib is connected to the longitudinal reinforcing rib through the annular reinforcing rib.

[0041] In an embodiment, the vehicle door inner trim panel structure further comprises at least one of an upper trim panel, an inside handle and a map pocket, the inside handle, the upper trim panel and the map pocket are connected to the trim panel body respectively, and the inside handle, the upper trim panel and the map pocket are prepared by the above method.

[0042] In an embodiment, the map pocket is clamped to the trim panel body; and / or

[0043] The upper trim panel is screw-connected to the trim panel body; and / or

[0044] The trim panel body is provided with a trumpet mouth, and the sound hole in the trumpet mouth is arranged in an equilateral triangle shape.

[0045] In an embodiment, the inner release handle and the decorative plate body are screw connected; and / or

[0046] A positioning structure is arranged between the decorative plate body and the inner release handle.

[0047] The application also provides a vehicle comprising the vehicle door interior trim panel structure.

[0048] The technical scheme of the application configures the components of the bio-based polypropylene composite material as 38-42 parts by mass of bio-based polypropylene, 35-40 parts by mass of homopolymer polypropylene, 7-10 parts by mass of toughening agent, 2-3 parts by mass of reinforcing agent, 10-20 parts by mass of filler, 3-5 parts by mass of compatibilizer, and 0.3-0.5 parts by mass of lubricant. The decorative plate body produced by the bio-based polypropylene composite material of the present application can reduce the density of the decorative plate body while ensuring the strength and rigidity, that is, the weight of the decorative plate body is reduced, which is conducive to the lightweight of the decorative plate body and the reduction of carbon emissions of the decorative plate body. BRIEF DESCRIPTION OF DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained according to the structures shown in the drawings without creative labor for those skilled in the art.

[0050] Figure 1 A first-order modal analysis result diagram of a vehicle door body made of the bio-based polypropylene composite material provided by the application;

[0051] Figure 2 An indentation resistance analysis result diagram of region 1 of the vehicle door body made of the bio-based polypropylene composite material provided by the application;

[0052] Figure 3 An indentation resistance analysis result diagram of region 2 of the vehicle door body made of the bio-based polypropylene composite material provided by the application;

[0053] Figure 4 An indentation resistance analysis result diagram of region 3 of the vehicle door body made of the bio-based polypropylene composite material provided by the application;

[0054] Figure 5 A structure diagram of the vehicle door interior trim panel structure provided by the application;

[0055] Figure 6 A structure diagram of the decorative plate body of the vehicle door interior trim panel structure provided by the application.

[0056] BRIEF DESCRIPTION OF DRAWINGS

[0057] 100, vehicle door inner trim panel structure; 110, upper trim panel; 120, trim panel body; 121, flange structure; 122, reinforcing rib; 123, transverse reinforcing rib; 124, longitudinal reinforcing rib; 125, annular reinforcing rib; 126, trumpet mouth; 127, buckle part; 128, mushroom buckle; 129, positioning structure; 130, inside opening handle; 140, map pocket; 140, boss structure; 150, groove structure; 160, clamping column.

[0058] The objectives, functional characteristics and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present application will be apparently and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present application.

[0060] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0061] In addition, if the embodiments of the present application involve the description of "first", "second", etc., the description of "first", "second", etc. is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, "and / or" or "and / or" appearing throughout the text means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B simultaneously satisfy the scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the person skilled in the art, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope of the present application.

[0062] The door trim panel structure is one of the automobile door, which is installed on the door in the vehicle space to play the function of decoration and handrail installation. In order to ensure the lightweight of the vehicle body, the door trim panel is required to be light enough, so some door trim panels in the prior art are made of plastic material, so that the cost and weight of the door trim panel are reduced. However, the rigidity and strength of the door trim panel structure made of plastic material on the market are generally insufficient.

[0063] To solve the above problems, a bio-based polypropylene composite material is provided. The bio-based polypropylene composite material can be applied to vehicles, such as but not limited to vehicle interiors, including door trim panel structures, instrument panels, auxiliary instrument panels, seat back panels, etc. The present application is described by taking the application of the bio-based polypropylene composite material to the decorative panel body 120 of the door trim panel structure as an example.

[0064] Please refer to Table 1 and Table 2 below. In an embodiment of the present application, the bio-based polypropylene composite material comprises: 38-42 parts by mass of bio-based polypropylene; 35-40 parts by mass of homopolymer polypropylene; 7-10 parts by mass of toughening agent; 2-3 parts by mass of reinforcing agent; 10-20 parts by mass of filler; 3-5 parts by mass of compatibilizer; and 0.3-0.5 parts by mass of lubricant.

[0065] The technical scheme of the present application configures the components of the bio-based polypropylene composite material as 38-42 parts by mass of bio-based polypropylene, 35-40 parts by mass of homopolymer polypropylene, 7-10 parts by mass of toughening agent, 2-3 parts by mass of reinforcing agent, 10-20 parts by mass of filler, 3-5 parts by mass of compatibilizer, and 0.3-0.5 parts by mass of lubricant. As can be seen from Table 1 to Table 3, the decorative panel body 120 produced by the bio-based polypropylene composite material of the present application can reduce the density of the decorative panel body 120 while ensuring the strength and rigidity, that is, the weight of the decorative panel body 120 is reduced, which is conducive to the lightweight of the decorative panel body 120 and the reduction of carbon emissions of the decorative panel body 120.

