WO2022110153A1

WO2022110153A1 - Multi-color bathroom wall panel and preparation method therefor

Info

Publication number: WO2022110153A1
Application number: PCT/CN2020/132803
Authority: WO
Inventors: 胡福涛
Original assignee: 苏州科逸住宅设备股份有限公司
Priority date: 2020-11-30
Filing date: 2020-11-30
Publication date: 2022-06-02

Abstract

A preparation method for a multi-color bathroom wall panel, comprising the following steps: heating an upper mold (1) having a mold cavity (11) to 130-155°C and maintaining the temperature, spraying a powder coating onto a surface of the mold cavity (11), and waiting for at least 40 seconds after the spraying is complete, wherein the powder coating is used to form a multi-color coating layer; laying, on a lower mold (2) having a mold core (21), a sheet molding compound used to form a substrate, wherein the area of the laid sheet molding compound accounts for 50-95% of the area of an orthographic projection of a resultant multi-color bathroom wall panel; and during molding, combining the two molds and maintaining the temperature for 1-6 minutes, and then opening the molds to obtain the multi-color bathroom wall panel, wherein the multi-color bathroom wall panel comprises the substrate composed of the sheet molding compound and the multi-color coating layer disposed on the substrate. The raw material composition of the powder coating and the raw material composition of the sheet molding compound both comprise an unsaturated polyester resin, and the raw material composition of the powder coating further comprises paints. The softening point of the powder coating is lower than the heating temperature of the upper mold (1).

Description

Color bathroom wall panel and preparation method thereof

technical field

The invention relates to the technical field of home improvement building materials, in particular to a preparation method of a colored integral bathroom wall panel and a colored bathroom wall panel prepared by the preparation method.

Background technique

Existing SMC color wall panels are mainly used for printing, dipping of veneer materials, and integral molding with SMC to achieve personalized color requirements, or as disclosed in the patent application for invention publication number CN107284107A, sandblasting is used, and primer is sprayed before wood is used. Texture transfer paper transfer to achieve blank paper color moulded wallboard. The above two processes have the following defects: 1. Molded color SMC wallboard with decorative paper material. After the surface protective material falls off during use, there will be mildew, yellowing, and discoloration at the lower end because the paper fiber is exposed in a humid environment. The use of the whole bathroom; 2. Although the process used in the CN107284107A patent application can solve the problem of decorative paper materials, the process is complicated. First, the monochrome wallboard must be molded, and then sandblasting, painting, transfer printing and other processes. The operating environment Harsh, time-consuming and labor-intensive.

SUMMARY OF THE INVENTION

In view of this, in order to overcome the defects of the prior art, the purpose of the present invention is to provide a preparation method of a colored bathroom wall panel, the molding material compression molding and the coating of the powder coating are completed at the same time, the preparation process is simple, and the preparation method The prepared colored bathroom wall panel has high bonding strength between the colored coating on the surface and the base material.

In order to achieve the above object, the present invention adopts the following technical scheme:

A preparation method of a colored bathroom wall panel, comprising the following steps:

heating the upper mold with the cavity to 130-155 ℃ and keeping the temperature, spraying powder coating on the surface of the cavity, waiting for at least 40s after spraying, the powder coating is used to form a color coating;

A sheet-like molding compound is placed on the lower mold with a core, and the sheet-like molding compound is used to form the matrix, and the laying area of the sheet-like molding compound is 50%～ 95%; during molding, the mold is closed for 1 to 6 minutes, and then the mold is opened to obtain a colored bathroom wall panel, which includes a substrate of sheet molding compound and a colored coating formed on the substrate;

The raw material components of the powder coating and the sheet molding compound both include unsaturated polyester resins, and the raw material components of the powder coating also include pigments; the softening point of the powder coating is lower than the heating temperature of the upper mold.

Unsaturated polyester resins have unsaturated bonds (carbon-carbon double bonds). By setting the raw material compositions of powder coatings and sheet molding compounds with unsaturated polyester resins, during molding, the unsaturated bonds in the sheet molding compound , The unsaturated bond in the powder coating is opened, and the sheet molding compound can undergo a cross-linking reaction with the powder coating, so that a chemical bond is formed between the sheet molding compound and the powder coating, resulting in fusion, forming an integrated product, the color coating and the substrate. combination is stronger.

