Creaming: When an emulsion is prepared it is not possible to make all drops
exactly same size. The larger droplets move to the surface because they have
less density than water. These droplets cause uneven distribution of water and
form a layer on the surface and causes uneven distribution of emulsion. This
defect is called creaming. This defect increase yarn breakage during spinning.
Causes of creaming
·
Improper oil selection
·
Not accurate mixing ratio of
oil, water and emulsifier
·
Bad agitation of the mixture
Remedy to avoid creaming
·
Using slow running paddles to
stir the mixture, thus the droplet size can be kept small
·
Using oil of high specific
gravity
·
Emulsion should not be stored
for long time
Breaking:
Sometimes the mixture is not uniform and so in
some places it is dense and in others it is light. The defect is called
breaking.
It is caused by faulty stirring equipment.
It can be avoided by high speed agitation.
Why fish oil and vegetable
oil is not use in making emulsion?
Drawbacks
of fish oil
- It is very costly
- It has a very bad smell
- If the percentage of fish oil is more then it will lead to
combustion of fire
Drawbacks
of vegetable oil
- In comparison to mineral oil, it is very costly
- It allows dirt and bust to lap around the rollers and thus it
jams the rollers
- It causes build up of static electricity between the fibres and
rollers which causes the fibres to stick to the rollers
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