A processing technology of a light-weight spare tire cover plate for vehicle

Abstract

The application discloses a processing technology of a lightweight spare tire cover plate for vehicles, which comprises the following processes: taking a paper core to stretch and shape, laying glass fiber cloth on the upper surface and the lower surface of the paper core to form an upper glass fiber layer and a lower glass fiber layer respectively; then spraying polyurethane foaming agent on the surface of the upper glass fiber layer; turning over, spraying polyurethane foaming agent on the surface of the lower glass fiber layer, and then performing molding, foaming, and forming an upper PU layer and a lower PU layer respectively; and adhering a fabric to the surface of the upper PU layer through polyurethane glue to obtain the spare tire cover plate. The lightweight plate is formed by taking a honeycomb paper or a corrugated paper as a center, covering glass fiber on both sides of the paper, filling foaming polyurethane, and performing molding, and a layer of fabric is attached to the lightweight plate as a patch, so that the lightweight plate can be applied to the field of spare tire cover plates for vehicles and light weight is realized.

Description

Technical Field

[0001] This invention relates to the field of honeycomb sandwich panel technology, specifically to a processing technology for a lightweight automotive spare tire cover. Background Technology

[0002] With the development of the automotive industry, while ensuring the strength and safety of vehicles, the industry is moving towards lightweighting to reduce the curb weight of vehicles, which helps improve their power and reduce fuel consumption. Current automotive lightweighting measures mainly utilize lightweight materials. The spare tire cover is an interior component of the vehicle's trunk, serving both decorative and load-bearing functions. To meet the combined requirements of lightweighting and strength in automobiles, we propose a processing technology for a lightweight automotive spare tire cover. Summary of the Invention

[0003] The purpose of this invention is to provide a manufacturing process for a lightweight automotive spare tire cover to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a lightweight vehicle spare tire cover, comprising the following structures from top to bottom: a fabric layer, an upper PU layer, an upper fiberglass layer, a paper core, a lower fiberglass layer, and a lower PU layer.

[0005] Furthermore, the paper core is made of corrugated paper or honeycomb paper, with a basis weight of 600–1800 g / m². 2 The thickness is 10-20mm.

[0006] Furthermore, the upper and lower PU layers are formed by spraying and foaming with a polyurethane foaming agent, with a thickness of 3–10 mm and a spraying amount of 300–800 g / m³. 2 .

[0007] Furthermore, the basis weight of the upper and lower glass fiber layers is 40–700 g / m². 2 The thickness is 0.3 to 2.0 mm.

[0008] Furthermore, the basis weight of the patch is 150–450 g / m². 2 The thickness is 1-5mm.

[0009] Furthermore, the patch is adhered to the surface of the upper PU layer using polyurethane adhesive.

[0010] A manufacturing process for a lightweight automotive spare tire cover includes the following steps:

[0011] Take the paper core, stretch and shape it, and lay glass fiber cloth on its upper and lower surfaces to form an upper glass fiber layer and a lower glass fiber layer, respectively.

[0012] Then, a polyurethane foaming agent is sprayed onto the surface of the upper fiberglass layer; the surface is flipped over, and a polyurethane foaming agent is sprayed onto the surface of the lower fiberglass layer. The layers are then molded and foamed to form the upper PU layer and the lower PU layer, respectively.

[0013] The spare tire cover is obtained by adhering the fabric to the surface of the upper PU layer using polyurethane adhesive.

[0014] Furthermore, the molding process is as follows: mold temperature 110~120℃, pressure 5~20MPa, duration 35~45s.

[0015] Furthermore, the coating temperature of the polyurethane adhesive is 10℃~40℃, and the adhesive application rate is 10~25g / m². 2 .

[0016] Furthermore, the polyurethane foaming agent is prepared by the following process:

[0017] Mix polyether polyol and biomass polyol, then add glass fiber, pore-forming agent, catalyst and additives in sequence, and stir until uniform; add isocyanate and mix until uniform to obtain polyurethane foaming agent.

[0018] Furthermore, the polyurethane foaming agent comprises the following components by weight: 20-40 parts biomass polyol, 60-80 parts polyether polyol, 180-250 parts isocyanate, 1-3 parts glass fiber, 5-9 parts foaming agent, 1-2 parts catalyst, and 1-2 parts additives.

