阅读说明：本技术 一种高强度再生纳米纤维素混合膜的生产方法 (Production method of high-strength regenerated nano-cellulose mixed membrane ) 是由 王博楼 于 2019-10-29 设计创作，主要内容包括：本发明公开了一种高强度再生纳米纤维素混合膜的生产方法,其特征在于：所述生产方法包括如下步骤,制取溶解浆--制取高浓度纳米混合溶解浆--制取纳米混合溶解浆--制成再生纳米纤维素混合膜--制成成品；它是以甲基吗啉水合物(NMMO)为溶剂的一种新的高强度再生纳米纤维素混合膜的生产方法,在外观,强度,性能都优化的同时解决原NMMO法纤维素膜的原纤化,疵点高,产品质量不稳定等问题。(The invention discloses a production method of a high-strength regenerated nano cellulose mixed film, which is characterized by comprising the following steps: the production method comprises the following steps of preparing dissolving pulp, preparing high-concentration nano mixed dissolving pulp, preparing a regenerated nano cellulose mixed film and preparing a finished product; the method is a novel production method of a high-strength regenerated nano cellulose mixed film taking methylmorpholine hydrate (NMMO) as a solvent, optimizes appearance, strength and performance, and solves the problems of fibrillation, high defects, unstable product quality and the like of an original cellulose film prepared by an NMMO method.)

1. A production method of a high-strength regenerated nano-cellulose mixed film is characterized by comprising the following steps: the production method comprises the following steps of preparing dissolving pulp, preparing high-concentration nano mixed dissolving pulp, preparing a regenerated nano cellulose mixed film and preparing a finished product;

the method comprises the following steps: preparation of dissolving pulp

Evaporating prepared NMMO, namely methylmorpholine hydrate to reach the concentration of 83-89%, rotationally stirring in a thin film evaporator for 1-2.5 hours at 90-120 ℃ under vacuum pumping, and dividing into three parts, wherein the three parts are respectively used for dissolving cotton pulp, wood pulp and bamboo pulp to obtain cotton dissolving pulp, wood dissolving pulp and bamboo dissolving pulp; wherein the mass ratio of the cotton pulp, the wood pulp and the bamboo pulp to the NMMO used for dissolving respectively is 4-11%;

step two: preparing high-concentration nano mixed dissolving pulp

Uniformly mixing more than two prepared dissolving pulps at 90-120 ℃ to obtain mixed dissolving pulp, taking 10% of the mixed dissolving pulp, adding 1% -20% of nano cellulose, and uniformly stirring at the temperature of 90-120 ℃ and the rotating speed of 100r/min-800r/min to obtain high-concentration nano mixed dissolving pulp;

step three: preparing nano mixed dissolving pulp

Uniformly stirring the high-concentration nano mixed dissolving pulp in a closed stirrer at the temperature of 90-120 ℃, slowly adding the high-concentration nano mixed dissolving pulp into the mixed dissolving pulp at the rotating speed of 100r/min-800r/min to obtain uniform and transparent nano mixed dissolving pulp;

step four: preparing regenerated nano cellulose mixed membrane

Spraying the prepared nano mixed dissolving pulp through a spinneret plate to form a nano cellulose mixed film with the width of 1-5 m, drawing the nano cellulose mixed film through a drawing roller, entering a coagulating bath, and performing regeneration molding to obtain a regenerated nano cellulose mixed film;

step five: making into final product

And washing the regenerated nano-cellulose mixed membrane with distilled water at the temperature of 40-60 ℃, then drying in a drying zone at the drying temperature of 60-90 ℃, and winding into a barrel after drying to obtain a regenerated nano-cellulose mixed membrane finished product.

2. The method for producing a high-strength regenerated nanocellulose hybrid membrane as claimed in claim 1, wherein: the drafting rate of the drafting roller is-12% -12%.

3. The method for producing a high-strength regenerated nanocellulose hybrid membrane as claimed in claim 1, wherein: the coagulating bath consists of methyl morpholine and distilled water, the temperature is 0-40 ℃, the proportion of the methyl morpholine in the coagulating bath is 0-20%, and the proportion of the distilled water is 80-100%.

4. The method for producing a high-strength regenerated nanocellulose hybrid membrane as claimed in claim 1, wherein: the solvent methylmorpholine hydrate is a commercially available methylmorpholine hydrate with water content of about 50%.

