Low basis weight high flame retardant sanitary paper and method of making same

Abstract

The present application belongs to the technical field of sanitary paper preparation, and particularly relates to low-quantity high-flame-retardant sanitary paper and a preparation method thereof, and is especially suitable for 15g / m2-25g / m2 thin civil and public health flame-retardant sanitary paper.

Description

Technical Field

[0001] This invention belongs to the field of sanitary paper preparation technology, specifically relating to a low basis weight, high flame retardant sanitary paper and its preparation method, which is particularly suitable for thin civilian and public health flame retardant sanitary paper of 15g / m²-25g / m². Background Technology

[0002] Toilet paper, as an essential daily hygiene product, is widely used in various daily and public settings. Existing ordinary toilet paper is made from plant fibers, has a low oxygen index, is highly flammable, and lacks self-extinguishing properties when exposed to open flame, posing a significant fire hazard. Current flame-retardant paper products are mostly thick industrial paper, which suffers from poor softness, a stiff feel, powdering, and high cost, failing to meet the needs of thin, skin-friendly, and soft household toilet paper. Some thin flame-retardant papers use a single flame-retardant coating process, resulting in poor flame-retardant effects, and their formulas and processes lack core barriers to entry, making them easily imitated and circumvented by competitors, hindering the formation of proprietary technology protection. Therefore, this invention provides a toilet paper product with low basis weight, high softness, high flame retardancy, and unavoidable flame characteristics, overcoming the shortcomings of existing technologies. Summary of the Invention

[0003] Purpose of the invention

[0004] To address the problems of existing ordinary toilet paper being flammable, existing flame-retardant paper being unable to meet civilian needs, and the technology being easily imitated, this invention provides a low basis weight, high flame-retardant toilet paper and its preparation method. Through the precise design of core formula, structure, and process, a high technical barrier is built, ensuring the product's flame-retardant performance and user experience while preventing competitors from easily circumventing and infringing on its rights.

[0005] Technical solution

[0006] 1. Raw material components

[0007] Based on oven-dry weight, the raw materials include: 75-90 parts bleached wood pulp fiber, 0-15 parts bamboo pulp fiber, 2-5 parts halogen-free composite flame retardant, 0.5-1.5 parts nano silica, 0.3-0.8 parts polyamide epichlorohydrin wet strength agent, and 0.2-0.6 parts amino silicone oil softener. Among them, the halogen-free composite flame retardant is a mixture of ammonium polyphosphate, melamine phosphate, and chitosan in a mass ratio of 1:1:0.3. This ratio is the core flame retardant system, and adjusting the ratio will lead to a significant decrease in flame retardant and softening properties.

[0008] 2. Product Structure

[0009] The product features a dual-layer synchronous wet-laid composite structure, without post-coating or adhesive bonding. The upper layer is a soft contact layer made from wood pulp and softener, ensuring skin-friendliness and water absorption. The lower layer is a flame-retardant reinforcing layer made from wood pulp, bamboo pulp, composite flame retardant, and additives, achieving core flame retardancy and strength enhancement. The two layers of fibers are interwoven in a wet state, tightly bonded without delamination, and the finished product's quantitative control is between 15g / m² and 25g / m².

[0010] 3. Preparation method

[0011] (1) Pulping treatment: Mix bleached wood pulp and bamboo pulp in proportion, and pulp to 26-34°SR. Control the pulping concentration to 3.5%-4.5% to ensure fiber interweaving performance;

[0012] (2) Slurry preparation: Divide the mixed slurry into two equal parts to prepare the soft layer slurry and the flame retardant layer slurry respectively. The flame retardant layer slurry needs to be thoroughly stirred and dispersed to ensure that the additives are evenly distributed;

[0013] (3) Synchronous papermaking: A double-layer papermaking device is used to achieve synchronous dewatering and bonding of two layers of slurry, avoiding the delamination problem caused by later bonding;

[0014] (4) Post-drying treatment: Control the drying temperature to 90-110℃ to prevent the paper from becoming brittle and the flame retardant from failing due to excessive temperature. The finished product is obtained after conventional calendering, slitting and winding.

[0015] Beneficial effects

[0016] 1. Excellent flame retardant performance, with an oxygen index (LOI) of ≥28% for the finished product. It self-extinguishes upon contact with an open flame and is free from dripping or flame spread, ensuring high fire safety.

[0017] 2. The product has a basis weight of 15-25g / m², a softness of ≤30mN, is skin-friendly and does not shed powder, and fully meets the standards for use in household toilet paper;

[0018] 3. The core ternary flame retardant has a fixed ratio, and the dual-layer synchronous copying is a necessary structure. The process parameter range is narrow, and competitors cannot circumvent it by simply replacing raw materials or adjusting the process, resulting in extremely high technical barriers.

[0019] 4. It adopts a halogen-free flame retardant system, which is free of halogens, formaldehyde and heavy metals. It produces low smoke, low toxicity and no corrosive gases when burning. Chitosan is biodegradable and the overall environment is environmentally friendly.

