Lesson 6: Science Lab: Fire Retardancy and Fabrics (Science)

Teaser: Create a slogan for the importance of flame retardant clothing.

Lab: Determine the fire retardancy of several fabrics

Student Expectation: divide the students into groups of four and prepare 250mL of a 10 g/L and 250mL of a 50 g/L borax solution. You may need to heat the solutions on the hot plate and stir to completely dissolve the borax. Treat a cotton ball and 3 pieces of fabric with each solution.

Remember that you will also need a control. The fabric soaked in water will be the control. What happens when a flame is applied to the dried materials? Create a table to record your observations and explain the efficacy of the treatments.

Hints for the teacher:

Students may bring in fabrics or old clothing for this lab. Using warm water helps the borax to dissolve. Emphasize this retardancy lasts only until the fabric is washed or gets wet.

Student Worksheets

Name _____________________ Flame Retardancy Lab

Names of lab team members: _______________________

Fire has been a major concern of race car drivers since the beginning of racing. Before cars had seat belts as standard equipment, some race car drivers would ‘belt’ themselves into the car by tying themselves to the seat with a rope. However, many drivers refused to belt themselves in since many drivers lived through crashes because they were thrown from the car before it started on fire. Many drivers died or were seriously injured due to car fires.

Fire-retardant materials are used to protect drivers. Today’s lab will look at treatments that can increase a fabric’s fire retardancy.

Day 1

• Prepare a 250 mL solution of 10 g/L borax solution.
• Prepare a 250 mL solution of 50 g/L borax solution.
• Cut 3 - 2 cm x 2cm fabric squares of two different fabrics
• Get 3 cotton balls

1) Where have you seen flame retardant fabrics in your home?

2) Prepare two solutions:
Hint: Use warm water in your mixture. It will help dissolve the borax. Use the stirrer stick to mix thoroughly.

1. 250 mL of 10g/L borax solution

Show your calculation to create this solution.

How many grams of Borax are needed to create this solution?

Before mixing your solution, check your calculation with your teacher.

1. 250 mL of 50 g/L borax solution

Show your calculation to create this solution.

How many grams of Borax are needed to create this solution?

Before mixing your solution, check your calculation with your teacher.

1. 250 mL of water

3) Use tweezers or tongs to dip the fabric squares and cotton balls into each of the solutions. Keep the fabric in the solution for 3 seconds.

4) Squeeze out excess moisture (be sure to wear plastic gloves) over the sink.

5) Set fabrics on wax paper. Carefully mark each fabric sample as dipped in 10 g/L solution, 50 g/L solution and water. The fabrics will dry overnight.

Second day:

Set up a rectangular cake pan with about ¼ to ½ inch of water with the sterno in the center. Wait for your teacher’s directions about lighting the sterno.

Safety warning: goggles must be warn by all students and tongs must be used by the student burning the fabrics.

Assignments:

1. Recorder: must accurately describe the results of each experience
2. Timer – time three seconds of burning
3. Responsible for burning the fabrics – be sure you are using tongs.
4. Observer(s) check accuracy and thoroughness of timing and recording of results

Original Use of Fabric	Fabric	Control Water (Describe fabric following the burn)	10 g/L Borax (Describe fabric following the burn)	50 g/L Borax (Describe fabric following the burn)

What did you observe?

Why is it important for a division of responsibilities among the lab partners?

Why is independent product test necessary?

Assessment/Checking for Mastery:

Name _______teacher answer key_________ Quiz on fire retardancy and fabrics lab

1) List two of the three major factors that influence the flammability of fabrics:

(Answer: need 2 or 3

1. type of fiber
2. fabric weight and construction
3. presence/absence of a flame retardant)

2) True or False: There is NO material that is fireproof.
(Answer: True)

3) A chemical that enables a material to resist burning when exposed to a high energy ignition source such as a gasoline fire is called

1. fire retardant
2. flame retardant
3. fireproof

(Answer: a)

4) A chemical that enables a material to resist burning when exposed to a low energy ignition source such as a match is called

1. fire retardant
2. flame retardant
3. fireproof

(Answer b)

5) Give two real life examples of fabrics which need to be flame retardant: Answers: tent; suits worn by fireman, race drivers, astronauts; shoes of workers that work near hot or flammable materials; material around the space shuttle; gloves worn by blacksmith or glass maker)

6) What is the difference between durable flame retardants and non-durable flame retardants?
(Possible answers: durable must withstand washing; non-durable are usually
inorganic, inexpensive materials which do not withstand washing.)

Name _____________________________________ Quiz on fire retardancy and fabrics lab

1) List two of the three major factors that influence the flammability of fabrics:

2) True or False: There is NO material that is fireproof.

3) A chemical that enables a material to resist burning when exposed to a high energy ignition source such as a gasoline fire is called

1. fire retardant
2. flame retardant
3. fireproof

4) A chemical that enables a material to resist burning when exposed to a low energy ignition source such as a match is called

1. fire retardant
2. flame retardant
3. fireproof

5) Give two real life examples of fabrics which need to be flame retardant:

6) What is the difference between durable flame retardants and non-durable flame

retardants?

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