INVESTIGATION AND EVALUATION OF THE QUALITY OF EMBROIDERED ELEMENTS

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2 KAUNAS UNIVERSITY OF TECHNOLOGY SVETLANA RADAVIČIENĖ INVESTIGATION AND EVALUATION OF THE QUALITY OF EMBROIDERED ELEMENTS Summary of Doctoral Dissertation Technological Science, Materials Engineering (08T) 2014, Kaunas

3 The doctoral dissertation was carried out in at Kaunas University of Technology, Faculty of Design and Technologies, Department of Clothing and Polymer Products Technology, Traineeship in Riga Technical University (2012 m.), supported by Lithuanian State Science and Studies Foundation and Research Council of Lithuania ( ). Scientific Supervisor: Assoc. Prof. Dr. Milda JUCIENĖ (Kaunas University of Technology, Technological Sciences, Materials Engineering 08T) since 2009 m. Scientific Advisor: Assoc. Prof. Dr. Vaida DOBILAITĖ (Kaunas University of Technology, Technological Sciences, Materials Engineering 08T) since 2009 m. Board of Materials Engineering Science field: Prof. Dr. Virginija DAUKANTIENĖ (Kaunas University of Technology, Technological Sciences, Materials Engineering 08T) chairperson; Dr. Kristina BRINKIENĖ (Lithuanian Energy Institute, Technological Sciences, Materials Engineering 08T); Prof. Dr. Saulutė BUDRIENĖ (Vilnius University, Physical Sciences, Chemistry 03P); Assoc. Prof. Dr. Jurgita DOMSKIENĖ (Kaunas University of Technology, Technological Sciences, Materials Engineering 08T); Prof. Dr. Viktoras GRIGALIŪNAS (Kaunas University of Technology, Technological Sciences, Materials Engineering 08T). Official Opponents: Dr. Aušra ABRAITIENĖ (Textile Institute of the Center of Physical Sciences and Technology, Technological Sciences, Materials Engineering 08T); Prof. Dr. Salvinija PETRULYTĖ (Kaunas University of Technology, Technological Sciences, Materials Engineering 08T). Public defence of the Dissertation will take place at the open meeting of the Broad of Materials Engineering Science field at 10 a.m. on the 9 of January 2015 in Dissertation Defence Hall at the Central Building of Kaunas University of Technology. Address: K.Donelaičio st , LT 44029, Kaunas, Lithuania Phone (370) ; fax. (370) , . doktorantura@ktu.lt The Summary of the Dissertation was send on December 09, The Dissertation is available at the library of Kaunas University of Technology (K.Donelaičio st. 20, Kaunas)

4 KAUNO TECHNOLOGIJOS UNIVERSITETAS SVETLANA RADAVIČIENĖ SIUVINĖTŲ ELEMENTŲ KOKYBĖS TYRIMAS IR VERTINIMAS Daktaro disertacijos santrauka Technologijos mokslai, medžiagų inžinerija (08T) 2014, Kaunas

5 Disertacija rengta metais Kauno technologijos universitete, Dizaino ir technologijų fakultete, Aprangos ir polimerinių gaminių technologijos katedroje bei stažuojantis Rygos Technikos Universitete. Mokslinius tyrimus rėmė Lietuvos mokslo ir studijų fondas ir Lietuvos mokslo taryba. Mokslinis vadovas: Doc. dr. Milda JUCIENĖ (Kauno technologijos universitetas, technologijos mokslai, medžiagų inžinerija 08T) nuo 2009 m. Mokslinis konsultantas: Doc. dr. Vaida DOBILAITĖ (Kauno technologijos universitetas, technologijos mokslai, medžiagų inžinerija 08T) nuo 2009 m. Medžiagų inžinerijos mokslo krypties taryba: Prof. dr. Virginija DAUKANTIENĖ (Kauno technologijos universitetas, technologijos mokslai, medžiagų inžinerija 08T) pirmininkė; Dr. Kristina BRINKIENĖ (Lietuvos energetikos institutas, technologijos mokslai, medžiagų inžinerija 08T); Prof. dr. Saulutė BUDRIENĖ (Vilniaus universitetas, fiziniai mokslai, chemija 03P); Doc. dr. Jurgita DOMSKIENĖ (Kauno technologijos universitetas, technologijos mokslai, medžiagų inžinerija 08T); Prof. dr. Viktoras GRIGALIŪNAS (Kauno technologijos universitetas, technologijos mokslai, medžiagų inžinerija 08T). Oficialieji oponentai: Dr. Aušra ABRAITIENĖ (Fizinių ir technologijos mokslų centro Tekstilės institutas, technologijos mokslai, medžiagų inžinerija 08T); Prof. dr. Salvinija PETRULYTĖ (Kauno technologijos universitetas, technologijos mokslai, medžiagų inžinerija 08T). Disertacija ginama viešame medžiagų inžinerijos mokslo krypties tarybos posėdyje, kuris įvyks 2015 m. sausio 9 d., 10 val. Kauno technologijos universitete Disertacijų gynimo salėje. Adresas: K. Donelaičio g , LT 44029, Kaunas, Lietuva. Tel.(370) ; faksas (370) , el.paštas: doktorantura@ktu.lt. Disertacijos santrauka išsiųsta 2014 m. gruodžio 9 d. Su disertacija galima susipažinti: Kauno technologijos universiteto bibliotekoje (K. Donelaičio g. 20, LT 44239, Kaunas).

