Preparation method of decorative base paper

Abstract

The invention relates to the technical field of decorative base paper preparation, and discloses a decorative base paper preparation method, which comprises: S1, raw material pretreatment: mixing softwood pulp and hardwood pulp according to a specific mass ratio, adding water to prepare a mixed slurry with a preset concentration, defibering through a defibering machine, and carrying out thermal insulation stirring for a certain time at a suitable temperature; s2, pulping treatment: feeding the pretreated mixed pulp into a double-disc pulping machine for pulping, and controlling the pulping degree and the wet weight range to be specific; according to the preparation method of the decorative base paper, the decorative base paper has higher whiteness and opaqueness, and the phenomenon of bottom penetration during printing can be avoided; the transverse ring crush index and the longitudinal fracture length meet the specific strength requirements, and the damage-resistant requirements in subsequent processing and long-term use can be met; the water absorption height is in a relatively low range, so that the adhesiveness of printing ink and the adhesion stability of a coating film can be ensured, and the water-absorbing material is suitable for various application scenes such as furniture veneering and floor decoration.

Description

Technical Field

[0001] This invention relates to the field of decorative base paper preparation technology, specifically a method for preparing decorative base paper. Background Technology

[0002] As the core substrate of decorative materials, decorative base paper needs to have high whiteness, opacity, dry and wet strength and surface smoothness to meet the requirements of subsequent printing, lamination and other processing technologies, while also being suitable for the durability requirements of long-term use scenarios such as furniture and flooring. Existing methods for preparing decorative base paper have several drawbacks. Inappropriate raw material ratios can lead to difficulties in balancing paper strength and formability. Some processes employ a single drying method, which can result in uneven paper moisture content and surface wrinkling. Furthermore, the lack of targeted environmental control during the addition of auxiliary materials can reduce their effectiveness and negatively impact the final paper performance. Summary of the Invention

[0003] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a method for preparing decorative base paper that achieves high whiteness and opacity, preventing the paper from showing through during printing; its transverse ring crush index and longitudinal breaking length meet specific strength requirements, satisfying the anti-damage needs of subsequent processing and long-term use; and its water absorption height is within a low range, ensuring the adhesion of printing inks and the stability of film bonding. This method is suitable for various applications such as furniture veneers and floor decoration, and solves the problems mentioned in the background technology.

[0004] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a method for preparing decorative base paper, comprising the following steps: S1. Raw material pretreatment: Softwood pulp and hardwood pulp are mixed in a specific mass ratio, water is added to make a mixed pulp of a preset concentration, and after being decomposed by a decomposition machine, it is kept warm and stirred at a suitable temperature for a certain period of time. S2. Pulping treatment: The pretreated mixed pulp is fed into a double-disc refiner for pulping, and the pulping degree and wet weight are controlled within a specific range. S3. Addition of auxiliary materials: Add dry strength agent, wet strength agent, sizing agent, filler and dye to the pulp in sequence, and stir evenly at a specific speed to obtain the molded pulp; S4. Forming: The forming pulp is fed into a fourdrinier paper machine, and the wire density, wire vacuum and press pressure are controlled to obtain a wet paper sheet; S5. Drying process: The wet paper sheets are sequentially subjected to pre-drying, main drying and post-drying, and the drying temperature is controlled at each stage to ensure that the moisture content of the dried paper sheets is within the preset range. S6. Post-processing: The dried paper is calendered, and the calendering temperature and linear pressure are controlled to finally obtain decorative base paper with a specific basis weight. Preferably, the softwood pulp is bleached sulfate softwood pulp, which has high whiteness and a specific fiber length; the hardwood pulp is bleached sulfate hardwood pulp, which has higher whiteness than softwood pulp and shorter fiber length than softwood pulp. Preferably, the dry strength agent in step S3 is a compound of cationic starch and polyacrylamide, which are mixed in a specific mass ratio; the wet strength agent is polyamide epichlorohydrin resin and has a certain solid content. Preferably, the sizing agent in step S3 is an alkyl ketene dimer, added in the form of an emulsion of a specific concentration; the filler is a compound of light calcium carbonate and talc, which are mixed in a specific mass ratio and have a particle size within a preset range.

[0005] Preferably, in step S4, the wire section speed of the long-wire paper machine is within a specific range, the forming wire is a polyester wire with a specific mesh count, and the pressing section adopts a three-roll, two-pressure zone structure, with the upper pressure roll being a rubber roll and the lower pressure roll being a cast iron roll.

