Spraying method of glue for mold protection

Abstract

The invention relates to a glue spraying method for mold protection. The glue spraying method sequentially comprises the following steps that 1, a mold is designed and manufactured; 2, mold surface pretreatment; step 3, performing protection treatment on an unsprayed area of the mold; 4, spraying glue is prepared; step 5, spraying treatment; and step 6, standing treatment. A coating formed by spraying the glue is uniform, good in stability in the production process, not prone to falling off and good in protection strength during product processing.

Description

Technical Field

[0001] The present invention relates to the technical field related to mold processing, and in particular to a method for spraying glue for mold protection. Background Art

[0002] Negative mold vacuum forming technology, also known as negative mold vacuum forming and in-mold graining (IMG) technology, is a process that uses a negative mold engraved with a grain pattern to mold a smooth film material into a grained surface in the shape of an interior decoration part. Alternatively, after the grained surface is formed, the surface is vacuum-adsorbed onto the substrate at the same station of the machine to produce the desired product.

[0003] Vacuum forming technology, a relatively advanced process, has only recently been introduced, and the technology still needs to mature and improve. A new technology, from development to widespread adoption, must possess irreplaceable advantages. While vacuum forming technology is relatively simple, its technical barriers are high. This is due to the high precision required for mold forming.

[0004] Existing molds generally need to be sprayed with glue during the production process to protect the molds.

[0005] After extensive searching, it was found that the prior art publication number is CN112642603A, which discloses a blue glue spraying system and method for mold protection with uniform coating, including a controller, a glue spraying room, and a glue spraying device arranged outside the glue spraying room; the glue spraying device has a glue storage barrel and a top cover that can be opened and closed on the glue storage barrel, and an air motor is installed on the top of the glue storage barrel; a valve assembly is also installed on the top of the glue storage barrel, and a glue outlet pipe is provided at the bottom of the glue storage barrel, and the glue outlet pipe extends into the glue spraying room through the glue outlet pipe and the valve assembly; the glue spraying room is equipped with a dust-proof exhaust treatment device, a lighting device, and a heat preservation device, and the glue outlet pipe and the air blow pipe are connected to a spray gun, and the spray gun is located in the glue spraying room. By providing a controller and an air motor connected to the controller, a valve assembly, an air intake device, a dust-proof exhaust treatment device, a lighting device, and a heat preservation device, a good working environment is provided for the spraying work, with a high degree of automation. At the same time, the controller controls the valve assembly to make the glue storage barrel discharge glue uniformly, thereby achieving the purpose of uniform spraying.

[0006] In summary, the specific composition of the spray glue is not disclosed in the existing spraying method for mold protection. The coating formed by the spray glue is uneven and unstable during the production process, and is easy to fall off, thereby causing failure in product processing.

[0007] In view of the above-mentioned defects, the designer actively carried out research and innovation in order to create a method for spraying glue for mold protection to make it more valuable for industrial use. Summary of the Invention

[0008] In order to solve the above technical problems, the purpose of the present invention is to provide a method for spraying glue for mold protection.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] A method for spraying glue for mold protection comprises the following steps in sequence:

[0011] Step 1: Mold design and production:

[0012] Design the model using 3D design software, make the mold using 3D printing, and use chemical etching to process the surface texture;

[0013] Step 2: Mold surface pretreatment:

[0014] Perform surface cleaning on the mold surface using cleaning tools;

[0015] Step 3: Protective treatment of the unsprayed area of ​​the mold:

[0016] Perform masking treatment on the unsprayed areas on the mold surface;

[0017] Step 4: Preparation of spray glue:

[0018] The spray glue is composed of a polyurea elastomer component A and a polyurea elastomer component B. The polyurea elastomer component A and the polyurea elastomer B are stirred and mixed in a mixing barrel to form a spray glue for use;

[0019] Step 5: Spraying:

[0020] Spray glue on the mold surface through spraying equipment to form a protective film;

[0021] Step 6: Let it sit for a while:

[0022] The sprayed mold is placed in a static room for static treatment.

