A 50-160g one-time molding flame-retardant double-coated paper and its preparation method

Abstract

Brief Introduction: This invention discloses a 50-160g one-piece, single-piece flame-retardant offset paper and its preparation method. It is compatible with both white and natural colors, and is produced using a single papermaking machine. In-pulp flame retardancy and on-machine online flame-retardant sizing are completed simultaneously, eliminating the need for secondary processing. The product combines excellent printing and writing performance with B1-level flame retardancy, making it suitable for office, printing, writing, and archival paper applications. It features stable processing, comprehensive protection, and high market value.

Description

Technical Field

[0001] This invention belongs to the field of cultural paper technology, specifically relating to a 50-160g one-time forming flame-retardant double-sided offset paper and its preparation method, which is suitable for fire-resistant and safe paper use scenarios such as white and natural color cultural printing, writing, office, and archives. Background Technology

[0002] Ordinary double-sided offset paper does not have flame-retardant properties and is prone to rapid combustion and spread when exposed to fire, posing a safety hazard. Existing flame-retardant paper mostly adopts a two-stage coating process, which easily causes paper deformation, wrinkling, dusting, and reduced printing performance. There is a lack of a dedicated technical solution for flame-retardant double-sided offset paper that can be used for both white and natural colors and can be formed in one machine in 50-160g. Summary of the Invention

[0003] This invention employs a single-machine, one-time, simultaneous forming process on a single papermaking machine, designed for 50-160g offset paper. It is compatible with both white bleached wood pulp and unbleached wood pulp systems. The process—including in-pulp flame-retardant modification, paper forming, dewatering, online flame-retardant sizing and coating, low-temperature segmented drying, in-machine soft calendering, and finished product winding—is completed continuously in one papermaking machine, eliminating the need for secondary processing. The product maintains the excellent printing and writing properties of offset paper while meeting the GB 8624 B1 flame-retardant standard, exhibiting self-extinguishing properties, low smoke and halogen-free characteristics, and a smooth, non-deformable surface.

[0004] Beneficial effects

[0005] 1. Mainstream cultural double-sided offset paper weights of 50-160g are fully covered, formed in one machine in one go, without secondary processing, the paper is flat, wrinkle-free and deformation-free;

[0006] 2. Compatible with both white and natural color systems, applicable to a wider range of scenarios and providing more comprehensive protection;

[0007] 3. Stable flame retardant performance, LOI≥30%, meeting GB 8624 B1 level, self-extinguishing upon removal of flame, no dripping, low smoke and halogen-free;

[0008] 4. It has good printability, does not bleed ink when writing, and has high smoothness, meeting the requirements for use in cultural and archival paper.

[0009] 5. The process is simple, the production efficiency is high, the cost is low, the technical solution is independent and clear, and it does not conflict with existing products. Detailed Implementation

[0010] Example 1: 50g white flame-retardant writing paper

[0011] Example 2: 80g white flame-retardant office printing paper

[0012] Example 3: 120g natural color flame retardant environmentally friendly double-sided offset paper

[0013] Example 4: 160g white flame-retardant offset paper for archival use

Claims

1. A 50-160g one-time forming flame-retardant double-sided coated paper, comprising a paper base layer, characterized in that: The paper has a basis weight of 50g / m² to 160g / m², and is produced by a single paper machine in one continuous process. The paper contains flame-retardant components in the pulp, and the surface of the paper is coated with a flame-retardant sizing layer applied online simultaneously. The paper is white or natural-colored, with a limiting oxygen index (LOI) ≥ 30%, and a flame retardant rating of GB 8624 B1. It features good printability, no ink bleeding when writing, flatness and no deformation, self-extinguishing after being removed from the flame, and low smoke and halogen-free properties.

2. A method for preparing the flame-retardant double-sided offset paper as described in claim 1, characterized in that: The entire process is completed continuously in a single paper machine. The steps are as follows: (1) In-pulp flame retardant treatment: add phosphorus and nitrogen composite flame retardant, inorganic flame retardant filler and dispersant to bleached wood pulp or unbleached wood pulp, and form it on the wire after full dispersion; (2) Vacuum dewatering and press dewatering; (3) On-machine online synchronous flame retardant coating and sizing; (4) Low temperature segmented drying to ensure that the paper is flat, wrinkle-free and deformation-free; (5) In-machine soft calendering and winding, no secondary processing is required, and the finished flame retardant double-sided offset paper is directly produced.

3. The flame-retardant double-sided offset paper according to claim 1, wherein the pulp components, by weight, include: 100 parts wood pulp fiber, 3-10 parts phosphorus-nitrogen composite flame retardant, 2-6 parts nano aluminum hydroxide, and 0.1-0.4 parts dispersant.

4. The flame-retardant double-sided coated paper according to claim 1, wherein the on-machine coating liquid comprises, by weight: Ammonium polyphosphate 10-20 parts, oxidized starch 5-12 parts, water-based acrylic emulsion 3-8 parts, defoamer 0.1-0.4 parts, water 55-75 parts.

5. The method according to claim 2, characterized in that: The coating amount on the machine is 0.8~2.5g / m²; the drying temperature is 50~70℃ in the first section, 70~90℃ in the middle section, and 90~105℃ in the last section.

6. The flame-retardant double-sided offset paper according to claim 1, characterized in that: White is suitable for printing, writing, archives, documents, office supplies, and publications; natural color is suitable for environmentally friendly cultural paper, printing and packaging without bleaching requirements, and archive storage.