**2. Plasma treatment for improvement of wettability, printability, and dyeability of nonwovens**

done have been used in plasma-enhanced chemical vapor deposition processes to obtain surface coatings with different functionalities such as oleophobic, hydrophobic, and corrosion-

Atmospheric pressure plasma CVD (APCVD) offers a continuous processing opportunity in textile production. The disadvantages such as costs and operating difficulties related to high vacuum equipment are eliminated and the need to interrupt the line is avoided since a continuous coating process is possible instead of a batch process. An atmospheric pressure

On a commercial scale, reactor geometry, gas feed, heat distributions are important for

On a commercial scale, reactor geometry, gas feed, heat distributions are important for

Oxidative chemical vapor deposition (OCVD) is a novel technique to obtain uniform polymer layers on a variety of flexible and rigid substrates that does not require any solvent to be

ALD (atomic layer deposition) is another vapor phase vacuum film deposition technique that can generate thin conformal deposited layers by successive surface reactions of a precursor and a reactive gas [27, 28]. This technique has the advantages of precise thickness control and uniformity and conformability of the deposited layer on the substrate [27]. Metallic, nitride, or oxide films such as aluminum oxide can be deposited on nonwovens by this technique [28]. In comparison to the regular thermal ALD, in plasma-enhanced ALD, the reactant gas flows through a plasma source providing shorter deposition time, and lower deposition tempera‐

processed while depositing uniform, thin polymer layers on various substrates [26].

tures allow coating on heat-sensitive fibers and denser films can be produced [28].

Metal containing precursor injection

Oxidative chemical vapor deposition (OCVD) is a novel technique to obtain uniform polymer layers on a variety of flexible and rigid substrates that does not require any solvent to be processed

ALD (atomic layer deposition) is another vapor phase vacuum film deposition technique that can

2. Plasma treatment for improvement of wettability, printability, and dyeability of

Plasma treatment, depending on the type of process gas, changes not only the surface

DuPont's Tyvek is a flash-spun and calendered nonwoven substrate made of high-density

polyethylene fibers. It is a paper-like, dense substrate providing a smooth medium for printing signs, banners, and other graphics. Tyvek has a corona discharge treatment on one side. SEM crosssectional image (Fig. 6) shows the micropores created on the treated side where the ink is wicked through [30]. Electronic charging during corona treatment of the substrate oxidizes the surface and increases the wettability of the substrate. This improves adhesion of ink, adhesive, and coating to

morphology but also leads to a change in chemical composition of the surface. For instance, when oxygen is used as process gas, different oxygen-containing functional groups, such as –OH, –C=O, – COOH, are introduced onto the surface of the nonwoven [3, 29]. Therefore, oxygen plasma

treatment was found to increase the dye-uptake and printability of textiles [3].

generate thin conformal deposited layers by successive surface reactions of a precursor and a reactive gas [27, 28]. This technique has the advantages of precise thickness control and uniformity and conformability of the deposited layer on the substrate [27]. Metallic, nitride, or oxide films such as aluminum oxide can be deposited on nonwovens by this technique [28]. In comparison to the regular thermal ALD, in plasma-enhanced ALD, the reactant gas flows through a plasma source providing shorter deposition time, and lower deposition temperatures allow coating on heat-

6

resistant [24].

220 Non-woven Fabrics

*1.2.2.1. Industrial-scale production-line application*

plasma CVD system is schematically shown in Fig. 5.

Figure 5: Schematic view of the APCVD system [25]

**Figure 5.** Schematic view of the APCVD system [25]

delivering coatings that are uniform across the substrate [12].

sensitive fibers and denser films can be produced [28].

nonwovens

Tyvek [31].

while depositing uniform, thin polymer layers on various substrates [26].

delivering coatings that are uniform across the substrate [12].

Plasma treatment, depending on the type of process gas, changes not only the surface mor‐ phology but also leads to a change in chemical composition of the surface. For instance, when oxygen is used as process gas, different oxygen-containing functional groups, such as –OH, – C=O, –COOH, are introduced onto the surface of the nonwoven [3, 29]. Therefore, oxygen plasma treatment was found to increase the dye-uptake and printability of textiles [3].

DuPont's Tyvek® is a flash-spun and calendered nonwoven substrate made of high-density polyethylene fibers. It is a paper-like, dense substrate providing a smooth medium for printing signs, banners, and other graphics. Tyvek® has a corona discharge treatment on one side. SEM cross-sectional image (Fig. 6) shows the micropores created on the treated side where the ink is wicked through [30]. Electronic charging during corona treatment of the substrate oxidizes the surface and increases the wettability of the substrate. This improves adhesion of ink, adhesive, and coating to Tyvek® [31].

**Figure 6.** SEM cross-sectional image of plasma surface treated Tyvek® [30]

Enercon Industries Corp. [32] manufactures industrial atmospheric plasma treatment systems for nonwovens operating at low temperature and atmospheric pressure.