[0023] As a further improvement of the present invention, the present invention further includes step 7, texture production: vacuum adsorption molding of the mold after static treatment, demoulding and cutting and edge wrapping treatment.

[0024] As a further improvement of the present invention, the present invention further includes step 8, film tearing processing: tearing off the protective film on the mold after the texture is produced.

[0025] As a further improvement of the present invention, the ratio of the polyurea elastomer component A to the polyurea elastomer component B in the spray glue in step 4 is 1:1.

[0026] As a further improvement of the present invention, the polyurea elastomer component A in the spray glue includes 30% to 50% of diphenylmethane diisocyanate and 50% to 70% of a prepolymer of diphenylmethane diisocyanate and polyether polyol;

[0027] The polyurea elastomer B component in the spray glue comprises 60% to 80% of a polyether polyol combination material, 10% to 30% of diethyltoluenediamine and less than 10% of an auxiliary agent.

[0028] As a further improvement of the present invention, the preparation process of the spray glue comprises the following steps in sequence:

[0029] Step 41: pour 30% to 50% of diphenylmethane diisocyanate and 50% to 70% of a prepolymer of diphenylmethane diisocyanate and polyether polyol into a first stirring barrel, and stir and mix them to obtain a polyurea elastomer component A;

[0030] Step 42: pour 60% to 80% of the polyether polyol composition, 10% to 30% of diethyltoluenediamine, and less than 10% of an auxiliary agent into a second stirring barrel in sequence, and stir and mix them uniformly to obtain a polyurea elastomer component B;

[0031] Step 43: Pour the polyurea elastomer component A and the polyurea elastomer component B into the third stirring barrel in sequence, introduce nitrogen to purge for 10 to 15 minutes, turn off the nitrogen after the purge and start stirring, heat to 30°C to 40°C after stirring, maintain for 1 to 2 hours, then heat to 40°C to 50°C, maintain for 1 to 2 hours, then continue to heat to 55°C to 65°C, maintain for 1 to 2 hours, and then cool to room temperature to obtain spray glue.

[0032] As a further improvement of the present invention, in step 41, the stirring speed is 100 to 150 rpm, and the stirring time is 20 to 30 minutes;

[0033] In step 42, the stirring speed is 100-150 rpm, and the stirring time is 25-30 minutes;

[0034] In step 43, the stirring speed is 150-200 rpm, and the stirring time is 15-30 minutes.

[0035] As a further improvement of the present invention, step 5, spraying treatment, comprises the following steps in sequence:

[0036] Step 51: Heat the mold to 200-300°C and maintain for 10-15 minutes, then cool to 100-150°C, and then perform the first spraying operation on the mold. The spray gun air pressure is 5-6 kg, the spraying height is 300-360 mm, and the spraying thickness is 0.06 mm.

[0037] Step 52: After standing for 15 to 20 minutes, heat the mold to 200 to 300° C. and maintain for 10 to 15 minutes, then cool to 100 to 150° C. and perform a second spraying operation on the mold. The spray gun pressure is 5 to 6 kg, the spraying height is 300 to 360 mm, and the spraying thickness is 0.10 mm.

[0038] Step 53: After standing for 15 to 20 minutes, heat the mold to 200 to 300°C and maintain for 10 to 15 minutes. Then, cool it to 100 to 150°C and perform a second spraying operation on the mold. The spray gun air pressure is 5 to 6 kg, the spraying height is 300 to 360 mm, and the spraying thickness is 0.15 mm.

[0039] As a further improvement of the present invention, during the first spraying operation, spraying is performed from the outside of the mold toward the inside of the mold, and the inclination angle between the spray gun and the mold surface is between 30 and 45 degrees;

[0040] During the second spraying operation, spray from the outside of the mold to the inside of the mold, and the tilt angle of the spray gun to the mold surface is between 30 and 45 degrees;

[0041] During the third spraying operation, spray from the outside of the mold toward the inside of the mold, and the inclination angle of the spray gun to the mold surface is between 30 and 45 degrees.

