Definition of Marker | Marker Efficiency | Factors on which marker efficiency depends on

Marker is a thin paper which contains the patterns of all the components needed to produce a garment ensuring the least fabric wastage. Marker is made according to the order. Sheet is provided by buyer. Size wise garments quantity is important information to make the actual maker. Marker width is kept equal to make the minimum fabric width. But marker length depend on the following several parameter:

1. Patterns for how many sizes of garments are being used to make the marker
2. How many garments will be produced by one lay of fabric
3. Length of cutting table
4. Production planning
5. Efficiency of marker

Marker efficiency
The ratio of area for pattern pieces that are placed on the marker to the total area of the marker expressed as percentage is called marker efficiency.

Marker efficiency is the important part of garments manufacturing. Direct cost of garments could be utilized by marker efficiency. Salary of a marker planner truly depends upon the capability to increase the marker efficiency.

The skillness of marker maker is evaluated by the efficiency of marker. Higher the maker efficiency, higher the skillness of marker maker and vice versa. Marker efficiency is calculated by two parameters:

1. Total area of the entire pattern in marker
2. Total area of the marker

It is calculated in percentage. It can be defined by following formula:

Marker efficiency = Area of the pattern in the marker / Area of the marker 100%

Higher the marker efficiency, least the fabric wastage. Lower the fabric means higher the profit.


Factors on which marker efficiency depends on-

1. Skillness of marker makers: Marker efficiency mainly depends on the skillness, cordiality, sense of responsibility, experience and technical knowledge of marker maker. The more trail of marker making, the more possibility of more marker efficiency.
2. Sizes of garments: The more sizes of patterns are included in marker the possibility of more marker efficiency. But increase of huge sizes patterns, the result may be opposite.
3. Length of marker: When the marker length is more, then it’s easier to place the patterns in it which causes more marker efficiency. But illegal increasing of marker length may decrease the marker efficiency.
4. Pattern engineering: Sometimes the patterns can be modified by changing its design, dividing by pattern engineering technique which may be increase the marker efficiency.
5. Types of fabric: Marker efficiency is more for symmetric fabric. Because here it is possible to place the patterns in different directions. But for asymmetric fabric, marker efficiency is low due to the difficulties of placing patterns marker.
6. Method of marker making: Marker efficiency is more for computerized method than manual method. But it is more time consuming system. Marker efficiency may be more than computerized system in case of extremely skilled and experienced marker maker.

Shedding | Shedding mechanism | Study on Shedding mechanism of Tapped Loom.

Introduction: Shedding is the raising of the warp yarns to form a shed through which the filling yarn, carried by the shuttle, can be inserted. The shed is the vertical space between the raised and upraised warp yarns.

The shedding mechanism separates the warp threads into two layers to form a tunnel known as shed. A shed may be formed by means of tappets, dobby, and jacquard.

Shed is classified according to the position of the ends:

• Closed Shed
• Open Shed.

Closed Shed is classified on two parts.

• Bottom Closed Shed,
• Center Closed Shed.

Open Shed are classified on two parts.

• Semi-open Shed,
• Open Shed.

Shedding mechanism is 5 kinds:

• Paddle shedding
• Tappet shedding
• Dobby shedding
• Jacquard shedding
• Combined shedding

Types of Tappet Shedding Mechanism: Generally there are two types of shedding

• Negative tappet shedding
• Positive tappet shedding

Negative Tappet Shedding: In a tappet shedding mechanism, if the tappet controls only one movement, either an upward or downward movement of the healed shafts, then the shedding is known as “negative tappet shedding”. The healed shafts are returned by some external devices like springs, dead weights, rollers, etc.

Positive Tappet Shedding: In a tappet shedding mechanism, if the tappet controls both upward and downward movements of the healed shafts, then the shedding is known as positive tappet shedding.

