A study on coarse Hanji yarn manufacturing and properties of the Hanji fabric

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  • Fibers and Polymers 2013, Vol.14, No.2, 311-315


    A Study on Coarse Hanji Yarn Manufacturing and Properties of the

    Hanji Fabric

    Tae Young Park and Seung Goo Lee1*

    Division of Fashion Design and Beauty, Howon University, Kunsan 573-930, Korea1BK21 FTIT, Department Advanced Organic Materials and Textile System, Chungnam National University,

    Daejeon 305-764, Korea

    (Received August 10, 2011; Revised November 1, 2011; Accepted July 5, 2012)

    Abstract: Hanji (Korean traditional paper) yarn displays excellent humidity control, air permeability, and absorbency as wellas pleasantness to the touch due to its structural characteristics, and thus, it has been developed as a new eco-friendly fibrousmaterials. In this study, Hanji, having a basis weight of 8 and 10 g/m2, was prepared using mulberry fibers. The preparedHanji was cut into Hanji tape of 5-10 mm in width using a rotary slitter and then the tape was twisted to manufacture Hanjiyarn. To ensure a uniform twist of Hanji yarn and a smooth twisting process, a water supply system was designed to providewater directly at the twisting zone. At a fixed spindle speed, the feeding speed of the delivery roller was varied to providedifferent twist numbers for the Hanji yarn. The Hanji yarn manufactured with water treatment has higher tensile propertiesand a softer touch than the Hanji yarn prepared without water treatment. The Hanji yarns have count numbers of 7-11 Ne andtensile strengths of 1.0-1.2 gf/d. Moreover, the fabric from Hanji yarn shows an excellent color fastness of 4.0 grade, stainingof 4-5 to washing, and 4-5 grade to dry cleaning.

    Keywords: Hanji, Mulberry fiber, Hanji yarn, Water supply system, Twist


    The traditional method for manufacturing Hanji yarn

    consists of preparing the paper yarn according to a twisting

    process, which includes preparing Hanji using mulberry

    fiber as a raw material, cutting the Hanji to a predetermined

    length, and twisting it using a spinning wheel [1]. The

    obtained paper yarn, however, has unstable twists, poor

    strength, and elongation, and thus it cannot be formed into a

    fabric using a conventional power loom and knitting machine;

    rather a table loom must be used. Therefore, the mass

    production of coarse Hanji yarn using mulberry fiber is

    limited. The fabric from Hanji yarn has been used traditionally

    in shrouds, neck ties, and crafts.

    The manufacturing of a uniform and light-weight paper

    sheet using long mulberry fiber is difficult. Generally, the

    preparation of the paper yarn used in Japan involves cutting

    paper sheets made of Manila hemp into a tape with a

    predetermined width using a cutting apparatus, then twisting

    the tape to produce the paper yarn. Various paper making

    techniques, cutting machines, and twisting methods have

    been developed in Japan [2-7].

    Therefore, for the prevention of yarn cut-off in a knitting

    or weaving process and stable management of the paper

    yarn fabric, various raw materials and paper-reinforcing

    agents have been used in the preparation of the paper [2,3].

    Such paper yarn has, however, disadvantageously poor

    flexibility compared to common yarn. To improve this

    flexibility, several methods have been proposed. For example,

    a wax or oil, steaming has been added [4-6]. As a result, the

    flexibility is more or less improved, but there are still

    limitations. Therefore, an additional twisting process [8] is

    required to make flexible paper yarn while maintaining a

    uniform twist and preventing the yarn cut-off in the weaving

    or knitting process. Also, it is necessary to use the paper-

    reinforcing agent in the proper amount and select a raw

    fiber material with a relatively long fiber length in a range

    suitable for paper making. Also, some methods for preparing

    composite yarn with other yarns or covered yarn can be

    applied [1,9].

    Generally, paper yarn has excellent humidity control, air

    permeability, absorbency, and deodorant efficiency. Also,

    though it is prepared using staple fiber as a raw material,

    paper yarn is classified as a filament yarn. It is unique to the

    touch due to its slightly fluffy texture and has recently

    gained attention as a high value-added fashion material

    because it is an eco-friendly material.

    In this study, the property of Hanji yarn and a method for

    manufacturing Hanji yarn using mulberry fiber are studied.

    A new system for supplying water during the twisting

    process to prevent yarn cut-off and provide a uniform twist

    is proposed. The fineness of Hanji yarn is determined by

    adjusting the Hanji weight and width of the Hanji tape yarn.

    Also, from the analysis of the tensile properties, color

    fastness to the washing of the prepared Hanji yarn, and Hanji

    fabric, an end use for the Hanji yarn is investigated. The

    development of such coarse Hanji yarn may be used in

    producing fine Hanji yarn.