[0042] As a further improvement of the present invention, in step 6, the static treatment, the sprayed mold is allowed to stand in a static chamber for 0.25 to 4 hours.

[0043] By means of the above solution, the present invention has at least the following advantages:

[0044] The coating formed by the spray glue of the present invention is relatively uniform, has good stability during the production process, is not easy to fall off, and has good protection during product processing;

[0045] The spray glue of the present invention consists of a polyurea elastomer A component and a polyurea elastomer B component, and has good structural stability.

[0046] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1 This is a schematic flow chart of a method for spraying glue for mold protection according to the present invention;

[0049] Figure 2 It is a schematic flow diagram of step 4 of the present invention;

[0050] Figure 3 It is a schematic flow diagram of step 5 of the present invention. DETAILED DESCRIPTION

[0051] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0052] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0053] Example

[0054] like Figures 1 to 3 As shown,

[0055] A method for spraying glue for mold protection comprises the following steps in sequence:

[0056] Step 1: Mold design and production:

[0057] Design the model using 3D design software, make the mold using 3D printing, and use chemical etching to process the surface texture;

[0058] Step 2: Mold surface pretreatment:

[0059] Perform surface cleaning on the mold surface using cleaning tools;

[0060] Step 3: Protective treatment of the unsprayed area of ​​the mold:

[0061] Perform masking treatment on the unsprayed areas on the mold surface;

[0062] Step 4: Preparation of spray glue:

[0063] The spray glue is composed of a polyurea elastomer component A and a polyurea elastomer component B. The polyurea elastomer component A and the polyurea elastomer B are stirred and mixed in a mixing barrel to form a spray glue for use;

[0064] Step 5: Spraying:

[0065] Spray glue on the mold surface through spraying equipment to form a protective film;

[0066] Step 6: Let it sit for a while:

[0067] The sprayed mold is placed in a static room for static treatment.

[0068] Preferably, the method further includes step 7, texture production: vacuum adsorption molding of the mold after static treatment, demoulding, and cutting and edge wrapping.

[0069] Preferably, the method further includes step 8, film tearing processing: tearing off the protective film on the mold after texture production.

[0070] Preferably, the ratio of the polyurea elastomer component A to the polyurea elastomer component B in the spray glue in step 4 is 1:1.

[0071] Preferably, the polyurea elastomer component A in the spray glue comprises 30% to 50% of diphenylmethane diisocyanate and 50% to 70% of a prepolymer of diphenylmethane diisocyanate and polyether polyol;

[0072] The polyurea elastomer B component in the spray glue comprises 60% to 80% of a polyether polyol combination material, 10% to 30% of diethyltoluenediamine and less than 10% of an auxiliary agent.

[0073] Preferably, the preparation process of the spray glue comprises the following steps in sequence:

[0074] Step 41: pour 30% to 50% of diphenylmethane diisocyanate and 50% to 70% of a prepolymer of diphenylmethane diisocyanate and polyether polyol into a first stirring barrel, and stir and mix them to obtain a polyurea elastomer component A;

[0075] Step 42: pour 60% to 80% of the polyether polyol composition, 10% to 30% of diethyltoluenediamine, and less than 10% of an auxiliary agent into a second stirring barrel in sequence, and stir and mix them uniformly to obtain a polyurea elastomer component B;

[0076] Step 43: Pour the polyurea elastomer component A and the polyurea elastomer component B into the third stirring barrel in sequence, introduce nitrogen to purge for 10 to 15 minutes, turn off the nitrogen after the purge and start stirring, heat to 30°C to 40°C after stirring, maintain for 1 to 2 hours, then heat to 40°C to 50°C, maintain for 1 to 2 hours, then continue to heat to 55°C to 65°C, maintain for 1 to 2 hours, and then cool to room temperature to obtain spray glue.

[0077] Preferably, in step 41, the stirring speed is 100-150 rpm, and the stirring time is 20-30 minutes;

[0078] In step 42, the stirring speed is 100-150 rpm, and the stirring time is 25-30 minutes;

[0079] In step 43, the stirring speed is 150-200 rpm, and the stirring time is 15-30 minutes.