[0020] 5. All additives used are compliant raw materials for sanitary paper, with no harmful residues or skin irritation. They meet the requirements of GB 4806.8 Hygiene Standard for Food Contact Paper and Toilet Paper, and are safe and hygienic for direct contact with human skin. Detailed Implementation

[0021] Example 1

[0022] Raw material composition (octane dry weight): 85 parts bleached wood pulp fiber, 5 parts bamboo pulp fiber, 3 parts halogen-free composite flame retardant, 1 part nano silica, 0.5 parts polyamide epichlorohydrin wet strength agent, and 0.3 parts amino silicone oil softener.

[0023] Preparation process: beating degree 30°SR, drying temperature 100℃, finished product quantity 20g / m².

[0024] Performance testing: Oxygen index (LOI) = 29.2%, self-extinguishing after removal from flame, no dripping, softness 26mN, transverse wet strength 0.85N / m.

[0025] Example 2

[0026] Raw material composition (octane dry weight): 90 parts bleached wood pulp fiber, 2.5 parts halogen-free composite flame retardant, 0.8 parts nano silica, 0.4 parts polyamide epichlorohydrin wet strength agent, and 0.2 parts amino silicone oil softener.

[0027] Preparation process: beating degree 28°SR, drying temperature 95℃, finished product quantity 15g / m².

[0028] Performance testing: Oxygen index (LOI) = 28.5%, self-extinguishing upon removal from flame, softness 24 mN, transverse wet strength 0.78 N / m.

[0029] Example 3

[0030] Raw material composition (octane dry weight): 78 parts bleached wood pulp fiber, 12 parts bamboo pulp fiber, 4 parts halogen-free composite flame retardant, 1.2 parts nano silica, 0.7 parts polyamide epichlorohydrin wet strength agent, and 0.5 parts amino silicone oil softener.

[0031] Preparation process: beating degree 32°SR, drying temperature 105℃, finished product quantity 25g / m².

[0032] Performance testing: Oxygen index (LOI) = 30.1%, self-extinguishing upon removal from flame, softness 28 mN, transverse wet strength 0.92 N / m.

[0033] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection. Any non-substantial improvements based on the core formula, structure, and process of the present invention shall fall within the scope of protection of the present invention.

[0034] summary

[0035] This invention discloses a low basis weight, high flame retardant toilet paper and its preparation method, belonging to the field of toilet paper preparation technology. Based on oven-dry weight, the raw materials include bleached wood pulp, 0-15 parts bamboo pulp, a specific ratio of halogen-free composite flame retardant, nano-silica, and appropriate additives. The product is a double-layer synchronous wet-pressed composite structure with a basis weight of 15g / m²-25g / m². During preparation, the freeness is controlled at 26-34°SR, and the drying temperature is 90-110℃. This invention has an oxygen index ≥28%, is self-extinguishing upon removal from flame, meets softness standards, and uses environmentally friendly and hygienic raw materials with no harmful residues. The core flame retardant ratio and double-layer synchronous process create a very high technical barrier, making it difficult for competitors to circumvent infringement. It is suitable for fire-resistant toilet paper in various scenarios such as homes, hotels, and hospitals.

Claims

1. A low basis weight, high flame resistant sanitary paper, characterized in that, Based on oven-dry weight, the raw material components include: 75-90 parts bleached wood pulp fiber, 0-15 parts bamboo pulp fiber, 2-5 parts halogen-free composite flame retardant, 0.5-1.5 parts nano silica, 0.3-0.8 parts wet strength agent, and 0.2-0.6 parts softener; the halogen-free composite flame retardant is composed of ammonium polyphosphate, melamine phosphate, and chitosan in a mass ratio of 1:1:0.3; the toilet paper has a double-layer synchronous wet-pressed composite structure, with the upper layer being a soft contact layer and the lower layer being a flame-retardant reinforcing layer, and the finished product basis weight is 15g / m²-25g / m².

2. The low basis weight, high flame retardant toilet paper according to claim 1, characterized in that, The wet strength agent is polyamide epichlorohydrin, and the softener is amino silicone oil.

3. A method for preparing the low basis weight, high flame retardant toilet paper according to claim 1 or 2, characterized in that, Includes the following steps: (1) Mix bleached wood pulp and bamboo pulp and beat them together, controlling the freeness to be 26-34°SR and the beating concentration to be 3.5%-4.5%; (2) Divide the mixed slurry into two parts. Add softener to one part and stir evenly to obtain the upper softening layer slurry. Add halogen-free composite flame retardant, nano silica and wet strength agent to the other part in sequence, stir and disperse for 30-40 minutes to obtain the lower flame retardant layer slurry. (3) Using a double-layer papermaking equipment, two layers of pulp are fed into the wire section simultaneously, and wet-state dewatering and composite molding are performed simultaneously to obtain a double-layer integrated wet paper sheet; (4) Dry the wet paper at 90-110℃, then calender, cut and roll to obtain the finished product.

4. The application of the low basis weight, high flame retardant toilet paper as described in claim 1 or 2 in fire-resistant toilet paper for use in homes, hotels, hospitals, kitchens, and public health areas.