    *Corresponding author: lsgoo@cnu.ac.kr

    DOI 10.1007/s12221-013-0311-4

  • 312 Fibers and Polymers 2013, Vol.14, No.2 Tae Young Park and Seung Goo Lee


    Paper-making Process

    Mulberry fiber was beaten using a knife beater, and a

    concentration of 1.5 % was used. As the paper-reinforcing

    agent and a dispersing agent, 0.5 % epoxy and 0.5 %

    polyacrylamide, respectively, were used. The Hanji papers

    with basis weights of 8 and 10 g/m2 were prepared through a

    paper-making apparatus of Fourdrinier type, to a width of

    110 cm, and compressed and dehydrated using a press. The

    dehydrated Hanji was dried through a drying roller at

    110 oC, taken up to a length of 10,000 m and cut to a width

    of 220 mm.

    Preparation of Hanji Tape and Hanji Yarn

    Hanji was cut using a rotary slitter to produce the Hanji

    tape having a width range of 5 to 10 mm and the Hanji tape

    was taken up to a cone. The Hanji yarn was prepared by

    twisting the Hanji tape with a specially designed process. In

    this study, a water-supply apparatus was equipped in the

    twisting machine to feed water for smoothing the paper. By

    using a water-supply apparatus, water was uniformly supplied

    at a rate of 60 cc/min to the central part of the paper yarn.

    Figure 1 shows schematic diagram of the Hanji yarn

    production process, in which Hanji tape was supplied to a

    traveler through a yarn guide. Subsequently, the Hanji tape

    passed a yarn guide and was taken up around the bobbin in a

    spindle. The spindle speed was set to 4,100 rpm and the

    feeding speed of the delivery roller was varied to give

    different amounts of twist to the Hanji yarn. The produced

    Hanji yarn was dried in a drying oven.

    Preparation and Dyeing of Hanji Fabric

    Hanji fabric with 22 basket structure was prepared using

    a rapier loom to a fabric density of 5240/inch2. Hanji fabric

    was pretreated with 25 % Glauber salt for 5 s and dyed with

    reactive dyestuffs, Rifazol Brill and Blue R 0.12 %. The

    dyeing was performed at 60 oC for 30 min, followed by

    washing and drying.

    Evaluation of the Properties of Hanji Yarn and Fabric

    The fineness of the Hanji yarn was measured according to

    ASTM D1059. The tensile properties of Hanji yarn was

    measured according to ASTM D 2256, and the properties of

    the Hanji fabric was measured by ASTM D 5034. Also, the

    color fastness to washing and dry cleaning of the dyed fabric

    were measured according to AATCC 61/1A and 132,

    respectively. The surface structure of Hanji and Hanji yarn

    were observed by scanning electron microscopy (SEM). In

    addition, the yarn irregularity (U%) was evaluated with an

    Uster Tester 5-S800.

    Results and Discussion

    Structure and Tensile Properties of Hanji

    To manufacture very fine Hanji yarn, it is important to

    produce light-weight Hanji. In this study, Hanji was prepared

    with basis weights of 8 and 10 g/m2. When the weight is less

    than 8 g/m2, Hanji fails to have a uniform distribution of the

    mulberry fiber, but when the weight exceeds 10 g/m2, Hanji

    is not suitable for preparation of fine Hanji yarn.

    Figure 2 shows the surface structure of Hanji prepared by

    the paper making process, in which mulberry fiber was

    randomly distributed. Such a distribution of fiber orientation

    directly affects the tensile properties of the Hanji yarn.

    Referring to Figures 3 and 4, the breaking stress and strain of

    Hanji in the machine direction (MD) were slightly higher

    compared to the cross direction (CD). However, the difference

    was not significant, and thus, the distribution of mulberry

    fiber in the Hanji was nearly isotropic. The distribution of

    mulberry fiber might be selectively determined by the production

    rate or the type of paper-making machine. A parallel-laid

    distribution of raw fiber material is advantageous in the

    preparation of fine and strong yarn but confers a low

    breaking strain and a poor flexibility to Hanji yarn.

    Figure 1. Schematic diagram of the manufacturing system for

    Hanji yarn: (A) cone (Hanji tape yarn), (B) delivery roller, (C)

    water-supplying apparatus, (D) yarn guide, (E) traveler, (F) ring,

    (G) bobbin, and (H) spindle.

    Figure 2. SEM micrographs of the surface structure of Hanji: (A)

    8 g/m2 and (B) 10 g/m2.

  • Hanji Yarn Manufacturing Fibers and Polymers 2013, Vol.14, No.2 313

    Tensile Properties of Hanji Yarn

    Various Hanji yarns were produced with a range of 7 to

    11 Ne. The yarn count is determined by paper parameters

    such as the basis weight and width of Hanji tape. The

    product of the basis weight (g/m2) and cutting width (mm) is

    referred to as the paper characteristic factor (k). Figure 5

    shows the tensile strength of Hanji yarn with different twist

    numbers, in which the number in the bracket refers to the

    yarn count of Hanji yarn. The maximum breaking stress of

    Hanji yarn in this study was in the range of 1.0-1.2 gf/d, and

    the twist number showing the maximum breaking stress was

    650-700 tpm. Because Hanji tape is very stiff, it is necessary

    to feed water to the Hanji tape just prior to twisting to ensure

    better twisting. As the width of the Hanji tape was smaller,

    the twist number with the maximum breaking stress was

    gradually reduced. Also, for the same k value, the maximum

    strength of Hanji yarn increased as the width of the tape

    decreased. It is believed that the binding frequency between

    fibers in the thickness direction increased due to stable and

    better twist formation of the Hanji yarn as the width of the

    Hanji tape decreased.