5. The method for producing a high-strength regenerated nanocellulose hybrid membrane as claimed in claim 1, wherein: the mixed dissolving pulp is prepared by combining 1-99 percent of cotton dissolving pulp, 1-99 percent of wood dissolving pulp and 1-99 percent of bamboo dissolving pulp in a weight ratio, wherein the weight ratio of the added nano-cellulose is 0.1-2 percent of the mass fraction of the mixed dissolving pulp.

6. The method for producing a high-strength regenerated nanocellulose hybrid membrane as claimed in claim 1, wherein: the technical indexes of the regenerated nano-cellulose mixed membrane comprise:

the thickness is 20um to 600um, the difference between thickness webs is less than or equal to 1.5um, the MD tensile strength is greater than or equal to 30N/15mm, and the MD elongation is greater than or equal to 11%.

7. The method for producing a high-strength regenerated nanocellulose hybrid membrane as claimed in claim 1, wherein: the indexes of the cotton pulp, the wood pulp and the bamboo pulp are as follows:

wherein S10 and S18 represent solubility, and R10 and R18 represent basicity resistance.

Technical Field

The invention relates to the technical field of mixed film production and preparation, in particular to a production method of a high-strength regenerated nano cellulose mixed film.

Background

The cellulose is from plants and is the most abundant renewable resource on the earth, and the cellulose is fully utilized, so that the environment can be protected, and limited petroleum resources can be saved. The existing methods for manufacturing cellulose films are mainly viscose method and solvent method. The viscose method can generate a large amount of carbon disulfide in the manufacturing process to cause environmental pollution, and the cellulose membrane of the viscose method has high residual sulfur content and is not suitable for being used as a food packaging material which requires no toxicity to human bodies, especially in a high-temperature heating state.

The solvent method is that the regenerated cellulose membrane can be obtained by dissolving cellulose in methylmorpholine hydrate (NMMO) at a certain temperature, and then carrying out a series of processes such as solidification, washing, plasticization, bleaching and the like. The NMMO is a green environment-friendly solvent, the whole dissolving process is a physical reaction, the production process is environment-friendly, and the solvent can be recycled. However, the appearance of the NMMO cellulose film, such as many defects, poor transparency, serious fibrillation and the like, cannot meet the actual requirements of production and life, and the value of the NMMO cellulose film is greatly reduced, so that the NMMO cellulose film is not put into actual production at present.

The similar degradable membranes mainly comprise cellulose membranes prepared by a viscose method and polylactic acid (PLA) membranes

Firstly, viscose method cellulose membrane: the cellulose pulp is converted into cellulose sulfonate solution after being treated by caustic soda and carbon disulfide to prepare the degradable regenerated cellulose membrane. Wherein, the carbon disulfide is a toxic substance, and a large amount of toxic gas is discharged into the nature in the production process; in addition, viscose process cellulose films have a high sulfur content and are not suitable for food packaging.

Secondly, polylactic acid (PLA) film: is a novel biodegradable material, and is prepared from starch raw material extracted from renewable plant resources (such as corn). The starch raw material is saccharified to obtain glucose, the glucose and certain strains are fermented to prepare high-purity lactic acid, polylactic acid with certain molecular weight is synthesized in a chemical synthesis mode, and the degradable polylactic acid film is prepared by the methods of hot molding, blow molding, bidirectional stretching and the like. However, the polylactic acid film is not high temperature resistant, is easy to deform, is easy to become hard and brittle under the condition of long standing time, and does not have the function of permeation separation.

Therefore, a method for producing a high-strength regenerated nanocellulose hybrid membrane is urgently needed to solve the above-mentioned problems.

Disclosure of Invention

In order to solve the problem, the invention discloses a production method of a high-strength regenerated nano cellulose mixed film, which is a novel production method of the high-strength regenerated nano cellulose mixed film by taking methylmorpholine hydrate (NMMO) as a solvent, and solves the problems of fibrillation, high defect, unstable product quality and the like of the original cellulose film by an NMMO method while optimizing appearance, strength and performance.

