Study of Properties of Overcoating Fabrics during Design of Women’s Clothes in Diff erent Forms

The article presents a study of the process of designing women’s garments of the coating and suiting assortment, made from diﬀ erent fabrics to determine the fabric properties eﬀ ect on the parameters of shaping the volume-silhouette form of clothes. An expert evaluation of the signiﬁ cance of material properties for the creation of tectonic forms of clothes was carried out and the most signiﬁ cant properties were determined, i.e. rigidity, thickness, drapeability, mass per unit area, type of weave, raw material composition. An experimental study of physical and mechanical characteristics of overcoating fabrics was performed. To validate the research results, we made samples of women’s coats in diﬀ erent forms at a garment company. It was determined that the raw material composition of fabrics does not aﬀ ect signiﬁ cantly their physical and mechanical characteristics (drapeability, rigidity). The weave of fabrics which determines other indicators was considered to be more signiﬁ cant. As a result, the relationships between the physical and mechanical properties of fabrics of the coat group and the shaping of women’s coats in diﬀ erent vol-ume-silhouette forms were identiﬁ ed. The latter can be used in the design of garments for an individual and mass production.


Introduction
Modern fashion off ers the consumer a wide range of volume, silhouette and design solutions of clothes made of various materials. In the theory of clothing design, fashionable structural parameters of the form, as well as the methods of shaping that determine the plastic properties of materials are given subjectively, giving rise to a number of inconsistencies to the architectonic demands of fashion. Th e international experience of well-known brands in the fashion industry shows that the design of new forms and design & technological solutions of clothes begin with the consideration of material properties in order to create new design solutions, i.e. the modern process of designing clothes is based on the principles of tectonics. Th e tectonic approach to the formation of clothes should take into account not only the compositional features of goods, but also the physical and mechanical characteristics of materials the clothes are made from, providing the goods with the necessary level of ergonomics, aesthetics and quality in general. Th e main direction of the development of the tectonic approach to the design of clothes is the in-depth study of physical and mechanical characteristics of textile materials and the study of their infl uence on the tectonic form of clothes [1]. KyoungOk Kim, Shigeru Inui and Masayuki Takatera (2011) investigated the eff ect of pressing on the fl exural rigidities of the fabric face side, adhesive interlining and bonded composite fabric, and verifi ed the prediction method for the fl exural rigidity of these. Predicting the methods of fl exural rigidity for the composite with the fabric face side and adhesive interlining based on laminated theory were verifi ed by measuring the fl exural rigidities and thickness of samples using the KES-FB system [2]. Authors [3] made a comprehensive review of the measurement methods developed to evaluate the fabric and garment drape. Moreover, the parameters proposed for measuring drapeability were considered. Th e authors suggested that the use of the fl at fabric methods does not accurately refl ect the drape of fabrics when worn. In the work [4], the author recommended quilted fabrics from the point of view of their usability for outdoor clothing on the basis of the results of the study of their comfort-related properties, e.g. thermal resistance, thermal conductivity, thermal absorptivity, water vapour resistance and air permeability.
