Fabric Strength Tester | Determination of Heavy Fabric Strength by Horizontal Strength Tester

Name of the Experiment: Determination of heavy fabric strength by horizontal strength tester. 

Introduction: 
The strength of a fabric gives us an idea how much load we can apply on it and it is very important for fabric. The strength of the fabric is very necessary for it because if the fabric strength is not good then it will break with excessive tensile force and thus the dresses produced may tear with the outside force. The strength of a fabric varies with EPI, PPI, and Count Variation. The strength of the fabric also varies if the length and width of the fabric to be tested is changed. The strength of the fabric also depends on the construction of the fabric. A plain fabric is stronger than a twill fabric if made from yarnof same count. 

Fabric Strength Tester

The m/c used here is a horizontal strength tester. Therefore, the experiment has two objects: 

1. To find out the strength of the fabric.
2. To be precise in testing.

Theory: 
Strength is a measure of the steady force necessary to break a material and is measured in pound. The m/c works in constant rate of extension principle. When the tension is high on the fabric then the fabric breaks. 

Apparatus: 

1. Heavy fabric.
2. Fabric strength tester.
3. Scissors.

M/c specification: 
The Fabric Strength Tester 
Goodbrand & Co. Ltd. 
Capacity: 2000lb 

Testing atmosphere: 
Temperature – 29oC and relative humidity – 76% 
Standard atmosphere: temperature – 20oC and relative humidity - 65%. 

Sample: 
Size – 6inch × 2inch. 
No. of sample – 20 (For warp way-10, for weft way-10). 

Working procedure: 

1. At first 10inch × 2inch fabric was cut out from a big piece of fabric. The excess amount of fabric was cut because the two jaws will require at least 2inch each to grip the fabric. Thus 10 samples were cut down for testing warp way strength and 10 samples for weft way strength.
2. Now, the first sample is fixed with the upper jaw J1 and the lower jaw J2.
3. The m/c is started and observed the dial until the sample is torn out.
4. When the sample is torn out the m/c is stopped and the reading is taken.
5. By this way the others’ reading are taken.
6. At last average and CV% are calculated.

Data: 
Warp way:

Reading	Fabric strength (Lbs)	Avg strength (Lbs)	SD%	CV%
1	290	300.5	3.06	4.32
2	320
3	290
4	290
5	295

Weft way: 

Reading	Fabric strength (lbs)	Avg strength (lbs)	SD%	CV%
1	190	189	3.08	4.92
2	180
3	200
4	190
5	200

Calculation: 
The average warp way strength = 300.5 lbs 
The average weft way strength= 189 lbs

Remark: 
The strength of a fabric varies with (1) EPI variation, (2) PPI variation & (3) Count variation. The strength of the fabric also varies if the length and width of the fabric to be tested is changed. If we take a sample which size is 3inch×6inch and another sample size 2inch×6inch then the strength of the first sample will be greater than the second one. Thus if we increase the length of the second sample then the strength of the second sample will be decreased. The strength of the fabric also depends on the construction of the fabric. A plain fabric is stronger than a twill fabric if made from yarn of same count. The CV% for warp =4.62% &for weft =4.92%. it means there is a lot of variation in strength of the fabric. 

Working Procedure of Straight Knife Cutting Machine

Working Procedure of Straight Knife Cutting Machine

Abeed Hasan 
Dept. of Textile Engineering, 
Khulna University of Engineering & Technology 
Email: 1521033abeed@gmail.com

Introduction: 
Straight knife cutting machine is the world’s most popular and most versatile. Available in all standard electrical configurations, with the largest variety of sizes and blade speeds in the industry. It is widely used in Bangladeshi garment industry. In apparel manufacturing industry, straight knife cutting machine is the most used cutting machine. It is also the world’s most popular and most versatile cutting machine in the garments factory of Bangladesh. It is a complex electro mechanical device where the cutting blade gets motion from a meter. This machine is called straight knife cutting machine because its cutter is straight in shape. It is used for both woven & knit fabric. In this machine different types of straight knife are used according to the different cutting objects. 

Objectives:

1. To know about the working procedure of the machine.
2. To know about the different parts of the machine.
3. To know the advantage and precaution factor of this machine.

Apparatus:

1. Straight knife cutting machine.
2. Cutting Table.
3. Fabric.

Name of the machine parts:

1. Sharp Belt
2. Three pinion shaft
3. Leaver
4. Sharp on leaver
5. Operating handle
6. Power cable carry handle
7. Motor
8. Oil Can
9. On/Off Switch
10. Base Plate.
11. Four Wheel
12. Pressure foot.
13. Motor Stand
14. Sharp Mechanical Base 

Figure: Parts of straight knife cutting machine

M/C description:

1. A base plate :Usually in rollers for easy movement.
2. An electric motor: Transmit motion to blade.
3. Handle: For the cutter to direct the blade.
4. Knife: It cut the fabric
5. Knife guard: It used as safety device to prevent any accident
6. Grinding wheel: Used to sharp the knife during cutting.
7. Stand: The backbone of the machine
8. Roller wheel: To move the machine over cutting table easily.

Working process of straight knife cutting machine:

1. At first we know about the different parts of the machine.
2. After that fabric spread on the cutting table & marker placed on the fabric.
3. Then connected the machine with an electrical source.
4. Then turned on the switch and cut them with the help of straight knife cutting machine.

Precaution:

1. Reducing lay height.
2. The weight of the motor should be light.
3. The operator should be skilled and conscious.

Conclusion: 
It is the most useful cutting instrument in apparel cutting. In apparel industry, more than 99% cases this knife is used. This machine is called straight knife cutting machine because its cutter is straight in shape. It is used for both woven & knit fabric. In this machine different types of straight knife are used according to the different cutting objects. This machine provides good efficiency.