Polyester (PET) non-woven fabric
Polyester (PET) nonwoven products have good hand feel, strength, appearance and drape, and can be used to make sanitary napkin fabrics, baby and adult diapers, wet wipes, wound dressings, sterilization wraps and other medical and sanitary products. However, PET has a regular molecular structure, high crystallinity and orientation, and does not contain hydrophilic groups, which limits the application of such nonwovens.
Experimental method
Pretreatment of PET non-woven fabric
The PET non-woven fabric was first boiled in boiling water for 1 h to remove impurities on the surface.
(1) Alkaline etching pretreatment: Weigh a certain amount of sodium hydroxide and prepare a finishing solution with a bath ratio of 1:20 and a sodium hydroxide mass concentration of 40 g/L. The PET non-woven fabric was immersed in the finishing solution at 80 ℃ for 120 min, with continuous stirring and turning. After the treatment, the fabric was taken out and washed three times with 80 ℃ hot water. Soak in 1 mL/L acetic acid solution at room temperature for 10 min, then wash repeatedly with cold water, and dry at 60 °C. (2) PDA pretreatment: Weigh a certain amount of dopamine hydrochloride powder and dissolve it in 0.01 mol/L Tris buffer solution. Use 0.1 mol/L hydrochloric acid solution to adjust the pH to about 8.5 to prepare a 2 g/L dopamine solution. Put the cleaned PET non-woven fabric into it, shake it in a 30 °C water bath for 24 h, then take it out, wash it with deionized water 4 times, and dry it at room temperature. 1.2.2 Preparation of PTL solution Prepare 0.1 mol/L Tris solution, weigh a certain amount of thiourea dioxide (TD), prepare 20 mmol/L TD solution, and adjust the pH to about 7.4 with 0.1 mol/L hydrochloric acid solution. Weigh a certain amount of lysozyme, and then use TD solution to prepare 2 g/L lysozyme solution (PTL solution).
1.2.3 PTL coating finishing of non-woven fabrics Dipping method: Place PET non-woven fabrics and pre-treated PET non-woven fabrics in PTL solution respectively, and react at 37 ℃ for 1 h; then wash the fabrics with deionized water and dry at 60 ℃. The above is recorded as 1 finishing. Repeat the finishing of PET non-woven fabrics 1 to 4 times. Use an automatic shaping dryer to bake at 140 ℃ for 1 min.
Spraying method: Use a spray gun to evenly spray 5 mL of PTL solution on the surface of PET non-woven fabrics and pre-treated PET non-woven fabrics, and dry at 60 ℃. The above is recorded as 1 finishing. Repeat the finishing of PET non-woven fabrics 1 to 4 times. Use an automatic shaping dryer to bake at 140 ℃ for 1 min.
Test method
Pretreatment of PET nonwoven fabric
The antibacterial PET nonwoven fabric was first boiled in boiling water for 1 h to remove impurities on the surface.
(1) Alkaline etching pretreatment: Weigh a certain amount of sodium hydroxide and prepare a finishing solution with a bath ratio of 1:20 and a sodium hydroxide mass concentration of 40 g/L. The PET nonwoven fabric was immersed in the finishing solution at 80 ℃ for 120 min, and was stirred continuously. After the treatment, the fabric was taken out and washed with 80 ℃ hot water for 3 times. It was immersed in 1 mL/L acetic acid solution at room temperature for 10 min, then washed repeatedly with cold water, and dried at 60 ℃.
(2) PDA pretreatment: Weigh a certain amount of dopamine hydrochloride dry powder and dissolve it in 0.01 mol/L Tris buffer solution. The pH was adjusted to about 8.5 with 0.1 mol/L hydrochloric acid solution to prepare a 2 g/L dopamine solution. Put the cleaned PET nonwoven fabric into it, shake it in a 30 ℃ water bath for 24 hours, take it out, wash it with deionized water 4 times, and dry it at room temperature.
Congo red staining
The non-woven fabric sample was soaked in 1 mg/mL Congo red solution for 1 h, then taken out, rinsed with deionized water 3 times, and then soaked in deionized water for 24 h, then taken out and dried at room temperature.
Contact angle test
Use a micro-injector to drop 5 μL of deionized water on the fabric to be tested, and use the DAS100 contact angle meter to take real-time photos and record and measure its contact angle.