In the research by C. K. Chan et al (2006), the Kawabata Evaluation System was adopted to investigate the mechanical properties of uniform fabrics currently in use on the basis of diff erent commercial types of uniform materials obtained from different sources [5]. Th e paper [6] investigated the eff ect of a slight variation in the fabric structure and fi nishing on the fl exural and drape properties of woven fabrics for tailored garments. Th e obtained results showed that a variation in weft density and weft yarn count can infl uence fabric fl exural stiff ness and drapeability. Experimentally, the main physical and mechanical characteristics of fabrics of a suiting group were identifi ed according to standardised methods. Th e conducted experimental researches represented the basis for the development of a suiting group fabrics classifi cation in terms of their fl exural rigidity to develop the recommendations for designing clothes of diff erent three-dimensional forms [7]. Th e interdependence between the drape parameters and mechanical properties of fabrics was studied in [8]. A good correlation was found with the fl exural and shear properties of the fabric. Based on a series of laboratory experiments performed to investigate the total hand value and lowstress mechanical properties, the paper [9] compares the impact of fusible interlining and printable interlining on a woollen fabric using the Kawabata Evaluation System. Th e total hand value and fi ve mechanical properties, i.e. tensile, fl exural, shearing, surface friction and compression, were obtained. Th e results proved that printable interlinings can replace fusible interlinings on woollen fabrics and improve the fabric total hand value and its fl exural, shearing and tensile properties. Th e Kawabata Evaluation System was used to measure the mechanical properties of the samples of suiting fabrics and each sample was made into a shoulder-back as a part of a men's suit [10]. Th e aim of the paper [11] was to investigate the feasibility of using a wool handle metre as an economical and eff ective method to predict the handle characteristics of wool-rich woven fabrics suitable for winter suiting. An independent set of woven samples was selected to validate the regression models on the basis of the Kawabata Evaluation System for Fabrics, subjective handle evaluation and the formability index F-FAST. Th e paper [12] compares the mechanical properties, hand and tailorability of wool blended fabrics for outerwear clothing. Th e fabrics in plain and twill weave of identical fi brous composition, and identical warp and weft count were tested on KESF-B instruments for the fabric objective evaluation under small loads. Th e mechanical properties of a plain and twill weave fabric showed the diff erence in its fl exural, shearing and surface properties. Th e authors [13] noted that fabric characteristics such as rigidity, drapeability, crease resistance, as well as relaxation characteristics, inherent to the single-cycle stretching of textile materials, have a signifi cant impact on the quality of the appearance of garments. To clarify the impact of fabric mechanical behaviour on the changes in form and quality of garment appearance associated with it, the impact of particular parameters of the fabric mechanical properties on the quality of the garment appearance was investigated in [14]. Th e obtained results indicated that the quality of the garment appearance is strongly affected by three components, i.e. formability, elastic potential and draping. In the work by Petrova O. S. [15], it was determined that such groups of properties as physical and mechanical (rigidity, drapeability, crease resistance, thickness, linear density in warp (in weft ), mass per unit area), artistic and aesthetics (colour, pattern, texture), and hygienic (thermal resistance and thermal conductivity) are the most important. As a result of further researches, the author found that rigidity, drapeability, crease resistance, linear density in warp (in weft ), mass per unit area and thickness are the most important properties. Kirsanova O. A. [16] considered the relationships between the structure of the form of a garment and the materials making it. In order to provide clothes with the form of a certain confi guration, it was necessary to choose among the whole assortment range of materials only the ones that can in accordance with their physical and mechanical characteristics ensure the compliance with the given form and maintenance. Th e authors [17] considered the uniformity of clothes and factors aff ecting this indicator. Despite the fact that they considered the stability and preservation of the form of clothes during their use, such conducted research can be used in the design stage as well. Th ey found that the uniformity of clothes is a complex characteristic caused by the compositional, constructive features of clothes and by fabric properties. In their opinion, the following properties of fabrics aff ect the uniformity of clothes: fl exural rigidity, raw material composition, thickness, mass per unit area, drapeability, type of weave, crease resistance. It was confi rmed by the research [18] that the following fabric characteristics have the greatest infl uence on the tectonic form of clothes: type of weave, thickness, mass per unit area, rigidity, drapeability, linear density and raw material composition. Th e aim of this work was to determine the relationships between the physical and mechanical properties of fabrics of the coating group and the shaping of women's coats in diff erent volume-silhouette forms which can be used in the design of garments for an individual and mass production.