[0019] In the above technical solution, the upper PU layer and the lower PU layer (hereinafter collectively referred to as PU layers, and the same applies to the upper and lower glass fiber layers) are formed by spraying, molding, and foaming with a polyurethane foaming agent. The polyurethane foaming agent uses polyether polyol and biomass polyol as the main raw materials, crosslinks with diisocyanate, and, under the action of catalysts, foaming agents, etc., is made into a high molecular polymer, which covers and fills the surface and gaps of the glass fiber layer, effectively enhancing the spare tire cover's resistance to compression and impact.

[0020] Furthermore, biomass polyols are obtained through the following process:

[0021] Rosin-based polyol and deionized water were mixed and heated to 90–96°C, and stirred for 30–60 min. Sodium dodecylbenzenesulfonate was added. The temperature was lowered to 20–30°C, and the pH of the system was adjusted to 4.5–5.2 using hydrochloric acid. Aldehyde ramie was added. The addition was completed within 30 min. The temperature was raised to 85–95°C, and the reaction was carried out for 90–120 min. The pH of the system was adjusted to neutral using sodium hydroxide solution. The precipitate was washed with alkali, filtered, and dried to obtain biomass polyol.

[0022] Furthermore, the ratio of rosin-based polyol to deionized water is 10g / 100mL;

[0023] The mass ratio of rosin-based polyol, aldehyde-based ramie, and sodium dodecylbenzene sulfonate is 10:(2-4):(0.02-0.10);

[0024] The concentration of hydrochloric acid is 30 wt%, and the concentration of sodium hydroxide solution is 2 mol / L.

[0025] Furthermore, rosin-based polyols are obtained by the following process:

[0026] Maleic pine anhydride was mixed with a polyol and heated to 200–210°C in a nitrogen atmosphere. The mixture was kept at this temperature for 20–40 minutes. Xylene was added and the mixture was refluxed with water until no more water was added. The mixture was then cooled, vacuumed under reduced pressure, and discharged at a lower temperature to obtain rosin-based polyol.

[0027] Furthermore, the molar ratio of maleic anhydride to polyol is 1:(1-3);

[0028] The polyol is one or a mixture of neopentyl glycol, diethylene glycol, glycerol, trimethylolpropane, pentaerythritol, dipentaerythritol, and pentaerythritol.

[0029] In the above technical solution, maleic pine anhydride is mixed with a polyol and subjected to an esterification reaction to prepare rosin-based polyol. The introduction of a multi-hydroxyl structure helps improve the reactivity of the polyurethane foaming agent. Combined with its rosin-based cyclic structure, it can effectively improve the heat resistance and mechanical strength of the PU layer. The rosin-based polyol is then mixed with aldehyde-based ramie. In the reaction system, the hydroxyl groups in the rosin-based polyol react with the aldehyde groups in the aldehyde-based ramie to form an acetal structure of rosin-based polyol. This effectively improves the cold resistance, impact resistance, and radiation resistance of the foaming system made with the polyurethane foaming agent, and enhances the adhesion between the PU layer and glass fiber, contributing to the improvement of the interlayer bonding performance and mechanical properties of the spare tire cover. Furthermore, the reaction also increases the molecular weight of the polyurethane foaming system, making it less prone to relative sliding between molecules and adhesion with glass fiber. This improves the mechanical properties of the PU layer, resulting in a spare tire cover with superior strength. Quality control of rosin-based polyols and aldehyde-based ramie ensures that the produced biomass polyols retain their high hydroxyl value.

[0030] In the initial stage of contact between the polyurethane foaming agent and the glass fiber layer, the hydroxyl groups present in the system can form hydrogen bonds with the silanol groups on the surface of the glass fiber, thereby improving the adhesion between the two. The coating enters the gaps in the glass fiber cloth and undergoes cross-linking and foaming, which helps to further improve the adhesion between the PU layer and the glass fiber, and the strength of the prepared tire cover can also be further improved.

[0031] Furthermore, aldehyde-based ramie is obtained by the following process:

[0032] Under a nitrogen atmosphere, ramie fibers and sodium periodate solution were mixed in the dark and the mixture was kept at a constant temperature of 27–32°C with shaking for 100–150 min. The reaction was terminated with glycerol solution, allowed to stand, filtered, precipitated with acetone, filtered under vacuum, washed with ethanol, and dried to obtain aldehyde-based ramie.