[0066] Secondly, referring to Table 3, Table 3 is a comparison and analysis table of the lightweight and carbon emissions of the bio-based polypropylene composite material and the traditional polypropylene composite material provided by the present application; the results in Table 3 show that the total weight of the decorative panel body 120 and the door trim panel structure can be reduced by 9.8% by using the bio-based polypropylene composite material instead of the traditional polypropylene composite material. The carbon emissions of the bio-based polypropylene composite material of the present application are reduced by 20.71% compared with the traditional polypropylene composite material. As can be seen from Table 1 to Table 3, the decorative panel body 120 prepared by the bio-based polypropylene composite material of the present application can meet the performance requirements of rigidity, strength and other modalities through the design and optimization of material components, and the weight of the decorative panel body 120 can be reduced by more than 5% while the carbon emissions are reduced.

[0067] Table 1 Comparison table of process parameters of comparative examples and bio-based polypropylene composite materials

[0068]

[0069] Table 2 Comparison table of test results of comparative examples and bio-based polypropylene composite materials

[0070]

[0071] Table 3 Comparison and analysis of lightweight and carbon emissions of bio-based polypropylene composite materials and traditional polypropylene composite materials

[0072]

[0073] Optionally, in an embodiment, the bio-based polypropylene composite material further comprises 0.1-0.3 parts by mass of a scratch aid, which can increase the scratch resistance of the decorative plate body 120 and reduce the probability of scratches on the decorative plate body 120.

[0074] Optionally, in an embodiment, the bio-based polypropylene composite material further comprises 0.3-1 parts by mass of a light stabilizer; it can be understood that the addition of the light stabilizer can not only reduce the problems such as discoloration, embrittlement, cracking, and strength reduction of the bio-based polypropylene composite material caused by UV irradiation, but also delay material aging; thus, it can be seen that the addition of the light stabilizer can prolong the service life of the bio-based polypropylene composite material and reduce maintenance or replacement costs.

[0075] Optionally, in an embodiment, the bio-based polypropylene composite material further comprises 0.3-1 parts by mass of an antioxidant; it can be understood that the addition of the antioxidant can not only reduce the problems such as embrittlement, cracking, and strength reduction of the bio-based polypropylene composite material caused by oxidation, but also in the processing (such as injection molding, extrusion) or high-temperature use environment, the antioxidant can inhibit the thermal-induced oxidation reaction, thereby inhibiting the yellowing or darkening caused by oxidation, reducing the molecular weight caused by oxidation, and further maintaining the tensile strength, elasticity, and other properties of the bio-based polypropylene composite material.

[0076] Further, in the present embodiment, the bio-based polypropylene composite material further comprises 0.3-1 parts by mass of an antioxidant, 0.1-0.3 parts by mass of a scratch aid, and 0.3-1 parts by mass of a light stabilizer, which can further prolong the service life of the bio-based polypropylene composite material and reduce maintenance or replacement costs.

[0077] In the present embodiment, the parts by mass of the antioxidant is 0.5, the parts by mass of the scratch aid is 0.1, and the parts by mass of the light stabilizer is 0.5, which can ensure the material properties while reducing production costs.

[0078] Optionally, in an embodiment, the reinforcing agent is selected from nano-sized mica; it can be understood that the lamellar structure of nano-sized mica can form a physical cross-linking network in the matrix, and when uniformly dispersed, it can effectively transfer stress, thereby improving tensile strength, bending modulus and impact resistance. The lamellar structure of nano-sized mica can also delay the diffusion of thermal decomposition gas, prolonging the thermal decomposition path of the material. Secondly, when nano-sized mica is compounded with an antioxidant, thermal oxidation aging can be further delayed. The lamellar structure of nano-sized mica can also reduce the surface friction coefficient, thereby improving the scratch resistance of the bio-based polypropylene composite material and improving the surface gloss of the product produced by using the bio-based polypropylene composite material. Of course, the present solution is not limited to this, and in other embodiments, the reinforcing agent can also be selected from calcium-silicon-magnesium whiskers.

[0079] Optionally, in an embodiment, in order to achieve carbon emission reduction, the filler of the present solution is selected from wheat straw fiber. Of course, the present solution is not limited to this, and in other embodiments, the filler can also be selected from coconut shell fiber.

[0080] Optionally, in an embodiment, the compatibilizer is selected from maleic anhydride grafted polypropylene (MAPP); the maleic anhydride groups (-CO-CH=CH-CO-) on the molecular chain of MAPP can undergo esterification reaction with the hydroxyl groups (-OH) on the surface of the wheat straw fiber to form covalent bond connection; the interfacial tension between the fiber and PP (bio-based polypropylene and homopolymer polypropylene) is reduced, and the dispersion of the wheat straw fiber in the molten PP (bio-based polypropylene and homopolymer polypropylene) is promoted. Of course, the present solution is not limited to this, and in other embodiments, the compatibilizer can also be selected from a silane coupling agent.

[0081] Optionally, in an embodiment, the light stabilizer is selected from an ultraviolet absorber; wherein the ultraviolet absorber can be UV-531 or UV-587.

[0082] In the present embodiment, the mass fraction of the light stabilizer is 0.5, which can ensure the material cost while prolonging the service life of the bio-based polypropylene composite material. Of course, the present solution is not limited to this, and in other embodiments, the mass fraction of the light stabilizer can also be 0.6.

