Technical Data

General Properties

Glass excels by its very good chemical resistance against water, saline solutions, acids, alkalis and organic solvents, and exceeds most plastics in this regard, It is only attacked by Hydrofluoric acid and at elevated temperature by strong alkalis and concentrated Phosphoric acid. Further advantages of glass are its dimensional stability even at elevated temperatures, and its high transparency.

Borosilicate Glass: Borosilicate glass has very good chemical and physical properties. It is considered as the technically all-round glass for applications requiring very good chemical and thermal resistance (including resistance to thermal shock), & high mechanical stability. Typical applications are e.g, components for chemical apparatus, round-bottom flasks, & beakers, etc.

Application

  • Typically, these glasses can be used for most laboratory applications.
  • Laboratory functions under clear visibility (transparent) observations like normal heating, cooling, mixing, washing, sterilizing etc. Suitable for thermal resistance, thermal shock, mechanical resistance and chemical resistance.
  • Light sensitive products must be stored/ handled in Amber glass which is also a part of our production. Amber glass is formulated to absorb light in the Ultra Violet region ofthe electromagnetic spectrum.

Mechanical Resistance

Thermal Stresses: During the production and processing of glass, hazardous thermal stresses may be introduced. During cooling of the melted glass, in the range between the upper and lower annealing point, the transition from the plastic state to the brittle state takes place. At this stage, existing thermal stresses can be eliminated through a carefully controlled annealing process.

Once the lower annealing point is reached, the glass may be cooled more rapidly, without introducing any major new stresses. Glass responds in a similar way when heated, e.g. through direct exposure to a Bunsen flame, to a temperature higher than the lower annealing point. Uncontrolled cooling may result in the “freezing in” of thermal stresses which would considerably reduce resistance to breakage and mechanical stability. To eliminate inherent stresses, glass must be heated up to a temperature between the upper and lower annealing point, be kept atthis temperature for approx. 30 minutes and be cooled by observing the prescribed cooling rates.

MECHANICAL  stresses

From a technical viewpoint, glasses behave in an ideally elastic way. This means that, after exceeding the limits of elasticity, tensile and compressive stresses do not result in plastic deformation, but breakage occurs. The tensile strength is relatively low and may be greatly diminished even further by scratches or cracks.

Chemical Composition

Borosilicate glass is a glass which contains a significant proportion of Boric Acid (Boric Oxide 8203) in addition to its main component which is quartz sand (Silicon Dioxide SiO2.) The level of the Boric Oxide content in the batch (the mixture of all the glass raw materials) has an equally lasting effect on the melting behaviour of the glass as on all its other properties (incl. chemical resistance). In line with the wide variety of possible chemical compositions, including the addition of extra metal oxides, borosilicate glasses form a very extended family.

Raw Material: Borosilicate Glass Tube (low expansion/ low Alkali type)

SI0281%
B20213%
Na20 / K204%
Al2O32%

Safety Measures & Handling Guidelines

LABSOLV glassware posses the following thermal properties;

Coefficient of Linear expansion32.5 X 10-7 /°C
Thermal Conductivity0.0027 (Cal/cm3 °C/sec)
Specific Heat0.2
Strain Point515°C (safe operation Temp.)
Annealing Point565°C
Softening Point820°C

The above data supports the fact thatthe coefficient of linear expansion is very low and hence the temperature gradient is also low enabling the glass to withstand highertemperature and thermal shock.

LABSOLV glassware is screen printed and annealed in a furnace at 565°C to ensure minimum residual stress.

Chemical resistance

LABSOLV borosilicate glassware has superior chemical resistance. This class of glassware represents the least reactive glassware available. It is highly resistance to water, neutral and acid solutions, concentrated acids as well as chlorine, bromine, iodine and organic materials due to its relatively low alkali content.

Safety Measures &Handling Guidelines

LABSOLV Glasswares are manufactured with care from high quality Borosilicate tubes. However, certain precaution while using the same will extend the life and performance of the ware adding value to the cost with increased satisfaction.

