Ever since the inception of "blue jeans" in the 1870s as workwear for miners and cowboys, these iconic garments have evolved to become a popular item of casual wear throughout the world today. Coming in various fits to suit different tastes and fashions an important part of their appeal is the distressed look, visibly aged and worn, but still intact and functional. Proses of washing improves the fastness properties of indigo-dyed denim jeanswear and in addition by altering the types of washes, various fashion looks are achieved.

Dalam buletin teknis ini kami akan menjelaskan bagaimana baju denim diproses basah dan menyoroti parameter terkait yang harus dikendalikan dalam produksi denim dan proses pencucian berikutnya.

The "wash down" and other "post make" processes applied to denim garments are many and varied. Often the objective is to distress the garment so that it looks old and worn. This distressing gives the garments a "fashion" appeal and also softens an otherwise harsh fabric. These "post make" process can have a devastating effect on the sewing threads and therefore the seams, if care is not taken in their selection and application. After wash / post processing repair rates can be very high with harsh wash down treatments and 40% repair levels are not uncommon.

We highlight the Coats range of sewing threads that have been designed specifically to withstand the rigours of denim wet processing and which in addition can add a fashion element of their own through contrast colours and other decorative applications. For example, Benang Corespuns such as Coats Epic and Dual Duty offer excellent all round sewing performance due to their construction and specially formulated lubrication. The high tenacity filament core provides the toughness for the majority of the most punishing applications. The cotton wrap of Dual Duty allows its colour to fade with the fabric whilst the polyester wrap of Epic retains more of its original colour.

Merek	Gambar	Keterangan
		Coats Dual Duty menawarkan karakteristik pencucian yang sangat baik sehingga ideal untuk jeans.
		Tersedia dalam berbagai jenis ukuran global Coats Dual Duty, terutama dalam ukuran tex yang berat, memberikan tampilan yang unik untuk topstitching atau untuk penjahitan rincian saku.
		Coats Dual Duty True Indigo was developed to respond to customer requests for a sewing thread that will achieve a faded effect similar to that on denim fabric after popular wash down processes such as a rinse, medium stone wash, double stone wash and bleach wash. stone wash and bleach wash.
		Coats Epic adalah benang jahit corespun yang direkayasa untuk memenuhi berbagai macam aplikasi.
		Coats Epic Ruggerd diproduksi dalam berbagai pilihan warna untuk denim, menggunakan zat warna yang khusus dipilih yang sanggup menahan perubahan warna saat diberi pemutih yang digunakan dalam proses pemudaran denim.
		Coats Epic Multicolor adalah benang corespun space dyed berkinerja tinggi untuk penjahitan multi-warna.

Embroidery Recommendations for Denim

Merek	Gambar	Keterangan
		Coats Sylko adalah benang poliester trilobal untuk bordir mesin.
		Coats Sylko Metallic adalah benang komposit rekayasa tinggi untuk bordir mesin.

Since indigo dyes are insoluble in nature, it is dyed under special dyeing conditions. The dyeing happens through a fermentation process by breaking the dye molecules into simpler substances. In this stage, it dissolves in the solution and the fabric yarn gets dyed. At a later stage, when it is taken to oxidisation by exposing it to air, the beautiful, deep and rich blue of indigo is achieved.

Proses pencelupan yang rumit inilah yang membuat pencucian denim begitu menantang dan rumit..

Proses pencucian menanamkan efek-efek berikut ini pada baju denim:

• Tampilan / perubahan warna
• Pelembutan
• Stabilitas dimensi
• Penanganan yang berbeda

Tingkat dari efek-efek di atas tergantung pada kondisi pengolahan seperti waktu, suhu, liquor ratio dari kemasan pencucian dan bahan kimia yang digunakan.

Langkah-Langkah dalam Proses Pencucian Denim

Pencucian denim adalah proses yang berurutan, yang terdiri dari banyak langkah. Beberapa langkah utama yang dibahas di sini adalah:

1. Pra-penanganan

2. Pencucian

3. Pewarnaan dan Pencelupan

4. Pelembutan

Proses ini adalah bagian pertama dan yang paling penting dari pencucian denim, yang meliputi:

1. Membersihkan kotoran

2. Menghilangkan kanji

3. Mengurangi resiko kekusutan

1. Membersihkan kotoran

Kotoran dari tahap-tahap produksi kain atau baju dapat berbahan dasar minyak atau bahan kimia. Mereka dapat menyebabkan masalah selama tahap pencucian setelahnya, sehingga harus dibersihkan.