[0083] Optionally, in an embodiment, the antioxidant is selected from hindered amine and phosphite. Hindered amine, although not directly absorbing UV, can inhibit the UV-induced radical reaction, prolonging the effective period of the UV absorber. It can be understood that the tertiary carbon hydrogen in the PP molecular chain is prone to breakage under the action of heat, light or stress, forming an alkyl radical (R·). These radicals react with oxygen to form a peroxide radical (ROO·), which in turn takes the hydrogen of the adjacent carbon atom to form ROOH. The use of both hindered amine and phosphite in the antioxidant can make them work together. Phosphite mainly attacks primary oxidation products (ROOH) and blocks the source of free radicals; while hindered amine specifically kills the formed free radicals (ROO·) and cuts off the chain reaction. Of course, this solution is not limited to this. In other embodiments, the antioxidant can also be selected from antioxidant 1010 or antioxidant 330.

[0084] In this embodiment, the hindered amine is hindered amine 1790 and the phosphite is phosphite 168.

[0085] Optionally, in an embodiment, the lubricant is selected from one or both of zinc stearate and calcium stearate; it can be understood that zinc stearate can form a molecular layer lubricating film, reduce the friction between polymer chains, reduce the melt viscosity, and is particularly beneficial to the injection molding of thin-walled door parts (such as the body 120 of the decorative plate). Moreover, the formation of a lubricating layer on the surface of the mold can also reduce the sticking of the product to the mold and prolong the service life of the mold. Secondly, calcium stearate can also form a lubricating layer, reduce the friction between polymer molecules, reduce the risk of product sticking to the mold, and prolong the service life of the mold.

[0086] It should be noted that when the bio-based polypropylene composite material simultaneously uses zinc stearate and calcium stearate as lubricants, the melt viscosity can be further reduced, the risk of product sticking to the mold can be further reduced, and the service life of the mold can be prolonged.

[0087] Optionally, in an embodiment, the scratch aid is selected from organic silicone; organic silicone (such as polydimethylsiloxane (PDMS)) forms a molecular-level lubricating film on the surface of the material, which can reduce the friction coefficient and make it difficult for sharp objects (such as keys and nails) to scratch the surface. Moreover, the molecular chain of some modified silicones (such as amino silicone oil) has elasticity and can temporarily deform and rebound under external force, reducing the depth of scratches. Secondly, organic silicone can also control the surface gloss to achieve a matte or silk texture. When organic silicone migrates to the surface, it also has a demolding effect, which can also reduce the ejection resistance of the injection molded part. When organic silicone is compounded with the above-mentioned light stabilizer (such as hindered amine), the organic silicone can delay the surface powdering.

[0088] Optionally, in an embodiment, the toughening agent is selected from POE (polyolefin elastomer) ; the addition of POE can improve the toughness of the bio-based polypropylene composite while having less impact on the rigidity of the bio-based polypropylene composite. Of course, the present solution is not limited thereto, and in other embodiments, the toughening agent can also be selected from SBS (styrene-butadiene-styrene block copolymer).

[0089] In the raw material for preparing the decorative plate body 120 using the bio-based polypropylene composite, the bio-based polypropylene, the homopolymer polypropylene, the toughening agent, the reinforcing agent, the filler, the compatibilizer, the light stabilizer, the antioxidant, the lubricant, and the scratch aid are mixed uniformly in the high-speed mixer according to the above-mentioned mass fractions, and then the mixed material is added to the extruder for plasticizing and mixing, and after sufficient mixing, the product raw material is obtained by extruding and granulating. Then, the product raw material is injected into the injection molding machine to produce the decorative plate body 120.

[0090] Further, in order to ensure uniform mixing of the raw material, in the present solution, the temperature of the extruder during the extruding and granulating is in the range of 170℃ to 250℃; and / or, the rotating speed of the extruder during the plasticizing and mixing is in the range of 280r / min to 320r / min; and / or, the rotating speed of the extruder when the mixed material is added is in the range of 28r / min to 32r / min.

[0091] Optionally, in an embodiment, in order to sufficiently remove the moisture in the product raw material during the granulating, and to avoid the generation of bubbles or silver streaks during the injection molding, the present solution performs drying treatment on the granules obtained by the extruding of the extruder, and the drying temperature is in the range of 80℃ to 100℃, and the time is in the range of 3h to 4h.

[0092] The present application also provides a preparation method of the interior door trim structure, which adopts the bio-based polypropylene composite injection molding, and the specific components of the bio-based polypropylene composite refer to the above-mentioned embodiments. Since the bio-based polypropylene composite adopts all the technical solutions of the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here.

[0093] Optionally, in the present embodiment, the preparation method of the vehicle door inner trim panel structure comprises: extruding and granulating the bio-based polypropylene composite material and drying to obtain product raw materials; adding the product raw materials into an injection molding machine and injection molding at a temperature of 210-230°C to obtain the vehicle door inner trim panel structure. Specifically, when injection molding the vehicle door inner trim panel structure 100, the product raw materials are first poured into the hopper of the injection molding machine, and during the injection molding process, the process parameters are adjusted and controlled, including mold temperature, melt temperature, injection time, holding time and holding pressure, so that the product raw materials can quickly fill the mold, and at the same time, the appearance of the product can be improved and the product defects can be reduced. Of course, the present scheme is not limited to this, and in other embodiments, the preparation method of the vehicle door inner trim panel structure can also comprise: uniformly mixing the bio-based polypropylene composite material, injecting it into an injection molding machine, and injection molding at a temperature of 210-230°C to obtain the vehicle door inner trim panel structure.