6 INTRODUCTION An embroidery process is one of the ways to assemble textiles. Embroidered elements do not only perform traditional decorative and informative functions, but are also applied in other areas, such as medical diagnostics and rehabilitation, production of implants, manufacture of fiberreinforced plastic composite materials, manufacture of smart garments or textile items, etc. The exact conformity of embroidered element to designed parameters is relevant to both traditional embroidered elements having decorative and informative functions, and embroidered elements of special purpose. Due to incorrect compatibility of combining properties for textiles and embroidery threads with the technological parameters some unwanted defects often occur, such as shifting of individual fragments of embroidered element, nonconformity of size and / or shape of embroidered element compared with designed digital element, puckering of embroidered element and / or fabric around it. New and innovative materials used in embroidery technologies broaden the scope of embroidery process. For example, introduction of luminescent embroidery threads in textiles has two functions - decorative and improving visibility in the dark, i.e. protective function. The latter is a promising development of special-purpose products to soldiers, firemen and medical personnel. The purpose of clothing with these embroidered elements is improved visibility in the dark, providing information in public places, such as movie theatres and the like. A number of scientific studies have been done on investigating the properties of luminescent threads and utilisation options. However, in most cases they are limited to the analysis of the influence of chemical composition on the fluorescent properties of threads. Researches of the quality and functionality of element embroidered with luminescent threads are missing. In the process of embroidery electro-active threads are integrated into products to generate an electrical circuit. Thus produced "electronic systems can change, process, transmit information, therefore they are applied in the development of smart clothing used in the healthcare area for early diagnosis, monitoring, treatment and rehabilitation of patients. In this case, it is crucial to ensure the exact compliance of embroidered element with the designed one. For stabilisation of textiles various interlining materials are used - with or without an adhesive layer that can be detached or cut after the embroidery process has been finished, as well as other interlinings. However, use of the said auxiliary interlinings does not always give a positive result; their use, and application options are not widely analysed, leading to a lack of detailed research on the subject. 5

7 The analysis of scientific literature has shown that the focus is made on the sewing process and the quality of the systems assembled by this process. Assembling of textiles by an embroidery process and technological factors influencing the quality and functional properties of embroidered element have not been studied widely. In particular, there is a lack of research that examines the quality problems, namely the conformity of shape and dimensions of embroidered elements to the designed ones, puckering defects, etc. Some studies refer to the interface of quality problems with the assembled textiles properties and technological parameters, but in most cases they are just reviews. Since the researches of embroidered textile systems are not widely performed, there is no objective methodology to quantify nonconformities and defects of embroidered element, to evaluate the influence of various factors on the quality characteristics of embroidered element, while at the same time offering the solution to these problems. There are scientific theses analysing on allied / similar problems, but due to the specific individual issues they are not suitable for investigating quality problems of embroidered elements. The most common methods consider only individual defects, but the evaluation of defects obtained during embroidery process is complex and time-consuming, as well as requires expertise in the area of materials engineering science. Relevance of the Dissertation. Development of an objective evaluation methodology would be useful for assessment of noncompliance of the shape and size with designed digital element, puckering of embroidered element and fabric around it, and would allow determining the cause of formation of these defects. The research results would allow establishment of conformity of assembled textiles, i.e. fabrics, embroidery threads and interlinings, in order to get embroidery element of higher quality. The objective evaluation methodology would be used to ensure the required aesthetic and functional properties of embroidered element, and could be used to develop standards for embroidered products. The aim of the doctoral dissertation - to develop research and evaluation methods of the quality of embroidered elements, and to investigate the influence of composition and properties of assembled textile materials, as well as the technological parameters on defect formation. Objectives identified to achieve the goal of the Thesis: 1. To determine the influence of composition and mechanical properties of textile materials, as well as filling type of embroidery and stitch direction on the shape accuracy of embroidered elements and defect formation. 2. To develop research and evaluation methods of fabric buckling inside embroidered element. 6

8 3. To determine and evaluate the influence of composition and mechanical properties of textile materials, and filling type on puckering (surface irregularities) of embroidered element. 4. To determine the influence of technological parameters of embroidery process on the quality and fluorescent characteristics of element embroidered with liuminescent threads. Novelty and practical value of the dissertation. The Thesis also contains the original research methodology for material buckling inside embroidered element (in limited area), the original research and evaluation methodology, including the assessment criteria. The Thesis also contains the assessment of puckering of embroidered element, based on the number of puckers and their height; the options of puckering defects of embroidered element are presented. The Thesis evaluates the possibility of increasing the efficiency of research and evaluation of the quality of embroidered element, using the 3D scanner for estimating puckering of embroidered element and fabric around it.the Thesis studies and evaluates the functional properties of luminous elements. The research can provide information about applicability of elements embroidered with liuminescent threads not only for textile decoration, but also for extension of their functional properties. The quality assessment criteria for embroidered elements established in the Thesis complement the classic textile materials science, and the ability to use software packages becomes an advantage for follow-up and applicability of the research. Defensive propositions: 1. The surface filling factors and mechanical properties, such as bending rigidity, elongation, formability of textile materials influence nonconformity of the shape of embroidered element to designed digital element. 2. Stitch direction and different filling types affect the dimensional accuracy of embroidered element and defect formation. 3. Fluorescent luminance properties of liuminescent embroidered elements vary depending on the filling type used during embroidery process and stitches forming direction in relation of the fabric yarns system. Approval of the research results. The results of the research are presented in 11 scientific publications, 5 of them in the issues that correspond to the list of Institute of Scientific Information (ISI), 1- in the issue, which corresponds to the list of data base of an Institute of Scientific Information, 2 publications in the other referred scientific publications in International Database and 3 publications in reviewed proceedings of Lithuanian scientific conferences. The results are presented at 7 international and 7 Lithuanian conferences. 7