2. Menghilangkan kanji

Selama tahap ini, kanji yang digunakan selama proses tenunan dibersihkan agar sesuai untuk proses lebih lanjut.

3. Mengurangi resiko kekusutan

Obat anti kusut digunakan untuk menghindari kekusutan yang dapat terjadi karena parameter mesin seperti kecepatan putaran, reaksi kimia, produksi kain dan penyimpanan.

After pre-treatment, denim garments may be subjected to different types of wash. Some of the commonly used wash types are:

1. Pencucian Batu

2. Pencucian Asam

3. Pencucian Bilas

4. Pencucian Enzim

5. Pencucian Pemutih

1. Pencucian Batu

Inilah proses paling umum dan dasar untuk menghasilkan tampilan pudar pada baju denim. Menjelang akhir tahun tujuh puluhan, batu apung dianggap dapat mempercepat proses penuaan pada baju denim celup indigo.

Komponen Pencucian

Batu yang digunakan secara luas saat ini adalah batu apung, yang memiliki banyak pori-pori. Pori-pori ini memiliki tepi yang sangat tajam, yang dapat menghasilkan tingkat abrasi yang sangat tinggi.

Proses

Proses pencucian dengan batu pada umumnya adalah sebagai berikut:

The degree of colour fading and change of garment feel depends very much on the ratio of weight of the stone to the fabric weight, which can vary from 0.5:1 to 3:1. During the treatment, the outer most layer of the indigo-dyed yarn is partially separated and the portion of the fibre inside, which is undyed, comes to the surface. The surface gets a softer handle through the mechanical process with pumice stones.

The degree of the wash-down effect depends upon several factors – the Ukuran of the stone, stone ratio, liquor ratio, duration of treatment, garment load, etc.

Ukuran

The Ukuran of pumice stones available for stone washing vary from 1 cm to 7 cm in diameter. Pumice stones, around 2 to 3 cm in diameter, are used for finer denim qualities. The common Ukuran employed for normal denim qualities is 3 to 6 cm in diameter.

Peralatan

Different wash names like sand wash, golf ball wash, micro wash and micro-sand wash — which are types of stone wash — refer to the use of very small Ukuran pumice stones.

Equipment

Mesin cuci tabung digunakan untuk pencucian dengan batu. Kapasitas mesin cuci tabung dapat mencapai 200 kg. Beberapa mesin ini dilengkapi dengan fasilitas memiringkan untuk mengosongkan baju yang telah dicuci.

Stone Wash Effects

• Under normal circumstance (fabric-stone ratio at 1:2), colour fading is irrespective of the fabricstone ratio.
• Batu-batu yang lebih kecil memberikan efek memudar yang sedikit lebih baik, tapi hal ini akan mengurangi kontras warna karena abrasi lebih seragam.
• Efek memudar meningkat seiring dengan waktu pencucian dengan batu. Namun, peningkatan efek menjadi tidak signifikan jika waktu pencucian melebihi 90 menit.

2. Pencucian Asam (Moon Wash)

Pencucian dengan asam atau ice washing biasanya dilakukan dengan menggulingkan kering baju dengan batu apung yang telah direndam dalam larutan asam, sehingga pemutihan lokal akan menghasilkan warna biru tajam yang tidak seragam / warna kontras putih pada baju.

Komponen Pencucian

Pumice stones pre-soaked in sodium hypochlorite (5 to 10%) or potassium permanganate (3 to 6%).

Proses

Proses pencucian dengan asam pada umumnya adalah sebagai berikut:

Proses involves soaking of pumice stones in a net or mesh fabric in solutions of potassium permanganate for at least one or two hours and then draining off the excess liquor. This treatment results in a very strong bleaching effect at the raised parts whereas the lower parts remain dark. The selection of sodium hypochlorite or potassium permanganate depends upon the dyestuff and the required effect.

Kelemahan

Acid washing or moon washing is a tedious and dirty bleaching process, since the manganese dioxide formed out of the potassium permanganate must be removed from the trousers after Proses. The hypochlorite bleaching process is fast, efficient and cheap, but it also suffers from a number of disadvantages. Proses is relatively difficult to control because it is difficult to obtain the same level of bleaching in repeated runs.

Furthermore, hypochlorite is a harsh chemical that can damage cellulose, resulting in severe strength loss, breakages and pinholes at the seams and pockets. Since hypochlorite is a hazardous chemical, precautions should be considered while using it in the production floor.

