Laboratory management [GLT 301] SECOND LECTURE
LABORATORY FURNITURE
Laboratory benches: they cab be either foxed or removable/flexible. As fixed benches should be used for Laboratories which are not likely to change for a long time. For laboratory works that requires tapid changes, flexible or movable benches should be used. Any of the bench type choosen must be rigidly constructed. The bench top must be chosen with care, because it has a lot of role to play in the work done in the laboratory.
Qualities of a good bench
1. It must be rigid and solidly constructed.
2. It must be smooth, impervious and reasonably hard.
3. It must be resistant to attack by acids, alkaline and other solvent that might spill on it.
4. It must be able to withstand each, scratches and not be easily indented.
5. It must be hard, and kind to glasses/glass wares.
Materials for bench-top
A wide range of materials have been used in the past and present to construct bench top.
In choosing materials for bench tops the following factors must be considered;
1. Availability of the material.
2. Consider the length of life.
3. Consider the durability.
4. Consider the resistance to attack.
5. Consider the cost.
6. Consider the ease of cleaning.
7. Consider the general appearance.
The choice of material is determined by the nature or type of work to be undertaken or carried out, the work might require that the material chosen must be able to withstand moisture, heat, attack by chemicals or pest and contamination with electrical properties or burns from hot object.
Various materials that are used for the laboratory bench frames and tops include;
1. Timber wood: The tops must be covered with impervious plastic laminate, when treated this way, the timber wood tops have the following qualities:
i. It will be easy to clean
ii. Resistance to most chemical attacks.
iii. It is rigid
Others that can be used are Teak, Mahogany and Iroko.
2. Teak:
i. They are durable.
ii. Resistance to attack by chemicals.
iii. Resistance to heat.
iv. Very expensive.
v. Not readily available.
Assignment
Find out the qualities of Mahogany and iroko with their merit and Demerits.
5. Metals
A number of metal have been used as been used as bench top which include;
i. Stainless steel
ii. Aluminum
iii. Galvanized ion etc.
It is important that the metal used must have corrosion resistance finishes,
Stainless steel
It is used as bench top in Laboratories, dark-room and bio-chemical laboratories.
Qualities
i. It has a good appearance
ii. It is resistant to most chemicals, but attacked by sulphuric acid and hydrochloric acid
Disadvantages
i. It can conduct heat
ii. It is expensive
iii. Easily corroded.
Aluminum
Pure and its alloy: it is widely used in explosure laboratories, it has a fairly good appearance, and it is fairly resistant to other chemicals but attacked by alkaline and mercury.
In alloy form: it is heat resistant, it is not expensive.
RESINS
Phenolic resin: is an oil based chemicals used to saturate and impregnate craft paper in a composite systen to form a phenolic resin sheet.
ADVANTAGES
i. It is chemical and solvent resistant
ii. Stain and corrosion resistant
iii. It is also moisture resistant
iv. Maximum heat resistant is 350°F or 176°C above this, it cannot resist heat
v. It is abrasion resistant
vi. It is impact and stress resistance.
Exposy Resins: It is an oil based by product, which is poured in a mode, heated and formed into a homogeneous laboratory table top.
ADVANTAGES
i. Impressive heat and chemical resistant.
ii. Resist discolouration, blistering and cracking, even under fhe hatches condition.
iii. Smooth and eliminate distracting glare or light reflection.
iv. Provides the safest, most economical and long lasting work surface available.
v. It is also very durable.
CERAMICS
i. It is chemical resistant, heat/temperature resistance, they are easy ti clean after extreme staining.
ii. Scratch resistant.
iii. Ease of decontamination when handling radioactive substances.
Laboratory Bench Arrangement
1. Peninsular bench arrangement
2. Island bench arrangement
3. Wall bench arrangement.
[Laboratory flooring will the discussed in the next class.... don't forget to read on the assignment given....]
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