Method for synchronously hot-pressing and compounding PET (Polyethylene Terephthalate) film and impregnated bond paper on board

Abstract

According to the method for synchronously hot-pressing and compounding the PET film and the impregnated bond paper on the board, the melamine impregnated bond paper and the PET film provided with the adhesive coating are synchronously cured on the base material board, special laminating equipment and an independent gluing procedure are not needed, and one-time forming can be realized by directly utilizing existing melamine board hot-pressing equipment; the technological process is simple, convenient to operate and suitable for industrial large-scale production.

Description

Technical Field

[0001] This invention relates to the field of home decoration board processing technology, and in particular to a method for simultaneously hot-pressing PET film and impregnated paper onto a board. Background Technology

[0002] As the home decoration industry increasingly demands environmental friendliness and aesthetics, PET series films (such as PETG film and BOBET film) and high-gloss boards, due to their high transparency, high strength, and high gloss, as well as their environmental friendliness, lack of odor, and absence of harmful gases such as benzene, formaldehyde, and dioxins, are gradually becoming the preferred materials for surface treatment of decorative boards. Currently, there are two main traditional processes for bonding PET high-gloss film to the surface of melamine boards: one is using UV adhesive, and the other is using hot-applied PUR adhesive. Both processes require separate adhesive application to the board surface before bonding, increasing production steps and making the process cumbersome. Secondly, specialized PET film bonding equipment is required, which not only increases equipment investment costs but also occupies additional factory space. Moreover, UV adhesive is prone to yellowing, and the board surface is prone to yellowing after long-term use, affecting the decorative effect. PUR adhesive requires curing treatment after bonding, which cannot achieve rapid delivery and reduces production efficiency. In addition, the separate adhesive application process requires additional costs for adhesive raw materials and labor, further increasing the overall production cost. To address the problems of cumbersome processes, large equipment investment, high costs, slow delivery, and poor yellowing resistance in existing technologies, this invention proposes a PET film lamination method that requires no separate adhesive application or special equipment and can be carried out simultaneously with the melamine paper lamination process on melamine boards, achieving one-time molding and effectively overcoming the shortcomings of existing technologies. Summary of the Invention

[0003] The purpose of this invention is to provide a method for simultaneously hot-pressing a PET film and an impregnated melamine film onto a board, thereby enabling the PET film and the melamine impregnated melamine film to be simultaneously hot-pressed onto the board.

[0004] To achieve the above objectives, the present invention provides a method for simultaneously hot-pressing a PET film and an impregnated paper onto a substrate, comprising the following steps: S1: Substrate pretreatment: Select wood-based panels as the substrate and sand or clean the surface of the substrate. S2: Stack the PET film and the melamine-impregnated paper together, and cover the substrate surface with the stacked PET film and the melamine-impregnated paper. The melamine-impregnated paper is laid flat on the substrate surface, with the side of the PET film with the adhesive coating facing the melamine-impregnated paper. S3: The stacked assembly is fed into a hot press to simultaneously cure the resin of the melamine-impregnated paper and the adhesive coating of the PET film, achieving a composite of the three components.

[0005] Furthermore, in step S3, when the stacked assembly is fed into the hot press, the hot pressing temperature is controlled at 150-220℃, the hot pressing pressure is 2.5-4MPa, and the hot pressing time is 20-80 seconds.

[0006] Furthermore, one side of the PET film is provided with an adhesive coating, the components of which, by mass percentage, include: 50-70% melamine-urea-formaldehyde resin, 5-10% polyethylene glycol modifier, 2-5% latent curing agent, 3-8% nano silica dispersion, and the balance being deionized water.

[0007] Furthermore, the latent curing agent is an imidazole curing agent or a dicyandiamide curing agent. The imidazole curing agent can be selected from one of 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, or 2-phenylimidazole, and the dicyandiamide curing agent can be selected from one of pure dicyandiamide, formaldehyde-modified dicyandiamide, epoxy-modified dicyandiamide, or urea-formaldehyde-modified dicyandiamide.

[0008] Furthermore, the thickness of the PET film is 0.01-0.3 mm.

[0009] Furthermore, the hot pressing process adopts a segmented temperature control mode. The first segment temperature is 150-190℃, lasting for 10-15 seconds; the second segment temperature is 190-220℃, lasting for 20-45 seconds.

[0010] Furthermore, in step S2, before stacking the PET film and the melamine-impregnated paper, the surface of the melamine-impregnated paper is subjected to electrostatic dust removal treatment.

[0011] Furthermore, the coating amount of the adhesive coating is 15-25 g / m². 2 .

[0012] Furthermore, in step S3, after hot pressing, the composite board is naturally cooled to room temperature. During the cooling process, the surface of the board is kept free from pressure contact, and the cooling time is ≥30 minutes.

