The level of textile fabrics ’s air permeability differs depending on the following

Fabric air permeability is a measure to what extent it gives air passing through the fabric. The porosity of fabric is the demonstration of the air gap as a percentage within the fabric. It has been important for especially the tent fabric and parachute. Knitting Expo will introduce you the level of textile fabrics ’s air permeability differs depending on the following.

I. Fabric Structure: Woven fabric specifications

Fabric construction: –warp count x weft count/ends per inch x picks per inch

Fabric area density/GSM

Cover factor—changing the area density and/or the cover factor may affect strength, stiffness, stability, porosity, filtering quality and abrasion resistance of fabric. Application of jammed fabrics or closely woven fabrics finds use in waterproof, windproof, bulletproof requirements.

Type of weave

Crimp

Fabric width

thickness

Under the same tightness of the fabric, the air permeability of the fabric is inversely proportional to the yarn density; from the aspect of the texture of the fabric, under the same arrangement density and tightness, the air permeability is ranked as plain weave/twill/satin/porous structure; the fabric with a larger volume fraction has a lower air permeability.

II. Fibre Properties

Type of interlace, type of fibre (spun or strand), size of the fibre (Linear toughness), twist factor in the fibre, strand toughness (ends and picks) and fold are other material parameters that affect the air permeability of a material. Moreover, the moisture regains of the fibre has a significant effect on the air permeability.

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When the wool fabric increases with the moisture regain, the air permeability drops significantly due to the radial expansion of the fibre. The surface shape and cross-sectional shape of the fibre will increase the resistance of the airflow due to the increase of the shape barrier and the specific surface machine: The shorter the fibre, the greater the rigidity as well as the probability of product hairiness, hence the poorer the air permeability.

III. Yarn Structure

The tighter the structure of the yarn, the smaller the penetration within the yarn but the greater the penetration between the yarns. The material, twist and smoothness of the yarn contributes to permeability. The material type and amount of yarn twist, count and yarn structure manufactured by Ring spinning, Open end, Air textured, condenser spinning methods does impact on fabric air permeability. Some important parameters related are pore in the fabric were taken in to account like the cross-section of the pore, depth of pore or thickness of fabric and number of pores per unit area.

IV. Environmental Conditions

Under the constant temperature, the air permeability of the fabric decreases with the increase of relative humidity, due to the hygroscopic expansion of the fibres which reduces the internal voids of the fabric and some moisture can block the passage. Under the constant relative humidity, the air permeability of the fabric increases as the ambient temperature increases. Because when the ambient temperature rises, on the one hand, the thermal motion of the gas molecules is intensified, leading to the diffusion of molecules, which enhances the permeability. On the other hand, the thermal expansion of the fabric as a whole improves the permeability of the fabric.

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V. Other Aspect

Besides the above, air permeability of material also hangs on parameters like the material cover and material permeability. Sum cover of material is known as the ratio area concealed by the covering and the stuffing fibres to the area concealed by the material. The kind of knit decides the way in which the fibres are twisted in the material. The air permeability of the materials can be altered by changing the way of knitting. When the size of the fibre changes, the same happen in the fibre of the material hence the permeability of the material changes.

Advanced fabric production project demands developing strategies with regard to new fabric constructions and it should have the desired end-usage properties as per there applications. For specified Fabric, we need to have complete knowledge and understanding of porous barrier between the human body and environment. This should support heat and water vapour exchange between the body and environment in order to keep the body temperature within the homeostasis range.

Besides thermo-physiological protection, fabrics also play an important role by heat protection due to the flames or convection heat, contact heat, radiant heat as well as due to the sparks and drops of molten metal, hot gases and vapours.

Source: textile school

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The design is an arrangement of part, form, color, fabric, and line. For example, to create a version of a style. This definition is applicable for apparel or clothing. In general, the design is arrangement putting out creative ideas on paper or any of the three-dimensional form.There are different types of designs such as industrial design, graphic design, textile design, fashion design, etc.