9 Structure of the doctoral dissertation. The doctoral dissertation consist introduction, 3 chapters, conclusions, list of references (126 entries) and list of sceintific publications. The material of the doctoral dissertation is presented in 110 pages, including 79 figures and 14 tables. CONTENT OF THE DOCTORAL DISSERTATION Introduction presents relevance of the dissertation, states the objective of the paper, describes the novelty and practical value thereof. Chapter I overviews research references related to the subject of the dissertation. Chapter II of Part 1 lists the key characteristics of investigated textiles. Standard and original research methods have been developed and applied to define the characteristics of textiles, embroidery threads and adhesive interlinings. Density P m and P a of investigated threads have been determined in compliance with LST EN , whereas linear density of threads T a and T m as well as fabric surface density W have been established in compliance with LST ISO Characteristics of bending rigidity of fabrics and laminated systems have been defined based on screening method in compliance with FAST methodology and using the rig device produced by KTU scientists. Averages of values of the investigation results as well as variation coefficients ranging from 1.3 to 10.0 % have been computed. Variation coefficients of bending rigidity of fabrics ranging from 1.3 to 9.5 % and of elongation of fabrics did not exceed 10%. Characteristics of fabrics formation F and shear resistance G have been determined. Mechanical properties of embroidery threads have been investigated in compliance with ISO 2062, also thread breaking characteristics (breaking force, relative breaking elongation and specific breaking force) have been defined. Against the obtained curves of mechanical hysteresis, the following parameters have been determined: general elongation e b, %, elastic elongation e e, % and residual elongation e l, % of embroidery threads. Curves obtained in the process of investigation of creep and creep recovery of embroidery threads have been employed to define general deformation ε b, % of embroidery threads and components thereof, i.e. resilient elongation ε t, %, elastic elongation ε e, %, residual elongation ε l, %. In the process of embroidery, interlinings/accessories have been used in order to stabilise fabrics. For the investigations, non-woven adhesive interlinings different by surface density, thickness, adhesive cover type, etc., have been selected. 8

10 Chapter II of Part 2 Embroidered textiles consist of the following: fabric, upper embroidery thread, lower embroidery thread (Fig. 1.). Fig. 1. Diagram of Assembling of Textiles by the Embroidery Process, where 1 outer embroidery hoop, 2 inner embroidery hoop, 3 test sample, 4 upper embroidery thread, 5 lower embroidery thread, 6 point or intertwining of embroidery threads Forming Technique of Strip-Shaped Embroidered Elements. Two different filling types, i.e. T (tatami) (Fig. 2, a) and Z (zigzag) (Fig. 2, b), have been selected. A L B a b Fig.2. Embroidery Area Forming Diagram: a Filling Type T; b Filling Type Z; where: A stitch length; B distance between stitches; C embroidery width; L- embroidered element length; legend: embroidery contour; embroidery thread; needle insertion place forming direction of embroidery stitches Digital element features the following: width C = 2, 3, 4, 6 and 7 mm, length of 60 mm and stitch density (distance between stitches) B = 0.42 mm. 6 test samples have been embroidered in each selected directions (warp, weft and bias direction of 45 ). Forming Technique of Round and Square Embroidered Elements. For embroidered elements, the following three different filling types have been selected: CCS (Concentric Circle Stitch), RS (Radial Stitch), FS (Fill Stitch). Radius of round digital element is r = 25 mm, whereas side length of square element is 50 mm. Investigation Technique of Dimension Conformity Between Embroidered Element and Digital Element. Dimension conformity between embroidered element and designed digital element has been measured 24 hours after the embroidery process and removal of test sample from the embroidery hoop. Technique for measurement and computation of geometric parameters of strip- C 9

11 shaped embroidered element has been offered. Width, length and area of embroidered element have been determined. To define nonconformities, percentage change in width, length and area have been calculated. Computed variation factors of the research results of narrowing of embroidered element ΔC p has not exceeded 9.0 %, of ΔL p has ranged from 0.4 to 2.0 % and of ΔS p has not exceeded 5 %. Radius r r of round embroidered element is measured from the centre to the edge of embroidered element. Origin point of the measurements in progress is located on the vertical axis that tallies with axis y of the coordinate system, i.e. the weft direction of fabric. Axis x of the coordinate system tallies with the warp direction of fabric. Radius r r of embroidered element is measured every 22.5, the direction of measurement tallies with the clockwise direction (Fig. 3, a). Values of height k r and width l r of square embroidered elements have been measured at the origin point, end point and every 6.25 mm (Fig. 3, b). Deviation ΔΦ of angle values of embroidered element has been computed. O k l a b Fig.3. Radius Measurement Diagram of Embroidered Element: a Round Form, b Square Form Deviation ΔΦ of angle values of embroidered element in respect of angle values of digital element has been measured. Variation factor of the results demonstrated by width l r and height k r of square embroidered elements have ranged from 0.3 % to 5.6 %, whereas variation factor of angle measurement results have varied from 0.8 % to 7.9 %. The original research methodology for investigation of fabric puckering inside embroidered element. Inside embroidered element, fabric is compressed in the small space confined by embroidery threads. Scientific publications discussing research techniques with respect to buckling and puckering of textiles in a confined space have not been found. For investigation of fabric puckering inside embroidered element, clamps of original structure have been developed to fasten 10