[0013] The specific steps include: Substrate Pretreatment: Select wood-based panels as the substrate, including OSB, MDF, particleboard, plywood, oak, fir, bamboo fiberboard, reed board, and fire-resistant board. Sand or clean the substrate surface to ensure a flatness error ≤0.1mm / m, removing surface impurities and burrs. Then, place the substrate in an environment with a temperature of 20-25℃ and humidity of 55-65% for 24 hours to equilibrate, controlling the substrate moisture content to 6-8% to avoid air bubbles due to excessive moisture content or poor adhesion due to excessive moisture content during hot pressing.

[0014] Composite Layer Material Preparation: ① Select melamine-impregnated paper with a resin content of 130-150% and volatile matter ≤7% to ensure sufficient resin flow and curing during hot pressing, forming a strong bond with the substrate. Before preparation, electrostatically remove dust from the surface of the melamine-impregnated paper to avoid affecting the lamination effect. ② Select PET film with a thickness of 0.01-0.3mm and a light transmittance ≥89% to ensure a high-gloss decorative effect on the laminated surface. The matte finish should be 1-10 degrees, with properties such as stain resistance, abrasion resistance, and slight self-healing. Apply an adhesive coating of 1-5 micrometers thickness to one side of the PET film, bonding it to the original coating of the impregnated paper and the PET film coating.

[0015] Stacking and assembly: On a clean workbench, stack the substrate in the following order: “substrate → melamine impregnated paper → PET film”. Ensure that the side of the PET film with the adhesive coating faces the melamine impregnated paper and that the edges of the three are aligned to avoid misalignment that could cause defects on the edges of the laminated board. Avoid touching the surface of the composite layer during stacking to prevent oil and dust contamination.

[0016] One-time hot pressing: The stacked assembly is fed into a hot press, with the flatness error of the press plate ≤0.05mm; a segmented temperature control mode is used for hot pressing. The first stage temperature is controlled at 150-190℃ for 10-15 seconds, allowing the resin of the melamine impregnated paper to initially soften and penetrate the adhesive coating of the PET film; the second stage temperature is increased to 190-220℃ for 20-45 seconds, with a total hot pressing time of 30-60 seconds and a hot pressing pressure controlled at 2.5-4MPa; during this process, the resin of the melamine impregnated paper and the melamine-urea-formaldehyde resin in the adhesive coating of the PET film are simultaneously cured, forming a three-dimensional network cross-linked structure, realizing the integrated composite of the substrate, melamine impregnated paper, and PET film.

[0017] Cooling and shaping: After hot pressing, the composite board is removed from the hot press and allowed to cool naturally to room temperature. During the cooling process, the surface of the board is kept free from pressure contact to avoid scratches or deformation. The cooling time is ≥30 minutes. After cooling, the composite board is cut and trimmed according to requirements to obtain the finished decorative board.

[0018] The technical solution of this invention simultaneously cures melamine-impregnated paper and PET film with adhesive coating onto a substrate, eliminating the need for specialized bonding equipment and a separate adhesive application process. It can be directly formed in one step using existing melamine board hot pressing equipment, resulting in a simple process, convenient operation, and suitability for large-scale industrial production. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] like Figure 1 As shown, this invention provides a method for simultaneously hot-pressing a PET film and an impregnated paper onto a substrate, the specific steps of which are as follows: Example 1 Substrate pretreatment: Select 18mm thick MDF as the substrate, and sand or clean its surface to ensure that the surface flatness error is ≤0.05mm / m; then place the sanded MDF in an environment with a temperature of 23℃ and a humidity of 60% for 24 hours to equilibrate, and control the moisture content of the substrate to 7%.

[0025] Composite layer material preparation: ① Select melamine-impregnated film paper with a resin content of 140% [resin content = (dry weight of impregnated paper - dry weight of base paper) / dry weight of base paper × 100%) and volatile matter (the proportion of mass lost after drying to constant weight to the dry weight before drying) of 5%, and remove surface dust using electrostatic dust removal equipment; ② Select PET skin-feel film with a thickness of 0.05mm; Stacking and assembly: Stack the substrate in the order of “substrate → melamine impregnated paper → PET film”, so that the adhesive coating of the PET film is tightly bonded to the melamine impregnated paper and the edges of the three are aligned.

[0026] One-time hot pressing: The assembly is fed into a hot press and hot pressing is performed using a segmented temperature control method: the first segment temperature is 170℃ and lasts for 12 seconds; the second segment temperature is 200℃ and lasts for 30 seconds; the total hot pressing time is 42 seconds and the hot pressing pressure is 3MPa.

[0027] Cooling and shaping: After hot pressing, the composite board is removed and allowed to cool naturally to room temperature for 40 minutes. Then, it is cut and trimmed to obtain the finished decorative board.

