阅读说明：本技术 一种楠竹制浆工艺 (Phyllostachys pubescens pulping process ) 是由 洪嘉远 史梦华 董超 朱宏伟 刘永丰 邓凤伟 林本平 于 2021-08-06 设计创作，主要内容包括：本发明公开了一种楠竹制浆工艺,包括以下制备步骤：步骤A：取楠竹进行筛选、削片,得到竹片；步骤B：洗涤；步骤C：洗涤后的竹片通过喂料螺旋进入蒸煮管,所述喂料螺旋的出口和所述蒸煮管的入口用T型管连接,所述T型管用于加蒸汽和药液,所述蒸煮管的数量为至少3根,至少3根所述蒸煮管依次连接,每根所述连蒸管设有至少7个蒸汽孔本发明提供的楠竹制浆工艺,制浆工艺温和,能保留部分木素,减少纤维素和半纤维素的溶出,进而提高制浆得率,提高资源的利用率。(The invention discloses a phyllostachys pubescens pulping process, which comprises the following preparation steps: step A: selecting phyllostachys pubescens, and slicing to obtain bamboo chips; and B: washing; and C: the phyllostachys pubescens pulping process is mild, can retain part of lignin, reduces dissolution of cellulose and hemicellulose, further improves pulping yield, and improves utilization rate of resources.)

1. The phyllostachys pubescens pulping process is characterized by comprising the following preparation steps:

step A: selecting phyllostachys pubescens, and slicing to obtain bamboo chips;

and B: washing the bamboo chips obtained in the step A;

and C: the washed bamboo chips enter a cooking pipe through a feeding screw, an outlet of the feeding screw is connected with an inlet of the cooking pipe through a T-shaped pipe, the T-shaped pipe is used for adding steam and liquid medicine, the number of the cooking pipes is at least 3, the cooking pipes are sequentially connected at least 3, and each continuous cooking pipe is provided with at least 7 steam holes.

2. The phyllostachys pubescens pulping process according to claim 1, wherein the qualification rate of the bamboo chips obtained by screening and chipping in the step A is not less than 70%, and the water content is 20-50%.

3. The phyllostachys pubescens pulping process of claim 1, wherein the liquor added in step C comprises sodium hydroxide and sodium sulfide.

4. The phyllostachys pubescens pulping process according to claim 1, wherein in the step C, the ratio of the liquor added into the continuous steaming pipe to the oven-dried wood chips is 1: 2.5.

5. the phyllostachys pubescens pulping process according to claim 3, wherein in the step C, the sodium hydroxide used in the cooking accounts for 20% of the weight of the oven-dried wood chips, and the degree of vulcanization is 15%.

6. The phyllostachys pubescens pulping process of claim 1, wherein the pressure of the steam connecting pipe ranges from 0.2 to 0.25MP, and the retention time of the bamboo chips in the steam boiling pipe ranges from 20 to 50 minutes.

7. The phyllostachys pubescens pulping process according to claim 1, further comprising the steps of:

step D: extruding the steamed bamboo chips into filiform bamboo chips by a filament drawing machine;

step E: feeding the filiform bamboo chips to a high-concentration mill for grinding to obtain pulp;

step F: e, feeding the pulp processed in the step E to a low-concentration mill for grinding;

step G: and F, feeding the pulp processed in the step F into a pressure screen, feeding the good pulp of the pressure screen to a pulp storage tower through a pulp washer, and feeding the residue pulp of the pressure screen into a residue pulp mill.

8. The phyllostachys pubescens pulping process according to claim 7, wherein in the step G, the screen gap of the pressure screen is 0.25mm, the pulp inlet pressure is 3.0-7.0 kPa, the pressure difference between the pulp inlet and the pulp outlet is 20-30 kPa, the flow ratio of the residue pulp to the good pulp is 20-30%, and the operation load is controlled to be 40-60%.

9. The phyllostachys pubescens pulping process according to claim 7, further comprising a step H after the step G: and feeding the slurry ground by the slurry mill into a second-stage pressure screen, conveying the good slurry of the second-stage pressure screen to a slurry storage tower through a slurry washer, and returning the slurry ground by the slurry mill to be ground again after the slurry of the second-stage pressure screen passes through a slag remover.

Technical Field

The invention relates to the technical field of pulping, in particular to a phyllostachys pubescens pulping process.