12 investigated test sample. Test samples have been shot by digital camera OLYMPUS E6201. The following geometric characteristics of embroidered element have been defined: embroidery width C r, embroidery thickness D r, pucker height inside element E r, pucker length inside element F r (Fig. 4). Variation factor value of embroidered element thickness D r have ranged from 4.0 to 9,6 %, of embroidered element width C r has not exceeded 5.8% and of height of pucker inside embroidered element F r. have ranged from 8.3 to 9.6 %. Theoretical element C t = C sk D t = h + 2d F t = C t Embroidered element C r < C t D r > D t ΔC = C t - C r E r > 0 F r < F t Fig. 4. Measurement Diagram of Geometric Characteristics of Embroidered Element, where: 1 stationary clamps, 2 mobile clamps, 4 removable parts of clamps, 6 test sample; where: C t theoretical width of embroidered element, mm; C r actual (real) width of embroidered element, mm; AC nonconformity between C t and C r; D t theoretical thickness of embroidered element, mm; D r actual (real) thickness of embroidered element, mm; F t theoretical length of fabric inside embroidered element, mm; F r actual amount of fabric inside embroidered element, mm; E t theoretical height of pucker inside embroidered element amounting to 0; E r actual height of pucker inside embroidered element, mm The assessment methodology for puckering of embroidered element. Height measurement of embroidered element puckers has been started 24 hours after the embroidery process and removal of test samples from the hoop. Puckering of embroidered element is characterised by number of puckers n and height of pucker f. Embroidered element pucker height f v of variation coefficients v range from 2.5 to 10.0 % Processing of 3D Scan and Data of Embroidered Elements. 3D scanning technology has been applied to assess puckering of both embroidered element and fabric around embroidered element. Test sample with area of 52.5 mm 87.5 mm and with embroidered element in the centre has been investigated. The area under investigation has been split into longitudinal and transverse sections spaced by 2.5 mm. Correlation function of investigated surface is described by the following formula: F ( x) = k 0 l 2 H ξ where: k 0 dispersion (point scattering); H Hurst exponent; ξ lateral correlation length. (1) 11

13 Lateral correlation length ξ defines the distance between the given point and next pucker. Relation between lateral length and the Hurst exponent is described by the following expression of approximating correlation function: where: x scanned length, ξ lateral parameter, H Hurst exponent, o σ 2 section point scattering. Study of the obtained sections has enabled to compute empiric and approximating correlation functions. The research methodology for fluorescent luminance of embroidered element. To define fluorescent properties of square embroidered element, variation of fluorescent luminance intensity of the elements embroidered with different filling types has been analysed through measuring change of fluorescent luminance of embroidered element in time. Test samples have been attached to a black vertical plate and left for 24 h hours in impenetrable darkness. Then test samples have been illuminated by a glow halogen lamp of 75 W for 10 minutes providing over the surface of test sample constant irradiance of lx. The lamp has been connected to indicated voltage of 240 V, the value whereof has been controlled by an electrodynamic voltmeter with 0.5 accuracy class. As soon as illumination has been turned off, luminosity meter KONICA MINOLTA LS110 has been employed to measure fluorescent luminance of embroidered elements of test samples. Measurement results have been recorded in a PC every 1 sec as long as luminance reached the measurement limit of 0.01 cd/m 2 of the luminosity meter. Irradiance of test sample has been registered by luxmeter MASTECH MS6610. Chapter III of Part One. The influence of properties of embroidery threads on the shape of embroidered element. Analyzing the influence of filling type and mechanical properties of embroidery threads on the width of embroidered element it has been observed that the width dimensions of embroidered elements in all cases had not correspond with the dimensions of designed element. Embroidery with Filling Type Z using the selected embroidery threads, where the widths of designed digital element of test samples are C sk = 2, 3, 4, 6 and 7 mm has in all cases shown the higher narrowing values of embroidered element than by embroidery with Filling Type T. Linear dependences (Fig.5.) have been established between the width C r, of embroidered element and recovery power ε of embroidery threads, using embroidery with Filling Types T and Z in the bias direction. (2) 12