[0094] Optionally, in the present embodiment, in order to better melt the product raw materials, the temperature of the injection molding material during the injection molding process at a temperature of 210-230°C is in the range of 200-230°C.

[0095] Further, in order to improve the injection molding efficiency, reduce the injection molding cycle, and at the same time improve the appearance quality of the product and the performance requirements of the product, the rotational speed of the screw of the injection molding machine during the injection molding process at a temperature of 210-230°C is in the range of 40-45 r / min.

[0096] It can be understood that too high a pressure is not desirable, and when the melt pressure approaches the upper limit of the injection pressure, more gas is easily produced, causing the plastic to produce bubbles, cavities, discoloration and other defects. In the present scheme, the injection pressure during the injection molding process at a temperature of 210-230°C is in the range of 120-120 bar; and / or, the holding pressure is in the range of 35-45 bar, which is beneficial to improving the flowability of the melt while reducing the shrinkage of the product.

[0097] Referring to Table 1 and Table 2, Table 1 is a comparison table of process parameters of the bio-based polypropylene composite material provided by the present application and the comparative example, and Table 2 is a comparison table of test results of the bio-based polypropylene composite material provided by the present application and the comparative example; it should be noted that Comparative Example 1 in Table 1 and Table 2 is a conventional polypropylene composite material (i.e. a composite material enhanced by conventional PP+EPDM+T20), and Examples 2-6 are the above-mentioned bio-based polypropylene composite material.

[0098] Referring to Table 1 and Table 2, the material of Example 2 is different from that of Comparative Example 1, and the rest of the preparation conditions are the same. Compared with the traditional polypropylene composite material, the decorative plate body 120 product prepared by using the bio-based polypropylene composite material can have lower density of the decorative plate body 120 while meeting the rigidity and strength requirements, which is beneficial to the lightweight of the decorative plate body 120.

[0099] However, Example 3 changes the number of pouring heads of the decorative plate body 120 on the basis of Example 2, that is, changes the number of pouring gates. Referring to Table 2, increasing the number of pouring heads helps to improve the appearance quality of the decorative plate body 120. The main reason is that the pouring quantity is optimized, which is beneficial to improve the flow speed and pouring speed of the material in the mold, thereby improving the appearance effect of the decorative plate body 120. Therefore, increasing the number of pouring heads is beneficial to meet the rigidity and strength requirements, so that the density of the decorative plate body 120 is lower, which is beneficial to the lightweight of the decorative plate body 120 while improving the appearance effect of the decorative plate body 120 prepared by using the bio-based polypropylene composite material.

[0100] Example 4 changes the size of the pouring head of the product on the basis of Example 2, that is, changes the size of the pouring gate. Referring to Table 2, Example 4 also helps to improve the appearance quality of the decorative plate body 120 compared with Example 2. The main reason is that the size of the pouring head is optimized, which is beneficial to improve the flow speed and pouring speed of the material in the mold, thereby improving the appearance effect of the decorative plate body 120. Therefore, setting the pouring head to variable cross-section is beneficial to meet the rigidity and strength requirements, so that the density of the decorative plate body 120 is lower, which is beneficial to the lightweight of the decorative plate body 120 while improving the appearance effect of the decorative plate body 120 prepared by using the bio-based polypropylene composite material.

[0101] It should be noted that the number of traces left by a small amount of traces is less than that of a small amount of traces, but the two are close.

[0102] Further, the increase of the holding pressure is beneficial to improve the flowability of the melt and can reduce the shrinkage of the product. Example 5 increases the holding pressure on the basis of Example 4. For the increase of the holding pressure, it is found that there is no trace left on the decorative plate body 120, that is, the trace of the obtained product is obviously reduced compared with Example 4, and the surface quality is also improved accordingly.

[0103] In order to better improve the apparent quality, the product key factor adjustment related product process parameters are adjusted in embodiment 6, the reasonable number of pouring head, pouring head size, injection temperature, holding pressure, screw speed, injection pressure and the like are selected. It can be known from table 2 that embodiment 6 is helpful to improve the surface roughness of the product compared with embodiment 5, and the trace phenomenon is reduced. Mainly because the injection temperature is improved, the internal stress of the product and the orientation degree of the product can be well reduced, the melt is fully solidified, and the apparent quality of the product is improved.

[0104] It can be known from table 2 that the bio-based polypropylene composite material of the scheme can realize that the apparent quality of the decorative plate body 120 is high, there is no shrinkage, no bubble and the like defects, at the same time, the tensile strength of the decorative plate body 120 is ≥19MPa, the bending strength is ≥30MPa, the bending modulus is ≥1200MPa, more importantly, the bio-based polypropylene composite material of the scheme is reduced by more than 5% compared with the traditional polypropylene composite material, and the product light weight is realized.

[0105] Referring to table 4 and Figure 1 Table 4 is a first-order modal analysis result table of a vehicle door body made of the bio-based polypropylene composite material provided by the application; Figure 1 is a first-order modal analysis result table of a vehicle door body made of the bio-based polypropylene composite material provided by the application; For the above decorative plate 110 body design rationality, through comprehensive analysis of the strength and modal of the structure, whether the assembly structure meets the design requirements is obtained, first, the modal is analyzed, the six directions of the ten plastic buckle tables on the decorative plate body 120 are fully fixed, so that the constraint modal result of the decorative plate body 120 is obtained (see table 4 for details), it is found through analysis that the constraint modal of the decorative plate body 120 is 30.26Hz, which is greater than the design requirement of 30Hz, and the whole vehicle resonance phenomenon will not be produced, which meets the design requirements of the product. It can be known from table 4 that the product of the decorative plate body 120 prepared by the bio-based polypropylene composite material of the scheme is ≥30Hz in the constraint modal.