[0033] Furthermore, the ratio of ramie fiber to sodium periodate solution is 1:50mL;

[0034] The concentration of sodium periodate solution is 0.2–0.3 mol / L;

[0035] The concentration of the glycerol solution is 1 mol / L.

[0036] In the above technical solution, aldehyde-based ramie is obtained by oxidizing ramie. During the reaction, the oxidant periodate permeates, diffuses, and reacts from the amorphous region to the crystalline region of ramie, causing oxidation and depolymerization of the ramie and fiber dissolution, thereby obtaining aldehyde-based ramie (denoted as aldehyde-based ramie). This increases the hydroxyl groups in the polyurethane foaming agent system, enabling it to participate in the reaction, increase the crosslinking density between the molecular chains of the PU layer, and enhance its compressive strength, thus improving the mechanical strength of the prepared tire cover. The introduction of ramie adds a cellulose structure to the polyurethane foaming agent system, which can enhance the strength of the cell walls and improve the cell structure, thereby effectively improving the apparent density, mechanical properties, and thermal stability of the PU layer. As oxidation proceeds, the crystallinity of ramie decreases, and the cohesive force weakens, improving its flexibility. This allows the PU layer to maintain high strength while improving its toughness, resulting in a tire cover with excellent comprehensive performance.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] 1. The present invention describes a lightweight automotive spare tire cover manufacturing process, which involves taking honeycomb paper or corrugated paper as the center, covering both sides with glass fiber, filling with foamed polyurethane, molding to form a lightweight sheet, and then attaching a layer of fabric as a backing, so that it can be applied to the field of automotive spare tire covers and achieve its lightweighting.

[0039] 2. The lightweight spare tire cover of the present invention describes a processing technology that prepares biomass polyols by using rosin-based polyols, aldehyde-based ramie, etc., and applies them to the polyurethane foaming agent components. This can improve the strength and thermal stability of the PU layer and help improve the mechanical properties and heat resistance of the spare tire cover. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] In the following specific implementation methods, all experiments are small-scale laboratory tests, which can be scaled up proportionally.

[0042] The paper core is made of honeycomb paper with a basis weight of 1200 g / m². 2 The thickness is 20mm, and it comes from Foshan Heshenglong Packaging Products Co., Ltd.

[0043] The weight of the fiberglass cloth is 500 g / m². 2 The thickness is 1mm, and it comes from Henan Changyu New Material Technology Co., Ltd.

[0044] The patch is made of PET felt with a weight of 300g / m². 2 The thickness is 2.5mm, and it comes from Nangong Jiatong Felt Products Co., Ltd.

[0045] Polyurethane adhesive: BEPU5103 A / B, sourced from Shanghai Baigao Chemical; coating temperature: 30℃, application rate: 20g / m². 2 ;

[0046] The polyether polyols are a mixture of CHE-2801, CHE-303, and CHK-350D in a mass ratio of 3:10:1, and all are sourced from Changhua Chemical Technology Co., Ltd.

[0047] The isocyanate is polymeric MDI M20S, sourced from BASF AG;

[0048] Glass fiber: 200 mesh glass fiber powder, sourced from Shanghai Maclean Biotechnology Co., Ltd.;

[0049] Foaming agent: CP1421, sourced from Dow Chemical (Shanghai) Co., Ltd.;

[0050] Catalyst: CS90, sourced from Shanghai Qiguang Industry & Trade Co., Ltd.;

[0051] The additive is surfactant B8444, which is sourced from Evonik Degussa (China) Investment Co., Ltd.

[0052] Polyvinyl alcohol: PVA-L-9, sourced from Kuraray Corporation;

[0053] Ramie fiber: 8-10 mm in length, sourced from Lu'an Shengda Ramie Textile Co., Ltd.; pre-alkali treatment is used, the treatment process is: soaking in 5% sodium hydroxide solution at 85℃ for 4 hours, solid-liquid ratio 1:30; washing to neutral, drying to constant weight;

[0054] All numbers of "parts" mentioned below refer to mass components.