Air permeability test
Refer to GB/T 5453-1997 “Textiles – Determination of air permeability of fabrics”, and use the YG461E-Ⅲ fully automatic air permeability meter for testing. Test 10 times at different parts of the sample and take the average value.
Fabric surface morphology
Use SU1510 scanning electron microscope at 5 kV voltage to observe the microscopic surface morphology of non-woven fabrics before and after finishing (magnification 1 200).
Fourier transform infrared spectroscopy analysis
The surface total reflection infrared spectroscopy of non-woven fabrics before and after finishing was detected using Nicolet i S 10 Fourier transform infrared spectrometer. The scanning range was 400~4 000 cm-1, the number of scans was 32, and the resolution was 4 cm-1.
Results and discussion
Effect of finishing method on PTL/PET non-woven fabrics
In order to increase the amount of finishing agent applied to the surface of non-woven fabrics, the fabric was treated by multiple “coating-drying” methods. The surface of the PTL coating can be covered with a new coating, and the coating thickness will increase with the number of repeated finishing. Using the unfinished PET non-woven fabric as the control sample, the samples that were repeatedly finished 1~4 times by the dipping method and the spraying method were tested for antibacterial properties.
As the number of PTL coating finishing increases, the antibacterial rate of PET non-woven fabrics also increases. PTL finishing PET nonwoven fabric has good antibacterial effect on Staphylococcus aureus. After one dipping finishing, the antibacterial rate can reach 98.82%, and after one spray finishing, the antibacterial rate can also reach 96.47%. After finishing three times, both the dipping method and the spraying method can achieve an antibacterial rate of more than 99%, and the antibacterial rate is almost unchanged when the finishing times are further increased. The antibacterial property of PET nonwoven fabric against Escherichia coli is not as good as that of Staphylococcus aureus. After three times of dipping and spray finishing, the antibacterial rates of the fabric are 83.09% and 90.77% respectively.
The antibacterial rate is not much improved by increasing the finishing times. Lysozyme mainly hydrolyzes the β-1,4-glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine on the peptidoglycan main chain in the cell wall, decomposes the insoluble mucopolysaccharide of the cell wall into soluble glycopeptides, ruptures the cell wall, dissolves the bacteria, and achieves an antibacterial effect. Compared with natural lysozyme, the arginine and lysine residues in the modified PTL amyloid coating increased significantly, and the surface showed abundant amino acid residues with net positive charge. These abundant amino groups help to improve the antibacterial ability of the PTL coating.
Other studies have pointed out that the net positively charged PTL coating surface and negatively charged bacterial cells can cause the electrostatic field of the microbial membrane to become disordered through electrostatic adsorption, causing the bacteria to stop breathing and achieve an antibacterial effect. Congo red is a dye that can specifically bind to amyloid protein. Congo red staining of samples can examine the adhesion of amyloid protein to non-woven fabrics. Under the same staining conditions, the unfinished PET non-woven control sample was almost not colored, while the samples treated with PTL coating were all dyed bright red by Congo red, indicating that amyloid protein successfully adhered to the surface of PET non-woven fabrics.
Effect of PTL coating on PET nonwovens with different pretreatments
PET nonwovens have few hydrophilic groups on their surface and are chemically inert. To compare the effects of different surfaces on PTL coating, PET nonwovens were pretreated by alkali etching and PDA, respectively, and then PTL solution was applied to the surface of PET nonwovens pretreated with alkali etching and PDA by dipping and spraying, and the treatment was repeated three times. PET nonwovens, PET nonwovens pretreated with alkali etching, and PET nonwovens pretreated with PDA were named PTL/PET, PTL/alkali etching PET, and PTL/PDA/PET after PTL treatment, and their morphology, structure, antibacterial, hydrophilic, and breathable properties were observed, characterized, and tested.
Dongguan Liansheng Non woven Technology Co., Ltd. was established in May 2020. It is a large-scale non-woven fabric production enterprise integrating research and development, production, and sales. It can produce various colors of PP spunbond non-woven fabrics with a width of less than 3.2 meters from 9 grams to 300 grams.
Pretreatment of PET nonwovens
Post time: Jun-11-2025