Cleaning/Washing Of Clothes

Question 1

What six things determine how well clothes are washed?

Answer 1

Detergent

Water

Water temperature

Agitation

Fabric softener/conditioner

Water removal

Question 2

What are the two different type of detergent?

Answer 2

Liquid detergent

Powder detergent

Question 3

What are the five components of detergent?

Answer 3

Surfactants

Conditioners

Bleach

Fluorescents (optical brighteners)

Enzymes

Question 4

Describe the structure of a surfactant.

Answer 4

It has a hydrophilic head and a hydrophobic tail

Question 5

Why are surfactants used?

2

Answer 5

To reduce the surface tension of water

To enable the water molecules to wet the clothes

Question 6

How does the hydrophilic head in a surfactant work?

3

Answer 6

The hydrophilic head attaches to the surface of the water

This disrupts the bonding of water molecules (together)

Which enables the water molecules to thoroughly wet the clothes and help loosen dirt from fabric

Question 7

How does the hydrophobic tail in a surfactant work?

2

Answer 7

The hydrophobic tail attaches itself to the dirt or stain on fabric

This keeps the dirt particles suspended in the water

Question 8

What is the role of conditioners in the care of clothes?

Answer 8

They soften fabric and eliminate static cling

Question 9

How do conditioners soften fabric and eliminate static cling?

Answer 9

By coating the fabric fibres with a lubricating finish

This prevents static electricity forming when fabrics rub together

Question 10

What is the role of bleach in the care of clothes?

Answer 10

Bleach removes stains and brightens clothing

Question 11

How does bleach remove stains and brighten clothing?

Answer 11

By releasing small amounts of hydrogen peroxide

Question 12

What is the role of fluorescents in the care of clothes?

Answer 12

Enables fabric to absorb ultraviolet light and re-emit it as blue light

Question 13

Explain how fluorescents work?

3

Answer 13

They create a visual whitening effect on fabrics by enabling fabric to absorb UV light and re-emit is as blue light

As the blue light interacts with the yellow light emitted from the fabric it gives clothes a grey hue

This tricks the eye into thinking the clothes are whiter than they are by producing a white light

Question 14

What is the role of enzymes in the care of clothes?

2

Answer 14

They break down protein based stains such as blood or milk into smaller particles

This makes it easier for the detergent to clean fabrics

Question 15

Why does the type of water need to be considered when washing clothes?

Answer 15

As the type of water will affect the efficiency of washing fabrics

Question 16

What are the two types of water?

Answer 16

Hard and soft

Question 17

Why is hard water not used for cleaning clothes?

Answer 17

As it does not create a good lather of soap

Question 18

Why does hard water not create a good lather of soap?

Answer 18

Due to the presence of calcium and magnesium ions

Question 19

Instead of for washing clothes, what should hard water be used for?

Answer 19

Drinking

Question 20

How are clothes washed if they cannot be washed with water?

Answer 20

They must be dry-cleaned with a specific solvent

Question 21

Write a note on the scientific principle underlying the care of fabrics in relation to water.
(4)

Answer 21

Type of water effects the efficiency of washing fabrics

Hard water does form a good lather with soap - Ca and Mg ions

Some fabrics can’t be washed in water - dry-cleaning with a specific solvent

Hard water should be used for drinking instead of cleaning clothes

Question 22

Why should the water temperature be considered?

2

Answer 22

As water temperature can cause damage to the structure, colour, finish and shape of fabric when washing

E.g. cotton goes undamaged at high temperatures but wool will shrink

Question 23

Give an example of a fabric where water temperature is important when washing.

Answer 23

Wool as extreme heat (95 degrees) can cause wool to shrink, compared to cotton which may go undamaged

Question 24

In relation to care of fabric what is agitation?

Answer 24

The movement necessary to dislodge dirt or stains from fabric

Question 25

What does the amount of agitation needed depend on?

Answer 25

It depends on how dirty a fabric is or the type of fabric

Question 26

What will too much agitation do?

Answer 26

It will cause damage to the fabric

Question 27

In relation to agitation, how should delicate fabrics such as silk be washed?

Answer 27

They require a minimum action wash with a wool cycle spin

Question 28

In relation to agitation, how should durable fabrics such as cotton be washed?
(2)

Answer 28

Maximum action wash

Normal spin

Question 29

Write a note on agitation in relation to the care of fabrics.
(4)

Answer 29

The movement necessary to dislodge dirt or stains from fabrics

Depends on -how dirt the fabric is - type of fabric

Delicate fabric - minimum action wash + wool cycle spin

Durable fabric - maximum action wash + normal spin

Question 30

What do fabric softeners/conditioners do to clothes?

4

Answer 30

Reduce static electricity

Reduces wrinkling which makes ironing easier

Enhances softness

Adds a pleasant smell

Question 31

How can water removal be carried out?

4

Answer 31

Drip, line or flat drying

Wringing

Spin drying

Tumble drying

Question 32

How can clothes be dried through wringing?

Answer 32

By squeezing or twisting fabric after hand washing

Question 33

How can clothes be spin dried?

Answer 33

Spin drying is completed at the end of a washing machine cycle by spinning clothes in the rotating drum

Question 34

Describe tumble drying.

Answer 34

Tumble drying dries clothes by spinning them in hot air inside a rotating drum