# Heating a block of Rubber by passing electricity

• sakthi
In summary, the conversation discusses the use of copper strips or wires to heat a piece of rubber to a specific temperature using electricity. The suggestion is made to use nichrome wire instead of copper and to incorporate carbon granules in the rubber matrix for even heating. The use of plastics as a heating element is also discussed, with the suggestion to use a lamination of plastic sheets with fine metal mesh. The conversation also mentions a calculator and the need to distribute heat evenly to avoid hotspots. The question is raised about finding the appropriate size of copper strips for a desired temperature increase. However, it is noted that the calculator is only accurate for higher temperatures and an equation is needed for smaller temperature increases.

#### sakthi

Hi everyone.

I want to heat a piece of Rubber by embedding copper strips or wires in it and passing electricity(120V - 2.5Amp) through it. The room temperature is 0(zero) deg Celsius and i want to heat the aluminum block(5" x 5" x 1") to 10 deg Celsius(Not more than 10 deg).

Question: How will I determine the size of the copper strips or wires that I have to use to generate enough heat to raise the temperature of the block to 10 dec C.

sakthi said:
Hi everyone.

I want to heat a piece of Rubber by embedding copper strips or wires in it and passing electricity(120V - 2.5Amp) through it. The room temperature is 0(zero) deg Celsius and i want to heat the aluminum block(5" x 5" x 1") to 10 deg Celsius(Not more than 10 deg).

Question: How will I determine the size of the copper strips or wires that I have to use to generate enough heat to raise the temperature of the block to 10 dec C.

Welcome to the PF.

You should probably use nichrome wire instead of copper. There is a calculator in post #2 of this thread that should help you:

.

I wouldn't recommend this method for heating a block of rubber.

Rubber itself is a thermal insulator so embedding resistive wires into the block is likely to lead to hotspots around the wires, without raising the block temperature evenly.

Conductive rubber can be made by incorporating carbon granules in the rubber matrix. Using this method will ensure even resistive heating.

Thank you berkeman.

I will try the calculator.

Studiot - Thank you for your suggestion.

So, I cannot use rubber at all.

Can I use some kind of thermoplastic. What is your take on that.

Plastics materials, natural or artificial = thermal insulator so the same comment applies.

A lamination of sheets of plastics with sheets of very very fine metal mesh might heat evenly enough.

You need to distribute the heat as widely as possible.

The problem to overcome is that the rate of heat transference away from the heating element must not be less than the rate of heat production in the element.

berkeman - The calculator holds good only for higher temperature(80 dec C onwards). I am looking something really small (10 deg C). Is there an equation to find out the size of the copper strips that will induce the heat.

Thank you

## 1. How does passing electricity through a block of rubber heat it up?

When electricity is passed through a block of rubber, the rubber's molecules start to vibrate due to the flow of electrons. This vibration causes the molecules to rub against each other, which generates heat energy and increases the temperature of the rubber.

## 2. Is it safe to heat rubber by passing electricity through it?

Heating rubber by passing electricity through it can be dangerous if not done properly. Rubber is a good insulator, which means it can trap and build up electrical charge. If the rubber is heated too quickly or with too much electricity, it can melt or even catch fire. It is important to follow proper safety precautions when attempting to heat rubber with electricity.

## 3. What type of rubber is suitable for heating with electricity?

Only certain types of rubber are suitable for heating with electricity. Natural rubber, also known as latex, and synthetic rubber, such as silicone and neoprene, are good options. However, certain types of rubber, like EPDM, are poor conductors of electricity and cannot be heated this way.

## 4. Can heating a block of rubber with electricity cause it to lose its elasticity?

Heating a block of rubber with electricity can cause it to lose some of its elasticity. The heat energy can break down the long polymer chains that give rubber its stretchiness, resulting in a stiffer and less elastic material.

## 5. What are the benefits of heating rubber with electricity?

Heating rubber with electricity can have several benefits. It allows for precise and controlled heating, making it useful in industrial processes like vulcanization. It can also be used for heating rubber in products like heating pads and hot water bottles. Additionally, heating rubber with electricity is a more energy-efficient method compared to other heating methods like burning fuel.