3. Pencucian Bilas or Mill Wash

The objective of rinse washing is to keep the fabric appearance as dark as possible. The denim is deUkurand width wise in open-width washing machine and the dye is not washed out.

Peralatan

One variety of the rinse wash is desizing ready to wear trousers in drum washing machines. The disadvantage in this process is very poor rub fastness.

4. Pencucian Enzim

As denim is made of cotton, it too consists of cellulose. Cellulases can be used to give denim a worn look. Enzymes have opened up new possibilities in denim finishing by increasing the variety of finishes available. For example, it is now possible to fade denim to a greater degree without running the risk of damaging the garment. Cellulases are the enzymes commonly used in enzyme wash. As the name suggests, it degrades cellulose.

Komponen Pencucian

Enzim adalah protein molekul yang mempercepat reaksi biokimia dalam kurun waktu singkat. Enzim yang paling umum digunakan dalam industri tekstil adalah alfa-amilase, protease, katalase dan selulase.

Enzim multi-komponen adalah selulase yang diperkenalkan oleh para produsen terkemuka yang mengandung berbagai selulase berbeda yang mempengaruhi bagian-bagian yang berbeda dari selulase.

Enzim mono komponen hanya memiliki satu komponen, dan sangat tepat dalam aksi mereka. Berbagai produk Denimax termasuk dalam kategori ini.

Advantages of Cellulase (Enzyme Wash) over Pumice (Stone Wash)

The most widely used application of cellulases (neutral and acid cellulases) is the replacement of pumice stones in the ‘stone washing’ process to produce the aged appearance of denim garments. Some of the advantages of enzyme wash are:

• Penggunaan selulase daripada batu apung mencegah kerusakan oleh abrasi pada mesin cuci dan garmen, menghilangkan kebutuhan pembuangan batu-batu yang telah digunakan, dan meningkatkan kualitas air limbah.
• The load of garments may also be increased by as much as 50% since stones are no longer added. Depending on the finishing effect required, a mixture of cellulases and pumice may be used, which causes the surface fibres to weaken and later be removed when subjected to either fabric to fabric abrasion or fabric to stone abrasion during the washing. The temperature and the pH used must be specific to the type of cellulase employed. For enzymatic stone washing, acid cellulase and neutral cellulase are available.
• Sementara batu apung sangat efektif pada permukaan serat, selulase juga bereaksi di dalam serat.

Proses

Proses pencucian dengan enzim pada umumnya adalah sebagai berikut:

Acid Cellulase: These enzymes are applied at an acid pH value of 4.5 to 5.5 at 50 - 60ºC. At the beginning of enzymatic treatments negative effects on the tensile strength could be observed. The application of acid cellulases reinforced the ‘backstaining’ problem. Backstaining is the result of soiling of the weft thread and the pocket lining by the detached indigo dyestuff.

Neutral Cellulase: neutral cellulase is used in denim washes. It is applied at pH value of 6 to 7 at 50 to 60ºC. Compared to acid cellulases, neutral cellulases have a less negative effect on the tensile strength. For improved surface abrasion, higher quantities are required in the case of neutral cellulase.

An enzyme dose of 2 to 4 grams per litre is normally sufficient. In general, the colour of the enzyme washed goods are more uniform, particularly when stone is not used. Since cellulases are only reactive on cellulose, any Ukurans or other impurities must be removed before the cellulase treatment.

Selulase netral masih lebih banyak digunakan dalam pencucian denim daripada selulase asam. Alasannya adalah karena kecenderungan pewarna indigo untuk mengendap kembali pada permukaan serat jauh lebih tinggi dalam medium asam daripada dalam medium netral.

Parameter Proses Pencucian dengan Enzim

• Pada enzim netral, kinerja terbaik dihasilkan pada pH 6 - 7.
• Un resultado satisfactorio puede obtenerse cuando una dosis de enzimas está en el rango de celulosa de 0.5 - 2.0 g/l.

Selulase netral masih lebih banyak digunakan dalam pencucian denim daripada selulase asam. Alasannya adalah karena kecenderungan pewarna indigo untuk mengendap kembali pada permukaan serat jauh lebih tinggi dalam medium asam daripada dalam medium netral.

5. Pencucian Pemutih

Pada pencucian dengan pemutih, obat pemutih oksidatif yang kuat ditambahkan selama proses pencucian, dengan atau tanpa batu apung. Tujuan dari pemutihan adalah untuk menghilangkan warna biru tua dengan menghancurkan molekul warna indigo dengan bahan kimia pemutih oksidatif.

