Development of the most popular high strength and

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Development of a high-strength fast drying lotion adhesive for paper tubes

the adhesive used for paper tubes in China is generally white glue, which has the disadvantages of low bonding strength and slow drying speed. However, with the rapid development of chemical fiber (filament), artificial plastic film and tape in recent years, a large number of new adhesives for paper tube packaging are needed. This kind of paper tube, especially chemical fiber FDY tube, has high requirements for paper adhesive due to its fast speed. At present, the decisive factors of domestic general tube winding speed are mainly the quality of paper and adhesive. It is required that the adhesive not only has good initial adhesion and high bonding strength, but also must be dried quickly, otherwise it cannot enter the next process. In order to meet these requirements, the general practice is to increase the solid content and add some 107 glue to the paper glue to improve the initial viscosity and drying speed, but this must increase the cost of the product, and the effect is not good

therefore, we adopted the process of copolymerization before crosslinking, and modified the original white glue by adding appropriate additives to meet the requirements of good initial viscosity, high bonding strength and fast drying speed

1 keep the central point of the sample unchanged. Experimental part

1.1 raw material base glue:

the elongation of some materials such as polyvinyl alcohol (PVA), EVA lotion, acrylic acid and vinegar can be above 1000% vinyl acetate (VAC). Additives: catalyst, emulsifier, crosslinking agent, plasticizer and filler, etc

1.2 experimental method

add a certain amount of EVA lotion, PVA and emulsifier into a four neck bottle with electric stirring, reflux condenser and thermometer, mix and dissolve, then add VAC, acrylic acid and catalyst for copolymerization reaction, and control the reaction temperature in water bath. After the polymerization reaction, add crosslinking agent for crosslinking reaction. Finally, add filler and plasticizer, stir for 0.5h, and then cool. 1.3 determination of main technical indicators

solid content: evaporation residue (gravimetric method); Viscosity: measure with ndj-i rotary viscometer at a constant temperature of 25 ℃; Mft: measured with QMB minimum film forming temperature tester; PH value: measured with precision pH test paper

2 results and discussion

2.1 effect of reaction temperature

the fixed copolymerization reaction time is 5h, and the sound insulation effect can be maintained by cross-linking and reverse use of single-layer tepex material parts. The time should be 3H. The effects of different reaction temperatures on product performance are investigated. The results are shown in Table 1

the experimental results show that the reaction temperature has a great influence on the viscosity and initial viscosity of the product. Low temperature, incomplete reaction, low product viscosity and poor initial viscosity. If the temperature is too high and the polymer main chain is too soft, it will affect the viscosity. Therefore, it is appropriate to control the reaction temperature range

2.2 effect of reaction time

the fixed reaction temperature is in the range of ℃. The effects of different copolymerization reaction time (fixed crosslinking reaction time is 3H) and different crosslinking reaction time (fixed copolymerization reaction time is 5.5h) on the product properties are compared. The results are shown in Table 2 and table 3

it can be seen that the reaction time has a great influence on the viscosity and initial viscosity of the product. With the increase of reaction time, the reaction tends to be complete. Therefore, after copolymerization for 5.5h, the viscosity has changed little; After 2.5h of crosslinking reaction, the viscosity tends to be stable. Considering the needs of production operation and production capacity, the copolymerization reaction time is 5.5h and the crosslinking reaction time is 2.5h

2.3 selection of additives

the use of appropriate additives can not only reduce the cost of the product, the screen needs to display normally, improve the solid content of the product, but also improve the drying speed. However, if it is improperly selected, it will not only not improve the drying speed, but also produce precipitation, which will affect the service performance of the product. Therefore, through dozens of tests among dozens of additives, we screened several additives with good dispersion and can react with the base material, and determined their dosage (all based on the base glue)

(1) emulsifier: it plays a good role in the stability of base rubber and the dispersion effect of filler. We choose sodium dodecyl sulfate as emulsifier, the dosage is 1 5%。

(2) catalyst: composed of hydrochloric acid and ammonium persulfate, it plays the role of adjusting the pH value of the reaction system and initiating polymerization and cross-linking reactions. The dosage is 1 0%。

(3) crosslinking agent: Although medicinal starch can react with the base material under the action of catalyst, which can prevent the precipitation of filler and increase viscosity, it is easy to mildew and affect the service performance of products. For this reason, we use a small amount of titanium dioxide as a composite crosslinking agent in pharmaceutical starch, which can play a role in mold prevention. The dosage is 3 5%。

(4) plasticizer: the MFT of synthetic lotion is low, indicating that the lotion can be operated at a lower temperature; Otherwise, it must be used at a higher temperature. Otherwise, when the ambient temperature is lower than its MFT, the lotion particles cannot gather and melt into a film, and become powdery or cracked. Adding plasticizer can improve the MFT of lotion, and external plasticization is a simple and easy method. Through screening, we choose trimethylbenzene phosphate as external plasticizer, the dosage is%, and MFT is ℃

(5) filler: the purpose of filler is to improve the drying speed and solid content of products. We have selected several kinds of fillers, such as light calcium, heavy calcium, talc powder, borax, porcelain clay, clay, etc. through the test, it is found that the mixing of heavy calcium and borax can improve the drying speed and increase the hardness of the film, with the dosage of 3 5%。

3 performance index and application effect of the product

the main performance index of the product is as follows: (1) properties: uniform gray white lotion; (2) Solid content:%; (3) Viscosity: 0 38Pa. s; (4)MFT:℃; (5) PH value:; (6) Storage period: 8 months

it has been tried on the spiral paper tube machine produced by majer company in West Germany introduced by a textile equipment factory, and the effect is very ideal. The speed can reach meters per minute (FDY type) and meters per minute (DTY type), and the compressive strength of its products can reach 650n/cm and 1350n/cm respectively. The glue is also used in the production of other spiral web tubes, such as various BOPP films with high-speed winding, doy paper tubes, reels for silk carpets, etc., and the speed can reach 27 meters/minute

source: 21st century fine

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