Results

Hi again, i recently did my experiment on the weekend. I realise the hand looks freaky but i cut myself out of the picture... also, the method was used from the previous post.

Needless to say, i wore quite a lot of protective gear (long sleeved jumper, safety goggles) because it was pretty scary about putting your face and hands so close to a 'to-be-ruptured' rubber band. We all know it hurts. I didn't wear gloves though as it may interfere with the accuracy of the experiment.
Here are the results:



NB: Sorry you have to squint

All the measurements taken above are read and done by hand. The average is converted from kilograms to Newtons by using a formula: kilograms*9.8m/s/s= Newtons.

Climate graph

Click on graph to enlarge! Putting it together took longer than actually drawing it up...

More about the experiment

Hopefully by detailing the wording of the experiment, my experiment will be easier to understand.

'DOES TEMPERATURE AFFECT THE FORCE A RUBBER BAND CAN WITHSTAND BEFORE RUPTURE?'

Temperature is defined as the hotness or coldness of a body or environment. Temperature can be meausred using either Celcius, Fahrenheit of the Kelvin Scale. In my experiment, i'll be using (degrees) Celcius.

Elasticity is the tendancy of a material to return to its original shape after a load has been exerted on it. In my experiment however, i will be meausuring the load the rubber band can take before rupture by using a spring scale a.k.a. Newton Meter.
Sourced: wordnetweb.princeton.edu/perl/webwn, elasticity, Date accessed[11 April, 2010]

A spring scale measures the tension force applied to the object. Ultimately, a spring scale and a newton meter is the same thing; the spring scale meausures in kilograms (kg), whilst a newton meter measures in Newtons (N). If you multiply kilograms by 9.8m/s/s (metres squared and acceleration due to gravity) it will convert the amount of kilograms to Newtons.

Long awaited method

This is the 'refined' method which will hopefully meet all the requirements...

* During the research, I found that rubber bands were classified with a size number according to the thickness, length and width of the rubber band. In my experiment, I will be using size 16 rubber bands.

Equipment

Picture 1- Size 16 Rubber bands






Picture 2- Safety goggles

Picture 3- Spring balance hanging from hook

- 1 pack Esselte Superior Rubber Bands- Size Number 16x 45*
- Safety goggles
- gloves(optional)
- Oven
- Freezer
- Spring scale

Method (2):
1) Put on safety goggles and gloves.
2) Hang a spring scale from a secure hook as shown in picture 3.
3) Take 45x Size No.16 Rubber bands and sort them into 3 piles of 15 rubber bands each.
4) Place the first group of 15x rubber bands in the freezer at 0 degrees Celcius for 2 hours.
5) Take the rubber bands out of the freezer and immediately place a frozen rubber band onto the spring scale as shown in picture 3. Pull downwards on the rubber band.
6) Record the measurement on the scale (amount of grams exerted on the rubber band) just before the rubber band ruptures.
7) Repeat steps 3)-6), instead using the second group of 15x rubber bands at room temperature (20 degrees Celcius)left for 2 hours.
8) Repeat steps 3)-6)instead using the third group of 15x rubber bands heated in an oven at 70 degrees Celcius for 2 hours.
8) Record and tabulate results.

How can this experiment help?

By being able to come to a conclusion about whether or not a rubber band's elasticity/ strength/ durability is affected by temperature, rubber can be maufactured according to this finding in a way that is perhaps more sustainable to the environment and to consumers.

Understanding the relationship between various substances e.g. rubber and sulfur, may provide building blocks to producing one artificial type of rubber capable of being used for a range of purposes (there are a lot of types of rubber now, sorted according to use), thus cutting down cost and need for resources to manufacture the current types of rubber.

ALthough it seems as if rubber has already come so far and there is no need or chance that rubber's properties can be further refined, rubber still has the potential to further develop. Rubber can be found almost anywhere, at home, on a plane, in your shoes...

Who knows what rubber will be used for in the future?

Source:
- Middendorf, W.H. (1981), What every Engineer should know about Inventing, Marcel Dekker, New York.

Some uses of rubber bands

Some may be obvious, some not so obvious...

- Braces elastics (helps manoevure teeth to fit the jawline):




pretty yuck...





- Hair elastics (elastics found in hairpieces):







- Pants (Need more room? Just loop a rubber band through a hole in your pants and fasten it to a button)




- Car tyres (ok, they don't have rubber bands in them, but they have rubber..:D)

- Newspapers, tying flowers in bunches:

















- and much, much more...

why do rubber bands break?

As you know, when you stretch a rubber band too much, it suddenly snaps. A rubber band, although it may not seem so, is not exactly the same thickness or width all the way around the loop. Therefore, it is important to note that rupture of the rubber band will break at it's weakest point or the point where pressure is most directly exerted.

When an object such as rubber is stretched, stress is put upon the object, resulting in 'microtears' along the stretched part. THis is why when you strech a rubber band, there are very small 'wrinkly' lines in the band. The more stress is exerted, the more likely the rubber band will break. Eventually the rubber band will break.



TO

Intro (2)- BAckground research on Rubber

Taking off from before...

It was only an accident when Charles Goodyear (yes, the person who made the tyres on your car) mixed sulfur, lead and rubber on a hot surface that the formerly- natural rubber acquired a more usable consistency and texture. Goodyear dubbed this process 'vulcanization'. Vulcanization can be defined as the process of treating rubber with sulfur with a high heat using sulfur/ other 'curatives' to improve elasticity, strength and/or durability of the rubber.

Today, most of the rubber in this world is used for commercial/ domestic purposes and is produced synthetically. There are about 20 types of synthetic rubber, all classified according to their intended use and thus, their quality, and only one type of natural rubber.

Rubber bands are simply short lenghts of rubber, calcium carbonate, carbon black, clay, sulfur, stearic acid, zinc oxide, wax and oil formed into a loop (mentioned in previously in another post). These ingredients are put into a tube and mixed in a pressurized steam tank through the process of 'vulcanization'. When this is done, the tube is cut into rings to form the rubber bands that we know.

References:

• http://science.jrank.org/pages/7266/Vulcanization.html, vulcanization- rubber as a natural product, Date accessed [30th March 2010]
• Mark,J.E., Erman B. and Eirich F.R. (1994), Science and Technology of Rubber: 2nd edition, Academic Press Limited, London
• http://www.essortment.com/all/historyofrubbe_rcml.htm, history and development of rubber, Date accessed [30th March 2010]
• http://www.enotes.com/how-products-encyclopedia/rubber-band, history and development of rubber bands, Date accessed [31st March 2010].
  

Introduction (1)- Background about Rubber

Before the process of curing/ vulcanizing rubber was discovered, rubber was a product with much potential to be improved as it was extremely unreliable and temperamental according to the weather i.e. when it was humid, the rubber would 'follow' and turn warm and sticky, when it was cold, the 'unvulcanized' rubber would turn soft and fragile. This made the rubber unreliable for practical use.

Rubber originally and nuturally derives from plants which grow in the equitorial regions of the globe, particulary East Asia. It was initially used by the Mayans (for who knows how long) by extracting latex found in tree sap of rubber trees and combining it with the liquids of a nearby vine, resulting in a black substance with basic waterproofing qualities.

Since the mid 1700s when CHristopher Columbus discovered the Mayan's incredulous invention and introduced it to other 'developed' countries such as Europe and America, there has been many attempts to develope the natural rubber until it could hold it's shape and be sutiable for commercial use.

To be continued...