[0106] It should be noted that the six directions refer to front, back, left, right, up and down.

[0107] Table 4 is a first-order modal analysis result table of a decorative plate body

[0108]

[0109] Secondly, referring to table 5, and Figures 2 to 4 Table 5 is a dent resistance analysis result table of a vehicle door body made of the bio-based polypropylene composite material provided by the application; Figure 2 is a dent resistance analysis result table of region 1 of a vehicle door body made of the bio-based polypropylene composite material provided by the application; Figure 3This is a graph showing the dent resistance analysis results of region 2 of a vehicle door body made of the bio-based polypropylene composite material provided by the present invention; Figure 4 This is a graph showing the dent resistance analysis results of region 3 of a vehicle door body made of the bio-based polypropylene composite material provided by the present invention. On the basis of meeting the product modal requirements, according to the fixed mode of the modal, a 100N load was applied separately to three regions (region 1 is the center of the decorative panel body 120, region 2 is the leftmost region of the map pocket 140, and region 3 is the rightmost region of the map pocket 140). The load application head has a diameter of 100mm. The force was applied according to the above requirements to test the performance analysis results of the product. The analysis results show that: Region 1: The maximum displacement is 9.638mm; it is less than the maximum displacement of 10mm required by the design; Region 2: The maximum displacement is 3.146mm; it is less than the maximum displacement of 10mm required by the design; Region 3: The maximum displacement is 3.103mm; it is less than the maximum displacement of 10mm required by the design. Through analysis, it can be concluded that the selection of structural materials and structural optimization meet the design requirements.

[0110] Table 5 Analysis results of the dent resistance of the decorative panel body

[0111]

[0112] Combining the performance results and product appearance of the examples reveals that, during actual injection molding trials, key factors affecting the product quality of bio-based polypropylene composites, including optimal number of pouring heads, pouring head size, injection temperature, and holding pressure, also have a certain impact on mark retention. However, screw speed and injection pressure have a minimal impact on product performance and appearance. Therefore, to improve injection efficiency, reduce injection cycle time, and simultaneously enhance product appearance and performance, optimal optimization of injection speed and pressure is essential.

[0113] The present invention also proposes a vehicle door interior decorative panel structure 100, which includes a decorative panel body. The decorative panel body is manufactured using the above-mentioned method for preparing the vehicle door interior decorative panel structure. The method for preparing the vehicle door interior decorative panel structure refers to the above-mentioned embodiment. Since the vehicle door interior decorative panel structure 100 adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0114] Optionally, the vehicle door inner trim panel structure 100 further comprises at least one of an upper trim panel 110, an inside handle 130 and a map pocket 140, the inside handle 130, the upper trim panel 110 and the map pocket 140 are connected with the trim panel body 120 respectively, the inside handle 130, the upper trim panel 110 and the map pocket 140 are also prepared by the preparation method of the vehicle door inner trim panel structure as described above, so that the vehicle door inner trim panel structure 100 can be conveniently processed and formed. Of course, the present scheme is not limited to this, in other embodiments, the inside handle 130, the upper trim panel 110 and the map pocket 140 can also be formed by welding.

[0115] It should be noted that the upper trim panel 110, the inside handle 130 and the map pocket 140 also adopt the above-mentioned bio-based polypropylene composite material, and the production process and process parameters refer to the above, so as to improve the appearance quality of the vehicle door inner trim panel structure 100 while meeting the requirements of its stiffness and strength, and facilitate the realization of lightweight and reduction of carbon emissions.

[0116] Among them, the trim panel body 120 is designed as a "curved trapezoidal" structure shape according to the modeling requirements, which can improve the appearance of the trim panel body 120 while improving the strength of the trim panel body 120.

[0117] It should be noted that the "curved trapezoidal" structure shape means that the left and right sides of the trim panel body 120 are curved, and the upper edge length is less than the lower edge length.

[0118] Referring to Table 1 and Table 2. Optionally, the trim panel body 120 is provided with a plurality of pouring heads, the pouring heads are smaller in diameter away from the trim panel body 120, that is, the cross section of the pouring head is variable cross section. This is conducive to improving the appearance effect of the trim panel body 120.

[0119] Example 4 in Table 1 changes the size of the pouring head of the product on the basis of Example 2, that is, changes the size of the gate, and referring to Table 2, it can be seen that Example 4 also helps to improve the appearance quality of the trim panel body 120 compared with Example 2, mainly because the size of the pouring head is optimized, which is conducive to improving the material flow speed and pouring speed in the mold, thereby improving the appearance effect of the trim panel body 120; it can be seen that the pouring head is set to variable cross section, which is conducive to meeting the requirements of stiffness and strength, so that the density of the trim panel body 120 is lower, which is conducive to realizing the lightweight of the trim panel body 120 while improving the appearance effect of the trim panel body 120 prepared by the bio-based polypropylene composite material.

[0120] Further, the number of pouring heads ranges between 5 and 7, which is conducive to improving the appearance effect of the trim panel body 120.

