阅读说明：本技术 洞库用高模量快速修复加固材料 (High-modulus rapid repairing and reinforcing material for cave depot ) 是由 高树峰 于 2021-08-26 设计创作，主要内容包括：本发明属于无溶剂聚氨酯类喷涂材料技术领域,具体涉及洞库用高模量快速修复加固材料。该材料由A、B两种组分按体积比1:1.5混合制备而成：以质量计算,A组分的制备原料包括90～100％的异氰酸酯,0～10％的聚醚多元醇和蓖麻油中的一种或两种；A组分中的NCO含量为26.7-32％；聚醚多元醇的分子量为1000-2000、官能度为2；以质量计算,B组分的制备原料包括14.5～44.5％的官能度为3的多元醇或官能度为4的多元醇或两者的混合物,5～10％的扩链剂,35～50％的玻璃纤维粉或硅灰石粉中的一种或两种,0.3～0.6％的催化剂CUCAT-HA01,0.3～0.5％的硅烷偶联剂,10～20％的潜伏固化剂,0.2～0.4％的水解促进剂。本发明的材料用于潮湿基材的快速修复,材料固化速度快,固化后即可投入应用。(The invention belongs to the technical field of solvent-free polyurethane spraying materials, and particularly relates to a high-modulus rapid repairing and reinforcing material for a cave depot. The material is prepared by mixing A, B two components according to the volume ratio of 1: 1.5: the component A is prepared from 90-100% of isocyanate, 0-10% of one or two of polyether polyol and castor oil by mass; the NCO content in the component A is 26.7-32%; the polyether polyol has a molecular weight of 1000-2000 and a functionality of 2; the component B is prepared from 14.5-44.5% of polyol with the functionality of 3 or polyol with the functionality of 4 or a mixture of the two, 5-10% of chain extender, 35-50% of one or two of glass fiber powder or wollastonite powder, 0.3-0.6% of catalyst CUCAT-HA01, 0.3-0.5% of silane coupling agent, 10-20% of latent curing agent and 0.2-0.4% of hydrolysis accelerator by mass. The material of the invention is used for rapid repair of wet base materials, has rapid curing speed, and can be put into application after being cured.)

1. The high-modulus rapid repairing and reinforcing material for the cavern is characterized by being prepared by mixing A, B two components according to a volume ratio of 1: 1.5: the component A is prepared from 90-100% of isocyanate, 0-10% of one or two of polyether polyol and castor oil by mass percentage; the NCO content in the component A is 26.7-32%; the polyether polyol has a molecular weight of 1000-2000 and a functionality of 2;

calculated by mass percentage, the preparation raw materials of the component B comprise 14.5-44.5% of polyhydric alcohol with 3 functionality or 4 functionality or a mixture of the two, 5-10% of chain extender, 35-50% of one or two of glass fiber powder or wollastonite powder, 0.3-0.6% of catalyst CUCAT-HA01, 0.3-0.5% of silane coupling agent, 10-20% of latent curing agent and 0.2-0.4% of hydrolysis accelerator; wherein the glass fiber powder or the wollastonite powder is modified by a silane coupling agent, and the polyol comprises one or more than two of polyol TAE-305, TAE-285, polyester polyol Desmophen1150, hydrophobic polyol and castor oil modified hydrophobic polyol.

2. The high-modulus rapid repair reinforcement material for caverns, according to claim 1, wherein the isocyanate in the A component comprises one or more of methylene polyphenyl polyisocyanate, carbodiimide modified isocyanate, 2,4 '-diisocyanate diphenylmethane, and 4, 4' -diisocyanate diphenylmethane.

3. The high modulus rapid repair reinforcement material for caverns as recited in claim 1, wherein the polyether polyol in the A component comprises one or more than two of molecular weight 1000-.

4. The high modulus rapid repair reinforcement material for caverns of claim 1, wherein the chain extender in the B component comprises 2, 6-diethylaminotoluene, diethyltoluenediamine, and dimethylthiotoluenediamine.

5. The high modulus rapid repair reinforcement material for caverns of claim 1, wherein the silane coupling agent in the B component comprises one of SI69 and KH 560; the glass fiber powder or the wollastonite powder is needle-shaped, and the length-diameter ratio is 10: 1-15: 1.

6. The high modulus rapid repair reinforcement material for caverns of claim 1, wherein the latent curing agent in the B component comprises one of JH338, JH326 and JH306, and the hydrolysis promoter comprises salicylic acid.