Materials and methods
Th e main elements that characterise the form of clothes are volume, silhouette, compositional and constructive solutions, material, structure etc. Materials, in turn, aff ect the form of clothes by their aesthetic indicators (fabric appearance, texture, colour, decoration etc), and physical and mechanical characteristics. Depending on the values of these indicators, the purpose of goods, their model and design features, the technology of their production are determined. In order to assess the signifi cance of fabric properties to design the tectonic form of clothes, we conducted an expert evaluation. Expert and working groups consisted of 20 employees of experimental departments of the clothing companies Dolcedonna and Dana-moda (Kiev), i.e. draft smen, artistsdesigners and technologists. Th e experience of the working group members in the design and manufacture of clothes is from 10 to 34 years; hence, they can be considered experts. In order to assess the signifi cance, the following properties of fabrics were included in the questionnaire: raw material composition, type of weave, thickness, mass per unit area, linear density, fl exural rigidity and drapeability. During the selection of indicators of fabric properties, aesthetic properties were not included since they cannot be estimated with instrumental methods. Th e results of the survey showed that fl exural rigidity (X 8 , λ = 0.23) is the most important factor, followed by thickness (X 3 , λ = 0.18) and drapeability (X 9 , λ = 0.13) ( Table 1). Other indicators are arranged in the following order: mass per unit area, type of weave, raw material composition, linear density, crease resistance, breaking load. Th e value of the concordance coeffi cient W = 0.76 indicates the level of consensus of the experts' opinions, since the table value of the Pearson criterion χ 2 Т is less than the estimated χ 2 Р , i.e. χ 2 Т = 0 ÷ 12.6 < χ 2 Р =21.5. Crease resistance 0.05 Х 6 Breaking load 0.03 Х 7 Linear density 0.08 Х 8 Flexural rigidity 0.23 Х 9 Drapeability 0.13 ∑R = 0.5n (n+1) 1.00 Th us, on the basis of the analysis, it was determined that the core indicators of fabrics which aff ect the creation of the tectonic form of a garment and which need to be taken into account in the designprojecting stage are fl exural rigidity, thickness, drapeability coeffi cient, mass per unit area, type of weave and raw material composition. With regard to the aim of the research, we decided to analyse 9 samples of overcoating fabrics of a different raw material composition with diff erent properties (thickness, texture, mass per unit area, type of weave etc). Th e main focus was put on the determination of the following fabric properties: thickness, mass per unit area and linear density, fl exural rigidity and drapeability. Th e research was held in accordance with valid standards, considering all the demands of the objects in the experimental research. Th e processing of the measurement results was made using a mathematical apparatus for a statistical data analysis.
Th e thickness of the material was determined by using the manual thickness tool of indicative type ТР 10-1 [19]. Th e linear density and mass per unit area of fabrics were measured in accordance with GOST (State Standard) 3811-72 [20]. For the analysis of fabric rigidity by the console contactless method, we used the device type ПT-2 in accordance with GOST (State Standard) 10550-93 [21] (Figure 1).
where m is the total weight of all fi ve elementary samples of the fabric (g), A is the function of relative fl exure f 0 , which is determined in the standard [21] according to the value f: where f is a value of the arithmetic average of fl exure of samples (cm), l is the length of the weighed sample (cm) and is equal to: where L is the length of an elementary sample (cm).
Th e rigidity coeffi cient of a material C EI (%) was calculated as the ratio of rigidity values in longitudinal and transverse directions: .
Th e recommended values of mass per unit area and conventional rigidity of fabrics of the overcoating group are presented in Table 2 [23]. Th e research of drapeability of samples of suiting fabrics was performed on a device for the determination of drape by the disk method [24], since it was necessary to evaluate the fabric drapeability in their longitudinal and transverse directions at the same time. Th is method is not standardised; however, it is used very oft en in the garment industry due to its simplicity. Th e scheme of the device is given in Figure 2. In order to provide the sample with a constant natural form, the disc with the sample was lift ed up and moved down 5 times and aft er 3 min, the projection of sample 3 outlined on a paper circle with the diameter of 200±1 mm, which can be obtained by lighting from the top by parallel rays of a light perpendicular to the sample plate. Aft erwards, the projection area of the material was determined. During the research of fabric samples, the drapeability coeffi cient (C d ) was calculated using the results of weighing paper (with an error no more than 0.001 g) cut in accordance with the projections of undraped sample (mass m) and draped (mass m d ) with equation 5: where m is the projection area of an original undraped sample (g) and m d is the projection area of a draped sample (g). Th e recommended values of the drapeability coefficient C d for the main functional groups of fabrics are presented in Table 3 [23].