[0121] The embodiment 3 in Table 1 is based on the embodiment 2, the number of pouring heads of the decorative plate body 120 is changed, that is, the number of gates is changed, and it can be known from Table 2 that increasing the number of pouring heads helps to improve the appearance quality of the decorative plate body 120. The main reason is that the pouring quantity is optimized, which is beneficial to improve the material flow speed and pouring speed in the mold, thereby helping to improve the appearance effect of the decorative plate body 120. Therefore, increasing the number of pouring heads helps to make the density of the decorative plate body 120 lower under the condition of meeting the rigidity and strength requirements, which is beneficial to realize the lightweight of the decorative plate body 120 and improve the appearance effect of the decorative plate body 120 prepared by using the bio-based polypropylene composite material.

[0122] In the embodiment, the number of pouring heads is 6, which can reduce the number of gates, improve the production efficiency, and improve the appearance effect. Of course, the present scheme is not limited thereto, and in other embodiments, the number of pouring heads can also be 5.

[0123] Further, the outer periphery of the decorative plate body 120 is provided with a flange structure 121, and a reinforcing rib 122 is arranged between the flange structure 121 and the decorative plate body 120. This is beneficial to improve the rigidity and strength of the decorative plate body 120.

[0124] In an embodiment, the reinforcing rib 122 is provided in a plurality, and the plurality of reinforcing ribs 122 are arranged at intervals along the length extension direction of the flange structure 121. In the embodiment, the number of reinforcing ribs 122 ranges from 9 to 15, for example, 11 reinforcing ribs, which are mainly arranged around the buckle part 127 of the decorative plate body 120 for connecting the outer plate of the vehicle door.

[0125] It should be noted that the reinforcing rib 122 includes a first segment and a second segment connected to each other, the first segment is arranged on the decorative plate body 120, and the second segment is arranged on the flange structure 121, that is, the reinforcing rib 122 is in the shape of “L” as a whole. The length of the reinforcing rib 122 ranges from 10 mm to 40 mm, the height ranges from 10 mm to 20 mm, and the thickness ranges from 2 mm to 4 mm.

[0126] Further, in the embodiment, in order to prevent the decorative plate body 120 from being shrunk and warped and to strengthen the decorative plate body 120, the wall thickness of the decorative plate body 120 is set to be between 2.5 mm and 3 mm.

[0127] It should be noted that the wall thickness of the decorative plate body 120 is set to be between 2.5 mm and 3 mm, which means that the thickness of most of the wall bodies is between 2.5 mm and 3 mm, and the local thickening is allowed, which is beneficial to improve the strength while reducing the weight of the decorative plate body 120. The local thickening position is, for example but not limited to, the position for mounting the inside-opening handle 130 of the decorative plate body 120.

[0128] In order to solve the problem of low rigidity due to the large planar area of the decorative plate body 120, the decorative plate body 120 is provided with a transverse reinforcing rib 123, a longitudinal reinforcing rib 124 and an annular reinforcing rib 125, and the transverse reinforcing rib 123 is connected with the longitudinal reinforcing rib 124 through the annular reinforcing rib 125.

[0129] In order to further increase the strength of the decorative plate body 120, a plurality of reinforcing ribs with certain length and height are additionally arranged at the middle back of the decorative plate body 120.

[0130] The size of the longitudinal reinforcing rib 124 is 80mm-120mm in length, 1mm-2mm in width and 1mm-2mm in height, and the size of the transverse reinforcing rib 123 is 100mm-180mm in length, 1mm-2mm in width and 1mm-2mm in height.

[0131] In order to prevent the appearance of shrinkage and increase the flowability, the annular reinforcing rib 125 is arranged at the connection position of the transverse reinforcing rib 123 and the longitudinal reinforcing rib 124. In this embodiment, the annular reinforcing rib 125 is arranged at twelve positions, and the size is 4mm-5mm in diameter and 1mm-2mm in height. At the same time, a plurality of local reinforcing ribs are additionally arranged at the local positions of the decorative plate body 120 to improve the rigidity of the decorative plate body 120, and the size of the reinforcing rib is 10mm-15mm in length, 1mm-2mm in width and 1mm-2mm in height.

[0132] In this embodiment, the sound-absorbing cotton is arranged at the middle position of the decorative plate body 120, so that when the decorative plate body 120 and the outer plate are installed, the sound-absorbing cotton can not only avoid the gap between the decorative plate body 120 and the outer plate, that is, support the outer plate by using the sound-absorbing cotton to increase the strength of the inner plate and the decorative plate body 120, but also increase the sound insulation effect by using the sound-absorbing cotton.

[0133] Further, the sound-absorbing cotton is attached to the decorative plate body 120. Of course, the present scheme is not limited to this, and in other embodiments, the sound-absorbing cotton can also be abutted between the decorative plate body 120 and the outer plate.

[0134] Optionally, the map pocket 140 is clamped with the decorative plate body 120, and the clamping mode can facilitate the disassembly of the map pocket 140 and improve the production efficiency. Of course, the present scheme is not limited to this, and in other embodiments, the map pocket 140 can also be screw-connected with the decorative plate body 120.

[0135] The decorative plate body 120 is provided with a clamping column 160, and the map bag 140 is provided with a clamping hole corresponding to the clamping column 160. Such a clamping structure is simple and convenient to assemble and disassemble. Of course, the present scheme is not limited to this, and in other embodiments, an elastic buckle can be provided on the decorative plate body 120, and a buckle hole is provided on the map bag 140 corresponding to the elastic buckle. The elastic buckle is used to buckle on the buckle hole.