[0006] Preferably, the pre-drying in step S5 uses an air-cushion drying box and controls a specific drying time; the main drying uses multi-stage drying cylinders with the number of cylinders within a specific range and the temperature of each cylinder increasing sequentially; and the post-drying uses hot air drying and controls a specific wind speed. Preferably, the calendering process in step S6 uses a supercalender, the number of calendering rollers is within a specific range, the number of cold rollers and hot rollers is configured in a specific ratio, and the number of calendering cycles is 1-2.

[0007] Preferably, step S1 further includes adding a specific type of chelating agent to the mixed slurry, wherein the chelating agent is disodium ethylenediaminetetraacetate or pentasodium diethylenetriaminepentaacetate.

[0008] Preferably, in step S3, the pH value of the slurry is controlled to be in the neutral range when the auxiliary materials are added, nitrogen is introduced for protection during the stirring process, and a specific nitrogen flow rate is controlled.

[0009] Preferably, the performance indicators of the decorative base paper meet the following requirements: high whiteness and opacity, transverse ring crush index and longitudinal breaking length reaching specific strength requirements, and water absorption height within a low range.

[0010] (III) Beneficial Effects Compared with the prior art, the present invention provides a method for preparing decorative base paper, which has the following beneficial effects: 1. The preparation method of this decorative base paper balances the strength and formability of the paper by optimizing the ratio of softwood pulp to hardwood pulp and the pulping parameters, thus solving the problems of easy paper breakage or uneven forming in the prior art. 2. The preparation method of this decorative base paper, by adopting a segmented drying process, combined with the combination of air cushion drying, drying cylinder drying and hot air drying, effectively avoids paper cracking and wrinkling, and ensures the uniformity of paper moisture content; 3. The preparation method of this decorative base paper improves the efficiency of auxiliary materials, reduces fiber oxidative degradation, and further enhances paper performance by controlling the neutral pH environment and introducing nitrogen protection during the addition of auxiliary materials. 4. The method for preparing this decorative base paper results in a decorative base paper that combines high whiteness, high opacity, high strength, and low water absorption, making it suitable for various processing techniques and application scenarios, and highly practical. Attached Figure Description

[0011] Figure 1 This is a flowchart of a method for preparing decorative base paper according to the present invention. Detailed Implementation

[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0013] Please see Figure 1 A method for preparing decorative base paper includes the following steps: S1. Raw material pretreatment: Softwood pulp and hardwood pulp are mixed in a specific mass ratio, water is added to make a mixed pulp of a preset concentration, and after being decomposed by a decomposition machine, it is kept warm and stirred at a suitable temperature for a certain period of time. S2. Pulping treatment: The pretreated mixed pulp is fed into a double-disc refiner for pulping, and the pulping degree and wet weight are controlled within a specific range. S3. Addition of auxiliary materials: Add dry strength agent, wet strength agent, sizing agent, filler and dye to the pulp in sequence, and stir evenly at a specific speed to obtain the molded pulp; S4. Forming: The forming pulp is fed into a fourdrinier paper machine, and the wire density, wire vacuum and press pressure are controlled to obtain a wet paper sheet; S5. Drying process: The wet paper sheets are sequentially subjected to pre-drying, main drying and post-drying, and the drying temperature is controlled at each stage to ensure that the moisture content of the dried paper sheets is within the preset range. S6. Post-processing: The dried paper is calendered, and the calendering temperature and linear pressure are controlled to finally obtain decorative base paper with a specific basis weight. Softwood pulp is bleached sulfate softwood pulp, which has high whiteness and specific fiber length; hardwood pulp is bleached sulfate hardwood pulp, which has higher whiteness than softwood pulp and shorter fiber length.

[0014] In step S3, the dry strength agent is a compound of cationic starch and polyacrylamide, which are mixed in a specific mass ratio; the wet strength agent is polyamide epichlorohydrin resin with a certain solid content. In step S3, the sizing agent is an alkyl ketene dimer, which is added in the form of an emulsion of a specific concentration; the filler is a compound of light calcium carbonate and talc, which are mixed in a specific mass ratio and the particle size is within a preset range.

[0015] In step S4, the wire section speed of the long-wire paper machine is within a specific range, the forming wire is a polyester wire with a specific mesh count; the press section adopts a three-roll, two-pressure zone structure, with the upper pressure roll being a rubber roll and the lower pressure roll being a cast iron roll.

[0016] In step S5, pre-drying uses an air-cushion drying box with a specific drying time controlled; main drying uses multi-stage drying cylinders with the number of cylinders within a specific range and the temperature of each cylinder increasing sequentially; post-drying uses hot air drying with a specific air velocity controlled. In step S6, the calendering process uses a supercalender, the number of calendering rollers is within a specific range, the number of cold rollers and hot rollers is configured in a specific ratio, and the number of calendering cycles is 1-2.