7. The high modulus rapid repair reinforcement material for caverns according to claim 2, wherein when the raw material for preparing the component A comprises one or both of polyether polyol and castor oil, the preparation process comprises the following steps: one or two of polyether polyol and castor oil are taken according to the weight ratio and put in a reaction kettle, the pressure reduction and dehydration are carried out at the temperature of 100-120 ℃, the temperature is reduced to 60 ℃, then isocyanate is slowly added, the temperature is slowly increased to 70 ℃ after the reaction is carried out for 30min, the heat preservation is carried out for 2 hours, directly or after another isocyanate is added, the free NCO content is sampled and tested to reach the standard, and then the temperature is reduced, filtered and discharged.

8. The high modulus rapid repair reinforcement material for cave depot according to claim 1, wherein the modification process comprises the following steps: baking and dehydrating glass fiber powder or wollastonite powder at 110-120 ℃, then spraying a silane coupling agent on the glass fiber powder or the wollastonite powder, stirring at a high speed for dispersing, stirring uniformly, and then baking and drying at 120 ℃.

9. The high modulus rapid repair reinforcement material for cave depot according to claim 8, wherein the preparation process of the component B specifically comprises the following steps: the raw materials are taken according to the weight ratio, put into a stirring tank, stirred at a high speed and dispersed evenly, and filtered by a 80-mesh filter screen for discharging.

10. The high-modulus rapid-repairing reinforcing material for the cavern as claimed in claim 1, wherein the A, B components are mixed before use, and the temperature is kept at 50-65 ℃, the mixing temperature of the A component is 65-70 ℃, and the mixing temperature of the B component is 70 ℃.

Technical Field

The invention belongs to the technical field of solvent-free polyurethane spraying materials, and particularly relates to a high-modulus rapid repairing and reinforcing material for a cave depot.

Background

As the military cave depot is excavated in the mountain and a plurality of cave depots are tightly connected with the ocean at the same time, the cave depot is wet throughout the year, the requirement of the on-site environment on materials is high, and the cave depot has good corrosion resistance and needs to prevent water seepage.

The equipment facilities in the cave depot are very expensive, so the cave depot base material can not fall off or fall off to prevent the equipment from being damaged by crashing, and particularly, the base material can be firm to protect the personal safety and the equipment facilities safety when the earthquake and the impact happen.

And the field environment is moist, the base material is hardly likely to dry, so the selection of the material is more rigorous, and the material must be constructed on a moist base surface without falling off and swelling.

When the construction is carried out in the cave depot, the environment is closed, the requirement on the environmental protection of the used materials is high, and the construction method cannot contain restrictive toxic substances such as solvents and the like. Meanwhile, the construction efficiency is also higher, the construction needs to be carried out quickly, the application is put into practice quickly, and the construction efficiency is high and is urgent particularly in special periods.

However, most of the existing materials cannot meet the requirements at the same time, and the traditional waterproof material has no or weak reinforcing effect and weak corrosion resistance; most materials such as polyurea waterproof paint, polyurethane spraying anticorrosive material, epoxy glass fiber reinforced plastic and the like have high requirements on base materials, the base materials must be dried, the water content is required to be lower than 7 percent, otherwise, the base materials are bulged and fall off without binding force, and the actual environment of the cave depot site hardly meets the requirement of low water content; the anticorrosive coatings contain solvents, are not environment-friendly and cannot be constructed on site, even if the anticorrosive coatings are water-based materials, the anticorrosive coatings can reach enough thickness only by being brushed or sprayed for more than dozens of times, so that the anticorrosive coatings play a role in reinforcement, and a lot of anticorrosive coatings can crack even if being brushed thick, and are obviously not suitable for use; and the high-strength cement mortar materials have insufficient toughness, have unobvious anti-seismic effect and particularly need long-time maintenance, so that the application requirements can not be met frequently.

Disclosure of Invention

According to the defects in the prior art and in combination with the current research frontier, the invention provides the high-modulus quick repair reinforcement material for the cave depot, solves the problem that the existing wet substrate has more complex requirements on the performance of the coating, and is used for high-modulus quick repair of the cave depot wall substrate.