    Surface Structure of Hanji Yarn

    The effect of the feeding amount of water on the cut-off

    frequency during the preparation of Hanji yarn is shown in

    Table 1. The optimal water feeding amount was 60-90 cc/

    min and the cut-off number increased in the finer yarn

    manufacturing. Also, the drying time could be shortened by

    minimizing the water-feeding amount.

    Figure 6 shows the surface structure of Hanji yarn.

    Uniform twist formation with fewer fluffiness was observed

    Figure 3. Breaking stress of Hanji with different test direction.

    Figure 4. Breaking strain of Hanji with different test direction.

    Figure 5. Tensile strength of Hanji yarn with twist amount.

  • 314 Fibers and Polymers 2013, Vol.14, No.2 Tae Young Park and Seung Goo Lee

    on the surface of water-treated Hanji yarns ((A), (C), (E))

    compared to untreated yarns ((B), (D), (F)). Because the

    water-treated Hanji yarn had a stable twist formation

    compared to the untreated (control) Hanji yarn, the water-

    treated Hanji yarn had a better appearance with fewer cut off

    phenomena. The results of yarn evenness are shown in

    Figure 7. The sample designations are the same as those

    given for the specification of Hanji yarn in Table 2. In Figure 7,

    the water-treated Hanji yarn and finer yarn had lower yarn

    irregularities than untreated and coarse Hanji yarn, respectively,

    because of their comparatively stable and smooth twist

    formation. Also, considering that the water-treated Hanji

    yarn has a slightly smaller diameter than the control yarn of

    the same yarn count, the water treatment leads to relatively

    high cohesion between fibers and therefore an improvement

    of fiber binding. However, when the paper-reinforcing agent

    exceeded a concentration of 1 %, it was difficult to obtain a

    stable twist formation in Hanji yarn. In the case of adding

    1.0 % epoxy, for example, an unstable twisted structure was

    continuously appeared [9]. In addition, instead of a plastic

    hose with pinhole for supplying water as was used in this

    study, spray guns or padding apparatus may be used [8].

    Table 2 shows the breaking stress, breaking strain, and

    initial stiffness of Hanji yarn. The water-treated Hanji yarn

    showed an increased breaking stress and strain and also a

    decreased initial modulus compared to the control yarn.

    These properties were a result of the water treatment.

    Table 1. Effect of water amount on the cut-off number for

    preparation of Hanji yarn


    Hanji weight


    /cutting width


    Water amount






    (#/5,000 m)

    A1 10/5.0

    30 Unstable

  • Hanji Yarn Manufacturing Fibers and Polymers 2013, Vol.14, No.2 315

    Tensile Properties and Color Fastness of Hanji Fabric

    Table 3 shows the tensile properties and color fastness to

    washing and dry cleaning of the Hanji yarn fabric developed

    as a canvas fabric, in which the warp and weft yarn were 7

    Ne used in C1 of Table 1. As expected from the fabric

    density of 5240/in2, the tensile strength of the Hanji fabric

    in the warp direction was superior to that in the weft

    direction. In contrast, the breaking strain in the weft direction

    was higher than that in the warp direction. Generally, a warp

    yarn underwent high tension in the warping or weaving

    process and thus it was almost fully extended, whereas the

    weft yarn was relatively less extended. Therefore, the

    breaking strain of the less extended weft yarn was larger

    than that of the warp yarn.

    The color change of the Hanji yarn fabric to washing was

    4.0 grade and the staining evaluation was 4-5 grade to the

    cotton fabric as an accompanying fabric. Also, the color

    fastness of the fabric to dry cleaning was 4-5 grade. These

    values of color fastness to washing and dry cleaning and

    resistance to staining are sufficient for use in home textile

    applications, and thus the Hanji fabric, prepared in this

    study, can be readily used in home textiles such as bedding,

    table cloths, curtains, and carpets as well as fabrics for

    denim and canvases.


    In the present work, the manufacturing process of Hanji

    yarn included following: (1) a paper- making process to

    prepare Hanji, (2) the preparation of Hanji tape yarn using a

    rotary slitter, and (3) the preparation of paper yarn by the

    twisting process. To obtain a uniform twisting and stable

    structure of Hanji yarn, a moisture-supplying apparatus was

    implemented. The produced Hanji yarn was a coarse yarn in

    the range of 7-11 Ne and had a breaking stress of 1.0-1.2 g/d.

    Also, the twist number with the maximum breaking stress of

    the Hanji yarn was 650-700 tpm. The water-treated Hanji

    yarn showed an increase in the breaking stress and breaking

    strain and a decrease in initial modulus, compared to the

    untreated yarn. The fabric prepared from Hanji yarn had

    excellent color fastness to washing and dry cleaning and



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