[0136] Further, the clamping column 160 is provided with a plurality of clamping columns 160, and the map bag 140 is provided with a clamping hole corresponding to one clamping column 160. This is beneficial to improve the installation stability of the map bag 140. In the present embodiment, the diameter of the clamping column 160 is 4.5mm, the height range is 15mm-18mm, and the interval between the two clamping columns 160 is 35mm-50mm. The wall thickness of the clamping hole is in the range of 2mm-4mm, which is a circular ring. This is beneficial to ensure the strength of the clamping column 160 and the clamping hole.

[0137] Optionally, the upper decorative plate 110 is screw connected with the decorative plate body 120. It can be understood that the screw connection operation is simple, which is beneficial to improve the installation efficiency.

[0138] Further, the decorative plate body 120 is further provided with a lateral convex structure 140 and a groove structure 150, and the convex structure 140 and the groove structure 150 are respectively provided with mounting holes. The upper decorative plate 110 is provided with a groove matching part and a convex matching part corresponding to the convex structure 140 and the groove structure 150, respectively. The groove matching part is provided with a fastening hole corresponding to the mounting hole of the convex structure 140, and the convex matching part is provided with a fastening hole corresponding to the mounting hole of the groove structure 150. A screw is passed through the mounting hole and the fastening hole to achieve the purpose of fastening the decorative plate body 120 and the upper decorative plate 110.

[0139] It should be noted that the convex structure 140 is clamped in the groove matching part, and the groove structure 150 is used for clamping the convex matching part. In this way, the upper decorative plate 110 can be limited, which is beneficial to improve the installation effect of the upper decorative plate 110.

[0140] The groove structure 150 is designed as a U-shaped structure slot with an upward opening. And / or

[0141] Optionally, in order to improve the sound permeability, the decorative plate body 120 is provided with a loudspeaker opening 126, and the sound hole in the loudspeaker opening 126 is arranged in an equilateral triangular shape.

[0142] The horn mouth 126 is designed as two, one horn mouth 126 is designed as a large circular structure with a diameter ranging from 80mm to 120mm, and the other horn mouth 126 is designed as a small circular structure with a diameter ranging from 40mm to 60mm, the height of the equilateral triangle structure ranges from 0.3mm to 0.6mm, and the base ranges from 0.3mm to 0.5mm.

[0143] Optionally, the outer periphery of the decorative plate body 120 is provided with a plurality of spaced buckle portions 127, which are used to connect with the outer plate of the door; the buckle portion 127 is provided, which is beneficial to improve the connection efficiency of the outer plate of the door and the decorative plate body 120.

[0144] In this embodiment, the number of buckle portions 127 ranges from 8 to 14, for example, 10 buckle portions 127, which is beneficial to improve the installation stability of the outer plate of the door and the decorative plate body 120. Further, by screwing the self-tapping screw on the buckle portion 127, the fixing with the outer plate of the door is realized. The buckle portion 127 is designed as a lateral insertion type buckle table, the height of the buckle table ranges from 30mm to 40mm, the length ranges from 10mm to 15mm, and the width ranges from 10mm to 12mm, and the middle of the buckle table is reserved a hole diameter of 4mm to 6mm for the assembly of the self-tapping screw.

[0145] Further, in order to ensure the installation and fixation of the decorative plate body 120 and the outer plate of the door, the middle of the decorative plate body 120 is provided with a mushroom buckle 128, which is used to connect with the outer plate of the door.

[0146] The mushroom buckle 128 is provided with a plurality of, for example, 2, which is designed as an upwardly open "U-shaped" structure, the height ranges from 25mm to 40mm, the length ranges from 20mm to 30mm, and the radius ranges from 5mm to 8mm.

[0147] The above sound-absorbing cotton is arranged close to the mushroom buckle 128.

[0148] Optionally, the inner opening handle 130 and the decorative plate body 120 are screw connected, and it can be understood that the screw connection can improve the installation and disassembly efficiency of the inner opening handle 130.

[0149] Further, the positioning structure 129 is arranged between the decorative plate body 120 and the inner opening handle 130, and it can be understood that when the inner opening handle 130 is installed, the inner opening handle 130 can be positioned by the positioning structure 129 first, and then fastened by the screw structure, which can ensure the accuracy of the installation position of the inner handle and improve the installation efficiency of the inner opening handle 130.

[0150] The positioning structure 129 is configured as a positioning hole arranged on the inner open handle 130 and a latch piece arranged on the decorative plate body 120, which is simple and convenient for forming.

[0151] Further, the latch piece comprises a main positioning piece extending laterally and a plurality of auxiliary positioning pieces arranged on the upper and lower sides of the main positioning piece, which is beneficial to improve the positioning effect.

[0152] The present application also provides a vehicle comprising the vehicle door interior trim panel structure 100, the specific structure of which is referred to the above embodiments. Since all the technical solutions of the above embodiments are adopted in the vehicle, all the beneficial effects brought by the technical solutions of the above embodiments are at least possessed by the vehicle, which will not be repeated here.

[0153] The above description is only an exemplary embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation, direct / indirect application in other related technical fields based on the technical concept of the present application and the content of the specification and drawings are included in the patent protection scope of the present application.