The invention is realized by adopting the following technical scheme:

the invention provides a high-modulus rapid repairing and reinforcing material for a cave depot, which is prepared by mixing A, B two components according to the volume ratio of 1: 1.5: the component A is prepared from 90-100% of isocyanate, 0-10% of one or two of polyether polyol and castor oil by mass; the NCO content in the component A is 26.7-32%; the polyether polyol has a molecular weight of 1000-2000 and a functionality of 2;

the component B is prepared from 14.5-44.5% of polyol with functionality of 3 or polyol with functionality of 4 or a mixture of the two, 5-10% of chain extender, 35-50% of one or two of glass fiber powder or wollastonite powder, 0.3-0.6% of catalyst CUCAT-HA01, 0.3-0.5% of silane coupling agent, 10-20% of latent curing agent and 0.2-0.4% of hydrolysis accelerator by mass; wherein the glass fiber powder or the wollastonite powder is modified by a silane coupling agent, and the polyol comprises one or more than two of polyol TAE-305, TAE-285, polyester polyol Desmophen1150, hydrophobic polyol and castor oil modified hydrophobic polyol.

Further, the isocyanate in the component A comprises one or more than two of methylene polyphenyl polyisocyanate, carbonized diimine modified isocyanate, 2,4 '-diisocyanate diphenylmethane and 4, 4' -diisocyanate diphenylmethane.

Further, the polyether polyol in the A component comprises one or more than two of molecular weight of 1000-2000-.

Further, the chain extender in the component B comprises diethyl toluene diamine, 2, 6-diethylamino toluene, diethyl toluene diamine and dimethyl sulfur toluene diamine.

Further, the silane coupling agent in the component B comprises one of SI69 and KH 560; the glass fiber powder or the wollastonite powder is needle-shaped, and the length-diameter ratio is 10: 1-15: 1. The length-diameter ratio of the glass fiber powder or the wollastonite powder is too small, so that the reinforcing effect is weak; if the aspect ratio is too large, spraying may be difficult.

Further, the latent curing agent in the component B comprises one of JH338, JH326 and JH306, and the hydrolysis promoter comprises salicylic acid. The latent curing agent can reduce the performance influence of water on the polyurethane material and avoid bulging, foaming and the like.

As a preferred technical scheme of the invention, when the preparation raw material of the component A comprises one or two of polyether polyol and castor oil, the preparation process specifically comprises the following steps: one or two of polyether polyol and castor oil are taken according to the weight ratio and put in a reaction kettle, the pressure reduction and dehydration are carried out at the temperature of 100-120 ℃, the temperature is reduced to 60 ℃, then isocyanate is slowly added, the temperature is slowly increased to 70 ℃ after the reaction is carried out for 30min, the heat preservation is carried out for 2 hours, directly or after another isocyanate is added, the free NCO content is sampled and tested to reach the standard, and then the temperature is reduced, filtered and discharged.

As a preferred technical scheme of the invention, the modification process specifically comprises the following steps: baking and dehydrating glass fiber powder or wollastonite powder at 110-120 ℃, then spraying a silane coupling agent on the glass fiber powder or the wollastonite powder, stirring at a high speed for dispersing, stirring uniformly, and then baking and drying at 120 ℃.

As a preferred technical scheme of the invention, the preparation process of the component B specifically comprises the following steps: the raw materials are taken according to the weight ratio, put into a stirring tank, stirred at a high speed and dispersed evenly, and filtered by a 80-mesh filter screen for discharging.

Further, the A, B components are mixed before use, the temperature is kept at 50-65 ℃, the mixing temperature of the A component is 65-70 ℃, and the mixing temperature of the B component is 70 ℃.

The wet base material that can be used in the material of the present invention is a base material having a water content of 7% or more and 20% or less, and the base material must not contain open water.

Compared with the prior art, the invention has the beneficial effects that:

the material of the invention has extremely high bending elastic modulus which reaches above 4500MPa, and simultaneously, the compression strength and the bending strength are multiple times of those of cement, so that the material is not easy to shake and fall off. The hydrophobic polyol is selected, so that the tolerance of the material to the moisture of the base material is greatly improved, the latent curing agent is used, the applicability to a wet base material is improved again, the used catalyst is a special catalyst insensitive to water, the influence of water on the material performance is further reduced, and the high hardness and the extremely high modulus of the material can ensure good bonding force with the base material and cannot bulge or fall off, so that the base material has good reinforcing, strengthening and structure supporting effects on the cave depot base material. The material of the invention has no solvent, is environment-friendly and nontoxic, has high curing speed, can be cured within a few minutes, and can be put into application after being cured.