According to some preferred implementation aspects of the present invention, the spraying is to uniformly spray the powder coating on the surface of the cavity in the form of electrostatic spraying, and the spraying is completed at one time. Before spraying, it is necessary to design the spraying trajectory in advance, spray according to the spraying trajectory, and complete the spraying in one time; avoid repeated spraying on the already sprayed coating, the poor heat transfer of the coating leads to the low curing temperature of repeated spraying, and finally makes some coatings and substrates poor bonding. And after use, the spray gun for electrostatic spraying should be cleaned. There should be no powder in the spray gun pipeline and powder supply channel, and the powder left in the spray gun is easy to absorb water and polymerize.

According to some preferred implementation aspects of the present invention, the upper mold has a top plate and a side plate, and the cavity is formed between the top plate and the side plate; when spraying, the powder coating is sprayed on the inner surface of the top plate . During molding, the upper mold is pressed down, and the material between the upper mold and the lower mold is extruded into a predetermined shape through the cavity of the upper mold and the core of the lower mold. When the traditional upper mold and lower mold are being molded, there will be a certain distance between the side plate of the upper mold and the core of the lower mold, so that the gas in the cavity can be discharged during molding. In this application, since powder coating needs to be sprayed in the cavity, the distance between the side plate of the upper mold and the core during mold closing will be reduced, and the exhaust passages of the cutting edge of the mold will be reduced, resulting in the easy production of the final product. Bubble, yield decreased. Therefore, when the powder coating is sprayed, it is ensured that it is mainly located on the inner surface of the top plate, so as to prevent it from adhering to the side plate and to prevent the distance between the side plate and the core from being reduced.

According to some preferred implementation aspects of the present invention, when spraying, a protective cover is used to cover the side plate, so that the inner surface of the top plate is exposed, the protective cover has a bottom plate and a protective plate supported on the bottom plate, the protective cover The board is attached to the side board. In order to solve the above problem, in the present application, a protective cover is used to cover the side plate during spraying, to protect the side plate, and to expose the inner surface of the top plate. In this way, when spraying, the powder coating is mainly concentrated on the inner surface of the top plate to avoid molding. When the distance between the side plate and the core is reduced.

According to some preferred implementation aspects of the present invention, the distance between the end of the protective plate close to the top plate and the top plate is 0.5-1 cm, to prevent the distance between the protective plate and the top plate from being too close, and the spraying of the edge of the inner surface of the top plate will reduce to influence.

According to some preferred implementation aspects of the present invention, the mold temperature during the molding is 140-150° C., so that a chemical bond is formed between the powder coating and the sheet molding compound, and the unsaturated bonds on both sides are opened and connected, so that the coating The bonding of the layer to the substrate is stronger.

According to some preferred implementation aspects of the present invention, the moving speed of the upper mold during the molding is 0.1-3 mm/s, and the starting speed of the mold during molding is lower than that of the traditional molding, so that the gas in the mold is slowly and effectively discharged, and as far as possible Avoid up and down reciprocating exhaust to prevent air bubbles in the product caused by poor exhaust.

According to some preferred implementation aspects of the present invention, when the mold is opened after the molding is finished, the moving speed of the upper mold is first slow and then fast, or blowing air into the cavity through the gap between the side plate of the upper mold and the core to release the mold The stress between the mould and the colored bathroom wall panel prevents bad products.

According to some preferred implementation aspects of the present invention, when spraying, the spraying thickness of the coating powder is 70-120um. In some embodiments of the present invention, it is preferable that the spray thickness of the coating powder is 80um.

According to some preferred implementation aspects of the present invention, the raw material of the powder coating includes the following components: unsaturated polyester resin, curing agent, leveling agent, titanium dioxide, pigment and auxiliary.

According to some preferred aspects of the present invention, the raw material components and preparation steps of the powder coating are as follows:

1) First, pre-mix the unsaturated polyester resin, curing agent, leveling agent, titanium dioxide, pigment and auxiliary according to the following components;

2) The material obtained by pre-mixing in step 1) is extruded after being melted, and pulverized to obtain a powder with a predetermined particle size, which is the powder coating in this application.

The means such as mixing, melting, and pulverization are conventional technical means in the corresponding field, and are not the content to be protected by the present invention, and the detailed process will not be repeated here.

