Manufacturing Parameters

Special colour results, resign pattern and properties can be given to textiles by different manufacturing techniques such as dyeing. Printing, heat setting, coating, and application of different type of finishes.

The textile engineer can select each of the above variables to produce the best product for its intended use. The raw materials for the textiles processing can be in various forms such as fibres, spun yarn, monofilamant, muiltifilamant. Major textile manufacturing processes including spinning, twisting, texturizing, weaving, knitting, braiding, needle felting, bonding, tufting, laying, and knotting. The resulting textile products can be ribbon, felts, laid web, woven fabrics, knitted fabrics, scrims, belts, cord fabrics, mats, nets, laid-in fabric, lace stitch, needle-punched fabrics, narrow fabrics, ropes, screens, tapes, carpets wadding and cords. Dyes, pigments, auxiliaries, impregnating agents, and other chemicals can be added to these textile products to obtain specific colour effect and physical properties. Several chemical, physical and mechanical methods may be involved during the process such as scouring, bleaching, dyeing, printing, finishing, coating, impregnation, calendaring, pressing, punching, stretching etc are being process to reach the requirement.

1.1 Ecology and textile quality

Two trends have put on the textile industry in recent years for global quality in a safe environment: the demand for improved quality and product and production process control on the other hand, and the simultaneous demand for more ecologically and toxicologically beneficial processes and products on the other.

In this connection, the scientific committee made provision for a completely dedicated to ecology, in order to group together all those paper throw particular light on this subject. The numerous scientifically advanced papers treat all themes ecologically relevant to the textile industry. Many of the presented papers were devoted to the problem of textile effluent pollution by halogenated organic compounds (AOX).

1.1.1 Interaction: textile and people

In the individual industrial nations, legislation in the textile industry requires critical analysis of production processes, the dyes, chemicals and textile auxiliaries used in the processes. Many dyes, chemicals, and textile auxiliaries are strictly controlled, and even prohibited where possible. It is therefore necessary to introduce alternative processes based on ecologically less harmful products. A number of chemicals used in the textile industry are potential allergens. And, as far as others are concerned, it has already been shown that there are toxic or cancel inducing.

The interaction between a person’s skin and the chemicals on the finished textiles coming in contact with it is a complex phenomenon which is controlled by the natural condition of both systems, skin and textile, and by the conditions arising at the interface. It is especially important to understand the mechanisms which control the migration of the different chemical substances from the fabric to the skin, and their diffusion within the skin.

1.1.2 Internal and external factors

The migration of chemicals from the fabric to the skin is controlled by both internal and external factors. The external factors are: chemical composition, pH and the microflora of human perspiration and the presence of fats, surfactants, and cosmetics. As internal factors: we understand the interactions between the individual chemical substances found on the textile surface.

Assessment of the risk associated with contact between the skin and textiles comprises quantification of the migration and diffusion parameters of the individual substances and their sensitising potential and dermatological toxicity.

In assessing the toxicological and mutagenic potential of the chemicals used in the textile industry, interesting results are obtained with the in vitro biological test on bacteria for determining the genotoxicity of chemicals on textiles. (Ames test) Of 140 chemical substances subjected to the Ames test for mutagenic characteristics at the Germen Wool Research institute, five are positive. Mutagenic activity was practically only evident in connection with the presence of dyestuffs. In one case, the presence of benzidine, a dyes decomposition product, was indicated. The fact is that the Ames test has proved useful – in combination with other chemical analyses – in assessing potential textile mutagenic activity.

1.1.3 Environmental hygiene

Presented in the field of environmental hygiene were the results of production personnel are exposed to dust of complex composition in the textile industry. The dust can contain particles and fragments of different size and composition. The particles were measured and morphologically divided into different classes cuticular and contical cells, “skin flake” and fibre particles. Part icle size distribution was calculated to each class, providing reference points on their aerodynamic behaviour and their inter interaction with the human respiratory organs. Also determined were the amino acids, the protein fraction and the chemical composition of the inorganic fraction.

People professionally exposed to the above-mentioned dusts were medically examined in order to clarify the frequency and type or respiratory or allergic symptoms consequent upon dust exposure. This examination indicated that the risk of respiratory system diseases or allergies consequent upon dust exposure in the initial processing stages can be regarded as very limited.

There are sources of environmental pollution which cannot be eliminated by processing the raw materials during the initiate stage. They can be limited only at the effluent or exhaust air level. However, there are some sources of environmental pollution which can be limited or eliminated – with a more or less drastic change in processing technology or by using alternative products.

1.1.4 Economic benefits through savings

Textile firms can be encouraged to finance research with the aim of effluent recovery and recycling if sufficient economic benefit results from it through the saving of valuable materials, water and energy. They can be obliged to rationalize production processes for human and environmental protection by national or supranational legislation strictly regulating the immission of specific chemical substances into water courses, air and the soil.

The problem which arise from such restrictive legislation are complex, and affect a number of areas, like workplace hygiene, the toxicity of dyestuffs and auxiliary agents, the disposal of production process effluents and by products and atmospheric immission.

The answers, as the case may be, cannot be easy, since involved here are novel concepts and requirements which are gradually penetrating people’s consciousness. There are requirements which affect awareness of the relationships between manufacturer and the environment and manufacturer and consumer, thereby also affecting the manner of product presentation, which is now associated with global quality, the manufacturing processes and the finished product.

There is today close correlation between environmentally compatible industrial processes and the guarantee process and product quality. Modern textile technology enables the textile industry to produce qualitatively better and safer finished products using absolutely necessarily minimized quantity of water, energy, and chemicals, with recycling of a large proportion of the waste and with less polluting emissions, which require less costly disposal.

1.1.5 Ecological labelling

In recent years, projects and systems have been pushed through for the ecological labelling of textile in order to stimulate demand for “ecological quality”. However this is now spreading without planning and purpose, and often also little credibility. A number of labelling and brand name systems has in fact been proposed for certain textiles, all with consumer health protection as the declared goal. The individual systems can vary considerably from each other, both in the typology of the textiles included as well as in the individual parameters and tolerance limits. Textile producers must increasingly frequently “guarantee”, both for the finished product and all production stages, that their concept of high quality includes considerations in the field of environmental protection and human toxicological safety.

There is a debate as to whether the expression “human ecology” is sufficiently characterizing and comprehensible in connection with an ecological labelling system, for the concept of “ecology” always of course includes interaction with the environment! The subject of discussion is also whether this kind of labelling is really the expression of a genuine demand on the part of the consumers, or rather a trade and industry requirement, and whether the consumer is actually in a position to grasp the meaning of these labels. The problems arising here affect many areas:

Ø Analysis method testing;

Ø The demonstrability limits of the relevant substances on textiles;

The development of suitable analysis methods as a function of the tolerance boundaries used and of simulation methods for testing whether a substance which is toxic in air and water, its toxicity also releases its toxicity if it comes from a textile substrate in contact with the skin – this is a function of the complex chemical and biological interactions of different substances under different condition in use. Worldwide textile research is dealing with these problems.

Back to Index of March 2005