Working with glass

  • When working with glass, it is essential to consider its limitations regarding resistance to thermal shock and to mechanical stress. Strict safety measures must be observed: Exothermic reactions, such as diluting of sulphuric acid or dissolving solid alkaline hydroxides must always be carried out under stirring and cooling, and in suitable vessels such as Erlenmeyer flasks.
  • Do not heat up volumetric instruments, e.g. Measuring Cylinders and Volumetric Flasks, on heating plates.
  • Glass instruments must never be exposed to sudden temperature changes. Therefore, never take them out of a drying cabinet while hot, and place them on a cold or even wet lab bench. This applies especially to thick-walled glass instruments such as filtering flasks or desiccators.
  • When assembling apparatus, support the components in a way to ensure stability and to avoid mechanical stress. To compensate stresses or vibrations, use e.g. PTFE bellows.
  • Never subject glass instruments to sudden pressure changes; e.g. never admit air abruptly into evacuated glass apparatus. Glass vessels with flat bottom (e.g.Erlenmeyer flasks or flat-bottom flasks) must never be evacuated. The only exceptions are instruments specifically designed for vacuum use (e.g. desiccators, filtering flasks).
  • Never exert force on stiff stopcocks, ground joints, or glass/tubing connections. Apply effort only in a steady and controlled way upon empty glass instruments; never when they are under pressure or evacuated. Use appropriate safety devices, e.g. Protective gloves, goggles, screens, etc.

IMPORTANT

  • Avoid sudden change in temperature while heating or cooling as this may cause the ware to crack.
  • Avoid sudden exposure to high/ low temperature which may create thermal stress or thermal shock and thus create a permanent stress or damage. Gradually increase or decrease temperature to avoid thermal damage to ware.
  • Avoid sudden cooling to avoid thermal damage.
  • Avoid unattended evaporation work as the ware may crack or explode under dry conditions.
  • Avoid heating highly scratched glassware, as these will crack due to the low thermal strength.
  • Avoid sharp/ abrasive hard materials inside the glassware. This may have an impact on the mechanical strength of the ware thus creating weakening and further damaging the same.
  • Avoid large flame above the liquid level in the glassware as this will create difference in thermal effect and may cause thermal stress and damage.
  • Avoid placing glassware over direct flame or open heating elements especially thick walled glassware as this will create thermal stress and can damage the ware.
  • Avoid leaving glassware on electrical heating instruments like hot plate etc, after performing the work even if they are put-off as the heat will be retained for some time.
  • Avoid using hard/ sharp stirrer/ mixers to be in touch with the body of the glassware to prevent scratch/ damage to ware. Check and ensure sufficient gap between the rod/ blade and the wall is maintained before use with stirrers.
  • Avoid uncovered metal follower while using magnetic stirrer.
  • Avoid mixing sulphuric acid and water inside glassware with base fitted like a Measuring Cylinder
  • Avoid using glassware beyond the recommended safe limits of pressure and vacuum.
  • Avoid direct effect of pressure and vacuum on glassware. Safety screens should be used for Such applications.
  • Avoid Sudden change of pressure or vacuum. Gradual change should be introduced.
  • Avoid cleaning with high concentration Hydrofluoric Acid, hot Phosphoric Acid or Caustic Alkali.

Care & Maintenance

  • To avoid sticking of glass parts like stopcocks and other ground jobs, store them with thin strip of paper inserted between the joints while not in use.
  • Keep stopcocks and ground joints free of dirt. Preferably store the ground joints in lubricant after use.
  • For separation of stuck ground joints following methods can be adopted:
    1. Carefully rocking the cone in the socket
    2. Gently taping the socket rim on a wooden surface
    3. Heating the socket in a localised flame
    4. Using penetrating oil
  • For connecting ‘Taper Joints’, use lubricants such as Hydrocarbon grease (removable by most lab solvents/ acetone) and Silicon grease -for high temperature or vacuum application (removable by Chloroform). However for long term use water soluble organic and insoluble grease such as glycerine can be used.
  • While inserting rubber tubes on a glass tube apply glycerol, water or oil and insert using protective gloves.
  • Before using new glassware, especially for critical chemical test, soak the ware in dilute acid (1 % hydrochloric or nitric acid) for several hours to neutralize the slight alkalinity reaction which may affect the result.
  • All glassware should be washed or soaked as soon as the test/ use is over. Cleaning using a soft brush should be done with soap solution. If this is inefficient, only if required use aqua regia, nitric/fuming/chromic acid solutions. Rinse ware with distilled water before use. Do not use high concentration Hydrofluoric Acid, hot Phosphoric Acid or Caustic Alkali for cleaning.
  • Ensure that all Measuring /Volumetric glassware are free from any oil/ grease.
  • For all culture media/virus/ bacterial contaminated – boil the ware for 30 minutes or sterilize/ autoclave the same for safe handling.
  • Drying of washed ware if required can be done in baskets at not more than 120°C.

WE ARE HERE FOR YOUr
laboratory Glassware needs

get in touch with us

Let us know your requirement our team will contact you shortly.