[0055] Example 1: A manufacturing process for a lightweight automotive spare tire cover, comprising the following processes:

[0056] Step 1: Under a nitrogen atmosphere, ramie fibers and 0.2M sodium periodate solution were mixed in the dark and the mixture was kept at 27°C with shaking for 150 min. The reaction was terminated with 1M glycerol solution, allowed to stand, filtered, precipitated with acetone, filtered under vacuum, washed with ethanol, and dried to obtain aldehyde-based ramie. The ratio of ramie fibers to sodium periodate solution was 1:50 mL.

[0057] Maleic pine anhydride was mixed with diethylene glycol and heated to 200°C in a nitrogen atmosphere. The mixture was kept at this temperature for 30 min. Xylene was added and the mixture was refluxed with water until no more water was added. The mixture was then cooled, vacuumed under reduced pressure, and discharged at a lower temperature to obtain rosin-based polyol. The molar ratio of maleic pine anhydride to diethylene glycol was 1:3.

[0058] Rosin-based polyol and deionized water were mixed and heated to 90°C, then stirred for 60 min. Sodium dodecylbenzenesulfonate was added. The mixture was cooled to 20°C, and the pH of the system was adjusted to 5.2 using 30 wt% hydrochloric acid. Aldehyde ramie was added, and the mixture was heated to 85°C and reacted for 120 min. The pH of the system was adjusted to neutral using 2M sodium hydroxide solution. The precipitate was washed with alkali, filtered, and dried to obtain biomass polyol. The ratio of rosin-based polyol to deionized water was 10 g / 100 mL. The mass ratio of rosin-based polyol, aldehyde ramie, and sodium dodecylbenzenesulfonate was 10:2:0.02.

[0059] Mix polyether polyol and biomass polyol, then add glass fiber, pore-forming agent, and catalyst in sequence. Heat to 60°C and stir until homogeneous. Cool to 30°C, add isocyanate, and mix until homogeneous to obtain polyurethane foaming agent. The polyurethane foaming agent comprises the following components by mass: 20 parts biomass polyol, 80 parts polyether polyol, 200 parts isocyanate, 1 part glass fiber, 5 parts foaming agent, 1 part catalyst, and 1 part additive.

[0060] Step 2: Take the paper core, stretch and shape it, and lay fiberglass cloth on its upper and lower surfaces to form an upper fiberglass layer and a lower fiberglass layer, respectively. Then, spray polyurethane foam agent onto the surface of the upper fiberglass layer. Turn it over and spray polyurethane foam agent onto the surface of the lower fiberglass layer. Mold and foam to form an upper PU layer and a lower PU layer, respectively. The amount of polyurethane foam agent sprayed is 500g / m². 2 The thickness of the PU layer is 5mm; the molding process is as follows: mold temperature 110℃, pressure 5MPa, duration 35s; the fabric is adhered to the surface of the upper PU layer by polyurethane adhesive to obtain the spare tire cover.

[0061] Example 2: A manufacturing process for a lightweight automotive spare tire cover, comprising the following processes:

[0062] Step 1: Under a nitrogen atmosphere, ramie fibers and 0.25M sodium periodate solution were mixed in the dark and the mixture was kept at 30℃ with shaking for 120 min. The reaction was terminated with 1M glycerol solution, allowed to stand, filtered, precipitated with acetone, filtered under vacuum, washed with ethanol, and dried to obtain aldehyde-based ramie. The ratio of ramie fibers to sodium periodate solution was 1:50 mL.

[0063] Maleic pine anhydride was mixed with trimethylolpropane and heated to 205°C under a nitrogen atmosphere. The mixture was kept at this temperature for 30 min. Xylene was added and the mixture was refluxed with water until no more water was added. The mixture was then cooled, vacuumed, and discharged at a lower temperature to obtain rosin-based polyol. The molar ratio of maleic pine anhydride to trimethylolpropane was 1:3.

[0064] Rosin-based polyol and deionized water were mixed and heated to 93°C, then stirred for 45 min. Sodium dodecylbenzenesulfonate was added. The mixture was cooled to 25°C, and the pH of the system was adjusted to 5 using 30 wt% hydrochloric acid. Aldehyde ramie was added, and the mixture was heated to 90°C and reacted for 105 min. The pH of the system was adjusted to neutral using 2M sodium hydroxide solution. The precipitate was washed with alkali, filtered, and dried to obtain biomass polyol. The ratio of rosin-based polyol to deionized water was 10 g / 100 mL. The mass ratio of rosin-based polyol, aldehyde ramie, and sodium dodecylbenzenesulfonate was 10:3:0.06.

