Comprehensive Study Guide for Textile Industry Vocabulary and Manufacturing Processes

Classification and Characteristics of Textile Fibers

The fundamental building blocks of the textile industry are fibers (Sén-i), which are broadly categorized into natural fibers (Tennén sén-i) and chemical fibers (Kagaku sén-i). Natural fibers are further divided into plant-based fibers (Shokubutsu sén-i) such as cotton (Momén), linen/ramie (Asa), and specifically ramie (Ramii), and animal-based fibers like wool (Youmou) and silk (Kinu). In contrast, chemical fibers include synthetic fibers (Gousei sén-i) such as polyester, nylon, acrylic, and spandex (also known as elastane). There are also regenerated fibers (Saisei sén-i) like rayon and semi-synthetic options like acetate (Aseteeto). In manufacturing, these fibers are often combined through a process called blending (Kunbou). The structural form of the yarn is classified as either filament yarn (Firamento-shi), which consists of continuous strands, or spun yarn (Bouseki-shi), which is made by twisting shorter staples together.

Knitting Structures and Fabric Characteristics

Knitting (Ami) involves creating fabric by interlacing loops of yarn. The specific arrangement is referred to as the knitting structure (Ami soshiki). Common types include jersey or plain knit (Tenjiku-ami), rib knit (Gomu-ami or Furaisu-ami), and purl knit (Paaru-ami). More complex structures include piqué or lacoste (Kanoko-ami), interlock (Intaarokku-ami), and double knit (Daburu-nitto), which involves a double layer of loops. The geometric orientation of the knit is defined by the wale (Ueeru), representing the vertical column of loops, and the course (Koosu), representing the horizontal row. Technical attributes of the fabric are measured by the stitch density (Domoku), stitch length (Amikomi-chou), and the gauge (Geeji), which indicates the number of needles per inch. Fabric weight is recorded as $Metsuke$, typically measured in $g/m^2$. Dimensional stability is crucial, as fabrics can suffer from skewing (Shakou), curling of the edges (Kaaringu), or the formation of fiber balls known as pilling (Piringu). The final garment assembly often involves the cut and sew (Katto soo) method.

Knitting Machinery and Component Engineering

Industrial knitting utilizes specialized equipment like the circular knitting machine (Maru-amiki). The primary mechanical components include the cylinder (Shirinda) and the dial (Daiyaru). The actual knitting is performed by needles (Hari), specifically the latch needle (Ratchi-bari). Key parts of the needle include the hook (Fukku) for catching yarn and the latch (Bera or lidah jarum). Support components like the sinker (Shinka) and the cam (Kamu) assist in loop formation. Yarn is fed through a yarn feeder (Kyuushikou), while the tension device (Tenshon souchi) maintains the correct level of tightness. Selecting the proper needles for a pattern is known as needle selection (Senshin). Yarn thickness is measured using various systems: yarn count (Bante), denier (Deniru), or decitex (Desitekkusu). The yarn is also defined by its twist (Yori), which can be in the form of S-twist (S-yori) or Z-twist (Z-yori). Multiple yarns can be combined through plying (Goushi), and the machinery requires constant lubrication with lubricating oil (Junkatsuyu).

Specialized Production of Hosiery and Socks

The manufacturing of socks (Kutsushita) involves creating distinct sections: the waistband or elastic top (Kuchigomu), the heel (Kakato), the toe (Tsumasaki), and the sole (Ashizoko). Specialized hosiery like pantyhose (Pantii-stokingu) and knee-length (Nii-rengusu) socks require specific knitting techniques like plating (Pureeteingu-ami), where two yarns are used to create a face yarn (Omote-ito) and a back yarn (Urai-ito). Materials used frequently in hosiery include woolly nylon yarn, covered yarn, and elastic rubber yarn (Gomu-ito). Patterning is achieved through Jacquard knitting (Jakaado-ami), spiral patterns (Supairaru-gara), or links patterns (Rinkusu-gara). Machines may use a double cylinder (Daburu-shirinda) and a latch guard for stabilization. The closing of the toe section is a critical finishing step, performed via linking (Rinkingu) or the Rosso (Rosso) method.

Dyestuffs and Chemical Auxiliary Agents

Dyeing (Senshoku) requires the use of colorants, which are either dyes (Senryou) or pigments (Ganryou). Dyes are categorized by their chemical properties: reactive dyes (Hannou-senryou) for cellulose, acid dyes (Sansei-senryou) for wool and nylon, disperse dyes (Bunsan-senryou) for polyester, direct dyes (Chokusetsu-senryou), cationic or basic dyes (Kachion-senryou), vat dyes (Tatezome-senryou), and metal complex dyes (Kinzoku-sakuen-senryou). The process often involves leveling dyes for uniform color. Essential chemicals used in the dye house include sodium hydroxide ($NaOH$), also known as caustic soda (Kasei sooda), and sodium sulfate ($Na_2SO_4$), known as Glauber's salt (Boushou). Hydrogen peroxide ($H_2O_2$) is used for bleaching. Functional additives include anti-foaming agents or defoamers (Shouhouzai), leveling agents (Kinsenzai), retarding agents (Kansenzai) to slow down dye uptake, mordants (Baisenzai) for fixing color, and carriers (Kyariyaa) for synthetic fibers.