Designing in Textile Industry

There are different types of designs such as industrial design, graphic design, textile design, fashion design, etc.

Textile design

Is the design of fabrics for a Variety of purposes from clothes to carpets. In this professions, the color, shape, texture, and pattern are the key elements.

Fashion design

It is concerned with how needs are identified, related and in some cases stimulated. It affects the ways in which our materials, energy, skills and other resources are employed to satisfy them fully, it calls upon enterprise enthusiasm, inventiveness and ingenuity, scientific discovery and technical knowledge, the power of visualization together with knowledge of human capabilities and aesthetic sensibility. Designing requires patience and planning. Crating or styling the appearance of a person with reference to clothing, accessories beauty in corresponding with the personality of any individual is fashion designing.Fashion designing involves knowledge of basic elements of designing, understanding color cycle, a brief study of the history of clothing, knowledge of fibers and different fabrics.Fashion can be defined as a design that is accepted by a given segment of the population.

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Fashion is constantly changing and as a new design becomes popular a new standard of beauty becomes desirable. Often a new fashion begins when the proportion of a garment is altered, for example, a silhouette is changed in width or a skirt is lengthened. Usually, when a truly innovative fashion begins, it takes a long time for the general public to retain its eye and develop an appreciation for a new look. As more people wear the item interpret it in many different ways, the mass of people finds it easier to accept the fashion, as beautiful.Designing means moving from the state of randomness to the higher state of organization, to create a design or impression or to communicate an important/ innovative idea. On the highest-level design is the careful and knowledgeable manipulation of art elements to produce an expressive personal idea.

There are two basic divisions of designing in the field of garment technology.

1. Structural designing

2. Decorative designing

Structural Design

Structural designs are intrinsic parts of materials. They are created through manipulation of fabrications, color, or texture. Structural design created through fabrication depends on the use of color and texture in the yarns forming loops or interlacing patterns in the fabric. The knitting machines or looms must also have the technology for varying fabric structure. Structural designs formed as the material is made.Structural design includes the all over design of a garment. The form and shape plus all the details involved in assembling the sections of the garment such as darts, pleats, tucks, etc are the part of structural design.It may add a decorative quality if emphasized by color contrast or row of topstitching to outline the basic garment parts. In apparel, structural design is more important because it is the fundamental component of the design.To draw a structural design a form or human croquet is not necessary. The designers in the buying house do these designs. In this category, the designs are drawn on the specification chart where many trimmings are not used. This design will be simple and well defined by their construction, color, thread, and trimmings to be used. It will not be draped on the form. It will be speeded so that the pattern master can create a proper sample according to the specifications mentions such as its measurements, its sweep line (Hemline) its neckline and any other type of cuts used.

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Decorative Design

Here it refers to the design, which is drawn by the beginner (learners) as well as the boutique designers. These drawn will be draped over it. It is not produced in bulk so it will have more trimmings, prints, embroidery, buttons (that do not fasten) and tacked on bows. The customer will select the garment that is designed, then it will be very costly, in these designs the fabric style and color combinations are described so that one can select the design. In this design category specification charts are not prepared, not it is stitched for standard measurement. It is the design and outfit are made for an individual customer.The decorative design is created by printing, embroidery, quilting, appliqué, or other forms of fabric decoration. Some decorative designs are mass produced and very economical. Others are individual creations that are highly labor intensive. Roller and screen printing is probably the most commonly used forms of decorative design. Problems that are sometimes associated with printed designs are fuzzy patterns.In general, structural designs are more permanent better quality; and more durable than decorative designs. Structural designs are more expensive to produce than decorative designs due to slower production and longer set up time.

For more industry information, please pay attention to Knitting Fair.

Source: textile school

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A composite textile material (also called a composition material or shortened to composite) is a material made from two or more constituent materials with significantly different physical or chemical properties that, when combined, produce a material with characteristics different from the individual components.