[0065] Mix polyether polyol and biomass polyol, then add glass fiber, pore-forming agent, and catalyst in sequence. Heat to 60°C and stir until homogeneous. Cool to 30°C, add isocyanate, and mix until homogeneous to obtain polyurethane foaming agent. The polyurethane foaming agent comprises the following components by mass: 30 parts biomass polyol, 70 parts polyether polyol, 220 parts isocyanate, 2 parts glass fiber, 7 parts foaming agent, 1.5 parts catalyst, and 1.5 parts additives.

[0066] Step 2: Take the paper core, stretch and shape it, and lay fiberglass cloth on its upper and lower surfaces to form an upper fiberglass layer and a lower fiberglass layer, respectively. Then, spray polyurethane foam agent onto the surface of the upper fiberglass layer. Turn it over and spray polyurethane foam agent onto the surface of the lower fiberglass layer. Mold and foam to form an upper PU layer and a lower PU layer, respectively. The amount of polyurethane foam agent sprayed is 500g / m². 2 The thickness of the PU layer is 5mm; the molding process is as follows: mold temperature 115℃, pressure 10MPa, duration 40s; the fabric is adhered to the surface of the upper PU layer by polyurethane adhesive to obtain the spare tire cover.

[0067] Example 3: A manufacturing process for a lightweight automotive spare tire cover, comprising the following processes:

[0068] Step 1: Under a nitrogen atmosphere, ramie fibers and 0.3M sodium periodate solution were mixed in the dark and the mixture was kept at 32℃ with shaking for 100 min. The reaction was terminated with 1M glycerol solution, allowed to stand, filtered, precipitated with acetone, filtered under vacuum, washed with ethanol, and dried to obtain aldehyde-based ramie. The ratio of ramie fibers to sodium periodate solution was 1:50 mL.

[0069] Maleic pine anhydride and pentaerythritol were mixed and heated to 210°C in a nitrogen atmosphere and reacted for 30 min. Xylene was added and the mixture was refluxed with water until no water increase was observed. The mixture was then cooled, vacuumed, and discharged at a lower temperature to obtain rosin-based polyol. The molar ratio of maleic pine anhydride to pentaerythritol was 1:3.

[0070] Rosin-based polyol and deionized water were mixed and heated to 90–96°C, and stirred for 30–60 min. Sodium dodecylbenzenesulfonate was added. The mixture was cooled to 30°C, and the pH of the system was adjusted to 5.2 using 30 wt% hydrochloric acid. Aldehyde ramie was added. The addition was completed within 30 min, and the temperature was raised to 95°C. The reaction was carried out for 90 min. The pH of the system was adjusted to neutral using 2M sodium hydroxide solution. The precipitate was washed with alkali, filtered, and dried to obtain biomass polyol. The ratio of rosin-based polyol to deionized water was 10 g / 100 mL. The mass ratio of rosin-based polyol, aldehyde ramie, and sodium dodecylbenzenesulfonate was 10:4:0.10.

[0071] Mix polyether polyol and biomass polyol, then add glass fiber, pore-forming agent, and catalyst in sequence. Heat to 60°C and stir until homogeneous. Cool to 30°C, add isocyanate, and mix until homogeneous to obtain polyurethane foaming agent. The polyurethane foaming agent comprises the following components by mass: 40 parts biomass polyol, 60 parts polyether polyol, 250 parts isocyanate, 3 parts glass fiber, 9 parts foaming agent, 2 parts catalyst, and 2 parts additives.

[0072] Step 2: Take the paper core, stretch and shape it, and lay fiberglass cloth on its upper and lower surfaces to form an upper fiberglass layer and a lower fiberglass layer, respectively. Then, spray polyurethane foam agent onto the surface of the upper fiberglass layer. Turn it over and spray polyurethane foam agent onto the surface of the lower fiberglass layer. Mold and foam to form an upper PU layer and a lower PU layer, respectively. The amount of polyurethane foam agent sprayed is 500g / m². 2 The thickness of the PU layer is 5mm; the molding process is as follows: mold temperature 120℃, pressure 20MPa, duration 45s; the fabric is adhered to the surface of the upper PU layer by polyurethane adhesive to obtain the spare tire cover.