Detailed Description

The present invention will be described in further detail in order to make the object and technical solution of the present invention more apparent. The experimental methods described in the following examples are all conventional methods unless otherwise specified; the specific techniques or conditions are not indicated in the examples, and the techniques or conditions are described in the literature in the field or according to the product specification; the reagents and materials are commercially available, unless otherwise specified.

1. Reagents and materials

Isocyanate: methylene polyphenyl polyisocyanate (PAPI), carbodiimide modified isocyanate (LMDI), MDI50 (50% each of a mixture of 2,4 ' -diisocyanate diphenylmethane and 4,4 ' -diisocyanate diphenylmethane), 4 ' -diisocyanate diphenylmethane (MDI 100).

Polyol: TAE-305 and TAE-285, available from Tianjin petrochemical third petrochemical plant.

Hydrophobic polyol:750 (epoxidized C18-polymer of methyl ester of unsaturated fatty acids and trihydroxypropane) was purchased from BASF.

Polyester polyol: desmophen1150 is purchased from Bayer, Germany.

Polyether polyol: polyol TDIOL-1000 with a molecular weight of 1000 and polyol TDIOL2000 with a molecular weight of 2000 were used and purchased from the third petrochemical plant of Tianjin petrochemical industry.

Castor oil modified hydrophobic polyol M365 was purchased from Vertellus.

Castor oil: refined castor oil.

Chain extender: 2, 6-diethylaminotoluene (E200) was purchased from Henan Rabairi New materials science and technology, Inc.; diethyltoluenediamine (DETDA), dimethylthiotoluenediamine (E300).

Catalyst: CUCAT-HA01 was purchased from Guangzhou Yougun synthetic materials, Inc.

Silane coupling agent: SI69, KH 560.

Latent curing agent: JH338, JH326, JH306 are available from Jun and Shanghai chemical Co., Ltd.

Hydrolysis accelerator: salicylic acid.

The glass fiber powder and the wollastonite powder are needle-shaped, and the length-diameter ratio is 10: 1-15: 1.

2. Spray coating operation

A. Fixing a barrel heating belt outside the storage barrel of the component B, heating A, B components in the barrel to 50-65 ℃, and preserving heat of A, B components. The component B needs to be stirred before use.

The spraying equipment adopts a transformation ratio equipment DF-YB30/32 of polyurethane equipment Co. Temperature setting for the spray equipment: the A component is set to 65 ℃, the B component is set to 70 ℃, the pipeline temperature is set to 70 ℃, and the spraying pressure is set to 2000-.

3. Performance detection method

Tensile strength (MPa): resin casting performance test method GB/T2567;

flexural modulus of elasticity (MPa): resin casting performance test method GB/T2567;

bending strength (MPa): resin casting performance test method GB/T2567;

shore hardness (D): test method for waterproof coating of building GB/T16777-2008;

compressive strength (MPa): test method for waterproof coating of building GB/T16777-2008;

acid resistance: soaking in 50% sulfuric acid solution for 168 hr;

alkali resistance: soaking in 40% NaOH solution for 168 h;

water impermeability: soaking in water under 0.4MPa water pressure for 2 hr;

wet substrate binding (MPa): the adhesive force is tested by adopting a drawing method, and the test is carried out according to a method A in chapter 7 in the Standard test method for waterproof building coatings GB/T16777-2008.

Example 1

Preparation of component A:

taking 10 parts by weight of refined castor oil, putting the refined castor oil into a reaction kettle, dehydrating the refined castor oil for 1 hour at 100-120 ℃ under reduced pressure, then cooling the refined castor oil to 60 ℃, slowly adding 90 parts of PAPI, reacting for half an hour, slowly heating the refined castor oil to 70 ℃, preserving the heat for 2 hours, sampling and testing the refined castor oil, cooling the refined castor oil, filtering and discharging the refined castor oil when the free NCO content reaches 26.7%.

Preparation of the component B:

the length-diameter ratio is 10: baking the glass fiber powder of 1 at the temperature of 110-120 ℃ for dehydration for 2 hours, then spraying KH560 on the glass fiber powder, stirring at a high speed and dispersing at the rotating speed of 3000r/min for 20-30 minutes, and then baking at the temperature of 120 ℃ for 2 hours for later use.

