Glass funnel: the best at the best price

November 2, 2021

In every laboratory it is necessary to have an instrument that allows the transfer of liquids without spilling a drop . The best option is to use a glass funnel . This is usually much more common in chemistry laboratories and is made up of a hollow body with two ends of different lengths. It is very easy to identify since one end is much wider. It is usually made of different materials, glass being one of them.

The glass funnel is an essential element in the equipment of a laboratory. Over time, its design has undergone different modifications to create a funnel that perfectly adapts to the functionality that it meets today.

This laboratory instrument is required in situations where it is necessary to channel liquids and granular gaseous materials into containers with narrow mouths . Such is the variety of glass funnels, that there is even an exclusive one to separate liquid samples with different densities.

Thanks to the glass funnel it is possible to transfer a liquid from one container to another without spilling a drop. And it is that glass is the most widely used material for the manufacture of laboratory materials. This thanks to the fact that it has an unmatched chemical inertness. Unlike materials such as plastic or metal, glass almost never degrades or damages.

However, nowadays we find non-reactive polyethylene plastic funnels that are also widely used for the transfer of aqueous solutions between containers. Sometimes plastic can be used for the powder funnels that do not come in contact with some common solvent.

What is the glass funnel?

The glass funnel belongs to the basic equipment of a laboratory whose main function is to allow the transfer of a liquid between two containers. It is very common to find them in laboratories and, as they are made of glass, they are the ideal instrument for working with chemical substances.

And it is that glass is an inorganic material. This is manufactured from silica sand, sodium carbonate and limestone. To obtain the glass, these elements must be worked at 1500ºC . It is important to note that glass and crystal are two very different elements. Crystal is a non-amorphous solid. For its part, glass is amorphous and is a derivative of ceramics.

Although there are a wide variety of types of glass, for it to be useful as a laboratory material, it must first meet a number of requirements. Because of this, it is normal to use ordinary glass, made with soda (better known as sodium hydroxide and lime) and calcium oxide. Pyrex glass , which is made from silicon and boron, is also commonly used . Boron being the most used when manufacturing laboratory materials. The reason is because this material provides great resistance to thermal shock .

What is your function?

Glass funnels are manufactured to fulfill two functions: The first is attached to the funnel design and is to transfer substances; in other words, transporting a liquid between two containers (which are usually of different sizes). The second function of this tool is for filtering, in this way the filtering of substances is made much easier since two actions are carried out at the same time.

How is the glass funnel used?

Like funnels made of other materials, the glass funnel has the same use: the transfer and filtering of substances. First of all, it is usually used in pharmaceutical, chemistry and biology laboratories. However, the factor that differentiates this from the other funnels made with common materials is the resistance when working with various chemicals , whether they are corrosive or are at high temperatures.

An easy example would be the Büchner funnels that are made from Pyrex glass because of the substances often poured into it. In most cases it is not possible to wait for the temperature of a substance to drop before storing it. Either to prevent a reaction or because the procedure dictates it that way. Because of that, it is necessary to have a glass funnel that can have high resistance to thermal shock.

Types of glass funnels

There are many types of funnels, almost all of them arose thanks to the fact that over time they have experienced some variations in the original design with the purpose that they could be suitable to meet specific needs that arise as methods of dealing with substances evolve. These funnels are not only different in design, they are also different in materials. Thanks to this there is a great variety of glass funnels. These are:

Filtration funnels

Its shape is the standard conical. Often used to filter liquids by gravity . They are also usually made of plastic, although the largest production of this funnel is in glass.

Embudo Büchner

This type of funnel allows vacuum filtration while extracting the solid . This funnel is made of two materials: porcelain and glass. The purpose of these materials is to resist pressure and high temperatures.

Settling funnel

Of all the funnels, this one has a much more particular shape. It is only made of glass and is used to separate immiscible liquids . Usually to extract a solute from a solvent.

This type of funnel tends to be associated with other instruments, such as flasks, most of which are also made of glass.

Conical Filtration Glass Funnel

Funnel types used for cold filtration have an outlet tube. However, the funnel type for hot filtration does not have an outlet tube.

Flat glass funnel

It is the funnel with a normal design that allows to carry out the basic operations. It is normal to find them in different dimensions, some having longer necks than others.

Safety tube (shaped like a thistle flower)

The most common use of the safety tube is to add liquids to a laboratory apparatus or setup.

Adding or dripping funnel:

This type of funnel has a faucet that makes it easy for you to slowly add the liquid to a jar . Its design is cylindrical and with a graduation on the glass. They have a ground glass joint at their base.

Glass Funnel Features

Although glass funnels can have many variations, they start from a basic principle such as the hollow body and the ends with different lengths . The material from which the funnel is made does not change its function. So, having already known the different types of glass funnels, it will be very interesting to know what are the characteristics that differentiate one funnel from another.

Refractory

Glass funnels are highly resistant to high temperatures without affecting their performance.

Low thermal expansion

Different temperature changes have no influence on the volume of the instrument.

Chemical resistance

As they are made of glass, the funnels have a great resistance to corrosion, erosion and impregnation that certain chemicals can cause on a surface.

Dielectric strength

Glass funnels have the ability to withstand a certain voltage without affecting the material.

Zero porosity

By having a waterproof surface, it prevents residues of other substances.

However, it is important to bear in mind that the measurements of these characteristics will always depend on the type of glass with which the funnel has been made. For example, common glass has a lower chemical resistance capacity than borosilicate glass, which has in its composition between 70 and 80% sand and 13% boron trioxide.

Another type of glass that is also often used in the production of laboratory funnels is allusciminicate glass . This is optimal when it comes to working with alkalis and, although it is less resistant than borosilicate, it is much easier to manufacture and in the end provides great efficiency and resistance when performing its functions.

Importance of the glass funnel

The glass funnel is one of the main elements used in many areas of scientific study. Chemistry laboratories are one of the spaces where the presence of this instrument is most appreciated. The manufacture of glass funnels arises from the need to minimize the risk that a substance alters or damages an instrument due to the material of manufacture. Based on this and thanks to the fact that they have adequate characteristics, glass is defined as the default material for laboratory funnels.

Although the tires of a vehicle cannot be manufactured using other material than rubber, given this material is what provides a good performance to the car, the funnels that have to be used in the transfer of chemical substances must be manufactured with appropriate materials . Such action would compromise not only the success of the operation to be carried out, but also jeopardize the integrity of the person carrying out the operation.

Dr. Loony Davis5
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Born and raised in Brussels in an English family, I have always lived in a multicultural environment. After several work experiences in marketing and communication, I came to Smart Water Magazine, which I describe as the most exciting challenge of my career.
I am a person with great restlessness and curiosity to learn, discover what I do not know, as well as reinvent myself daily, someone who is curious about life and wants to know. I enjoy sharing knowledge.
This is my personal project but I also collaborate in other blogs, it is the case, the most important web on water currently exists in the US, if you are interested you can read my articles here.

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