Results
Th e tectonic system of the fi rst type (ТS1) is typical of the types of clothes, the form, the silhouette and the cutout which are subordinate to the human body outlines. Th e form of such clothes is characterised by a small degree of volume and an adjoining silhouette, and is formed in line with the properties of the material and its cut. Th e tectonic system of the second type (ТS2) is less dynamic than of the fi rst type and it can have one or two supporting areas (for shoulder products). Such products have a small or medium three-dimensional form, semi-adjoining silhouette, they are X-shaped, rectangular or expanded to the lower part. Th e clothes of such tectonic systems freely interact with the fi gure of a person and are kept mainly on the constructive belts of the fi gure. Th e tectonic system of the third type (ТS3) is embodied in the goods the form of which remains relatively unchanged in the dynamics and, in most cases, does not obey the human fi gure. Such goods are characterised by greater static, rigidity and the presence of one supporting area which holds the entire construction. Th is system is characterised by large volume, and rectangular or trapezium shaped forms. Th e tectonic system of the fourth type (ТS4) is characterised by preferred static, large or very large volume of the form, and an extended, less direct silhouette. Th e form of clothes is rigid or very rigid and is of trapezium, oval or rectangular form. As a result of the conducted analysis of modern clothes, the assortment range of clothes which are typical of diff erent types of tectonic systems was defi ned [25]. Th e clothes of the tectonic system of the fi rst type are presented by knitted or elastic fabric dresses, skirts, jumpers, lingerie and corsets that repeat or fi x the human body. Th e clothes of the tectonic system of the second type are presented by dresses, blouses, trousers, jackets. Th e tectonic systems of the third and fourth types are characterised by rigid or very rigid forms; therefore, the clothes of coating & suiting assortment range (jackets, raincoats, coats, cardigans, waistcoats) are typical of these systems (Figure 3).  A women's coat is the most diverse as to the constructive and decorative solutions type of clothing, which determines the immediacy of the problem of taking into account the properties of overcoating fabrics when designing clothes of the third and fourth type of tectonic systems. Th e question of the formalisation of the methods of designing the tectonic forms of women's coats made of diff erent materials remains unresolved.

TECTONIC SYSTEM OF CLOTHES
At a garment company, we selected the fabric samples, and their basic physical and mechanical characteristics were determined in the research laboratory using standardised methods. As the result of experimental research, the properties of nine samples of overcoating fabrics were identifi ed (Table 4). Th e results of the experimental research showed that samples F1 and F8 had the biggest thickness, whereas samples F3 and F4 had the smallest thickness. Samples F3, F8 and F9 had the maximum mass per unit area, when sample F4 had the minimum one. As presented in Table 2, the interdependence between the parameters of thickness, mass per unit area and type of weave was shown in this sample. For example, sample F8 had the biggest thickness and maximum mass per unit area, due to its complex double-layer weave. Sample F4 of linen weave was characterised by the smallest indicators of investigated quantities. However, other samples did not show such interdependence, which can be explained by the diff erent structure of yarn and threads in samples, as well as by diff erent weaves.   Th e ratio of rigidity indicators in warp and weft is refl ected through the rigidity coeffi cient. We found that  6 and 7). Th e more rigid the structure of the material, the greater the force which is required to bend it and the worse the drapeability. An increase in density and mass per unit area of the fabric causes an increase in fabric rigidity, and at the same time a decrease in its drapeability.  It was determined that raw material composition of the fabrics did not aff ect crucially their physical and mechanical characteristics (drapeability, fl exural rigidity), since fabrics of diff erent raw material composition were used in the research. Th e weave of fabrics was considered to be more important since it determines other physical and mechanical characteristics, a complex fabric weave increases its thickness and rigidity.