[0028] Example 2 Substrate pretreatment: Select 25mm thick OSB board as the substrate. After sanding, the surface flatness error is ≤0.05mm / m. Equilibrate for 24 hours in an environment of 25℃ and 55% humidity, and control the moisture content of the substrate to 6%.

[0029] Composite layer material preparation: ① Select melamine-impregnated film paper with a resin content of 135% and volatile matter of 6%, and treat it with electrostatic dust removal; ② Select PET high-gloss film with a thickness of 0.05mm and a light transmittance of 92%; Stacking and assembly: Stack the substrate in the order of “substrate → melamine impregnated paper → PET film”, ensuring that the adhesive coating adheres to the melamine impregnated paper.

[0030] One-time hot pressing: the flatness error of the hot press plate is ≤0.05mm. Segmented temperature control: first segment 180℃, lasting 15 seconds; second segment 210℃, lasting 35 seconds; total hot pressing time 50 seconds, hot pressing pressure 3.5MPa.

[0031] Cooling and shaping: Allow to cool naturally for 35 minutes, then trim and finish to obtain the finished product.

[0032] Example 3 Substrate pretreatment: Select 16mm thick particleboard as substrate, and after sanding, the surface flatness error is ≤0.05mm / m; equilibrate for 24 hours in an environment of 20℃ and 65% humidity, and control the moisture content of the substrate to 8%.

[0033] Composite layer material preparation: ① Select melamine-impregnated film paper with a resin content of 145% and volatile matter of 4%, and perform electrostatic dust removal; ② Select PET film with a thickness of 0.18mm and a light transmittance of 90%; Stacking and combining: Stack neatly in a preset order.

[0034] One-time hot pressing molding: The hot press is temperature controlled in stages: the first stage is 190℃ for 10 seconds; the second stage is 220℃ for 25 seconds; the total hot pressing time is 35 seconds and the hot pressing pressure is 2.8MPa.

[0035] Cooling and shaping: Allow to cool naturally for 30 minutes, then trim and finish the product (after pressing, wait for the temperature to drop to room temperature before trimming).

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for simultaneously hot-pressing a PET film and an impregnated paper onto a substrate, characterized in that, Includes the following steps: S1: Substrate pretreatment: Select wood-based panels as the substrate and sand or clean the surface of the substrate. S2: Stack the PET film and the melamine-impregnated paper together, and cover the substrate surface with the stacked PET film and the melamine-impregnated paper. The melamine-impregnated paper is laid flat on the substrate surface, with the side of the PET film with the adhesive coating facing the melamine-impregnated paper. S3: The stacked assembly is fed into a hot press to simultaneously cure the resin of the melamine-impregnated paper and the adhesive coating of the PET film, achieving a composite of the three components.

2. The method for simultaneously hot-pressing PET film and impregnated paper onto a substrate according to claim 1, characterized in that, In step S3, when the stacked assembly is fed into the hot press, the hot pressing temperature is controlled at 150-220℃, the hot pressing pressure is 2.5-4MPa, and the hot pressing time is 20-80 seconds.

3. The method for simultaneously hot-pressing PET film and impregnated paper onto a substrate according to claim 1, characterized in that, One side of the PET film is provided with an adhesive coating, the components of which, by mass percentage, include: 50-70% melamine-urea-formaldehyde resin, 5-10% polyethylene glycol modifier, 2-5% latent curing agent, 3-8% nano silica dispersion, and the balance being deionized water.

4. The method for simultaneously hot-pressing PET film and impregnated paper onto a substrate according to claim 3, characterized in that, The latent curing agent is an imidazole curing agent or a dicyandiamide curing agent.

5. The method for simultaneously hot-pressing PET film and impregnated paper onto a substrate according to claim 1, characterized in that, The thickness of the PET film is 0.01-0.3 mm.

6. The method for simultaneously hot-pressing PET film and impregnated paper onto a substrate according to claim 2, characterized in that, The hot pressing process adopts a segmented temperature control mode. The first segment temperature is 150-190℃ and lasts for 10-15 seconds; the second segment temperature is 190-220℃ and lasts for 20-45 seconds.

7. The method for simultaneously hot-pressing PET film and impregnated paper onto a substrate according to claim 1, characterized in that, In step S2, before stacking the PET film and the melamine-impregnated paper, the surface of the melamine-impregnated paper is subjected to electrostatic dust removal treatment.

8. The method for simultaneously hot-pressing PET film and impregnated paper onto a substrate according to claim 3, characterized in that, The coating amount of the adhesive coating is 15-25 g / m. 2 .

9. The method for simultaneously hot-pressing PET film and impregnated paper onto a substrate according to claim 1, characterized in that, In step S3, after hot pressing, the composite board is naturally cooled to room temperature. During the cooling process, the surface of the board is kept free from pressure contact, and the cooling time is ≥30 minutes.

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