According to some preferred implementation aspects of the present invention, the density of the powder coating is 1.2-1.4 g/cm ³ .

According to some preferred implementation aspects of the present invention, the particle size of the powder coating is 38-45um.

According to some preferred aspects of the present invention, the raw material components and preparation steps of the sheet molding compound are as follows:

A. First, mix unsaturated polyester resin, curing agent, coupling agent, filler, styrene and auxiliary agent according to the following components to make resin paste;

B. Apply the evenly mixed resin paste on the PE film through the scraper; then adjust the cutter to cut the glass fiber to control the length and content of the glass fiber; paste the PE film relatively to form an upper and lower uniform Sheet covered with PE film, and then squeeze the sheet through a compactor to fully impregnate the glass fiber and resin, form into a sheet, and then roll it up;

C. The rolled sheet is transported to the thickening chamber for thickening, the temperature of the thickening chamber is set to 45°C, and the thickening time is 24 hours to obtain a sheet molding compound.

The curing agent in the above raw materials includes tert-butyl peroxybenzoate (TBPB) and/or benzoyl peroxide, specifically, the curing agent is tert-butyl peroxide (2-ethylhexanoate), One or more of methyl ethyl ketone, tert-butyl peroxybenzoate, dibenzoyl peroxide, di(4-tert-butyl) cyclohexyl peroxydicarbonate, dilauroyl peroxide or aliphatic polyamine, etc. combination;

The coupling agent is a silane coupling agent and/or titanate; specifically, the silane coupling agent is γ-(methacryloyloxypropyl)trimethoxysilane, γ-(2,3 -Glycidoxy)propyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropyl Triethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, anilinemethyltriethoxysilane, γ-aminopropyltriethoxysilane, vinyltriethoxysilane One or more combinations of vinyltrimethoxysilane, vinyltrimethoxysilane, γ-chloropropyltriethoxysilane, and the like.

The unsaturated polyester resins used are ortho-, meta-, or epoxy vinyl ester unsaturated resins. The crosslinking agent is styrene; the filler is aluminum hydroxide micropowder with particle size less than or equal to 10um or calcium carbonate micropowder with particle size less than or equal to 10um or a mixture of the two; Molding agents, etc. can be selected according to the actual situation of conventional types.

The present invention also provides a colored bathroom wall panel prepared according to the above-mentioned preparation method, comprising a substrate of sheet molding compound and a colored coating formed on the surface of the substrate, the colored coating and the substrate There are chemical bonds between them. The thickness of the color coating is 60-100um, and the thickness of the sheet molding compound base is 2-6mm.

Compared with the prior art, the advantages of the present invention are: in the preparation method of the colored bathroom wall panel in the present invention, the main components of the powder coating and the substrate are similar, both contain unsaturated polyester resin, and the method of heating and softening is adopted. The powder coating is softened before molding. During molding, the powder coating and the sheet molding compound are cured together. The molding material is pressed and the color coating is painted at the same time, which not only makes the preparation process easy to control, but also makes the molding process form The combination between the color coating and the substrate is more firm and reliable, which solves the problems that the coating on the SMC product obtained by the traditional preparation method is easy to fall off and the adhesion is not strong.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic structural diagram of an upper mold, a lower mold and a protective cover in a preferred embodiment of the present invention;

In the drawings: upper mold-1, cavity-11, top plate-12, side plate-13, lower mold-2, core-21, protective cover-3, bottom plate-31, protective plate-32, support plate- 33, Snap-34.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described implementation Examples are only some of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1 Color bathroom wall panel

The colored bathroom wall panel in this embodiment includes a sheet-mounted plastic film (SMC) substrate and a colored coating formed on the surface of the substrate. The thickness of the color coating is 90um, the color coating is formed by powder coating, and the thickness of the sheet molding compound base is 3.5um.

Since the raw materials of the powder coating and the sheet-packed plastic film both contain unsaturated polyester resin, when the two are hot-pressed, the double bond in the unsaturated polyester resin is opened and connected, and the color coating and the sheet-like molding compound matrix are passed through carbon The chemical bonds of carbon bonds are connected to make the connection between the color coating and the substrate firm, and the color of the color coating can be changed by changing the pigment added in the powder coating, which makes the appearance of the bathroom wall panel more diverse.

