Elements or components of drafting system

Condenser

The purpose of condenser is to control the width of fiber strand, since during drafting, it continuously tends to spread out or moving apart. Spreading fiber masses are more difficult to maintain under control in drafting and they cause unevenness.
Note: A second sliver condenser is provided in the break draft zone. Also on a reciprocating bar, and a third is located in the main drafting zone. Spreading fiber masses are more difficult to maintain under control in drafting and they cause unevenness. 

Types of condenser:
1) Back zone condenser;   2) Middle zone condenser;    3) Front zone condenser   

Function of condenser:

1. To control the width of fiber strand
2. To straighten the fiber in sliver 
3. To control strength of roving 

Spacing the top & bottom apron (Spacer)

In order to maintain the closely defined minimum distance between the top & bottom apron spacer is used. Size of spacer is depends on the roving count. If roving count is increased, then spacer size will decrease. Different colors are used to identify different sizes spacer

Spacer color	Spacer Distance(mm)
White	3.4
Grey	3.8
Black	4.4
Orange	4.7
Green	5.9
Blue	8.9
Brown	11.1

Apron

• Apron is a one type of endless belt made of synthetic rubber which is used in drafting zone with special arrangement.
• Apron size is usually apron thickness. Apron thickness = 1-1.05 mm.
• The guiding length of fiber in apron is referred to as cradle length

Types of cradle	Cradle length (mm)	Fiber length(mm)
Short	36	Cotton up to 9"/8 ; 40 mm synthetic fiber
Medium	43	Cotton above 9"/8 ; 50 mm synthetic fiber
Long	50	60 mm synthetic fiber

Applying pressure to top rollers

The top roller must be pressed with relatively high force against the lower rollers to ensure guidance of the fibers. Pressures are in the range of 100 to 250N per roller and it depends on raw materials and volume. Adjustment may be continuous or in several steps.

So, pressure can be applied on the top roller by the following systems:

1. Loading by means of dead weight
2. Pneumatic weighting
3. Spring weighting 
4. Hydraulic weighting 
5. Magnetic weighting