Background

China is the world with the most abundant bamboo resources, and bamboo species, bamboo forest area and storage amount all occupy the world. Compared with wood, the bamboo wood has the advantages that the bamboo wood grows faster, can be maturely harvested in 3-4 years, can be naturally regenerated after being harvested, does not need seedling culture, and is simpler to nurse compared with the wood. The bamboo fiber has the characteristics between those of coniferous wood and broadleaf wood, and is an excellent raw material for papermaking. The pulping and bleaching process of the bamboo sulfate method is mature and perfect, and the bamboo pulp produced by the chemical method is rapidly developed along with the enforcement of the ban policy of imported waste paper and the gradual increase of the price of domestic commodity pulp, and the production scale and the yield of the bamboo pulp are rapidly increased. Bamboo pulping and paper making enterprises in China mainly concentrate on Sichuan and Guizhou areas, and the annual capacity of bamboo pulp in China is about 200 ten thousand tons. The Hunan bamboos are rich in variety, the variety of the bamboos in the whole province reaches 19 and 136, the variety of the bamboos accounts for about one third of the whole country, and the variety of the bamboos comprises phyllostachys pubescens (phyllostachys pubescens), phyllostachys pubescens (phyllostachys pubescens), phyllostachys guianensis, phyllostachys pubescens, and phyllostachys indica and the like, and the phyllostachys pubescens (phyllostachys pubescens) are main bamboo varieties and account for 98% of the total resource.

The phyllostachys pubescens is large in quantity, but is difficult to be used as a pulping raw material, because the average distribution density of the vascular bundles, the area of a single vascular bundle and the tissue ratio of a fiber sheath are not as good as those of sympodial bamboos such as Sagittaria sagittifolia, dendrocalamus latiflorus, cotton bambusoides, water bamboos and the like, the pulping yield is low, the fine pulp yield is 37-42%, the fine pulp yield of most varieties of sympodial bamboos is more than 48%, and therefore, the technical problem to be solved in the field is how to improve the pulping yield of the phyllostachys pubescens.

Disclosure of Invention

In order to solve the technical problems, the phyllostachys pubescens pulping process provided by the invention is mild, can retain part of lignin, reduces the dissolution of cellulose and hemicellulose, further improves the pulping yield and improves the utilization rate of resources.

The phyllostachys pubescens pulping process is characterized by comprising the following preparation steps:

step A: selecting phyllostachys pubescens, and slicing to obtain bamboo chips;

and B: washing the bamboo chips obtained in the step A;

and C: the washed bamboo chips enter a cooking pipe through a feeding screw, an outlet of the feeding screw is connected with an inlet of the cooking pipe through a T-shaped pipe, the T-shaped pipe is used for adding steam and liquid medicine, the number of the cooking pipes is at least 3, the cooking pipes are sequentially connected at least 3, and each continuous cooking pipe is provided with at least 7 steam holes.

In the phyllostachys pubescens pulping process, the qualified rate of the bamboo chips obtained by screening and chipping in the step A is preferably not less than 70%, and the water content is 20-50%.

In the phyllostachys pubescens pulping process, preferably, the liquor added in the step C includes sodium hydroxide and sodium sulfide.

In the phyllostachys pubescens pulping process, preferably, in the step C, the ratio of the liquor added into the continuous steaming pipe to the oven-dried wood chips is 1: 2.5.

in the phyllostachys pubescens pulping process, preferably, in the step C, the amount of sodium hydroxide used in the cooking is 20% of the weight of the oven-dried wood chips, and the degree of vulcanization is 15%.

In the phyllostachys pubescens pulping process, the pressure range of the continuous cooking pipe is preferably 0.2-0.25 MP, and the retention time of the bamboo chips in the cooking pipe is preferably 20-50 minutes.

The phyllostachys pubescens pulping process preferably further comprises the following steps:

step D: extruding the steamed bamboo chips into filiform bamboo chips by a filament drawing machine;

step E: feeding the filiform bamboo chips to a high-concentration mill for grinding to obtain pulp;

step F: e, feeding the pulp processed in the step E to a low-concentration mill for grinding;

step G: and F, feeding the pulp processed in the step F into a pressure screen, feeding the good pulp of the pressure screen to a pulp storage tower through a pulp washer, and feeding the residue pulp of the pressure screen into a residue pulp mill.

In the phyllostachys pubescens pulping process, preferably, in the step G, the sieve gap of the pressure sieve is 0.25mm, the pulp inlet pressure is 3.0-7.0 kPa, the pressure difference between the pulp inlet and the pulp outlet is 20-30 kPa, the flow ratio of the residue pulp to the good pulp is 20-30%, and the operation load is controlled to be 40-60%.