[0080] Preferably, step 5, spraying treatment includes the following steps in sequence:

[0081] Step 51: Heat the mold to 200-300°C and maintain for 10-15 minutes, then cool to 100-150°C, and then perform the first spraying operation on the mold. The spray gun air pressure is 5-6 kg, the spraying height is 300-360 mm, and the spraying thickness is 0.06 mm.

[0082] Step 52: After standing for 15 to 20 minutes, heat the mold to 200 to 300° C. and maintain for 10 to 15 minutes, then cool to 100 to 150° C. and perform a second spraying operation on the mold. The spray gun pressure is 5 to 6 kg, the spraying height is 300 to 360 mm, and the spraying thickness is 0.10 mm.

[0083] Step 53: After standing for 15 to 20 minutes, heat the mold to 200 to 300°C and maintain for 10 to 15 minutes. Then, cool it to 100 to 150°C and perform a second spraying operation on the mold. The spray gun air pressure is 5 to 6 kg, the spraying height is 300 to 360 mm, and the spraying thickness is 0.15 mm.

[0084] Preferably, during the first spraying operation, spraying is performed from the outside of the mold toward the inside of the mold, and the inclination angle between the spray gun and the mold surface is between 30 and 45 degrees;

[0085] During the second spraying operation, spray from the outside of the mold to the inside of the mold, and the tilt angle of the spray gun to the mold surface is between 30 and 45 degrees;

[0086] During the third spraying operation, spray from the outside of the mold toward the inside of the mold, and the inclination angle of the spray gun to the mold surface is between 30 and 45 degrees.

[0087] Preferably, in step 6, the static treatment, the sprayed mold is allowed to stand in a static chamber for 0.25 to 4 hours.

[0088] The first embodiment of the present invention:

[0089] Step 1: Mold design and production: Design the model using 3D design software, make the mold using 3D printing, and use chemical etching to process the surface texture.

[0090] Step 2: Pretreatment of mold surface: Use cleaning tools such as brushes to clean the mold surface and remove dust and other impurities on the mold surface.

[0091] Step 3: Protect the unpainted area of ​​the mold: Perform shielding treatment on the unpainted area of ​​the mold surface. The unpainted area of ​​the mold surface can be covered with a structure of material such as clay.

[0092] Step 4: Preparation of spray glue:

[0093] Step 41: pour 30% of diphenylmethane diisocyanate and 70% of a prepolymer of diphenylmethane diisocyanate and polyether polyol into a first stirring barrel in sequence, and stir and mix them uniformly to obtain a polyurea elastomer component A;

[0094] Step 42: Pour 80% of the polyether polyol composition, 15% of diethyltoluenediamine, and less than 5% of the additive into a second stirring barrel, and stir and mix them evenly to obtain a polyurea elastomer component B;

[0095] Step 43: Pour the polyurea elastomer component A and the polyurea elastomer component B into the third stirring barrel in sequence, introduce nitrogen to purge for 10 minutes, turn off the nitrogen after the purge and start stirring, heat to 30°C after stirring, keep it for 2 hours, then heat to 50°C, keep it for 1 hour, then continue to heat to 55°C, keep it for 1 hour, and then cool to room temperature to obtain spray glue.

[0096] Step 5: Spraying:

[0097] Step 51: Heat the mold to 200°C and hold for 15 minutes. Then, cool to 150°C and perform the first spraying operation on the mold. The spray gun has an air pressure of 5 kg, a spray height of 300 mm, and a spray thickness of 0.06 mm. During the first spraying operation, spray from the outside of the mold toward the inside, with the spray gun tilted at a 30-degree angle to the mold surface.

[0098] Step 52: After standing for 15 minutes, the mold is heated to 200°C and held for 15 minutes. After cooling to 150°C, a second spraying operation is performed on the mold. The spray gun has an air pressure of 5 kg, a spray height of 300 mm, and a spray thickness of 0.06 mm. During the second spraying operation, the spray gun is sprayed from the outside of the mold toward the inside, and the angle between the spray gun and the mold surface is 30 degrees.