Archaeologists say humans have been using composites for at least 4,000 to 6,000 years. In ancient Egypt, bricks made from mud and straw to encase and reinforce wooden structures such as forts and monuments. In parts of Asia, Europe, Africa and the Americas, indigenous cultures build structures from wattle (planks or strips of wood) and daub (a composite of mud or clay, straw, gravel, lime, hay, and other substances using a heat source for backing and drying from the sun).

Another advanced civilization, the Mongols, were also pioneers in the use of composites. Beginning around 1200 A.D., they began building high performance recurved reinforced bows out of wood, bone, and natural adhesive, wrapped with silk and pine resign (birch bark). These were far more powerful and accurate than simple wooden bows, helping Genghis Khan’s Mongolian Empire to spread across Asia.

The modern era of composites began in the 20th century with the invention of early plastics such as Bakelite and vinyl as well as engineered wood products like plywood. Another crucial composite, Fiberglas, was invented in 1935. It was far stronger than earlier composites, could be moulded and shaped, and was extremely lightweight and durable.

World War II hastened the invention of still more petroleum-derived composite materials, many of which are still in use today, including polyester. The 1960s saw the introduction of even more sophisticated composites, such as Kevlar and carbon fibre.

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A composite material (also called a composition material or shortened to composite) is a material made from two or more constituent materials with significantly different physical or chemical properties that, when combined, produce a material with characteristics different from the individual components. The individual components remain separate and distinct within the finished structure, differentiating composites from mixtures and solid solutions.

How composite materials are classified? The composite materials are commonly classified based on matrix constituent. The major composite classes include Organic Matrix Composites (OMCs), Metal Matrix Composites (MMCs) and Ceramic Matrix Composites (CMCs). … These three types of matrixes produce three common types of composites.

“Textile” is deﬁned as “…originally a woven fabric, but the term ‘textiles’ is now also applied to ﬁbers, ﬁlaments and yarns, natural or man-made, and most products for which they are the principal raw materials. Hence, textiles are ﬁbrous materials. Fibres in a textile are assembled into yarns or ﬁbrous plies, which are arranged to form a textile fabric.

Textile structural composites represent a class of advanced materials, which are reinforced with textile preforms for structural or load bearing applications. As ﬁbers and yarns in textiles are held together by friction, the yarns have to be bent or twisted to provide transversal forces, necessary for friction. The internal structure of a textile is the result of such bending of the yarns, introduced during manufacturing of the fabric.

The internal structure determines the interaction between the ﬁbers and yarns in dry fabric during manufacturing, transferring the applied load to structural ﬁbrous elements of the fabric, which resist the load by their deformation (primarily tension, bending/buckling, lateral compression and friction, and to a lesser extent torsion and shear).

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The internal structure means yarn material and its structure and fabric structure determines the performance of a consolidated composite as well: the stress response to the local deformation depends on the local orientation of ﬁbers, which is imposed by there in for cement architecture, and in its turn deﬁne whether damage will be initiated in that particular location and whether it will propagate.

Presently, textile structural composites are part of a larger category of composite materials (Shishoo et al 1971 and Wiemer et al 2000). In general, composites can be defined as a selected combination of dissimilar materials with a specific internal structure and external shape. The unique combination of two material components leads to singular mechanical BEHAVIOR OF TEXTILE PREFORMS DURING COMPOSITE MANUFACTURING

Composite manufacturing techniques, used for textile reinforcements, are covered in Fiber-Reinforced Polymer Composites: Manufacturing and Certiﬁcation Issues. Two main processes involved during the manufacturing are shaping of a textile preform on a three-dimensional mould and impregnation of the preform with resin. The behaviour of the preform during manufacturing is determined correspondingly by its formability and permeability.

The formability (drapability) of a textile fabric reﬂects the easiness of the initially ﬂat fabric to conform to (drape over) a given 3D shape. The permeability of the preform is a tensor coefﬁcient K of Darcy equation, relating the ﬂow velocity of a ﬂuid through the porous medium to the pressure gradient.

For more industry information, please pay attention to Knitting Fair.

Source: textile school

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