14 a Fig.5. Dependence of the width (C r, mm) of embroidered element on recovery power of embroidery threads power (ε, %) in the bias direction, where C sk = 3 mm: a) Filling Type T; b) Filling Type Z Narrowing of embroidered elements with Filling Type Z has ranged from 10 to 30 %. Meanwhile, the nonconformities for Filling Type T have ranged from 3.3 to 15 %. The investigations have shown that properties of embroidery threads influence the dimension changes of embroidered elements. It has been observed that using embroidery with Filling Type Z with polyester embroidery threads SV1 and viscose embroidery threads SV3, where the widths of digital element C sk = 6 and 7 mm, the widths of embroidered elements had decreased to the maximum values. The influence of textiles properties on the shape of embroidered element. The influence of physical textiles properties and the filling type of embroidered element on changes in dimensions of embroidered element has been analysed using fabrics A1 A15 and 100 % polyester thread SV6. Test samples have been embroidered with Filling Types T and Z in the weft and warp directions of fabrics. The selected dimensions of designed digital element are as follows: width C r 6 mm, length L r 60 mm. Test samples of fabrics A14, A15, A5and A12 embroidered with Filling Type T in the weft and warp directions have demonstrated the results closest to the designed width values. In the first case the nonconformity ΔC p has amounted to 1.7 %, and in the second case - to 3.3 %. Elements of fabrics A4 and A9 embroidered in the warp direction have demonstrated the smallest width values compared with the designed ones, the nonconformity ΔC p being 13.3 % and 11.7 %. The same trend has been observed in the weft direction. Elements of fabrics A4, A8 and A9 embroidered in the weft direction have narrowed to the maximum values, and the width change has amounted to 15 % and 13.3 % accordingly. A similar trend has also been observed with regard to elements formed using Filling Type Z. Elements of fabrics A4 and A9 embroidered in the warp and weft directions have demonstrated the largest narrowing compared to the designed one, in some cases amounting to %. The width change ΔC p of b 13

15 element of fabric A9 embroidered in the warp and weft directions has amounted to 28.3 and 30.0 % accordingly, while the one of fabric A4 as amounted to 25.0 and 28.3 %. A group of fabrics has been identified, characterised by close thickness values (h, mm), which can be classified in the same group in accordance with the range of products. Linear dependence has been observed to exist between the thickness h of fabrics (A6, A7, A8, A14 and A15) and the width values of elements embroidered with Filling Type T, i.e., the greater the thickness of fabric, the greater the width of embroidered element (Fig.6.). Fig.6. Dependence of the width C r of embroidered elements on the thickness h of fabric, using embroidery with Filling Type T; where: warp direction, weft direction The dependencies have been established between the width C r of embroidered element and linear filling indicators e m and e a of fabric. Strong relation has not been established, and the empirical correlation coefficient is low. However, relatively stronger relation has been demonstrated between the analysed indicators using warp direction. The maximum nonconformities of the width of embroidered element with regard to designed digital element have been caused by the values of fabric filling indicators and density in the warp and weft directions, i.e., at low values the nonconformities of embroidered element have ranged from 11.3 to 30.3 %. The research of influence of stitches direction on the shape precision of embroidered elements. Embroidered clothing elements, such as various emblems, company logos, inscriptions, are often formed from several or even a several of different colours and fragments. Embroidery threads, physicalmechanical textiles properties, forming direction of embroidery stitches, stitch density and other factors often result in nonconformities between the relevant parameters of embroidered and digital element. Upon measuring the values of radius r r and the width l, height k and angles Φ, the nonconformities in both dimensions and shape of element can be evaluated. The investigation of elements embroidered with Filling Type CCS has shown that in all cases the shape of embroidered element had not corresponded with the shape of designed element. The largest nonconformities in dimensions 14

16 have been observed at embroidered elements of cotton fabric A2. The nonconformity Δr pi of the outer outline radius in percent style has ranged from to 2.3%, while the nonconformity Δr pp of the primary portion radius has ranged from 2.6 to 5.2%. Square elements embroidered with Filling Type CCS have also demonstrated the deformation of the primary portion and the resulting gap between the primary portion and angle filling fragments, as well as broken outer outline. In all cases the nonconformity in dimensions (the width and height values) has been determined with the respective parameters of designed element. It has been noted that in all cases the 90 angle had not been maintained. The calculation of the values of all four angles Φ of elements of fabric A1 embroidered with Filling Type CCS has shown that the angles had decreased from 0.4 to 1.9 % (i.e., ranged from 88.3 to 89.7 ). The angles of embroidered elements of fabrics A2 and A11 have almost always been higher than the ones of designed digital element. The following defects have been observed at elements embroidered with Filling Type CCS (Fig.8):- uneven outline of the last row of stitches or angle filling, broken outline of the last row of stitches or angle filling, nonconformity to the shape of designed digital element, a gap between the round-shaped primary portion and the last row of stitches (or angle fragments in case of square-shaped elements) due to shifting of the portions. Such a distance can be easily detected by human eyes and the defects are clearly visible. Fig.8. Defects of elements embroidered with Filling Type CCS In elements of fabrics A1 and A2 of plain weave embroidered with Filling Type RS the values of radius r r value was closer to the digital ones. Fabric A2 has been characterised as the most flexible one of all the investigated fabrics, and has demonstrated the lowest surface density W and the lowest values of the 15

17 bending rigidity B, therefore the defect more significantly affects embroidered elements of this particular fabric. The maximum decreased values have been observed at the radii r r embroidered elements of warp satin fabric A11 - the nonconformity Δr pa11 of measured values of the radius have ranged from -1.1 to 3.3%. This fabric contains high floats of threads shifting easily, and embroidered element gets the shape of an ellipse (oval). The lowest values of both the width l r and the height k r have been observed at square-shaped elements of 100 % polyester fabric with an elastane filament embroidered with Filling Type RS. The width nonconformity Δl pa11 has ranged from -1.9 to -3.9 %; and the height nonconformity Δk pa11 has ranged from -0.6 to -2.9 %. The average dimensional reduction (nonconformity) in percent style has amounted to 2.4 % and for the width and 1.6 % for the height. The estimated angles values of embroidered elements have been higher than the ones of designed digital element. In this case, the maximum nonconformities in percent style have been observed at embroidered elements of fabric A2 and have ranged from 2.2 to 5.7 %. The angle values of fabrics A1 and A11 have increased to 4.8 and 4.3 % accordingly. The following defects have been observed at elements embroidered with Filling Type RS (Fig.9): a hole in the central portion of embroidered element, nonconformity with designed digital element, uneven "jagged" outline of embroidered element. 16 Fig.9. Defects of elements embroidered with Filling Type RS Therefore, the values of actual radius r r of element embroidered with Filling Type FS have demonstrated greater decrease almost in all cases. The values of radii r r of round-shaped embroidered elements of linen fabric A1 in all measurement directions have not met designed dimensions and have ranged from -3.7% to 0.6%. Due to fabric porosity thread slippage has been observed along the side edges of embroidered element. Embroidered elements of fabric A4 characterised by the lowest surface density (W A4 = g/m 2 ), the lowest fabric surface filling indicator (e s = 0.578) and one of the lowest density in the warp and weft directions (P ma4 = 18 cm -1, P aa4 = 20 cm -1 ) have featured the most