In the phyllostachys pubescens pulping process, preferably, the step G is followed by a step H of: and feeding the slurry ground by the slurry mill into a second-stage pressure screen, conveying the good slurry of the second-stage pressure screen to a slurry storage tower through a slurry washer, and returning the slurry ground by the slurry mill to be ground again after the slurry of the second-stage pressure screen passes through a slag remover.

The invention has the beneficial effects that: the phyllostachys pubescens pulping process provided by the invention uses a mild cooking process, and by using the T-shaped pipe added with steam and liquid medicine in the cooking stage and simultaneously using at least 3 cooking pipes connected in sequence, and each continuous cooking pipe is provided with at least 7 steam holes, the constraint of the traditional acid salt pulping process is broken, the pulping is mild, the toughness of bamboo chips is enhanced, the bamboo chips are prevented from being powdery, a large amount of lignin is prevented from being removed in the cooking stage, the dissolution of cellulose and hemicellulose in the cooking stage is reduced, and the pulping yield is further improved.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments.

All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The phyllostachys pubescens pulping process provided by the embodiment of the invention comprises the following preparation steps:

step A: selecting phyllostachys pubescens, and slicing to obtain bamboo chips;

and B: washing the bamboo chips obtained in the step A;

and C: the washed bamboo chips enter the cooking pipes through the feeding screws, the outlets of the feeding screws are connected with the inlets of the cooking pipes through T-shaped pipes, the T-shaped pipes are used for adding steam and liquid medicine, the number of the cooking pipes is at least 3, at least 3 cooking pipes are sequentially connected, and each continuous cooking pipe is provided with at least 7 steam holes;

wherein, add steam and liquid medicine simultaneously with different pipes from the top of T type pipe, the feed screw presses into the pie with the bamboo chip, and the bamboo chip that is pressed into the pie is washed away by steam and liquid medicine when falling into the cooking pipe from the feed screw export, more helps the bamboo chip to rise warm and absorb the liquid medicine.

In the prior art, although the phyllostachys pubescens is large in quantity and rich in resources, the phyllostachys pubescens is difficult to be used as a pulping raw material, because the average distribution density of the vascular bundles, the area of a single vascular bundle and the tissue ratio of a fiber sheath are not as good as those of sympodial bamboos such as Sagittaria sagittifolia, dendrocalamus latiflorus, cotton bamboos, water bamboos and the like, the pulping yield is very low, the fine pulp yield is 37-42%, and the fine pulp yield of most varieties of the sympodial bamboos is lower than 48%.

The phyllostachys pubescens pulping process provided by the embodiment of the invention uses a mild cooking process, and uses the T-shaped pipe added with steam and liquid medicine in the cooking stage, and simultaneously uses at least 3 cooking pipes connected in sequence, and each continuous cooking pipe is provided with at least 7 steam holes, so that the constraint of the traditional acid salt pulping process is broken, the pulping is mild, a large amount of lignin is prevented from being removed in the cooking stage, the dissolution of cellulose and hemicellulose in the cooking stage is reduced, and the pulping yield is further improved. Meanwhile, the bamboo chips can be made to have higher toughness by mild cooking, and the bamboo chips can be prevented from being pressed into powder in subsequent treatment, such as a silk drawing stage.

According to the phyllostachys pubescens pulping process provided by the embodiment of the invention, preferably, the qualified rate of the bamboo chips obtained by screening and chipping in the step A is not less than 70%, and the water content is 20-50%.

In the phyllostachys pubescens pulping process provided by the embodiment of the invention, preferably, the liquid medicine added in the step C comprises sodium hydroxide and sodium sulfide.

Because the phyllostachys pubescens is easy to be dipped and softened, the fine fibers are not as good as those of softwood fibers after grinding, so the phyllostachys pubescens is pulped by using sodium hydroxide as alkali, and the phyllostachys pubescens fibers can be effectively swelled by using the sodium hydroxide, and the flexibility and the adaptability of the fibers are obviously improved.

In the phyllostachys pubescens pulping process provided by the embodiment of the present invention, preferably, in step C, the ratio of the liquor added into the continuous steaming pipe to the oven-dried wood chips is 1: 2.5.

according to the phyllostachys pubescens pulping process provided by the embodiment of the invention, preferably, in the step C, the mass of sodium hydroxide used in cooking is 20% of the mass of oven-dried wood chips, and the vulcanization degree is 15%.

According to the phyllostachys pubescens pulping process provided by the embodiment of the invention, preferably, the pressure range of the steam connecting pipe is 0.2-0.25 MP, and the retention time of bamboo chips in the steam connecting pipe is 20-50 minutes. The cooking time can be flexibly shortened or prolonged within the range according to the requirement.