Komponen Pencucian

Sodium hypochlorite is generally used as an agent. As on date, ‘Chlorine Bleach’ is the most effective bleach agent for indigo since all shades can be obtained from it.

Kelemahan

Kelemahan dari metode pemutihan adalah fakta bahwa serat menjadi rusak dan timbulnya emisi air limbah yang tercemar.

Proses pencucian dengan pemutih pada umumnya adalah sebagai berikut:

Peralatan

Ecologically less harmful methods such as laccases, potasium permanganate, potasium persulfate, sodium caustic, peroxide have been tried. However, they cannot be compared with chlorine bleach as far as the effect and looks are concerned. The ‘White Bleach’ method is a variation of the normal bleach in which, chlorine bleach is carried out two to three times one after the other in different treatment baths.

Pemutihan dengan hipoklorit

• Optimum Dosage: 40 g/l when using a hypochlorite with 12% available chlorine. Increase in hypochlorite dosage effectively increases the colour fading to a certain limit.
• pH: At 7 or lower, the rate of bleaching is rather fast which may present difficulty in controlling the shade. It is suggested that the bleaching bath should be slightly alkali by adding soda ash to pH 9-10 such that bleaching effect could be effectively monitored by the bleaching time.
• Chlorine Bleach: 15 ml (150 g/l active chlorine)
• Temperature: 50 - 60ºC. A higher temperature increases the bleaching action and hence the colour fading. But for the temperatures above 70ºC, the effect would be similar.
• Time: 15 minutes
• Rinse: cold

Deklorinasi

After every chlorine bleach, the remaining chlorine must be removed by dechlorinating with sodium bisulphite. Deklorinasi can also be carried out with hydrogen peroxide instead of sodium bisulphite.

• Sodium Bisulphite: 3 g/l
• Sodium Bisulphite: 3 g/l
• Temperature: 40-50ºC
• Liquor Ratio: 1:5
• Rinse: warm or cold

Penghilangan Kanji

Denim garments that are made from indigo or sulphur slashed-dye will have Ukurans that are water-soluble and insoluble in nature.

Starch-based Ukurans are most commonly used. Methods employed to deUkuran them are washing with alkaline agents, acidic agents, oxidative chemicals and with enzymatic amylase.

The most effective and preferred method is enzymatic Penghilangan Kanji using amylase. The typical parameters are as follows:

• Amylase: 1 - 2 g/l
• pH: 6 - 7
• Temperature: 60 - 70ºC
• Time: 15 mins
• Liquor Ratio: 1:6 to 1:8
• Rinse: cold

Catatan: Penambahan deterjen mempercepat proses pembasahan.

Setelah pencucian, baju diwarnai atau dicelup. Pewarnaan digunakan untuk mengubah corak atau sifat warna indigo. Ia memberi garmen denim tampilan usang atau lawas. Proses ini memakan waktu dari 5 hingga 15 menit, dan diikuti penguat untuk zat warna dan pembersihan pewarna dangkal.

Perbandingan Berbagai Jenis Pewarna

Since denim is a heavy fabric, it needs Pelembutan. A major problem encountered during this process is yellowing, which is the change in shade or loss of whiteness. All organic polymers (like cotton) are prone to yellowing. Indigo-dyed fabric, in particular, is very prone to yellowing.

Penyebab: Sulit untuk ditentukan penyebab pasti dari efek menguning. Di antara banyak penyebab adalah paparan terhadap cahaya, kotoran, suhu proses yang salah, atau kombinasi dari semuanya.

Mengurangi resiko menguning: Sangat mustahil untuk menghilangkan efek menguning.

Namun, hal itu dapat diminimalkan dengan menjaga hal-hal berikut ini:

• Memastikan residu pemutihan dan netralisasi pemutih sangat diminimalkan atau dihilangkan.
• Meminimalkan back staining.
• Menghindari penggunaan bahan kimia yang menyebabkan efek menguning.
• Menghindari membiarkan baju dalam kondisi basah lebih lama dari yang diperlukan.
• Mengendalikan kondisi pengeringan dan penjemuran.

Overdyed: A stoned trouser is over dyed to create variety of shades and effects.

Damaged: Trousers are partially destroyed. This can be done by very aggressive chlorine bleach or by the American variation of shooting at the trousers with bullets. As part of the proof, some jeans manufacturers incorporate the empty bullet cartridge in the trouser pocket.

Scrubbed: The surfaces of the trousers are scrubbed with brushes in this process, to effect suede and partially fluffy appearance.