[0073] Comparative Example 1: A manufacturing process for a lightweight automotive spare tire cover, comprising the following processes:

[0074] Step 1: Under a nitrogen atmosphere, ramie fibers and 0.2M sodium periodate solution were mixed in the dark and the mixture was kept at 27°C with shaking for 150 min. The reaction was terminated with 1M glycerol solution, allowed to stand, filtered, precipitated with acetone, filtered under vacuum, washed with ethanol, and dried to obtain aldehyde-based ramie. The ratio of ramie fibers to sodium periodate solution was 1:50 mL.

[0075] Polyvinyl alcohol and deionized water were mixed and heated to 90°C, stirring until the polyvinyl alcohol was completely dissolved. Sodium dodecylbenzenesulfonate was added. The temperature was lowered to 20°C, and the pH of the system was adjusted to 5.2 using 30wt% hydrochloric acid. Aldehyde ramie was added; the addition was completed within 30 minutes. The temperature was then raised to 85°C, and the reaction was carried out for 120 minutes. The pH of the system was adjusted to neutral using 2M sodium hydroxide solution. The precipitate was washed with alkali, filtered, and dried to obtain biomass polyol. The ratio of polyvinyl alcohol to deionized water was 10 g / 100 mL. The mass ratio of polyvinyl alcohol, aldehyde ramie, and sodium dodecylbenzenesulfonate was 10:2:0.02.

[0076] Mix polyether polyol and biomass polyol, then add glass fiber, pore-forming agent, and catalyst in sequence. Heat to 60°C and stir until homogeneous. Cool to 30°C, add isocyanate, and mix until homogeneous to obtain polyurethane foaming agent. The polyurethane foaming agent comprises the following components by mass: 20 parts biomass polyol, 80 parts polyether polyol, 180 parts isocyanate, 1 part glass fiber, 5 parts foaming agent, 1 part catalyst, and 1 part additive.

[0077] Step 2: Take the paper core, stretch and shape it, and lay fiberglass cloth on its upper and lower surfaces to form an upper fiberglass layer and a lower fiberglass layer, respectively. Then, spray polyurethane foam agent onto the surface of the upper fiberglass layer. Turn it over and spray polyurethane foam agent onto the surface of the lower fiberglass layer. Mold and foam to form an upper PU layer and a lower PU layer, respectively. The amount of polyurethane foam agent sprayed is 500g / m². 2The thickness of the PU layer is 5mm; the molding process is as follows: mold temperature 110℃, pressure 5MPa, duration 35s; the fabric is adhered to the surface of the upper PU layer by polyurethane adhesive to obtain the spare tire cover.

[0078] Comparative Example 2: A manufacturing process for a lightweight automotive spare tire cover, comprising the following processes:

[0079] Step 1: Mix polyvinyl alcohol and deionized water, heat to 90℃, and stir until the polyvinyl alcohol is completely dissolved; add sodium dodecylbenzenesulfonate; cool to 20℃, adjust the pH of the system to 5.2 using 30wt% hydrochloric acid, and add hexamethylenetetramine; add the hexamethylenetetramine over 30 minutes, raise the temperature to 35℃, and react for 120 minutes; adjust the pH of the system to neutral using 2M sodium hydroxide solution, take the precipitate, wash with alkali, filter, and dry to obtain biomass polyol; the ratio of polyvinyl alcohol to deionized water is 10g / 100mL; the mass ratio of polyvinyl alcohol, hexamethylenetetramine, and sodium dodecylbenzenesulfonate is 10:1.4:0.02;

[0080] Mix polyether polyol and biomass polyol, then add glass fiber, pore-forming agent, and catalyst in sequence. Heat to 60°C and stir until homogeneous. Cool to 30°C, add isocyanate, and mix until homogeneous to obtain polyurethane foaming agent. The polyurethane foaming agent comprises the following components by mass: 20 parts biomass polyol, 80 parts polyether polyol, 180 parts isocyanate, 1 part glass fiber, 5 parts foaming agent, 1 part catalyst, and 1 part additive.