18 significant nonconformities in shape compared with designed digital element, ranging from 1% to 7% in the different measuring direction. Embroidered elements of fabrics A2 and A8 characterised by high density in the warp and weft directions, and the maximum surface filling indicators have featured similar nonconformities in shape and dimension. In this case the nonconformity of the radius value of embroidered elements of fabric A2 is Δr pa2m = -2.3 %, and Δr pa2a = 1.5 %. The nonconformity of the actual radius value of embroidered elements of fabric A8 is Δr pa8m = 4.3 %, Δr pa8a = 2.4 %. The maximum narrowing values have been observed at square-shaped embroidered elements of fabrics A4 and A8. The nonconformity between the actual width value of embroidered element and the designed one in percent style has been 5.8 and 5.0 % accordingly. The minimum nonconformities in width have been observed at embroidered elements of fabrics A1 and A2, and Δk p in this case has ranged from 2.4 to 3.6 %. The analysis of the height of embroidered elements has revealed that the height values of some fabrics had been higher than the designed ones. In the particular case the nonconformity values of fabric A2 have ranged from 0.8% to 1.8 % (i.e., 0.6 mm) and in case of fabric A8 the value Δk pa8 has ranged from 3.2% to 3.8 % (0.3 mm) accordingly. The nonconformity of the height values of square-shaped embroidered elements of the remaining fabrics has ranged from to -0.6 %. The angle values of elements embroidered with Filling Type FS of all the investigated fabrics have not matched the respective values of designed digital drawing and have varied within a wide range: from 86.6 to It has been determined that there is relatively strongest linear relation between shear rigidity characteristics G (Fig.10) of selected fabrics, weaker relation has been established between the value of radius r rv and fabric indicators for formability F and elongation E. Fig.10. Dependence of the radius r of embroidered element on shear rigidity characteristics of fabric G, N/m: where: SV1; SV3 17

19 The nonconformities in shape and dimensions of identified for elements embroidered with selected filling types, as compared with designed digital element (Fig.11). Fig.11. Defects of elements embroidered with Filling Type FS Occurrence of the defects has been influenced by surface filling indicators of selected fabrics and density in the weft and warp directions. Fabrics with lower density and lower surface density have been subject to bigger nonconformities in width l r, height k r and shape discrepancies. The influence of textiles properties on fabric puckering inside embroidered element. Unevenness of the width values D r of embroidered elements have been also influenced by properties of embroidery threads discussed in previous chapters. In many cases puckers with the greatest height values have formed inside elements embroidered with polyester embroidery threads SV1. The direction of embroidered fabric has also influenced pucker height inside element E r. In all the cases analysed, the puckers inside elements embroidered in the weft direction have been lower compared to the ones inside elements embroidered in the warp direction of. Formation of puckers with the greatest height values E r inside elements embroidered with polyester embroidery threads SV1 has been observed in all cases. This fact may be explained by the great value of reversible deformation of embroidery threads SV1. Significant difference of pucker shape has been determined in the process of embroidery with different embroidery threads, while applying designed element width C sk = 7 mm. Fabric has deformed, forming flat S-shaped puckers inside elements embroidered with embroidery threads SV2 and SV3. By decreasing the width of designed element in all cases, i.e., in the process of embroidery with all selected embroidery threads, low puckers have been formed inside embroidered element, as suggested by lower thickness values of embroidered element D r. When fabric is compressed in small space confined 18

20 by embroidery threads and the height of embroidered element is not small, material threads tighten, forming an uneven curvilinear outline of pucker. The width C r of embroidered element is in all cases smaller than the width C sk of designed element. While applying designed element width C sk = 7 mm, the width value C r of element embroidered with embroidery threads SV1 in the warp and weft directions has decreased the most, i.e., ΔC p has been 24 % and 25 %. Linear dependence has been observed to exist between reversible elongation ε of selected embroidery threads and the thickness D r of embroidered element (Fig.12). Embroidery with Filling Type Z, where the widths of designed digital element C sk are 6 and 7 mm has shown the stronger dependence in the weft direction than in the warp direction. a b Fig.12. Dependence of the thickness D r of embroidered element on reversible elongation ε of threads: a the warp direction; b the weft direction; where: C sk = 7 mm; C sk = 6 mm The same trend is observed in the analysis of the values of the width C r of embroidered elements and reversible deformation ε e of selected embroidery threads (Fig.13). The strongest relation in most cases has been established in the process of embroidery in the weft direction. a b Fig.13. Dependence of the width C r of embroidered element on reversible elongation ε of threads; a the warp direction; b the weft direction; where: C sk = 7 mm; C sk = 6 mm; C sk = 4 mm; C sk = 3 mm It has been determined that depending on textiles properties puckers of different shapes are formed inside embroidered element. On the basis of the research results a few types of pucker shapes have been distinguished (Fig.14): 19