[0099] Step 53: After standing for 15 minutes, the mold is heated to 200°C and held for 15 minutes. After cooling to 150°C, the mold is sprayed for the third time. The spray gun pressure is 5 kg, the spray height is 300 mm, and the spray thickness is 0.06 mm. During the third spraying operation, the spray gun is sprayed from the outside of the mold toward the inside, with the spray gun tilted at a 30-degree angle to the mold surface.

[0100] Step 6: Let the sprayed mold stand in a standing room for 1 hour.

[0101] Step 7: Texture production: After static treatment, the mold is vacuum-adsorbed and formed, demoulded, and cut and edged.

[0102] Step 8: tearing off the protective film on the mold after texture production. The protective film can be torn off manually.

[0103] The ratio of the polyurea elastomer component A to the polyurea elastomer component B in the spray glue in step 4 is 1:1.

[0104] The first example of the composition of spray glue:

[0105] Polyurea elastomer A component in spray glue:

[0106] 30% diphenylmethane diisocyanate;

[0107] 70% prepolymer of diphenylmethane diisocyanate and polyether polyol.

[0108] Polyurea elastomer B component:

[0109] 80% polyether polyol composition;

[0110] 15% diethyltoluenediamine;

[0111] 5% additives.

[0112] The second example of spray glue composition:

[0113] Polyurea elastomer A component in spray glue:

[0114] 40% diphenylmethane diisocyanate;

[0115] A prepolymer of 60% diphenylmethane diisocyanate and polyether polyol.

[0116] Polyurea elastomer B component:

[0117] 70% polyether polyol combination;

[0118] 25% diethyltoluenediamine;

[0119] 5% additives.

[0120] The third example of spray glue composition:

[0121] Polyurea elastomer A component in spray glue:

[0122] 50% diphenylmethane diisocyanate;

[0123] A prepolymer of 50% diphenylmethane diisocyanate and polyether polyol.

[0124] Polyurea elastomer B component:

[0125] 65% polyether polyol composition;

[0126] 30% diethyltoluenediamine;

[0127] 5% additives.

[0128] The fourth example of spray glue composition:

[0129] Polyurea elastomer A component in spray glue:

[0130] 40% diphenylmethane diisocyanate;

[0131] A prepolymer of 60% diphenylmethane diisocyanate and polyether polyol.

[0132] Polyurea elastomer B component:

[0133] 70% polyether polyol combination;

[0134] 25% diethyltoluenediamine;

[0135] 5% additives.

[0136] The coating formed by the spray glue of the present invention is relatively uniform, has good stability during the production process, is not easy to fall off, and has good protection during product processing;

[0137] The spray glue of the present invention consists of a polyurea elastomer A component and a polyurea elastomer B component, and has good structural stability.

[0138] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly referring to the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0139] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed or detachable connections, or integral connections; mechanical or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0140] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for spraying glue for mold protection, characterized in that: The following steps are included in sequence: Step 1: Mould design and production: Design the model through 3D design software, make the mold through 3D printing, and use chemical etching to process the surface texture; Step 2: Mold surface pretreatment: Perform surface cleaning on the mold surface using a cleaning tool; Step 3: Protect the unpainted area of ​​the mold: Perform masking treatment on the unsprayed area of ​​the mold surface; Step 4: Preparation of spray glue: The spray glue is composed of a polyurea elastomer component A and a polyurea elastomer component B. The polyurea elastomer component A and the polyurea elastomer B are stirred and mixed in a stirring barrel to form a spray glue for use; Step 5: Spraying: Spray glue on the mold surface through spraying equipment to form a protective film; Step 6: Standstill treatment: The sprayed mold is placed in a static room for static treatment.

2. A method for spraying glue for mold protection according to claim 1, characterized in that: It also includes step 7, texture production: the mold after static treatment is vacuum adsorbed into shape, demoulding and cutting and edge processing.