Embodiment 2 The preparation method of colored bathroom wall panel

This embodiment provides a method for preparing the colored bathroom wall panel in Embodiment 1, which specifically includes the following steps:

1) Preparation of powder coating

1.1) Pre-mix unsaturated polyester resin, curing agent, leveling agent, titanium dioxide, pigment and auxiliary according to the following components.

1.2) The material obtained by premixing in step 1) is extruded after being melted, and pulverized to obtain a powder with a predetermined particle size, that is, the powder coating in this embodiment is obtained.

The powder coating obtained in this example is red, the density is 1.3g/cm ³ , the particle size is 40um, and the softening point temperature is 140°C.

2) Preparation of sheet molding compound:

2.1) First, according to the following components, mix unsaturated polyester resin, curing agent, coupling agent, filler, styrene, auxiliary agent and glass fiber to make resin paste.

In this embodiment, the sheet molding compound specifically includes the following raw materials by weight, wherein E4 is the accelerator cobalt isooctanoate:

2.2) Apply the mixed resin paste evenly on the PE film by the scraper; then adjust the cutter to cut the glass fiber to control the length of the glass fiber; paste the PE film relatively to form a kind of upper and lower covered with The sheet of PE film is then squeezed by a compactor to fully impregnate the glass fiber with the resin, form a sheet, and then roll it up.

2.3) The rolled sheet is transported to a thickening chamber for thickening, the temperature of the thickening chamber is set to 45°C, and the thickening time is 24 hours to obtain a sheet molding compound.

3) Spraying

As shown in Figure 1, the mold used in this embodiment includes an upper mold 1 and a lower mold 2 that cooperate with each other. The upper mold 1 has a cavity 11, and the lower mold 2 has a core 21. During molding, the upper mold 1 is pressed down, Through the cavity 11 of the upper die 1 and the core 21 of the lower die 2, the substance located between the upper die 1 and the lower die 2 is extruded into a predetermined shape to form a product. The upper mold 1 has a top plate 12 and a side plate 13 , and a cavity 11 is formed between the top plate 12 and the side plate 13 ; when spraying, powder coating is sprayed on the inner surface of the top plate 12 .

When the existing upper mold 1 and lower mold 2 are being molded, there is a certain distance between the side plate 13 of the upper mold 1 and the core 21 of the lower mold 2, so as to discharge the gas in the cavity 11 during molding. In the present invention, since powder coating needs to be sprayed in the cavity 11, the distance between the side plate 13 of the upper mold 1 and the core 21 will be reduced when the mold is closed, and the exhaust passage of the cutting edge of the mold will be reduced, resulting in the final The products are prone to bubbles and the yield rate drops. Therefore, when spraying the powder coating, ensure that it is mainly located on the inner surface of the top plate 12 to prevent it from adhering to the side plate 13 and prevent the distance between the side plate 13 and the core 21 from being reduced.

As shown in FIG. 1 , in order to solve the above problems, in the present application, the protective cover 3 is used to cover the side plate 13 during spraying, so that the inner surface of the top plate 12 is exposed, so that the powder coating is mainly concentrated on the inner surface of the top plate 12 during spraying. On the other hand, the reduction of the distance between the side plate 13 and the core 21 is avoided.

Specifically, the protective cover 3 in this embodiment has a bottom plate 31 and a protective plate 32 and a supporting plate 33 supported on the bottom plate 31. The side plate 13 is located in the space formed between the supporting plate 33 and the protective plate 32. The supporting plate 33 The distance from the protective plate 32 is the same as the thickness of the side plate 13 . The protection plate 32 is attached to the inner surface of the side plate 13 , and the support plate 33 is attached to the outer surface of the side plate 13 . The top of the support plate 33 is also designed with a buckle 34 to fix the protective cover 3 on the upper mold 1 . The side plates 13 are distributed at the corners of the bottom plate 31 in the form of rods, and only need to play the role of fixed connection.

In this embodiment, in order to prevent the distance between the protective plate 32 and the top plate 12 from being too close, the spraying of the inner surface edge of the top plate 12 is affected, so the distance between the end of the protective plate 32 close to the top plate 12 and the top plate 12 is 0.5 cm , and the end is provided with an inclined surface, and the inclined surface faces the inside of the cavity 11 to avoid the influence on the spraying operation. In other embodiments, the end portion may also be arc-shaped.

