Laboratory tools are manufactured with the following main materials detailed below:
Glass
Historically, the laboratory has been made primarily with glass. The glass that makes up the majority of the material in the laboratory is of the type borosilicate as in its manufacturing process are added to the silica certain quantities of oxide of boron (B2O3), among other compounds. It is often called also glass brand by carrying the brand of the manufacturer on its surface. Some of the most well-known brands are Pyrex®, Last-Shott-Jena® or Corning®. With this glass are manufactured currently almost all of the utensils lab.
In addition to the borosilicate, which is essential, as each manufacturer varies the ratio of the other components, according to laboratory studies and for specific uses (see Table 1). This confers to this kind of glass a few different properties to the conventional glass, such as:
- Scratch-resistance.
- Chemical resistance, since it can hardly be attackable by the great majority of chemical reagents.
- Supports strong changes of temperature without hardly altered (coefficient of expansion of 32·10-7 l / ° C) in a temperature range between 20 and 300 ºC.
- Great transparency.
- Character insulator (it does not conduct electric current).
- Ease of cleaning.
| Component | soda-lime glass | borosilicate glass | |
| Pyrex® | Duran® | ||
| SiO2 | 71-75 | 80(81) | 81 |
| B2O3 | – | 13(12) | 13 |
| Na2O | 12-16 | -(4) | 4 |
| K2O | – | -(-) | 4 |
| CaO | 10-15 | -(-) | – |
| PbO | – | -(-) | – |
| Al2O3 | – | 2(2) | 2 |
| NaOH | – | 3(-) | – |
| KOH | – | 1(-) | – |
These properties and a price of manufacturing relatively low making it the ideal material for making of all kinds of household appliances laboratory.
On the other hand, the so-called soda-lime glass cannot be heated, nor can it endure extreme temperature changes. Soda-lime glass is used for everyday items such as bottles, drinking glasses, and flat glass, but its use is largely restricted to laboratory glassware such as Erlenmeyer flasks, beakers, test tubes, and crystallization dishes.
Some laboratory containers are made of amber glass. This glass is manu- factured by adding sodium sulfate, iron salts, and carbon. Iron polysulfides are used, depending on the proportion, giving the glass a color ranging from yellow to almost black. Acids as common as the H2SO4 or HCl and most organic reagents are marketed in such containers, and they are also used for storing light-sensitive chemicals.
Polymeric materials
In recent years, there has been a dramatic increase in the manufactured material with plastic polymers of high-strength, among which are both materials for continued use as a disposable. The use of plastic polymers for the manufacture of these materials, and involves a series of advantages such as durability and resistance to mechanical as well as chemical. With the use of this type of material, to avoid the breakage, so common in the glass material, increasing the overall safety of the laboratory.
Depending on the type of polymer used, the objects made are compatible with a variety of reagents including strong acids and bases, solvents, general use, and the majority of the organic reagents. In addition, it is used for the manufacture of containers of very diverse nature, graduates or not, drums, containers, caps and moving parts, such as keys, etc
Among the polymeric materials that are often used include the following:
Polypropylene (PP)
Translucent or transparent material, resistant to aqueous solutions, acids, bases, and general-purpose organic solvents; thermally stable between −10 and 130 ºC, and thus can be autoclaved, avoiding the formation of meniscus in test tubes and other measurement systems, which facilitates reading. It is incompatible with strong oxi- dizers. They are used mainly to manufacture beakers, conical funnels, graduated cylinders, Bu ̈chner funnels, wash bottles, centrifuge tubes, and desiccators.
Polymethylpentene (PMP)
Transparent, with properties similar to those of the PP, slightly more brittle and thermally stable up to 180 ºC. Incompatible with strong oxidizing agents, hydrocarbons, and some chlorinated solvents (softens losing mechanical properties). Its price of production is greater than that of PP. It is mainly used in the manufacture of beakers, test tubes and Petri dishes.
Polyethylene (PE)
It can be transparent, translucent or opaque. A stable aqueous solution, slightly basic or acidic. Compatible with the reagents of photo processing and inert against most of organic solvents. It is mainly used in the manufacture of beakers, containers, various, wash bottles and Petri dishes.
Polycarbonate (PC)
Transparent, rigid and stable in a wide temperature range (from -190 to 130 ºC). Incompatible with bases and strong acids and organic solvents. It is mainly used in the manufacture of containers for storage, Petri dishes, and desiccators.
Polytetrafluoroethylene teflon (PTFE)
Brand named Teflon® is opaque plastic, semi-rigid, and very resistant to strong acids and bases as well as organic compounds. It is thermally stable at a very high tempera- ture range between −200 and 260 ºC. If it were not for the high price, it could replace virtually any glassware. The biggest drawback is its opacity, which prevents a view inside PTFE utensils. It is used mainly to manufacture magnetic stirbars, vials, beakers, flasks, test-tube racks, spatulas, centrifuge tubes, replacement parts such as burette stopcocks, and stoppers.
Perfluoroalcoxi (PFA)
Translucent, flexible, cryogenic, chemically inert, easy to clean, thermally very stable and non-polluting. It is mainly used in the manufacture of containers of various, Petri dishes and flasks.
Other materials
In the laboratories also offers cookware manufactured with other types of materials.
Ceramic and porcelain
It is used for making utensils with a great resistance to high temperatures and all kinds of reagents. The crucibles that are used to heat, melt, burn, or calcination substances are manufactured with these materials, and are capsules with semi-spherical shape and a lump in the mouth, to facilitate the discharge. The plates touch\index{Board!!!touch} are made of porcelain, usually white.
Agate
This name refers to a set of mineral microcrystalline quartz which exhibits high hardness, stability versus reactive diverse and resistance to acids. It is used mainly for the manufacture of mortars that allow you to grind a solid with enormous efficiency.
Metals (stainless steel, aluminum…)
Many utensils are made with these materials, and in other sections are describe some of them.