3. A method for spraying glue for mold protection as claimed in claim 2, characterized in that: The step also includes step 8, film tearing processing: the protective film on the mold after the texture is produced is torn off.

4. A method for spraying glue for mold protection according to claim 1, characterized in that: In the step 4, the ratio of the polyurea elastomer component A to the polyurea elastomer component B in the spray glue is 1:

1.

5. A method for spraying glue for mold protection according to claim 4, characterized in that: The polyurea elastomer component A in the spray glue comprises 30% to 50% of diphenylmethane diisocyanate and 50% to 70% of a prepolymer of diphenylmethane diisocyanate and polyether polyol; The polyurea elastomer B component in the spray glue comprises 60% to 80% of a polyether polyol combination material, 10% to 30% of diethyltoluenediamine and less than 10% of an auxiliary agent.

6. A method for spraying glue for mold protection as claimed in claim 5, characterized in that: The preparation process of the spray glue comprises the following steps in sequence: Step 41, pouring 30% to 50% of diphenylmethane diisocyanate and 50% to 70% of a prepolymer of diphenylmethane diisocyanate and polyether polyol into a first stirring barrel in sequence, stirring and mixing to obtain a polyurea elastomer component A; Step 42, pouring 60% to 80% of the polyether polyol composition, 10% to 30% of diethyltoluenediamine and less than 10% of the auxiliary agent into the second stirring barrel in sequence, stirring and mixing them evenly to obtain the polyurea elastomer B component; Step 43, pour the polyurea elastomer A component and the polyurea elastomer B component into the third stirring barrel in sequence, introduce nitrogen to purge for 10 to 15 minutes, turn off the nitrogen after the purge and start stirring, heat up to 30°C to 40°C after stirring, keep the temperature to 40°C to 50°C for 1 to 2 hours, continue to heat up to 55°C to 65°C after keeping the temperature for 1 to 2 hours, and then cool to room temperature to obtain spray glue.

7. A method for spraying glue for mold protection according to claim 6, characterized in that: In step 41, the stirring speed is 100 to 150 rpm, and the stirring time is 20 to 30 minutes; In step 42, the stirring speed is 100 to 150 rpm, and the stirring time is 25 to 30 minutes; In step 43, the stirring speed is 150-200 rpm, and the stirring time is 15-30 minutes.

8. A method for spraying glue for mold protection according to claim 1, characterized in that: The step 5, spraying treatment, comprises the following steps in sequence: Step 51, heat the mold to 200-300°C and maintain for 10-15 minutes, then cool to 100-150°C, and then perform the first spraying operation on the mold, the spray gun air pressure is 5-6KG, the spraying height is 300-360mm, and the spraying thickness is 0.06mm; Step 52, after standing for 15 to 20 minutes, heat the mold to 200 to 300° C. and maintain for 10 to 15 minutes, then cool to 100 to 150° C., and then spray the mold for the second time, with a spray gun pressure of 5 to 6 kg, a spray height of 300 to 360 mm, and a spray thickness of 0.10 mm; Step 53, after standing for 15 to 20 minutes, heat the mold to 200 to 300°C and maintain for 10 to 15 minutes, then cool to 100 to 150°C, and perform a second spraying operation on the mold. The spray gun air pressure is 5 to 6KG, the spraying height is 300 to 360mm, and the spraying thickness is 0.15mm.

9. A method for spraying glue for mold protection according to claim 8, characterized in that: During the first spraying operation, spraying is performed from the outside of the mold toward the inside of the mold, and the inclination angle between the spray gun and the mold surface is between 30 and 45 degrees; During the second spraying operation, spraying is performed from the outside of the mold toward the inside of the mold, and the inclination angle between the spray gun and the mold surface is between 30 and 45 degrees; During the third spraying operation, spraying is performed from the outside of the mold toward the inside of the mold, and the inclination angle between the spray gun and the mold surface is between 30 and 45 degrees.

10. A method for spraying glue for mold protection according to claim 1, characterized in that: In the step 6, the static treatment, the sprayed mold is allowed to stand in a static chamber for 0.25 to 4 hours.

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