The above is the use of the protective cover 3 to limit the spraying of the powder coating on the inner surface of the top plate 12 during spraying. In other embodiments of the present invention, it is also possible to increase the gap between the lower end of the side plate 13 and the edge of the core 21, that is, to increase the gap between the cutting edges of the mold, for example, by 0.5 cm, so that after the powder coating is sprayed, the gap can be increased. , There is enough space to exhaust gas during molding.

The upper mold 1 with the cavity 11 is heated to 150°C and kept warm, and the powder coating prepared in step 1) is sprayed on the surface of the cavity 11. After spraying, wait for 60 s to allow sufficient time for the powder coating to soften. Under the electrostatic adsorption and softening after heating, the concave-convex surface formed by the spherical shape of the powder coating becomes a flat surface.

After spraying, remove the protective cover 3 and prepare for molding.

The spraying is to uniformly spray the powder coating on the surface of the cavity 11 in the form of electrostatic spraying, and the spraying is completed at one time. Before spraying, it is necessary to design the spraying trajectory in advance, spray according to the spraying trajectory, and complete the spraying at one time; avoid repeated spraying on the already sprayed paint, the poor heat transfer of the paint leads to the low curing temperature of repeated spraying, and the bonding force of some coatings is poor . And after use, the spray gun for electrostatic spraying should be cleaned. There should be no powder in the spray gun pipeline and powder supply channel. The powder left in the spray gun is easy to absorb water and cause polymerization.

While waiting for the powder coating to soften, the sheet molding compound prepared in step 2) is placed on the core 21 of the lower mold 2 at the same time. The laying area of the sheet molding compound is 75% of the orthographic projection area of the final colored bathroom wall panel.

Molding, keeping the temperature of the upper mold 1 at 150°C, closing the mold for 4 minutes, and then opening the mold to obtain a colored bathroom wall panel. as described in Example 1.

The moving speed of the upper mold 1 during molding is 0.3mm/s, and the starting speed of the mold during molding is lower than that of traditional molding, so that the gas in the mold can be discharged slowly and effectively, and the up and down reciprocating exhaust should be avoided as much as possible to prevent the cause of poor exhaust. Product has air bubbles. When the mold is opened after the molding is finished, the moving speed of the upper mold 1 is slow first and then fast, or blow air into the cavity 11 through the gap between the side plate 13 of the upper mold 1 and the core 21 to release the mold and the colored bathroom wall panel. The stress between them prevents the product from being defective.

For the convenience of description and understanding, the steps are distinguished and numbered. In actual preparation, the above steps, such as the preparation of powder coatings and the preparation of sheet molding compounds, can be carried out simultaneously or in random order.

Both the powder coating and the matrix include the raw material components of unsaturated polyester resin. The main components of the powder coating and the matrix are the same, which not only makes the curing conditions the same, the preparation process is easy to control, but also the powder coating and the sheet molding compound are cross-linked during molding. The reaction produces partial fusion to form an integrated product, and the color coating and the substrate are chemically bonded, so that the final product has high bonding strength and high peel strength between the substrate and the color coating.

Example 3 Testing and Analysis

According to the method specified in GB/T13095-2008, the color bathroom wallboard products prepared in Example 2 were tested for peeling resistance, stain resistance, chemical corrosion resistance and other items. The test results are as follows:

Table 1 Experimental results

Table 1 shows that the wallboard product prepared by the method of Example 2 has excellent performance in items such as peel resistance, stain resistance, chemical corrosion resistance, etc., especially excellent adhesion performance, and the color of the coating can be changeable .

In this application, powder coating is combined with sheet molding compound, and SMC is pressed according to the normal molding process, and the coating film is formed and cured at the same time of molding, which reduces the production process, reduces the probability of quality problems in the process, and improves the product quality. Pass rate, improve production efficiency and reduce costs; reduce intermediate links, thus reducing the input of production sites and labor wages; for molded products with complex shapes, it is easier to carry out surface coating; as a primer, no sealing is required. The hole is polished, and there is no peeling problem caused by poor adhesion between coatings.