21 1. Type 1 - even contour-shaped puckers are formed inside embroidered element (Fig. 14., a). 2. Type 2 flat S-shaped puckers are formed inside embroidered element (Fig. 14., b). 3. Type 3 uneven, complex contour-shaped puckers are formed inside embroidered element (Fig. 14., c). a b c Fig.14. Types of pucker shapes: a Type 1; b Type 2; c Type 3 Pucker shape has been established to depend on fabric structure. Puckers of Type 1 have been observed in embroidered elements of fabrics A1, A4, A10 and A13. Pucker shape of Type 2 is more complex it is formed both in the positive and negative directions of the x-axis and has the maximum point and the minimum point. Thus the pucker height can be measured between these points. Puckers of Type 2 have been formed inside embroidered elements of fabrics A2, A3, A5, A6, A9, A14 and A15. In case of Type 3 pucker is formed, having two maximum points and two minimum points. In this case, the pucker height E r is defined by the maximum distance between the maximum and the minimum points. Puckers of Type 3 have formed in the warp direction of fabrics A8 and A11, and in the weft direction of fabric A7. In the aforementioned directions, values of surface filling indicators in fabrics A7 and A8 have exceeded 1. It is necessary to identify a group of fabrics, i.e., A7, A8, A11, where the pucker shape and pucker height E r values inside embroidered element in one direction of fabric have been significantly different from the shape of pucker in other direction of fabric. Fabrics A7, A8, A11 contain elastane filaments: fabric A7 contains an elastane filament in the warp direction, whereas fabrics A8 and A11 contain an elastane filament in the weft direction. In the above said fabrics, linear filling indicators in opposite directions have been different. 20

22 Analysis of the research results illustrates that linear filling indicators e of fabrics and the pucker height values E r inside embroidered element are related by a rather close linear relation (Fig.15). Fig.15. Dependence of the pucker height E r on linear filling indicators e m and e a of fabric: warp direction (r = 0.874); the weft direction (r = 0.709) In this case, the greater linear filling indicator of fabric results in the higher pucker having formed inside embroidered element. In this situation, fabric threads under compression have no place for compaction, therefore, fabric buckles forming pucker of certain height and shape. Based on the research results it has been determined that reversible elongation ε e of embroidery threads, linear filling indicators e m and e a, of fabric influence the thickness D r and width C r of embroidered element, as well as formation of puckers of different height E r and shape inside embroidered element. In many cases formation of higher puckers is observed due to increase of the linear filling indicator values. The investigation of puckering of embroidered element. The analysis of scientific literature has shown that process of embroidery, causes and nature of puckering defects of embroidered element have not been widely investigated. Options of puckering defects of embroidered element. The following options of puckering of embroideredelement can be distinguished (Fig.17): 1. Embroidered element does not pucker, deformation of fabric threads is observed at the beginning and at the end, perpendicularly to the formation direction of embroidered element (Fig.17, a). 2. Embroidered element does not pucker, puckering is observed on fabric around embroidered element (Fig.17., b). 3. Embroidered element pucker, stretching fabric around it (Fig.17, c). the 21

23 a b c Fig.17. Puckering options of embroidered element In many cases, puckers of various complexities are formed perpendicular to the direction of stitch formation, in this particular case this being edges of embroidered element (the beginning and the end). A bigger pucker most often is observed at the end of embroidered element. The first option of puckering (Fig. 17., a) is observed in all embroidered test samples. However compression of fabric threads or puckers at the edges of embroidered element has differed in 22

24 intensity. A group of fabrics (A1, A4, A9 and A10) can be identified, where only the first option of puckering has been observed in the process of embroidery with both filling types (T and Z), and in both fabric directions (warp and weft). The second option of puckering (Fig.17, b) has been observed in elements of fabrics A3, A11 and A12 embroidered with Filling Types T and Z in the warp direction. In this case embroidered element does not pucker, and fabric forms puckers of various length (from 11 to 22 mm) and width (from 6 to 16 mm). The third option of embroidery puckering (Fig.17, c) has been observed at the test samples of fabrics A2, A7, A8, A11 A15. n the process of embroidery with Filling Types T and Z of fabric A7 in the warp direction, and in case of fabrics A8 and A11 in the weft direction, puckering of embroidered element has been observed. The test samples of fabric A7 embroidered in the warp direction with Filling Type Z have proved less puckering, namely less puckers are observed and they are lower than in case of embroidery with Filling Type T. In all described cases, puckers are formed at the beginning and at the end of embroidered element. Formation of a greater pucker has usually been observed at the end of embroidered element. This fact is especially relevant for fabrics containing elastane and for flexible fabrics. It shall be noted that puckering is influenced not only by surface density, thickness, fibre composition, weave or direction of fabric, but also the filling type. Thus it is possible to assess puckering not only for strip-shaped embroidered element, but also for elements of other geometric shapes. The investigation of the influence of adhesive interlining on puckering of embroidered elements. For stabilisation of textiles during embroidery process, interlining materials are used. However there is a lack of scientific research or for comprehensive guidance on the features of interlining materials to be used for particular textiles. Laminating stiffens the system, and at the same time changes the bending rigidity values thereof. Bending rigidity values of fabric A11 in the warp and weft directions have been established to be B-1 = 33.7 μnm and B-2 = 3.8 μnm respectively. Bending rigidity values B of the test samples in systems laminated with a longitudinal adhesive interlining in the warp direction have increased from 1.9 to 4.4 times compared to bending rigidity values of the nonlaminated test samples. Bending rigidity values B of the test samples in systems laminated with a cross adhesive interlining in the weft direction have increased from 1.8 to 4.6 times; whereas the ones of the test samples in systems laminated with a longitudinal adhesive interlining from 4.4 to 11.6 times. In case of laminated systems AFI1, AFI3 and AFI6 the bending rigidity values B in all cases have changed to the maximum values. A strong linear correlation between bending rigidity value B (a.1) of laminated systems and values of pucker height f of embroidered element during 23