A production method of a high-strength regenerated nano-cellulose mixed film is characterized by comprising the following steps: the production method comprises the following steps of preparing dissolving pulp, preparing high-concentration nano mixed dissolving pulp, preparing a regenerated nano cellulose mixed film and preparing a finished product;

the method comprises the following steps: preparation of dissolving pulp

Evaporating prepared NMMO, namely methylmorpholine hydrate to reach the concentration of 83-89%, rotationally stirring in a thin film evaporator for 1-2.5 hours at 90-120 ℃ under vacuum pumping, and dividing into three parts, wherein the three parts are respectively used for dissolving cotton pulp, wood pulp and bamboo pulp to obtain cotton dissolving pulp, wood dissolving pulp and bamboo dissolving pulp; wherein the mass ratio of the cotton pulp, the wood pulp and the bamboo pulp to the NMMO used for dissolving respectively is 4-11%;

step two: preparing high-concentration nano mixed dissolving pulp

Uniformly mixing more than two prepared dissolving pulps at 90-120 ℃ to obtain mixed dissolving pulp, taking 10% of the mixed dissolving pulp, adding 1% -20% of nano cellulose, and uniformly stirring at the temperature of 90-120 ℃ and the rotating speed of 100r/min-800r/min to obtain high-concentration nano mixed dissolving pulp;

step three: preparing nano mixed dissolving pulp

Uniformly stirring the high-concentration nano mixed dissolving pulp in a closed stirrer at the temperature of 90-120 ℃, slowly adding the high-concentration nano mixed dissolving pulp into the mixed dissolving pulp at the rotating speed of 100r/min-800r/min to obtain uniform and transparent nano mixed dissolving pulp;

step four: preparing regenerated nano cellulose mixed membrane

Spraying the prepared nano mixed dissolving pulp through a spinneret plate to form a nano cellulose mixed film with the width of 1-5 m, drawing the nano cellulose mixed film through a drawing roller, entering a coagulating bath, and performing regeneration molding to obtain a regenerated nano cellulose mixed film;

step five: making into final product

And washing the regenerated nano-cellulose mixed membrane with distilled water at the temperature of 40-60 ℃, then drying in a drying zone at the drying temperature of 60-90 ℃, and winding into a barrel after drying to obtain a regenerated nano-cellulose mixed membrane finished product.

Further, the draft ratio of the draft roller in the present invention is-12% to 12%.

Further, the coagulating bath consists of methyl morpholine and distilled water, the temperature is 0-40 ℃, the proportion of the methyl morpholine in the coagulating bath is 0-20%, and the proportion of the distilled water is 80-100%.

Furthermore, the solvent methylmorpholine hydrate is selected from commercially available methylmorpholine hydrates with water content of about 50%.

Further, the mixed dissolving pulp is formed by combining 1-99% of cotton dissolving pulp, 1-99% of wood dissolving pulp and 1-99% of bamboo dissolving pulp in a weight ratio, wherein the ratio of the added nano-cellulose is 0.1-2% of the mass fraction of the mixed dissolving pulp.

As a further technical index of the regenerated nano-cellulose mixed membrane of the present invention, it includes: the thickness is 20um to 600um, the difference between thickness webs is less than or equal to 1.5um, the MD tensile strength is greater than or equal to 30N/15mm, and the MD elongation is greater than or equal to 11%.

Further, the cotton pulp, wood pulp and bamboo pulp used in the present invention have the following indexes:

wherein S10 and S18 represent solubility, and R10 and R18 represent basicity resistance.

As a further step, the present invention is widely used in the following industries:

1. food packaging material: such as casings, cigarette films, everyday food contact bags, microwave oven heating bags, and the like.

2. Forestry machinery and carpenter's equipment: such as plant root wrapping, agricultural films.

3. Medical use: such as artificial kidney dialysis membrane, sustained-release capsule, etc.

4. Separation membrane: such as a seawater desalination permeable membrane, and can also be used for large-scale desulfurization and deodorization in the field of oil refining.

The invention has the beneficial effects that:

the invention relates to a production method of a novel high-strength regenerated nano cellulose mixed film by taking methylmorpholine hydrate (NMMO) as a solvent, which optimizes the appearance, strength and performance and solves the problems of fibrillation, high defects, unstable product quality and the like of the original cellulose film by an NMMO method.

In this summary, concepts in a simplified form are introduced that are further described in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

Advantages and features of the present invention are described in detail below.

Drawings

None.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention.

In the following description, a detailed construction will be set forth in order to provide a thorough understanding of the present invention. It is apparent that the invention may be practiced without limitation to the specific details known to those skilled in the art. The following detailed description of the preferred embodiments of the invention, however, the invention is capable of other embodiments in addition to those detailed.

The following provides a detailed description of embodiments of the invention.