Traditional liquid paint coating has many problems: cumbersome steps, complicated process and long process; special spraying workshop and spraying equipment are required; sewage treatment device is required; mold surface treatment is required; internal mold release agent is required; The color of the product is uneven; the product is prone to pores; the bonding force between the coating and the substrate is poor; the weather resistance of the product is poor; the product hardness is poor, it is easy to scratch, and the pollution resistance is poor. Different from general coatings, powder coatings are solvent-free solid powder coatings, which are solvent-free, pollution-free, recyclable, environmentally friendly, save energy and resources, reduce labor intensity, and have high mechanical strength of the coating film. The combination of coating powder and sheet molding compound has many advantages, such as simple process and short process; no special spraying workshop is required; spraying and product molding are completed at the same time; no sewage treatment is required;

In the preparation method of the colored integral bathroom wallboard of the present invention, when making the integral bathroom SMC wallboard, the upper mold for making the SMC wallboard is sprayed first, so that a layer of powder coating is attached to the inner surface of the cavity, and then the SMC raw material is placed on the bottom. In the core of the mold, molding is performed, and the powder coating is bonded to the surface of the SMC product during molding to form a color-coated SMC wallboard product. It makes SMC products rich and bright in color, and has the advantages of high acid and alkali resistance, anti-corrosion, anti-aging, anti-pollution, easy to clean, etc., integrated molding, combined by chemical reaction of molding materials, so that the product coating is not easy Falling off, strong adhesion, performance has been significantly improved.

The above-mentioned embodiments are only for illustrating the technical concept and characteristics of the present invention, and their purpose is to enable those who are familiar with the technology to understand the content of the present invention and implement them accordingly, and cannot limit the scope of protection of the present invention with this. Equivalent changes or modifications made in the spirit and spirit should all be included within the protection scope of the present invention.

Claims

A preparation method of colored bathroom wall panel is characterized in that, comprises the following steps:

heating the upper mold with the cavity to 130-155 ℃ and keeping the temperature, spraying powder coating on the surface of the cavity, waiting for at least 40s after spraying, the powder coating is used to form a color coating;

A sheet-like molding compound is placed on the lower mold with a core, and the sheet-like molding compound is used to form the matrix, and the laying area of the sheet-like molding compound is 50%～ 95%; during molding, the mold is closed for 1 to 6 minutes, and then the mold is opened to obtain a colored bathroom wall panel, which includes a substrate of sheet molding compound and a colored coating formed on the substrate;

The raw material components of the powder coating and the sheet molding compound both include unsaturated polyester resins, and the raw material components of the powder coating also include pigments; the softening point of the powder coating is lower than the heating temperature of the upper mold;

The spraying is to uniformly spray the powder coating on the surface of the cavity in the form of electrostatic spraying, and the spraying is completed once;

The upper mold has a top plate and a side plate, and the cavity is formed between the top plate and the side plate; when spraying, the powder coating is sprayed on the inner surface of the top plate;

When spraying, a protective cover is used to cover the side plate, so that the inner surface of the top plate is exposed, the protective cover has a bottom plate and a protective plate supported on the bottom plate, the protective plate and the inner surface of the side plate are fit;

The bottom plate is also provided with a support plate, the side plate is located in the space formed between the support plate and the protection plate, and the distance between the support plate and the protection plate is the same as the thickness of the side plate;

The protection plate is attached to the inner surface of the side plate, and the support plate is attached to the outer surface of the side plate; the top of the support plate is also provided with a buckle, and the buckle is used to attach the protective cover fixed on the upper die;

The distance between the end of the protection plate close to the top plate and the top plate is 0.5-1 cm;

One end of the protection plate close to the top plate is provided with an inclined surface, and the inclined surface faces the interior of the cavity;

The mold temperature during the molding is 140-150° C., so as to form a chemical bond between the powder coating and the sheet molding compound;

The moving speed of the upper mold during the molding is 0.1-3 mm/s;

When the mold is opened, the moving speed of the upper mold is first slow and then fast; or, blowing air into the cavity through the gap between the upper mold side plate and the core is used to release the mold and the colored bathroom wall panel. stress between

The raw material of the powder coating includes the following components: unsaturated polyester resin, curing agent, leveling agent, titanium dioxide, pigment and auxiliary;

By weight, the raw materials of the powder coating include the following components:

The preparation method of the powder coating comprises the following steps: premixing unsaturated polyester resin, curing agent, leveling agent, titanium dioxide, pigment and auxiliary; After pulverization, powder coating of predetermined particle size is obtained;