5 weight percent of chain extender E300, 25 weight percent of 4-functionality hydrophobic polyalcohol Vertellus M365, 14 weight percent of Desmophen1150, 10 weight percent of latent curing JH338, 0.2 weight percent of hydrolysis accelerator salicylic acid, 0.5 weight percent of catalyst CUCAT-HA01 and 45.3 weight percent of KH560 modified glass fiber powder are put into a stirring tank to be stirred and dispersed uniformly at a high speed, the rotating speed is more than 1500r/min, the stirring is carried out for 1 hour, and the materials are filtered and discharged by a 80-mesh filter screen.

The raw material parameters are shown in Table 1, and the performance parameters are shown in Table 2.

TABLE 1 example 1 feed parameters

TABLE 2 Performance parameters Performance of example 1

Example 2

The component A is directly selected from PAPI, and NCO percent is approximately equal to 31.

Preparation of the component B:

the length-diameter ratio is 15: baking and dehydrating the wollastonite powder 1 at the temperature of 110-120 ℃ for 2 hours, then spraying KH560 on the wollastonite powder, stirring at a high speed and dispersing at the rotating speed of 3000r/min for 20-30 minutes, and then baking at the temperature of 120 ℃ for 2 hours for later use.

8 weight percent of chain extender E200, 8 weight percent of 4-functionality hydrophobic polyol Vertellus M365 and 21 weight percent of750 percent of TAE285, 10 percent of latent curing agent JH306, 0.2 percent of hydrolysis accelerator salicylic acid, 0.5 percent of catalyst CUCAT-HA01 and 48.3 percent of KH560 modified wollastonite powder are put into a stirring tank, stirred at high speed and uniformly dispersed, the rotating speed is more than 1500r/min, the stirring is carried out for 1 hour, and the materials are filtered and discharged by a 80-mesh filter screen.

The raw material parameters are shown in Table 3, and the performance parameters are shown in Table 4.

TABLE 3 example 2 feed parameters

TABLE 4 Performance parameters Performance of example 2

Example 3

Preparation of component A:

taking 3 parts by weight of polyether polyol TDIOL2000 with molecular weight of 2000, putting the polyether polyol TDIOL2000 into a reaction kettle, decompressing and dehydrating for 1 hour at 100-120 ℃, then cooling to 60 ℃, then slowly adding 12 parts of LMDI, slowly heating to 70 ℃ after reacting for half an hour, keeping the temperature for 2 hours, then adding 85 parts of PAPI, sampling and testing when the content of free NCO reaches 29.8%, cooling, filtering and discharging.

Preparation of the component B:

the length-diameter ratio is 10: the glass fiber powder of 1 is baked and dehydrated for 2 hours at the temperature of 110-120 ℃, then SI69 is sprayed on the glass fiber powder, stirred and dispersed at high speed, the rotating speed is 3000r/min, stirred for 20-30 minutes, and then baked for 2 hours at the temperature of 120 ℃ for standby.

5 weight percent of chain extender E100, 10.5 weight percent of 4-functionality hydrophobic polyhydric alcohol Vertellus M365, 14.2 weight percent of TAE305, 17.3 weight percent of Desmophen1150, 12 weight percent of latent curing agent JH338, 0.2 weight percent of salicylic acid hydrolysis promoter, 0.5 weight percent of catalyst CUCAT-HA01 and 40.3 weight percent of SI69 modified glass fiber powder are put into a stirring tank, stirred at high speed and dispersed evenly at the rotating speed of more than 1500r/min for 1 hour, and filtered by a 80-mesh filter screen to discharge.

The raw material parameters are shown in Table 5, and the performance parameters are shown in Table 6.

TABLE 5 example 3 feed parameters

TABLE 6 Performance parameters Performance of example 3

Example 4

Preparation of component A:

taking 2 parts by weight of polyether polyol TDIOL1000 with the molecular weight of 1000, putting the polyether polyol TDIOL1000 into a reaction kettle, dehydrating the mixture for 1 hour at the temperature of 100-120 ℃ under reduced pressure, then cooling the dehydrated mixture to 60 ℃, then slowly adding 8 parts of MDI50, slowly heating the reacted mixture to 70 ℃ after half an hour, keeping the temperature for 2 hours, then adding 90 parts of PAPI, and cooling, filtering and discharging the product when the content of free NCO reaches 30.5% by sampling test.

