Fabric Dewatering machine:
Dewatering of fabric in finishing process:
In knit fabric finishing process squeezing or dewatering machine is used in case of tube or open form fabric for removing water 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 parameters are controlled during dewatering process.
Fig: Squeezer or dewatering machine.
Objectives and Functions of Dewatering Machine:
Various types of objectives are achieved by the de-watering process. Followings are the main objectives and functions of the dewatering machine.
1) To remove the water from the fabric.
2) To control the width of the fabric.
3) To control the length of the fabric.
4) To control the spirality of the fabric.
5)!To control the grain line of the fabric.
6)To control the over feeding system
7) Fabric is open from the rope form.
8) Width-wise stretch of the fabric is done.
9) Fabric is turn into plait form by this process.
10) GSM of the fabric is controlled during de-watering.
11) To control the crease mark of the fabric.
12) Excess or remaining water is removed or reduce by the dewatering machine.
13) In most of the cases, softener is applying during de-watering process.
14) Apply overfeed to give some compactor.
Process Sequence in Dewatering Machine:
Dyed fabric from trolley
↓
J box
↓
De-twisted
↓
Spreading
↓
Fabrics pass through second padding chamber
↓
Ballooning
↓
Fabrics pass through second padding chamber
↓
Spreading
Working Principle of Dewatering Machine:
Working Principle of Dewatering Machine:
After completing the dyeing process from the dyeing machine then the fabrics are ready for de-watering. In de-watering machine 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.
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 and out feed traveses which presentin albatros control the following function 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.
Follow the following fabric process routine:
The over stretching depends on these requirements.
Table: Unloading dia from deeatering Machine:
Item Un-loading dia from de- watering machine
1×1 Rib IN DIA + 20 % TO + 30 % OUT DIA
Interlock. IN DIA + 20 % + 30 % OUT DIA
Single jersey IN DIA + 10 % TO + 20 % OUT DIA
Polo PK IN DIA + 10 % TO + 15 % OUT DIA
2×1 Rib. IN DIA + 15 % TO + 20 % OUT DIA
Operational Parameters of Dewatering Machine;
1) Speed: As much as possible (40-60 m/min). Higher the GSM lower the speed.
2) Over feed:As required. Higher the GSM higher the over feed.
3) Padder pressure: 3-7 bar as required. Higher the GSM lower the padder pressure.
4) Width: Fabric width is adjusted as per required width.
Rule of Squeezing Machine or Dewatering:
.Twisting not allow in twister
.Air must be enough in first and 2nd balloon for all fabrics.
System of Single Jersey (S/J):
1) Dia of squeezer Ring guide 2” larger than dyed fabric.
2) 1st padder pressure 1.5-2 bar and 2nd padder pressure 5-6 bar setting.
3) Enough over feed for 1-2% compaction.
4) Delivered fabric 1” large than Required dia.
5) M/C RPM setting must be 40.
System of 1x1 rib and interlock:
,1) Dia of squeezer Ring guide 3-3.5” larger than dyed fabric.
2) 1st padder pressure 1.5 bar and 2nd padder pressure 5 bar setting.
3) Enough over feed for 1-2% compaction.
4) Delivered fabric 1.5-2” large than Required dia.
5) M/C RPM setting must be 50.
System of Pk or Lacust:
.Dia of squeezer Ring guide 2-3” larger than dyed fabric.
.1st padder pressure 2 bar and 2nd padder pressure 4 bar setting.
.Enough over feed for 2-4% compaction.
.Delivered fabric 1.5-2” large than Required dia.
.M/C RPM setting must be 30-35.
Calculation of Dewatering Machine:
--.GSM of fabric before J box – GSM of fabric after second padder
Extracted water % =
—————– x 100
……GSM of fabric before J box.
…GSM of fabric before J box – GSM of fabric after second padder
Residual water % = ——————× 100
……….GSM of fabric after second padder.
Softner take-up%,
---.GSM of fabric after second padder- GSM of fabric before second padder × 100
=
……GSM of fabric before second padder
Different parts and Speciation of Dewatering Machine and Their Functions:
Description of Dewatering Machine:-
After completing the dyeing process from the dyeing machine then the fabrics are ready for dewatering. This is the process to remove the water from the fabric completely by squeezing. De-watering machine plays an important role in knit finishing section of the knit fabrics. Dewatering machine or Squeezer is used for reducing water from the wet fabric. It reduces the water content of the fabric. This is the main function of the de-watering machine. But here also control the some important factor of the fabric quality.
Fig: Dewatering machine (Santex ag)
The basic function of the dewatering machine are:
1) To remove the water from the fabric.
2) To control the width of the fabric.
3) To control the length of the fabric.
4) To control the spirality of the fabric.
5) To control the grain line of the fabric.
6) To control the over feeding system.
Dewatering Machine Parts and Their Functions:
The dewatering machine is similar to extractor padder, with some additional attachments which have extra facilities. There is a magnetic sensor which senses the twist of fabric and its direction,which causes to turb the turn table in opposite direction to remove the twist automatically. The tubular fabric is ballooned by the compressed air before passing through the nip, so all loops are stretched very uniformly and in flat form water is removed.
De-watering machine has different parts and every single part has specific functions. Followings are de-watering machine parts name with their functions.
1. Hand Wheel :
It is a manual process. It is used for guide the spreader.
2. Turn Tube:
Fabric rotation is controlled by turn tube. It also helps in fabric feeding to the spreader.
3 Squeezing Roller:
It is the main part of the de-watering machine. Water of the wet fabric is squeezed by the squeezing roller.
4.Guide Wheel:
Guide wheel helps to feed the fabric into the squeezing roller.
5. Spreader:
When fabric is dye in a dyeing machine it found in rope form. After dyeing, when dyed fabric is put in basket it also remains in rope position. By spreader we can open fabric from the rope position. It can be spread and compressed in width direction by its hydraulic cylinder.
6. Security Sheild:
Security shield is an emergency switch settled with a plastic board very near to the padder. When it is close to the padder it is on and when it is pulled back then it is off. In case a big knot is going to pass the padder then it immediately pulls back the board to stop the machine. It is an automatic system to ensure the security of the padder. It helps to avoid any types of incidence.
7. Air injection Switch:
It pushes air into fabric to turn it to ballooning form. It helps to turn the rope form fabric into open form.
8. Photocell.
Photocell is an auto sensor which control air injection.
During de-watering process, softener is applying to the knit fabric. Also, various types of chemicals can be applied on the fabric by this de-watering machine. It is important to maintain uniform tension during operation otherwise GSM of the can be vary in different parts of the fabric.
Special Features of Dewatering Mchine:
1) Single squeeze roller and single padder present.
2) One for squeezing and other for applying softener finished.
3) Above 80% water can be removed
4)Maximum 60 inch diameter can be extended.
5) Softener tank present.
Maintenance During Operation:
1) Proper balloon form by compressor air otherwise crease mark appears.
2) Padder contract point adjusts perfectly according to the fabric construction otherwise accurate water will not remove.
3)Albatros must be clean every one or two hours later.
Specification of Dewatering Machine :
Brand Name: Santex ag
Company: Santex ag
Origin: Switzerland
Model: CH-9555, Tobel
Overfeed Range: 5% to +10%
Year of Manufacture: 1998
Type: Santa stretch Plus-140
Max Working Speed: 80 m/min
Maxm width capacity: 112 cm
Normal working Speed: 40~ 60 m/min
Maximum padder pressure: 40 PSI
Used Utilities: Water electricity, Compressed air.
Ref:-https//textilelearner.net
Comments
Post a Comment