Osman Gazi Armağan, Burçak Karagüzel Kayaoğlu,
Hale Canbaz Karakaş, *Fatma Seniha Güner
Faculty of Textile Technologies and Design, Textile Engineering,
*Department of Chemical Engineering, Istanbul Technical University,
Istanbul, Turkey Corresponding author:
In this study, the adhesion strength properties of laminated polypropylene nonwoven fabrics treated with low-temperature, low-pressure, radio frequency argon plasma were investigated. The change in wettability was determined by water contact angle measurements. In order to observe the effect of plasma treatment on the washing resistance of the laminated samples, washing treatment by means of 10 wash cycles was also carried out. After the peel-off test, the remaining adhesives on the peeled surfaces were examined by SEM images in order to see the effect of plasma treatment. Contact angles of highly hydrophobic polypropylene nonwoven samples decreased by increasing the plasma exposure time and discharge power. The peel bond strength of the plasma treated laminated fabrics improved by up to 150% compared to the untreated fabrics. SEM and AFM analyses also showed that the surface roughness increased due to the etching effect of the plasma treatment, leading to the improvement of the mechanical adhesion of the polypropylene nonwoven fabrics.
Key words: plasma treatment, adhesion strength, polypropylene, nonwoven, laminated fab- ric n Introduction Polypropylene is used in a wide range
of technical and industrial applications. However, it has very low surface tension resulting in weak hydrophilic and adhesion properties . Plasma technology can be used to improve the surface characteristics of polypropylene through
surface modification [2 – 17].
Polypropylene laminated fabrics are used in the textile industry for their functional
and technical properties instead of their aesthetic and appearance features. They
are utilised mainly as automobile interior coverings, footwear interiors, edge folds
and collars to support seaming in the apparel industry .
Plasma treatments were a breakthrough in textile processing technology being
a clean and dry process that requires no water or organic solvent during processing. Plasma surface modification changes surface properties without affecting the
bulk properties of materials, and less energy is consumed compared to conventional treatments .
Plasma induced surface modification is an effective way to produce functional
textiles. Numerous studies indicated that plasma treatment improves the adhesion
characteristics of surfaces. These studies stated that the etching effect of plasma
gases caused nano- or micro-roughness, which contributes to the enhancement of
adhesion on the surfaces [20 – 25]. Yehet al.  stated that a higher amount of
the total surface might be one of the main ways to improve the adhesion strength of
There are few studies in the literature studying the effect of plasma treatment
on the peel-off behavior of laminated textile fabrics. It was found that the adhesion strength of ultra high molecular weight polyethylene (UHMWPE) laminated woven fabric increased by about 3 – 4 times compared with the untreated
one when He/O2/N2 plasma treatment is applied . In another study, the adhesion interface strength of PU and PVC coated polyester woven fabric was improved by CO2 plasma treatment .
The adhesion improvement of polyamide laminated fabric through argon and CO2
plasma treatment was also studied. It was observed that the adhesion properties of
polyamide fabrics improved with plasma induced surface roughness compared to
the untreated samples .
The main problems of laminated fabrics are low bonding strength between layers
and resistance to washing. High adhesion strength is required in order to prevent
delamination during the end-use of the laminated fabric. PP nonwoven fabrics
are commonly used in laminated textiles.
However, as the fibre surface is smooth, surface modification might be beneficial as a pretreatment before lamination to improve adhesion. Therefore in the current study, the adhesion properties of argon plasma treated polypropylene laminated nonwoven fabrics were in
vestigated. Argon plasma treatment was selected to enhance the mechanical adhesion of laminated layers. There is very limited information in the literature on
the improvement of the washing resistance of laminated fabrics through plasma
modification. The washing resistance of these products also needs to be investigated because polypropylene laminated fabrics are also used for apparel purposes
besides their use in automotive interiors, as backing materials in home textiles and
carpeting etc. Therefore this study also investigated the effect of plasma treatment on the washing resistance of these products. The peel bond strength of the
plasma treated laminated samples was observed after 10 wash cycles.
The effects of the plasma treatment on the fabric surfaces were determined
by measurements on static contact angle of water. The wettability behaviour
of a material can be determined by the contact angle values. AFM and SEM
analyses were carried out to characterise the change in surface modification and
roughness. After the peel-off test, the remaining amount of adhesives on the
peeled surfaces was compared by SEM analysis.
n Materials and method
Point-bonded polypropylene spunbonded nonwoven fabrics with a weight per unit
area of 70 g/m2 and thickness of 0.46 mm were supplied by Mogul Tekstil San. Tic.
A.S. (Turkey). Nonwoven samples with a length of 12 cm and width of 10 cm were
washed with ethanol, rinsed with distilled