Preparation of the component B:

respectively enabling the length-diameter ratio to be 15: baking and dehydrating the glass fiber powder and the wollastonite powder of 1 at the temperature of 110-120 ℃ for 2 hours, then respectively spraying KH560 on the glass fiber powder and the wollastonite powder, stirring and dispersing at a high speed at a rotating speed of 3000r/min for 20-30 minutes, and then baking at the temperature of 120 ℃ for 2 hours for later use.

2 weight percent of chain extender E200, 4 weight percent of chain extender E300 and 26.9 weight percent of chain extender E750 percent, 5.9 percent of Desmophen1150, 10 percent of latent curing agent JH326, 0.3 percent of salicylic acid hydrolysis accelerator, 0.4 percent of catalyst CUCAT-HA01, 50.5 percent of KH560 modified glass fiber powder and wollastonite powder are put into a stirring tank, stirred at high speed and dispersed uniformly, the rotating speed is more than 1500r/min, stirred for 1 hour, filtered by a 80-mesh filter screen and discharged.

The raw material parameters are shown in Table 7, and the performance parameters are shown in Table 8.

TABLE 7 example 4 feed parameters

TABLE 8 Performance parameters Performance of example 4

Example 5

Preparation of component A:

taking 4 parts by weight of polyether polyol TDIOL2000 with molecular weight of 2000, putting the polyether polyol TDIOL2000 into a reaction kettle, decompressing and dehydrating for 1 hour at 100-120 ℃, then cooling to 60 ℃, then slowly adding 6 parts of MDI100, slowly heating to 70 ℃ after reacting for half an hour, keeping the temperature for 2 hours, then adding 90 parts of PAPI, and cooling, filtering and discharging when the content of free NCO reaches 29.8% by sampling test.

Preparation of the component B:

the length-diameter ratio is 10: baking and dehydrating the wollastonite powder 1 at the temperature of 110-120 ℃ for 2 hours, then spraying KH560 on the wollastonite powder, stirring at a high speed and dispersing at the rotating speed of 3000r/min for 20-30 minutes, and then baking at the temperature of 120 ℃ for 2 hours for later use.

10 weight percent of chain extender E300, 20 weight percent of 4-functionality hydrophobic polyhydric alcohol Vertellus M365, 5.5 weight percent of hydrophobic polyhydric alcohol Desmophen1150, 15 weight percent of latent curing agent JH306, 0.4 weight percent of salicylic acid hydrolysis accelerator, 0.6 weight percent of catalyst CUCAT-HA01, and 48.5 weight percent of KH560 modified wollastonite powder are put into a stirring tank, stirred at high speed and dispersed uniformly, the rotating speed is more than 1500r/min, stirred for 1 hour, filtered by a 80-mesh filter screen and discharged.

The raw material parameters are shown in Table 9, and the performance parameters are shown in Table 10.

TABLE 9 example 5 feed parameters

TABLE 10 Performance parameters Performance of example 5

The materials of embodiments 1-5 of the invention have good binding force with wet base materials, and common polyurea waterproof coatings and common polyurethane anticorrosive coatings in the market require that the base materials must be dried. The following comparative examples 1 and 2 are the formulation and adhesion tests of the common polyurea waterproof coating and the polyurethane anticorrosive coating.

Comparative example 1

The polyurea waterproof coating is sprayed by adopting the mixing and spraying method of the invention, and the bonding force is tested, and the formula of the waterproof coating is shown in Table 11.

TABLE 11 comparative example 1 raw material parameters

The binding force (the water content is 9%) with a wet base material is less than or equal to 0.7MPa, and the bag is bulged.

And the binding force (the water content is 18%) with a wet base material, and almost no binding force, swelling and falling are generated.

Comparative example 2

By adopting the mixing and spraying method of the invention, the polyurethane anticorrosive paint is sprayed, the binding force is tested, and the formula of the waterproof paint is shown in table 12.

TABLE 12 feed parameters for comparative example 2

The binding force (the water content is 9%) with a wet base material is less than or equal to 0.7MPa, and the bag is bulged.

And the binding force (the water content is 18%) with a wet base material, and almost no binding force, swelling and falling are generated.

It should be understood that the above description is only a preferred embodiment of the present invention, and not intended to limit the present invention, and although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications and equivalents may be made in the technical solutions described in the foregoing embodiments, or some technical features may be substituted. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.