25 embroidery with Filling Types T and Z has been established. A slightly stronger relation has been demonstrated by embroidery with Filling Type Z. Such dependence is observed when bending rigidity values B (a.1) of system laminated with a cross adhesive interlining exceed 10 μnm, i.e. of laminated systems AFI1, AFI3, AFI5 and AFI6. The aforesaid dependence has not been established for laminated systems featuring lower bending rigidity. Medium-strength linear dependence exists between bending rigidity B (m.) of the systems laminated with a longitudinal adhesive interlining in the direction of warp and height f of embroidery element during embroidery with Filling Types T and Z, i.e. r = 0.67 and r = 0.73 respectively. In most cases, embroidery with Filling Type T has demonstrated the greatest values of pucker height f of embroidered element characteristic of embroidered elements of systems laminated with a cross adhesive interlining in the weft direction. The greatest pucker height f, i.e. 3.9 mm, has been observed for embroidered element of laminated system AFI6, whereas pucker height values of laminated systems AFI3 and AFI5 have amounted to 3.3 mm and 3.4 mm respectively. The pucker height values of embroidered elements of systems laminated in the warp direction have been lower. The lowest height value f of embroidered element has been observed for laminated system AFI6, amounting to 1.5 mm. Investigations have illustrated that embroidery with Filling Type Z in the warp direction in all cases had shown significantly higher values of embroidery element, i.e. from 3.9 mm to 4.8 mm, compared to embroidery with Filling Type T. Assessment of the test samples of laminated systems by the quantity of puckers has shown that the greatest number of puckers had been observed for elements embroidered with Filling Type T in the weft direction. The greatest average number of puckers, i.e. n = 6, has been demonstrated by embroidered elements of laminated system AFI1. Embroidered elements of laminated systems AFI2 and AFI3 have also shown high number of puckers, i.e. n = 5. It shall be pointed out that embroidery with Filling Type T in the warp direction in all cases has demonstrated the same number of puckers in laminated systems, i.e. n = 2. Puckers have formed just at the beginning and at the end of embroidered elements. Embroidery with Filling Type Z has not demonstrated definitely expressed puckers in embroidered elements. Usually, puckers have been formed at the beginning and at the end of embroidered element, lifting the ends of embroidered element, thus being considered as a pucker. In all cases, difference between the height value of embroidered element at the beginning and at the end has ranged from 0.2 mm to 0.4 mm. Not in all cases laminating with an adhesive interlining has been established to demonstrate positive results, i.e. to decrease the quantity of 24

26 puckers n and reduce the height of puckers or embroidered elements f. Discussing the influence of lamination using adhesive interlining of different properties and different direction thereof on the pucker height of embroidered elements it shall be noted that the results of embroidery with different filling types in some cases are significantly different. Lamination has reduced the height of elements embroidered in the warp direction, namely the lowest value f (1.5 mm) has been established for embroidered element of system AFK6, and the highest value f (2.5 mm) has been established for embroidered element of system AFK4. In case of systems laminated with a cross adhesive interlining in the weft direction only the pucker height of embroidered element of system AFK1 has remained unchanged, while the rest f values have ranged from 3.1 to 3.9 mm. Pucker height f have decreased in almost all cases for embroidered elements of systems laminated with a longitudinal adhesive interlining in the weft direction, ranging from 1.9 to 2.8 mm. In the process of embroidery with Filling Type Z (Fig.19) in almost all cases the pucker heights f have increased from 4.1 (A11) to 4.8 mm (AFK1). Laminating of fabric with adhesive interlinings that feature various properties has different influence on occurrence of puckering defect in the test samples. Summarizing the research results it can be suggested that lamination of stretch fabric with a longitudinal adhesive interlining can stabilise fabric and, in some cases, reduce the height and number of puckers. The analysis of changes in the width of embroidered element of laminated systems has shown that the decrease in the width values of embroidered element after lamination had been lower in almost all cases, when using Filling Types T and Z, compared with the nonlaminated samples. In this case, it can be noted that the best results in all cases have been observed at laminated system AFK5 (Fig.19., a, b). Fig.19.. The width C r, of embroidered element, in mm, where: a) Filling Type T; b) Filling Type Z; where: (m) system laminated with a longitudinal adhesive interlining in the warp direction; (a.1) system laminated with a cross adhesive interlining in the weft direction; (a.2) system laminated with a longitudinal adhesive interlining in the weft direction 25