[0081] Step 2: Take the paper core, stretch and shape it, and lay fiberglass cloth on its upper and lower surfaces to form an upper fiberglass layer and a lower fiberglass layer, respectively. Then, spray polyurethane foam agent onto the surface of the upper fiberglass layer. Turn it over and spray polyurethane foam agent onto the surface of the lower fiberglass layer. Mold and foam to form an upper PU layer and a lower PU layer, respectively. The amount of polyurethane foam agent sprayed is 500g / m². 2 The thickness of the PU layer is 5mm; the molding process is as follows: mold temperature 110℃, pressure 5MPa, duration 35s; the fabric is adhered to the surface of the upper PU layer by polyurethane adhesive to obtain the spare tire cover.

[0082] Comparative Example 3: A manufacturing process for a lightweight automotive spare tire cover, comprising the following processes:

[0083] Step 1: Mix maleic anhydride and diethylene glycol, heat to 200°C in a nitrogen atmosphere, and keep the temperature for 30 min; add xylene, reflux with water until no water increase, cool down, reduce pressure and vacuum, cool down and discharge to obtain rosin-based polyol; the molar ratio of maleic anhydride to diethylene glycol is 1:3.

[0084] Mix polyether polyol and rosin-based polyol, then add glass fiber, pore-forming agent, and catalyst in sequence. Heat to 60°C and stir until homogeneous. Cool to 30°C, add isocyanate, and mix until homogeneous to obtain polyurethane foaming agent. The polyurethane foaming agent comprises the following components by mass: 20 parts rosin-based polyol, 80 parts polyether polyol, 180 parts isocyanate, 1 part glass fiber, 5 parts foaming agent, 1 part catalyst, and 1 part additive.

[0085] Step 2: Take the paper core, stretch and shape it, and lay fiberglass cloth on its upper and lower surfaces to form an upper fiberglass layer and a lower fiberglass layer, respectively. Then, spray polyurethane foam agent onto the surface of the upper fiberglass layer. Turn it over and spray polyurethane foam agent onto the surface of the lower fiberglass layer. Mold and foam to form an upper PU layer and a lower PU layer, respectively. The amount of polyurethane foam agent sprayed is 500g / m². 2 The thickness of the PU layer is 5mm; the molding process is as follows: mold temperature 110℃, pressure 5MPa, duration 35s; the fabric is adhered to the surface of the upper PU layer by polyurethane adhesive to obtain the spare tire cover.

[0086] Comparative Example 4: A manufacturing process for a lightweight automotive spare tire cover, comprising the following processes:

[0087] Step 1: Mix polyether polyol and biomass polyol, then add glass fiber, pore-forming agent, and catalyst in sequence. Heat to 60°C and stir until homogeneous. Cool to 30°C, add isocyanate, and mix until homogeneous to obtain polyurethane foaming agent. The polyurethane foaming agent includes the following components by mass: 100 parts polyether polyol, 180 parts isocyanate, 1 part glass fiber, 5 parts foaming agent, 1 part catalyst, and 1 part additive.

[0088] Step 2: Take the paper core, stretch and shape it, and lay fiberglass cloth on its upper and lower surfaces to form an upper fiberglass layer and a lower fiberglass layer, respectively. Then, spray polyurethane foam agent onto the surface of the upper fiberglass layer. Turn it over and spray polyurethane foam agent onto the surface of the lower fiberglass layer. Mold and foam to form an upper PU layer and a lower PU layer, respectively. The amount of polyurethane foam agent sprayed is 500g / m². 2 The thickness of the PU layer is 5mm; the molding process is as follows: mold temperature 110℃, pressure 5MPa, duration 35s; the fabric is adhered to the surface of the upper PU layer by polyurethane adhesive to obtain the spare tire cover.

[0089] Experiment: Spare tire cover plates obtained in Examples 1-3 and Comparative Examples 1-4 were used to prepare samples. Their performance was tested and the test results were recorded.

[0090] Mechanical property testing: Using GB / T 9341 as the reference standard, the bending strength and bending force of the specimens were tested.

[0091] Heat resistance test: The sample is made into a 1000mm×1000mm sample and supported by stainless steel tubes at its four corners. A load with a contact area diameter of 1000mm and a weight of 50kg is placed on the center of the sample and baked at 90℃ for 10min. After that, it is removed, allowed to cool naturally in an environment of 25℃ and left to stand for 2h. The maximum deformation of the sample is recorded.