[0017] Step S1 also includes adding a specific type of chelating agent to the mixed slurry, wherein the chelating agent is disodium ethylenediaminetetraacetate or pentasodium diethylenetriaminepentaacetate.

[0018] In step S3, when adding auxiliary materials, the pH value of the slurry is controlled to be in the neutral range. Nitrogen gas is introduced for protection during the stirring process, and a specific nitrogen gas flow rate is controlled.

[0019] The performance indicators of decorative base paper meet the following requirements: high whiteness and opacity, transverse ring crush index and longitudinal breaking length meet specific strength requirements, and water absorption height is in a low range.

[0020] It should be noted that the term "comprising" or any other variation thereof is 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. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0021] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing decorative base paper, characterized in that, Includes the following steps: S1. Raw material pretreatment: Softwood pulp and hardwood pulp are mixed in a specific mass ratio, water is added to make a mixed pulp of a preset concentration, and after being decomposed by a decomposition machine, it is kept warm and stirred at a suitable temperature for a certain period of time. S2. Pulping treatment: The pretreated mixed pulp is fed into a double-disc refiner for pulping, and the pulping degree and wet weight are controlled within a specific range. S3. Addition of auxiliary materials: Add dry strength agent, wet strength agent, sizing agent, filler and dye to the pulp in sequence, and stir evenly at a specific speed to obtain the molded pulp; S4. Forming: The forming pulp is fed into a fourdrinier paper machine, and the wire density, wire vacuum and press pressure are controlled to obtain a wet paper sheet; S5. Drying process: The wet paper sheets are sequentially subjected to pre-drying, main drying and post-drying, and the drying temperature is controlled at each stage to ensure that the moisture content of the dried paper sheets is within the preset range. S6. Post-processing: The dried paper is calendered, and the calendering temperature and linear pressure are controlled to finally obtain decorative base paper with a specific basis weight.

2. The method for preparing decorative base paper according to claim 1, characterized in that, The softwood pulp is bleached sulfate softwood pulp, which has high whiteness and a specific fiber length; the hardwood pulp is bleached sulfate hardwood pulp, which has higher whiteness than softwood pulp and shorter fiber length than softwood pulp.

3. The method for preparing decorative base paper according to claim 1, characterized in that, The dry strength agent mentioned in step S3 is a compound of cationic starch and polyacrylamide, which are mixed in a specific mass ratio; the wet strength agent is polyamide epichlorohydrin resin and has a certain solid content.

4. The method for preparing decorative base paper according to claim 1, characterized in that, The sizing agent mentioned in step S3 is an alkyl ketene dimer, which is added in the form of an emulsion of a specific concentration; the filler is a compound of light calcium carbonate and talc, which are mixed in a specific mass ratio and the particle size is within a preset range.

5. The method for preparing decorative base paper according to claim 1, characterized in that, In step S4, the wire section speed of the long-wire paper machine is within a specific range, the forming wire is a polyester wire with a specific mesh count, and the press section adopts a three-roll, two-pressure zone structure, with the upper pressure roll being a rubber roll and the lower pressure roll being a cast iron roll.

6. The method for preparing decorative base paper according to claim 1, characterized in that, The pre-drying in step S5 uses an air-cushion drying box and controls a specific drying time; the main drying uses multi-stage drying cylinders with the number of cylinders within a specific range and the temperature of each cylinder increasing sequentially; the post-drying uses hot air drying and controls a specific wind speed.

7. The method for preparing decorative base paper according to claim 1, characterized in that, The calendering process described in step S6 uses a supercalender, with the number of calendering rollers within a specific range, wherein the number of cold rollers and hot rollers is configured in a specific ratio, and the number of calendering cycles is 1-2.

8. The method for preparing decorative base paper according to claim 1, characterized in that, Step S1 also includes adding a specific type of chelating agent to the mixed slurry, wherein the chelating agent is disodium ethylenediaminetetraacetate or pentasodium diethylenetriaminepentaacetate.

9. The method for preparing decorative base paper according to claim 1, characterized in that, In step S3, when adding auxiliary materials, the pH value of the slurry is controlled to be in the neutral range. Nitrogen gas is introduced for protection during the stirring process, and a specific nitrogen gas flow rate is controlled.

10. The method for preparing decorative base paper according to claim 1, characterized in that, The performance indicators of the decorative base paper meet the following requirements: it has high whiteness and opacity, its transverse ring crush index and longitudinal breaking length meet specific strength requirements, and its water absorption height is in a low range.

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