In order to provide recommendations as to the design of clothes taking into account the properties of overcoating fabrics, all analysed samples were divided into three groups in accordance with their fl exural rigidity. Very soft forms are not characteristic of clothes of the coating assortment range; therefore, a classifi cation was applied to soft , rigid and very rigid forms (P2, P3 and P4). Th e overcoating fabrics should be used with the rigidity of up to 12000 μN·cm 2 for the manufacture of soft form goods; 12000-30000 μN·cm 2 for rigid; more than 30000 μN·cm 2 for very rigid forms. Th e samples of overcoating fabrics are recommended for the manufacture of garments of diff erent plastic forms, i.e. samples F1, F2, F4, F5 and F9 for the manufacture of soft form clothes (P2); samples F3 and F8 for rigid forms (P3); samples F6 and F7 for a very rigid form (P4) ( Table 5).
At the garment company Dolcedonna (Kyiv) [26], the samples of coats of diff erent tectonic systems were manufactured from analysed fabrics and the theoretical recommendations which were provided by us on the basis of fabric properties were verifi ed ( Table 5). Photos of fi nished goods are presented in Figure 8. Th e recommended and obtained type of the coat tectonic system is included in Table 6.
Having analysed the selected samples of materials and manufactured models of women's coats, we found out that four among six variants have the same recommended type of the tectonic system for the goods made of the selected material as well as the same model ( Table 6). All manufactured coats had a backing (100% PES) and were reinforced with the same adhesive interlining on the fronts, collars, cuff s of the coats, which provided the same base conditions for the analysis of the obtained results and reliability of the experiment. During the design of models from samples F1, F3, F5 and F7, the material properties were taken into account; therefore, for these fabrics, the recommended type of the tectonic system matches the actual one in the fi nished goods. Sample F4 was characterised by a small fl exural rigidity indicator and is hence recommended for the manufacture of goods TS3. Nevertheless, it can be seen from Table 4 that the actual type of the tectonic system of fi nished goods is TS4 (huge volume of the form, straight silhouette). Analogous, sample F9 is recommended for TS3, whereas the fi nished goods belong to TS4 (huge volume of the form, geometric form is oval). It should be noted that in both cases, the material was not rigid enough to create the tectonic form defi ned in the draft ; however, due to the use of adhesive layers, more rigidity was achieved, making it possible to use the indicated fabrics for the creation of volume and form-stable goods. As a result of the approbation, it was determined that the proposed recommendations regarding the design of tectonic forms of women's coats from the fabrics with diff erent physical and mechanical characteristics enable a shorter time of designing new clothes models. Our recommendations regarding the selection of overcoating fabrics provided by us, which should be used for designing the tectonic forms of clothes depending on their physical and mechanical characteristics during the designing of the new forms of the clothes from various materials, have been tested during the manufacture of the women's coats collections, season autumn-winter 2018-2019.

Conclusion
Based on the theoretical research and expert evaluation, we identifi ed the main characteristics and properties of materials which aff ect the creation of the predictable, in the design conditions, tectonic form of clothes and must be taken into account in the design stage. Th ese are rigidity, thickness, drapeability, mass per unit area, type of weave, raw material com-position and linear density. Th e connection between the plastics of forms and the fabric properties was analysed and a classifi cation of materials in accordance with the types of tectonic systems was developed. It was determined that the raw material composition of fabrics in this research does not aff ect signifi cantly their physical and mechanical characteristics (drapeability, rigidity). Th e type of weave is more important and determines other indicators. Th e recommendations regarding the design of clothes of a certain tectonic system were developed based on the determination of their physical and mechanical properties. Th ese recommendations were checked experimentally by manufacturing samples of women's coats at a garment company. A comparable analysis of recommended types of tectonic systems was conducted based on the results of the determination of sample properties and actual types of tectonic systems in the fi nished clothes from the collection.  TS3  TS3  TS4  TS3  TS4  TS4