Textile Dyeing and Finishing Operations

The industrial dyeing process follows a strict sequence of stages (Senshoku koutei). It begins with pre-treatment (Maeshori), which includes scouring (Seiren) to remove impurities and bleaching (Hyouhaku) using either oxidative or reductive methods. After dyeing, soaping (Soopingu) removes excess dye, and fixation (Kochaku) ensures the dye remains bonded. Dyeing methods vary: exhaust dyeing (Shinsen) involves an enclosed bath, while continuous dyeing (Renzoku-senshoku) processes fabric in a long stream. The ratio of dye liquor to the weight of the fabric is the liquor ratio (Yokuhi). Equipment used includes jet dyeing machines (Ekiryuu-senshokuki), open-width or spread machines (Kakufu-senshokuki), rope dyeing machines (Roopu-senshokuki), and cheese dyeing machines (Chiizu-senshokuki) for yarn packages. Thermal management is key, involving temperature increases (Shouon) and high-temperature/high-pressure (HT/HP) conditions (Kouon-kouatsu). The final steps include drying (Kansou), finishing (Shiage), and specialized treatments like mercerization (Shiruketto-kakou).

Quality Standards and Colorimetric Testing

Ensuring textile quality requires rigorous testing of color fastness (Kenroudo). This includes resistance to sunlight (Nikkou-kenroudo), washing (Sentaku-kenroudo), and moisture (Shitsujun-kenroudo). Testers look for color change (Hentais hoku) and staining (Osen) on adjacent fabrics. Evaluation is performed using the Blue Scale (Buruu-sukeeru) for light fastness and the Grey Scale (Guree-sukeeru) for other types. Color is defined by three dimensions: hue (Shikisou), lightness (Meido), and saturation (Saido). Non-colored tones are achromatic (Musaishoku). Metamerism (Metamerizumu) is a phenomenon where colors appear different under different light sources (Kougen). Standard color inspection is often done near a north window (Kitamado). Chemical testing involves measuring the pH (degree of acidity), where a value of $pH = 7.0$ is neutral (Chuusei). Other chemical activities include dissolution (Youkai), creating a solution (Youeki), and monitoring for hydrolysis (Kasuibunkai).

Production of Bedding and Sleep Gear

The manufacture of bedding (Shingu) encompasses several items: the floor futon or mattress (Shiki-futon), the quilt or duvet (Kake-futon), sitting cushions (Zabuton), and pillows (Makura). Down quilts (Umou-futon) use a mix of fine down (Daun) and feather (Fezaa). The internal structure relies on polyester or cotton filling (Nakawata) encased in a shell fabric (Gawa-kiji). Construction techniques include quilting (Kiruteingu), tufting (Nakatoji), and the cotton filling process (Wataire). A unique traditional process is cotton regeneration or uchi-naoshi. Production flow includes fabric inspection (Kentan), cutting (Saidan), and sewing, where the quality of the seam (Nuime) and stitch length (Itome) are critical. The comfort of bedding is determined by its moisture absorption (Kyuushitsusei) and air permeability or breathability (Tuukisei).

Workplace Safety and Occupational Health

Safety (Anzen) and the identification of danger (Kiken) are paramount in textile mills. Employees must use Personal Protective Equipment (PPE or Hogogu), such as protective masks (Bougo-masuku), rubber gloves (Gomu-tebukuro), and safety glasses (Hogo-megane). Electrical safety concerns include electric shock (Kanden) and current leakage (Rouden), requiring the use of grounding (Aasu) and fuses (Hyuuzu). Mechanical safety components like safety valves (Anzenben) on boilers and heat exchangers (Netsu-koukanki) must be monitored. In the event of an accident (Roudou-saigai), first aid (Okyuu-shochi) for injuries like burns (Yakedo) must be administered. Maintaining a healthy environment involves proper ventilation (Kanki) and the 5S principles of organization and orderliness (Seiri-seiton). Infrastructure must be checked for cracks (Kiretsu), and products may undergo anti-mite treatment (Bou-dani-kakou) for consumer health.

Production Management and Quality Assurance Systems

Quality (Hinshitsu) management involves product inspection (Kenpin) to catch defects (Furyou), including dyeing defects (Senshoku-furyou) and knitting defects (Ami-furyou). Products must adhere to set dimensions (Sunpou) and specifications (Kikaku), such as the Japanese Industrial Standards (JIS). Mandatory labeling includes quality labels (Hinshitsu-hyouji) and composition labels (Sosei-hyouji) that list the fiber blend ratio (Kon-you-ritsu). Process optimization uses standard work time (Hyoujun-sagyou-jikan), work analysis (Sagyou-bunseki), and daily work reports (Sagyou-nippou). Production management (Seisan-kanri) also covers maintenance (Mentenansu) of equipment and the inventory of consumables (Shoumouhin). Environmental factors in the factory, such as lighting intensity or illuminance (Shoudo), are measured in lux (Rukusu). Finally, finished products may be tested for durability, such as abrasion resistance (Taimamousei).