Laboratory Glasswares

Star Expansion Borosilicate Glass All the chemical research teams have used glass containers for a very basic reason - glass is transparent, thereby making the contents and the reactions clearly visible. However, owing to the fact that chemists must heat, cool and mix chemical substances, ordinary glass is not always sufficient for laboratory work.Laboratory work requires that the apparatus for handling chemicals/media offer maximum inertness when in contact with the widest range of chemical substances. Moreover such apparatus needs to withstand thermal shock without fracture, high temperatures without deformity and mechanical shocks from daily washing and sterilization.Star scientific glass co. represents optimum thermal, chemical and mechanical behavior. This glass is used in laboratories as well as for industrial applications where maximum thermal, chemical and mechanical resistance is required. Resistance to Chemical Borosilicate glass is inert to almost all materials except hydroflouric acid (HF) phosphoric acid (H Po ) and hot strong caustic solutions. Of these Hydrochloric acid has the most 3 4 serious effect, even when it is present in PPM parts per million) in solutions. Where as phosphoric acid and caustic solutions cause no problems when cold but at elevated temperature corrosion occurs. In case of caustic solutions up to 30% concentration can be handled safely at ambient temperature. Under actual operating conditions, the effect of turbulence,and traces of other chemicals in the solution may increase or decrease the rate of attack. So it is not possible to give exact figures for corrosion by caustic solutions. Thermal Properties Linear coefficient of thermal expansion the coefficient of thermal expansion of borosilicate glass over the temperature 0-300° C is 33 x 10-7/°C. This is very low when compared with other glasses and metals. That is why; borosilicate glass is often called low expansion borosilicate glass. Specific Heat Specific heat between 25°C and 300°C is average to be 0.233Kcal/Kg °C. Annealing Annealing of glass is the process where the glass is heated and kept for a defined period of time to relive internal stresses. Careful cooling under controlled conditions is essential to ensure that no stresses are reintroduced by chilling/cooling. Mechanical Properties The lack of ductility of glass prevents the equalization of stresses at local irregularities or flaws and the breakage strength considerably about a mean value. This latter is found to occur at a tensile strength of about 700kg/cm In order to allow for the spread of breaking stress, a large factor of safety is applied when determining the wall thickness requirement to allow operation up to values given in the table of working pressure. Optical Properties Borosilicate glass considerable absorption in the visible region of spectrum and therefore appears clear and colorless. In photo processes the transparency of ultra violet is of particular importance. It follows from the transmittance of material in UV region that photo chemical reactions such as & sulpho-chlorination can be performed in it.

Chemicals Composition

Component % by weight
SiO2 80.6
B2 O3 12.5
Na2 O 4.2
Al2 O3 2.2
Other 0.5

Enquiry Now

Looking for Product Name ?