A production method of a high-strength regenerated nano-cellulose mixed film is characterized by comprising the following steps: the production method comprises the following steps of preparing dissolving pulp, preparing high-concentration nano mixed dissolving pulp, preparing nano mixed dissolving pulp I, preparing a regenerated nano cellulose mixed membrane I and preparing a finished product;

the method comprises the following steps: preparation of dissolving pulp

Evaporating prepared NMMO, namely methylmorpholine hydrate to reach the concentration of 83-89%, rotationally stirring in a thin film evaporator for 1-2.5 hours at 90-120 ℃ under vacuum pumping, and dividing into three parts, wherein the three parts are respectively used for dissolving cotton pulp, wood pulp and bamboo pulp to obtain cotton dissolving pulp, wood dissolving pulp and bamboo dissolving pulp; wherein the mass ratio of the cotton pulp, the wood pulp and the bamboo pulp to the NMMO used for dissolving respectively is 4-11%;

step two: preparing high-concentration nano mixed dissolving pulp

Uniformly mixing more than two prepared dissolving pulps at 90-120 ℃ to obtain mixed dissolving pulp, taking 10% of the mixed dissolving pulp, adding 1% -20% of nano cellulose, and uniformly stirring at the temperature of 90-120 ℃ and the rotating speed of 100r/min-800r/min to obtain high-concentration nano mixed dissolving pulp;

step three: preparing nano mixed dissolving pulp

Uniformly stirring the high-concentration nano mixed dissolving pulp in a closed stirrer at the temperature of 90-120 ℃, slowly adding the high-concentration nano mixed dissolving pulp into the mixed dissolving pulp at the rotating speed of 100r/min-800r/min to obtain uniform and transparent nano mixed dissolving pulp;

step four: preparing regenerated nano cellulose mixed membrane

Spraying the prepared nano mixed dissolving pulp through a spinneret plate to form a nano cellulose mixed film with the width of 1-5 m, drawing the nano cellulose mixed film through a drawing roller, entering a coagulating bath, and performing regeneration molding to obtain a regenerated nano cellulose mixed film;

step five: making into final product

And washing the regenerated nano-cellulose mixed membrane with distilled water at the temperature of 40-60 ℃, then drying in a drying zone at the drying temperature of 60-90 ℃, and winding into a barrel after drying to obtain a regenerated nano-cellulose mixed membrane finished product.

Further, the draft ratio of the draft roller in the present invention is-12% to 12%.

Further, the coagulating bath consists of methyl morpholine and distilled water, the temperature is 0-40 ℃, the proportion of the methyl morpholine in the coagulating bath is 0-20%, and the proportion of the distilled water is 80-100%.

Furthermore, the solvent methylmorpholine hydrate is selected from commercially available methylmorpholine hydrates with water content of about 50%.

Further, the mixed dissolving pulp is formed by combining 1-99% of cotton dissolving pulp, 1-99% of wood dissolving pulp and 1-99% of bamboo dissolving pulp in a weight ratio, wherein the ratio of the added nano-cellulose is 0.1-2% of the mass fraction of the mixed dissolving pulp.

As a further technical index of the regenerated nano-cellulose mixed membrane of the present invention, it includes: the thickness is 20um to 600um, the difference between thickness webs is less than or equal to 1.5um, the MD tensile strength is greater than or equal to 30N/15mm, and the MD elongation is greater than or equal to 11%.

Further, the cotton pulp, wood pulp and bamboo pulp used in the present invention have the following indexes:

wherein S10 and S18 represent solubility, and R10 and R18 represent basicity resistance.

As a further step, the present invention is widely used in the following industries:

1. food packaging material: such as casings, cigarette films, everyday food contact bags, microwave oven heating bags, and the like.

2. Forestry machinery and carpenter's equipment: such as plant root wrapping, agricultural films.

3. Medical use: such as artificial kidney dialysis membrane, sustained-release capsule, etc.

4. Separation membrane: such as a seawater desalination permeable membrane, and can also be used for large-scale desulfurization and deodorization in the field of oil refining.

The beneficial effect of this embodiment does:

in this embodiment, a new method for producing a high-strength regenerated nano-cellulose mixed film using methylmorpholine hydrate (NMMO) as a solvent is used, which optimizes appearance, strength and performance and solves the problems of fibrillation, high defects, unstable product quality and the like of the original cellulose film produced by the NMMO method.

The present invention has been illustrated by the above embodiments, but it should be understood that the above embodiments are for illustrative and descriptive purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications may be made in accordance with the teachings of the present invention, which variations and modifications are within the scope of the present invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.