Claims

1. A bio-based polypropylene composite material, characterized in that: include: 38-42 parts by mass of bio-based polypropylene; Homopolymer polypropylene 35-40 parts by mass; 7 to 10 parts by mass of toughening agent; 2-3 parts by mass of reinforcing agent; 10 to 20 parts by mass of filler; 3 to 5 parts by mass of a compatibilizer; and 0.3-0.5 parts by mass of lubricant.

2. The bio-based polypropylene composite material according to claim 1, wherein The bio-based polypropylene composite material further comprises 0.1 to 0.3 parts by mass of a scraping aid; and / or The bio-based polypropylene composite material further comprises 0.3 to 1 parts by mass of a light stabilizer; and / or The bio-based polypropylene composite material further includes 0.3 to 1 parts by mass of an antioxidant.

3. The bio-based polypropylene composite material according to claim 2, wherein: The reinforcing agent is nano-mica; and / or The filler is wheat straw fiber; and / or The compatibilizer is maleic anhydride grafted polypropylene; and / or The light stabilizer is a UV absorber; and / or The antioxidant is selected from hindered amines and phosphites; and / or The lubricant is one or both of zinc stearate and calcium stearate; and / or The scraping aid is organic silicone; and / or The toughening agent is POE.

4. The bio-based polypropylene composite material according to claim 3, wherein: The bio-based polypropylene, homopolypropylene, toughening agent, reinforcing agent, filler, compatibilizer, light stabilizer, antioxidant, lubricant, and scraping aid are uniformly mixed in a high-speed mixer according to the above-mentioned mass parts, and then the mixture is added to an extruder for plasticizing and mixing. After sufficient mixing, it is extruded and granulated to obtain the product raw material.

5. The bio-based polypropylene composite material according to claim 4, wherein: During the extrusion granulation, the temperature of the extruder is in the range of 170° C. to 250° C.; and / or When the extruder performs plasticizing and mixing, the speed of the extruder ranges from 280 r / min to 320 r / min; and / or When the mixed material is added to the extruder, the speed of the extruder is in the range of 28 rpm to 32 rpm; and / or After the extruder extrudes and granulates, the extruded granules are dried at a temperature ranging from 80° C. to 100° C. for a time ranging from 3 hours to 4 hours.

6. A method for preparing a vehicle door interior decorative panel structure, characterized in that: The bio-based polypropylene composite material according to any one of claims 1 to 5 is used for injection molding.

7. The method for preparing a vehicle door interior decorative panel structure according to claim 6, wherein: The preparation method comprises: Extruding and granulating the bio-based polypropylene composite material and drying the granules to obtain a product raw material; The product raw materials are added to an injection molding machine and injection molded at a temperature of 210° C. to 230° C. to obtain a vehicle door interior decorative panel structure.

8. The method for preparing a vehicle door interior decorative panel structure according to claim 7, wherein: During the injection molding at a temperature of 210° C. to 230° C., the screw speed of the injection molding machine is in the range of 40 rpm to 45 rpm; and / or During the injection molding at a temperature of 210° C. to 230° C., the injection pressure range is between 120 bar and 120 bar; and / or During the injection molding at a temperature of 210° C. to 230° C., the holding pressure range is between 35 bar and 45 bar; and / or In the injection molding under the condition of a temperature of 210° C. to 230° C., when the screw rod of the injection molding machine extrude the injection material, the temperature range of the injection material is between 200° C. and 230° C.

9. A vehicle door interior trim panel structure, characterized in that: The vehicle door interior decorative panel structure includes a decorative panel body, and the decorative panel body is manufactured using the method for manufacturing a vehicle door interior decorative panel structure according to any one of claims 6 to 8.

10. The vehicle door interior trim panel structure according to claim 9, wherein: The decorative board body is provided with a plurality of pouring heads, and the diameters of the pouring heads decrease in a direction away from the decorative board body.

11. The vehicle door interior trim panel structure according to claim 9, wherein: The outer periphery of the decorative panel body is provided with a flange structure, and a reinforcing rib is provided between the flange structure and the decorative panel body; and / or The wall thickness of the decorative panel body is in the range of 2.5mm-3mm; and / or The decorative panel body is provided with transverse reinforcing ribs, longitudinal reinforcing ribs and annular reinforcing ribs, and the transverse reinforcing ribs are connected to the longitudinal reinforcing ribs through the annular reinforcing ribs.

12. The vehicle door interior trim structure according to claim 9, wherein: The vehicle door interior decorative panel structure also includes at least one of an upper decorative panel, an inner opening handle and a map pocket, and the inner opening handle, the upper decorative panel and the map pocket are respectively connected to the decorative panel body, and the inner opening handle, the upper decorative panel and the map pocket are manufactured using the preparation method of the vehicle door interior decorative panel structure as described in any one of claims 6 to 8.

13. The vehicle door interior trim structure according to claim 12, wherein: The map pocket is snap-fitted to the decorative panel body; and / or The upper decorative plate is connected to the decorative plate body with screws; and / or The decorative plate body is provided with a bell mouth, and the sound holes in the bell mouth are arranged in an equilateral triangle.

14. The vehicle door interior trim structure according to claim 12, wherein: The inner opening handle is connected to the decorative panel body with screws; and / or A positioning structure is provided between the decorative panel body and the inward opening handle.

15. A vehicle, characterized in that: The vehicle door inner decorative panel structure comprises the vehicle door inner decorative panel structure according to any one of claims 9 to 14.

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