Fabric surface properties

Fabric surface property, weight and thickness also influence cutting and sewing operations. 

H. Zhao, K-Y. Law and V. Sambhy, Fabrication, surface properties, and origin of superoleophobicity for a model textured surface, Langmuir 27, 5927-5935 (2011). 

The fabric properties rely on the constituent materials of the fabrics, fabric structural characteristics, and the fabric surface properties. The performance of nonwoven products requires different properties of the fabric. The relationship of nonwoven fabric structure—property—performance can either be characterised in analytical and empirical models, or be simulated in numerical methods. The examples of some important models were developed in various research papers and summarised in some books. ... 

Engineering design, then, involves many considerations (Fig. 1.7). The choice of a material must meet certain criteria on bulk and surface properties (strength and corrosion resistance, for example). But it must also be easy to fabricate it must appeal to potential consumers and it must compete economically with other alternative materials. In the next chapter we consider the economic aspects of this choice, returning in later chapters to a discussion of the other properties. 

Softening treatments of a rather different nature include biofinishing enzyme treatments to modify the fabric surface. This has been dealt with already in section 10.4.2. Even more esoteric is the use of so-called telluric treatments using minerals (microliths) of precisely defined lithological and metamorphic properties. A detailed account of these complex materials is available [493]. In essence, an enzyme is micro-encapsulated within the mineral... 

It is now opportune to consider the structure-property relationships of fluorochemical finishes in more detail [501,502]. Water repellency depends mainly on reducing the critical surface energy of the fabric surface. This parameter must be less than that of the wetting... 

Having said this, it was felt therefore that there is a need for a book addressing analysis and characterisation of polymers from the point of view of what we wish to call the primary analytical question. Many excellent textbooks and reference works exist which address one or more individual analytical techniques, see, for example, references [1-10]. These books form the basis of the knowledge of the technique expert. They also contain many excellent and varied examples on successful applications of analytical techniques to polymer analysis and characterisation. There are also books which address the multitude of analytical techniques applied in polymer analysis, see, for example, references [11-24], However, a synthetic chemist may wish to know the constitution of his/her polymer chain, a material scientist may want to find out the reasons why a fabricated sample had failed. What technique is best or optimal to study chain constitution will depend on the situation. Polymer failure may result from morphological features, which needs to be avoided, a contaminant, a surface property degradation, etc. When a sample has been processed, e.g., a film blown, molecular orientation may be the key parameter to be studied. A formulation scientist may wish to know why an additive from a different supplier performs differently. It is from such points of view that polymer analysis and characterisation is addressed in this book. 

Because of the assumptions underlying its derivation, the Kozeny-Carman equation is not valid at void fractions greater than 0.7 to 0.8 (Billings and Wilder, op. cit.). In addition, in situ measurement of the void fraction of a dust layer on a filter fabric is extremely difficult and has seldom even been attempted. The structure of the layer is dependent on the character of the fabric surface as well as on tfie characteristics of the dust, whereas the application of Eq. (17-12) implicitly assumes that K2 is dependent only on the properties of the dust. A smooth fabric surface permits the dust to become closely packed, leading to a relatively high value of K2. If the surface is napped or has numerous extended fibrils, the dust cake formed will be more porous and have a lower value of K2 [Billings and Wilder, op. cit. Snyder and Pring, Ind. Eng. Chem., 47, 960 (1955) and K. T. Semrau, unpublished data, SRI International, Menlo Park, Calif., 1952-1953]. 

CE chips are mainly obtained using various glass substrates, from inexpensive soda-lime glass to high-quality quartz.Various polymer materials are also used. The choice of a particular material depends on its surface properties, ease of fabrication, which can be quite different according to the material origin, disposability, and price. Microfabrication processes were recently reviewed and the reader is thus referred to dedicated literature for additional useful information on microfluidic device fabrication. ... 

While direct, this method is the most difficult experimentally due to the diminutive nature of fiber diameters and the uncertainty involved with contact angle measurements and hysteresis. The value i ) can also be measured on flat sheets of the fiber material but due to fabric finishes and different surface properties incurred during manufacture, the surface energetics of the sheet and fiber may be very dissimilar. Therefore, the value of co8i i was determined in the following manner from detergency data. The Kubelka-Munk Equation (12-13),... 

The behavior of liquids in narrow tubes is one of the most common examples in which capillary forces are involved. It will be shown later how important this phenomenon is in many different parts of everyday life and technology. In fact, liquid curvature is one of the most important physical surface properties that requires attention in most of the application areas of this science. The range of these applications is from blood flow in the veins to oil recovery in the reservoir. Properties of fabrics are also governed by capillary forces (i.e., wetting, etc.). The sponge absorbs water or other fluids where the capillary forces push the fluid into the many pores of the sponge. This is also called wicking process (as in candlewicks). 

The increasing demand for synthetic biomaterials, especially polymers, is mainly due to their availability in a wide variety of chemical compositions and physical properties, their ease of fabrication into complex shapes and structures, and their easily tailored surface chemistries. Although the physical and mechanical performance of most synthetic biomaterials can meet or even exceed that of natural tissue (see Table 5.15), they are often rejected by a number of adverse effects, including the promotion of thrombosis, inflammation, and infection. As described in Section 5.5, biocompatibility is believed to be strongly influenced, if not dictated, by a layer of host proteins and cells spontaneously adsorbed to the surfaces upon their implantation. Thus, surface properties of biomaterials, such as chemistry, wettability, domain structure, and morphology, play an important role in the success of their applications. 

In addition, modem fabrication techniques demand good molding characteristic, i.e., low melt viscosity, in order to enhance the shaping cycle and increase the productivity. When a layered silicate, e.g., montmorillonite is added as an inorganic filler, the fluidity and the surface properties can be improved (24). 

In the previous edition of this book, Dryhurst and McAllister described carbon electrodes in common use at the time, with particular emphasis on fabrication and potential limits [1]. There have been two extensive reviews since the previous edition, one emphasizing electrode kinetics at carbon [2] and one on more general physical and electrochemical properties [3]. In addition to greater popularity of carbon as an electrode, the major developments since 1984 have been an improved understanding of surface properties and structure, and extensive efforts on chemical modification. In the context of electroanalytical applications, the current chapter stresses the relationship between surface structure and reproducibility, plus the variety of carbon materials and pretreatments. Since the intent of the chapter is to guide the reader in using commonly available materials and procedures, many interesting but less common approaches from the literature are not addressed. A particularly active area that is not discussed is the wide variety of carbon electrodes with chemically modified surfaces. 

J.S. Rossier, F. Reymond and W. Schmidt, Patent Method for Fabricating Micro-Structures with Various Surface Properties in Multilayer Body by Plasma Etching, 2001, WO 2001/056771. 

---