Dewatering Machine | Working Principle of Dewatering Machine

Dewatering Machine: 

In knit fabric finishing process; de-watering machine is used in case of tube or open form fabric after dyeing. In case of piece goods fabric  hydro-extractor machine is used for water removing. During de-watering process additional chemical is used for soften the fabric. Different types of operational parameter are controlled during de-watering process. 

Dewatering machine

Objectives of Dewatering Machine: 

Various types of objectives are achieved by the de-watering process. Followings are the main objectives of the de-watering machine.

1. Fabric is open from the rope form.
2. Width-wise stretch of the fabric is done.
3. Fabric is turn into plait form by this process.
4. GSM of the fabric is controlled during de-watering.
5. To control the crease mark of the fabric.
6. Excess or remaining water is removed or reduce by the de-watering machine.
7. In most of the cases, softener is applying during de-watering process.
8. Apply overfeed to give some compactor.

Working Principle of Dewatering Machine: 
After completing the dyeing process from the dyeing m/c  then the fabrics are ready for de-watering. In de-watering m/c tubular fabrics are mainly processed. There is a magnetic sensor which scene the twist of the fabric and its direction and turn the fabric in opposite direction to remove twist automatically. Here dewatering is performed De-watering is the process to remove the water from the fabric completely by squeezing and it is done by the padder. A suitable expander is used before the fabric is passed through the nip of the padders, which expands the fabric flat wise and adjust the width. 

  

Fig: Passage Diagram of The fabric in Dewatering Machine

The expander width is adjusted as S/J- 20%, PK-25%, Int.-35%, Lacoste-40% wider than the required width. There is a pair of rubber coated padder, where water is removed from fabric when passed through the nip of it.

Normally squeezer contain single or double padders where, 

• One for removing water and
• Other for applying finishing chemicals such as softener.

But this finishing is done only for the tubular fabric. Open widths knitted fabrics are applied finishing treatment later in stenter machine.

Here present the compressor which given compress air to form ballooning before passing through the padder. This balloon remove crease mark but not form the maximum balloon otherwise shrinkage increase.

In feed & Out feed traverses which present in albatros control the following functions by over feeding system. 

1. To control the width (dia) of the fabric.
2. To control the spirality of the fabric.
3. To control the crease mark of the fabric.
4. To control the length of the fabric.

Operational Parameter of Dewatering Machine: 
Speed: As much as possible (40-60 m/min). Higher the GSM lower the speed.

Over feed: As required. Higher the GSM higher the over feed.

Padder pressure: 3-7 bar as required. Higher the GSM lower the padder pressure.

Width: Fabric width is adjusted as per required width.