The phyllostachys pubescens pulping process provided by the embodiment of the invention preferably further comprises the following steps:

step D: the steamed bamboo chips enter a filament drawing machine and are extruded into filiform bamboo chips through the filament drawing machine;

step E: feeding the filiform bamboo chips into a high-concentration mill for grinding;

step F: e, feeding the pulp processed in the step E to a low-concentration mill for grinding;

step G: and F, feeding the pulp processed in the step F into a pressure screen, feeding the good pulp of the pressure screen into a pulp storage tower through a pulp washer, and feeding the residue pulp of the pressure screen into a residue pulp mill.

Wherein, the bamboo chips can be prevented from being extruded into powder by filament drawing after mild cooking;

wherein the high-concentration mill is mainly used for grinding the bamboo chips into filaments;

wherein, the low-concentration mill grinding is mainly to ensure that the pulp meets the beating degree of the process requirement.

In the phyllostachys pubescens pulping process provided by the embodiment of the invention, preferably, in the step G, the screen gap of the pressure screen is 0.25mm, the pulp inlet pressure is 3.0-7.0 kPa, the pressure difference between the pulp inlet and the pulp outlet is 20-30 kPa, the flow ratio of the residue pulp to the good pulp is 20-30%, and the operation load is controlled to be 40-60%.

The phyllostachys pubescens pulping process provided by the embodiment of the invention preferably further comprises the following step H after the step G: the slurry ground by the slurry mill enters a second-stage pressure screen, good slurry of the second-stage pressure screen is sent to a slurry storage tower through a slurry washer, and the slurry of the second-stage pressure screen returns to the slurry mill after passing through a slag remover and is ground again.

Specific examples are provided below.

Example 1:

step A: chipping phyllostachys pubescens, sieving with a swing sieve, removing bamboo bran from the lower part, sieving out bamboo chips larger than 40mm, and pulverizing to control the length of qualified bamboo chips to 7-40 mm;

and B: b, feeding the bamboo chips prepared in the step A into a bamboo chip washing machine, enabling the washed bamboo chips to enter a cooking pipe through a metering screw and a feeding screw, adopting a continuous cooking process of three continuous cooking pipes, connecting an outlet of the feeding screw and an inlet of the continuous cooking pipe through a T-shaped pipe, adding steam and liquid medicine into the T-shaped pipe, enabling each continuous cooking pipe to be provided with 7 steam holes for cooking, raising temperature and heating so as to perform mild cooking, and taking out materials through a two-stage low-pressure discharger after the bamboo chips are cooked through the three cooking pipes;

and C: b, feeding the material prepared in the step B into a spinning machine, wherein the slurry after mild cooking is flaky and is extruded into threads through the spinning machine;

step D: c, feeding the filiform bamboo chips processed in the step C to a high-consistency mill through a feeding screw to grind;

step E: d, feeding the pulp obtained in the step D to a low-consistency mill for grinding to obtain pulp, wherein the required beating degree is 22-27;

step F: and E, feeding the pulp processed in the step E into a pressure screen system, conveying the good pulp of the pressure screen into a pulp storage tower through a pulp washer for storage and paper feeding, grinding the residue pulp of the pressure screen into a residue pulp grinder, feeding the ground pulp into a second-stage pressure screen, conveying the good pulp of the second-stage pressure screen into the pulp washer for conveying into the pulp storage tower, and returning the residue pulp to the inlet of the residue pulp grinder for re-grinding after passing through a slag remover. Wherein the whiteness of the pulp entering the pulp storage tower is controlled to be 24-27% ISO, and the dust degree is less than or equal to 800mm 2/kg;

the specific screening operation of the pressure screen is as follows: the screen gap of the pressure screen is controlled to be 0.25mm, the pulp inlet pressure is controlled to be 3.0-7.0 kPa, the pressure difference of an inlet and an outlet is controlled to be 20-30 kPa, the flow ratio of the residue pulp to the fine pulp is controlled to be 20-30%, and the operation load of the equipment is controlled to be 40-60%.

TABLE 1 quality of the finished slurry of example 1

As can be seen from Table 1, the pulping process of example 1 greatly improves the pulping yield, improves the pulping yield of the phyllostachys pubescens from 40-50% of the pulping yield of the traditional process to 82%, has good pulp performance, and meets the requirements of common packaging paper.

The phyllostachys pubescens pulping process provided by the invention is described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.