The density of the powder coating is 1.2-1.4 g/cm 3 ; the particle size of the powder coating is 38-45um;

When spraying, the spraying thickness of the coating powder is 70-120um.
A preparation method of colored bathroom wall panel is characterized in that, comprises the following steps:

heating the upper mold with the cavity to 130-155 ℃ and keeping the temperature, spraying powder coating on the surface of the cavity, waiting for at least 40s after spraying, the powder coating is used to form a color coating;

A sheet-like molding compound is placed on the lower mold with a core, and the sheet-like molding compound is used to form the matrix, and the laying area of the sheet-like molding compound is 50%～ 95%; during molding, the mold is closed for 1 to 6 minutes, and then the mold is opened to obtain a colored bathroom wall panel, which includes a substrate of sheet molding compound and a colored coating formed on the substrate;

The raw material components of the powder coating and the sheet molding compound both include unsaturated polyester resins, and the raw material components of the powder coating also include pigments; the softening point of the powder coating is lower than the heating temperature of the upper mold.
The method for preparing a colored bathroom wall panel according to claim 2, wherein the spraying is to uniformly spray the powder coating on the surface of the cavity by electrostatic spraying, and the spraying is completed once.
The method for preparing a colored bathroom wall panel according to claim 2, wherein the upper mold has a top plate and a side plate, and the cavity is formed between the top plate and the side plate; The powder coating is sprayed onto the inner surface of the top plate.
The method for preparing a colored bathroom wall panel according to claim 4, characterized in that, when spraying, a protective cover is used to cover the side panel, so that the inner surface of the top panel is exposed, and the protective cover has a bottom plate and a support The protective plate on the bottom plate is attached to the inner surface of the side plate.
The method for preparing a colored bathroom wall panel according to claim 5, wherein a support plate is further provided on the bottom plate, and the side plate is located in the space formed between the support plate and the protection plate, The distance between the support plate and the protection plate is the same as the thickness of the side plate.
The method for preparing a colored bathroom wall panel according to claim 6, characterized in that, the protective plate is attached to the inner surface of the side panel, and the support plate is attached to the outer surface of the side panel; the The top of the support plate is also provided with a buckle, and the buckle is used to fix the protective cover on the upper mold.
The method for preparing a colored bathroom wall panel according to claim 5, wherein the distance between the end of the protective plate close to the top panel and the top panel is 0.5-1 cm.
The method for preparing a colored bathroom wall panel according to claim 8, wherein one end of the protective plate close to the top plate is provided with an inclined surface, and the inclined surface faces the interior of the cavity.
The method for preparing a colored bathroom wall panel according to claim 2, wherein the mold temperature during the molding is 140-150 °C, so that a chemical bond is formed between the powder coating and the sheet molding compound. .
The method for preparing a colored bathroom wall panel according to claim 2, wherein the moving speed of the upper mold during the molding is 0.1-3 mm/s.
The method for preparing a colored bathroom wall panel according to claim 11, wherein when the mold is opened, the moving speed of the upper mold is first slow and then fast; Blowing air into the cavity is used to relieve the stress between the mold and the colored bathroom wall panel.
The method for preparing a colored bathroom wall panel according to claim 2, wherein the raw material of the powder coating comprises the following components: unsaturated polyester resin, curing agent, leveling agent, titanium dioxide, pigment and auxiliary agent.
The method for preparing a colored bathroom wall panel according to claim 13, wherein, in parts by weight, the raw material of the powder coating comprises the following components:
The preparation method of a colored bathroom wall panel according to claim 13, wherein the preparation method of the powder coating comprises the following steps: mixing unsaturated polyester resin, curing agent, leveling agent, titanium dioxide, pigment and pre-mixing the auxiliary agent; the pre-mixed material is extruded after being melted, and pulverized to obtain a powder coating with a predetermined particle size.
The method for preparing a colored bathroom wall panel according to claim 2, wherein the density of the powder coating is 1.2-1.4 g/cm 3 ; the particle size of the powder coating is 38-45um.
The method for preparing a colored bathroom wall panel according to claim 2, wherein when spraying, the spraying thickness of the coating powder is 70-120um.
A colored bathroom wall panel prepared by the preparation method according to any one of claims 2-17, comprising a substrate of sheet molding compound and a colored coating formed on the surface of the substrate, the colored coating and the The substrates are connected by chemical bonds.