[0092]

[0093]

[0094] Based on the data in the table above, the following conclusions can be clearly drawn:

[0095] The spare tire cover plates obtained in Examples 1-3 are compared with those obtained in Comparative Examples 1-4. The test results show that...

[0096] Compared to the comparative examples, the spare tire cover plates obtained in Examples 1-3 exhibit higher bending strength, bending force, and lower deformation. This clearly demonstrates that the present invention improves the mechanical properties and thermal stability of the prepared tire cover plate.

[0097] Compared to Example 1, the biomass polyol in Comparative Example 1 was obtained by reacting polyvinyl alcohol and aldehyde-based ramie; the biomass polyol in Comparative Example 2 was obtained by reacting polyvinyl alcohol and adipaldehyde; the biomass polyol in Comparative Example 3 was a rosin-based polyol; and the polyol component of the polyurethane foaming agent in Comparative Example 4 was a polyether polyol. The spare tire cover plates obtained in Comparative Examples 1-4 showed decreased bending strength and bending force, but increased deformation at high temperatures. This indicates that the design of the spare tire cover plate components and its processing in this invention can promote a comprehensive improvement in its mechanical properties and thermal stability.

[0098] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process method article or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process method article or apparatus.

[0099] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A processing technology of a light-weight spare tire cover plate for vehicles, characterized in that: The process comprises the following steps: Taking a paper core to stretch and shape, laying glass fiber cloth on the upper surface and the lower surface of the paper core to form an upper glass fiber layer and a lower glass fiber layer respectively; Then spraying polyurethane foaming agent on the surface of the upper glass fiber layer, turning over, spraying polyurethane foaming agent on the surface of the lower glass fiber layer, molding, foaming to form an upper PU layer and a lower PU layer respectively; Adhering the fabric to the surface of the upper PU layer by polyurethane glue to obtain a tire cover plate; The polyurethane foaming agent is prepared by the following process: Mixing polyether polyol and biomass polyol, adding glass fiber, foaming agent, catalyst and additive in sequence, stirring uniformly, adding isocyanate, mixing to obtain polyurethane foaming agent; The polyurethane foaming agent comprises the following components by mass: 20-40 parts of biomass polyol, 60-80 parts of polyether polyol, 180-250 parts of isocyanate, 1-3 parts of glass fiber, 5-9 parts of foaming agent, 1-2 parts of catalyst and 1-2 parts of additive; The biomass polyol is prepared by the following process: Mixing rosin-based polyol and deionized water, heating to 90-96℃, stirring for 30-60min; adding sodium dodecyl benzene sulfonate; cooling to 20-30℃, adjusting the pH of the system to 4.5-5.2 by hydrochloric acid, adding aldehyde-based ramie, adding within 30min, heating to 85-95℃, reacting for 90-120min to obtain biomass polyol; The aldehyde-based ramie is prepared by the following process: Mixing ramie fiber and sodium periodate solution in a nitrogen atmosphere, constant temperature oscillation reaction at 27-32℃ for 100-150min to obtain aldehyde-based ramie.

2. The processing technology of the light-weighted tire spare cover plate according to claim 1, characterized in that: The paper core is corrugated paper or honeycomb paper, with a weight of 600-1800g / m 2 and a thickness of 10-20mm.

3. The processing method of the light-weighted tire spare cover plate for vehicles according to claim 1, characterized in that: The thickness of the upper PU layer and the lower PU layer is 3-10 mm, and the spraying amount of the polyurethane foaming agent is 300-800 g / m 2 .

4. The processing method of the light-weighted tire spare cover plate for vehicles according to claim 1, characterized in that: The glass fiber cloth has a weight of 40-700 g / m 2 and a thickness of 0.3-2.0 mm.

5. The processing method of the light-weighted tire spare cover plate for vehicles according to claim 1, characterized in that: The molding process is as follows: mold temperature 110-120℃, pressure 5-20MPa, time 35-45s.

6. The processing method of the light-weighted tire spare cover plate for vehicles according to claim 1, characterized in that: The rosin-based polyol is prepared by the following process: Mixing maleopimaric anhydride and polyol, heating to 200-210℃ in a nitrogen atmosphere, holding for 20-40min to obtain rosin-based polyol; The polyol is one or more of neopentyl glycol, diethylene glycol, glycerol, trimethylolpropane, pentaerythritol and dipentaerythritol.

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