Objectives

1. To know about different parts formed this shedding
2. To learn the mechanism of tappet shedding

Main parts

1. Motor
2. Motor pulley
3. M/C pulley
4. Crank shaft
5. Crank shaft gear
6. Bottom shaft gear
7. Bottom shaft
8. Tappet
9. Connecting rod
10. Heald shaft
11. Top arm

Working principle : In our loom tappet gets motion in the following way. At first machine pulley gets drive by belt from motor pulley. Then machine pulley, which is directly joined with the crank shaft, gives motion to bottom shaft. This crank shaft gives motion to bottom shaft via gearing. Two tappets are joined with the bottom shaft. So when bottom shaft moves then the tappets also rotate. When it gets contact with tradle bowl it lifts the tradle levers and the heald shafts are lifted by tradle levers via links. As this is a negative shedding tappet the heald shafts are lowered by their own weight.

Conclusion: Tappet shedding mechanism is important for driving loom. It is also important for fabric design. By this experiment I learn this mechanism. This would be very helpful in my future life.

 

Definition | Take up | Seven wheel take up mechanism of loom (Cotton Weaving)

Take-up is to draw a fabric to the cloth roller regularly as it is woven. Texture of a fabric largely depends upon the number of ends and picks per centimeter or inch. This motion determines the number of picks of weft per inch or centimeter and contributes to the uniform texture of the fabric. It is the work of the weaver for accurately fixing the position of the fell of the cloth before starting a loom.

The process of withdrawing fabric from weaving zone at a constant rate and then winding the woven cloth on the cloth roller with the continuous progress of weaving is called take up motion.

Types

According to drive:

1. Positive take up.
2. Negative take up.

According to motion of the cloth/Rate of take up-

1. Continuous
2. Intermittent

According to drive given to the cloth roller-

1. Direct drive
2. Indirect drive

According to number of gear train:

1. 5-Wheel
2. 6-Wheel
3. 7-Wheel

According to brand name-

1. Sulzer
2. Pickanol
3. Toyota

Objects

1. To know about the construction of the mechanism.
2. To know about drive of the take-up motion.

Main parts of machine used in take up mechanism

1. Sley
2. Sleysword
3. Connecting rod
4. Monkey tail
5. Holding/Catching/Locking pawl.
6. Pulling pawl
7. Rachet Wheel
8. Standard wheel
9. Changewheel
10. Sewing wheel/Pinion
11. Stud/Compound wheel
12. Stud/Compound Pinion
13. Take up wheel
14. Take up roller
15. Cloth roller

Working principle
Sley sword to connecting rod. Connecting rod to monkey tail. Monkey tail to pawl. Pawl to rochet wheel. Rochet wheel to standard wheel. Standard wheel to change wheel. Change wheel to sewing wheel. Sewing wheel to stud wheel. Stud wheel to stud pinion Stud pinion to take up wheel. Take up wheel to take up. The positive take-up mechanism consists of seven wheels. These are

• Rachet
• Standard wheel
• Change pinion
• Stud pinion
• Stud wheel
• Swing pinion
• Take-up roller wheel

The motion is primarily imparted from the sleysword. The sleysword is connected to the slaythat gets motion from crank shaft and the crank shaft gets motion from motor by gearing. At the bottom of sleysword a connecting rod is connected which passes the motion to the monkey tail.

The monkey tail is fulcrum with two pawls: the upper is holding pawl and lower is pulling pawl. These two pawls are mounted freely to the ratchet wheel which is connected with the standard wheel by shaft. Over the standard wheel the change pinion is geared. The change pinion is connected with the stud pinion by shaft and the stud wheel is geared with the stud pinion upon it. The swing pinion is connected with the stud wheel and the cloth take-up roller wheel is geared with the swing pinion.

The cylinder upon which the woven fabric is wound, is connected with this wheel by shaft. Now when the sley moves one time after one pick insertion the connecting rod pass this motion to the monkey tail and as the pawls are fulcrum with monkey tail they get downward motion. Using this downward motion the pushing pawl pulls the rachet wheel one time and the holding pawl holds the rachet in this position. Finally the cloth roller gets the motion by gear train and thus fabric is wound on cloth roller continuously with the weaving of fabric.