Technical Infos Laboratory Glass

4
LABORATORY GLASSWARE
LABORGLAS
SIMAX GLASS
Products made of the SIMAX glass are smooth and imporous, perfectly transparent, catalytically indiff erent, corro-
sion-resistant even in long-lasting operations, su ciently homogeneous, and free of any heterogeneous particles.
The SIMAX glass is very friendly to the environment and is absolutely unexceptionable from the ecological view-
point.
The Glassworks KAVALIER have been counted among the most important world producers supplying products
from the borosilicate glass, type ..
CHEMICAL COMPOSITION
(main components in percentage by weight)
SiO
2
B
2
O
3
Na
2
O + K
2
O Al
2
O
3
80.6 13 4 2.4
RESISTANCE AGA/NST
water at 98 °C (pursuant to ISO 719) HGB 1
water at 121 °C (pursuant to ISO 720) HGA 1
acids (pursuant to ISO 1776) 1
eff ect of water solution of alkali mixture (pursuant to ISO 695) A2 or better
The SIMAX borosilicate glass . is highly resistant to eff ects of water, neutral and acid solutions, strong acids and
their mixtures, chlorine, bromine, iodine, and organic compounds. Even in long-term e ects and at temperatures
above  °C, this glass outstrips, with its chemical durability, most metals and other raw materials.
Due to e ects of water and acids, the glass releases only small amounts of mostly univalent ions. At the same time,
avery thin permeable siliceous gel layer is formed on the glass surface, which ensures resistance to further e ects.
Hydrogen uoride, hot phosphoric acid, and alkaline solutions attack the glass surface, depending on concentration
and temperature
.
SIMAX: PHYSICAL PROPERTIES
PHYSICAL DATA
Mean linear and thermal coe cient of expansion
_ ( °C;  °C) according to ISO . x
K
–
Transformation temperature Tg.  °C
Glass temperature at viscosity d in dPa.s  (upper cooling temperature)  °C
Glass temperature at viscosity d in dPa.s , (softening temperature)  °C
Glass temperature at viscosity d in dPa.s  (working range)  °C
Highest short-term admissible working range  °C
Density l at °C ,g. cm
–
Modulus of elasticity E (Young modulus) x 
MPa
Poisson ratio µ .
Thermal conductivity h ( to  °C) . x
K
–
MECHANICAL STABILITY OF SIMAX GLASS
Mechanical properties and service life of products made of the SIMAX glass are largely done by the stage of their
nish, especially in their entirety, i.e. depth failure on surface in manipulation and secondary thermal treatment
.
Glass mass scratch hardness of 6° of Mohs scale
Admissible tensile stress 3.5 MPa
Admissible bending stress 7.0 MPa
Admissible compressive stress 100.0 MPa
5
LABORATORY GLASSWARE
LABORGLAS
THERMAL PROPERTIES OF SIMAX GLASS
High resistance of product made of the SIMAX glass to sudden change in temperature – heat stability – is done by
low coe cient of linear thermal expansion, relatively low modulus of tensile elasticity, as well as relatively high
thermal conductivity resulting in alower thermal gradient in the product wall.
On cooling and heating the glass product, an undesirable internal stress arises. Breakage of the glass product due
to temperature change is caused by tensile stress on the product surface arising due to action of linear dilatability
of the glass on quick cooling from the product surface.
With amechanical failure in the product surface, the heat stability can be signifi cantly reduced
.
Wall thickness (in mm) Resistance to heat shock (D °C)
1 303
3 175
6 124
10 96
The manufacturer may perform an exact calculation, where necessary.
COOLING OF SIMAX GLASS
Cooling represents athermal process the purpose of which is keeping from formation of undesirable and
inadmissibly high thermal stress in the glass which would reduce the product resistance, and/or removing of stress
already arisen.
Cooling cycle comprises three stages:
Temperature increase (product heating) with heating rate from the inlet temperature to the upper cooling value.
Dwell (pause, tempering, stabilization) of products at upper cooling temperature for certain time when the
temperature diff erences in the product must be equalized, including stress reduction to an admissible limit.
Temperature decrease (cooling and additional cooling) of the product with cooling rate from the upper to the lower
cooling value (this stage is important as the permanent stress can arise), and from the lower cooling temperature
to the fi nal value or ambient temperature (important for subsequent practical manipulation with the product).
Concrete cooling cycle is specifi ed in the table..
TEMPERATURE RANGE
Maximum wall thickness
Rise Dwell Temperature Drop
20–550 °C 560 °C 560–490 °C 490–440 °C 440–40 °C
3 mm 140 °C/min 5 °C/min 14 °C/min 28 °C/min 140 °C/min
6 mm 30 °C/min 10 °C/min 3 °C/min 6 °C/min 30 °C/min
9 mm 15 °C/min 18 °C/min 1,5 °C/min 3 °C/min 15 °C/min
12 mm 8 °C/min 30 °C/min 0,6 °C/min 1,6 °C/min 8 °C/min
OPTICAL PROPERTIES OF SIMAX GLASS
The Glass SIMAX is transparent and clear; it does not show substantial absorption in visible spectrum.
Permeability of ultra-violet rays enables the products made of the SIMAX glass to be used for photochemical
reactions.
Refractive index (h = . nm) n
d
.
Photoelastic constant (DIN ) K
4,0.10
—6
mm
2
.N
—1
6
LABORATORY GLASSWARE
LABORGLAS
LIGHT TRANSMITTANCE
ELECTRICAL PROPERTIES OF SIMAX GLASS
At usual temperatures, the SIMAX glass is anon-conducting material – it is an insulant.
Speci c resistance in damp-proof medium ( °C) higher than


1.cm
Permittivity ¡ ( °C,  MHz) .
Loss angle tg b ( °C,  MHz) .x
–
Dielectric losses increase sharply with rising temperature and they change with frequency.
PLASTIC ACCESSORIES
The Simax laboratory glassware are complemented with various plastic accessories, the properties of which can be
found in the tables below.
PLASTICS USED WITH LABORATORY GLASS
Materials for laboratory glass accessories
Type Designation Thermal stability (° C)
PE Polyethylene – 40 to + 80
PP Polypropylene – 40 to + 140
PBT Polybutylene terephthalate – 45 to + 180
PTFE Polytetrafl uoroethylene – 200 to + 260
ETFE Ethylene tetrafl uoroethylene – 100 to + 180
VMQ Silicone rubber – 50 to + 230
NR Rubber for food – 40 to + 70
FKM Fluorocarbon - Viton – 20 to + 200
N.K. Natural cork – 20 to + 200
D
urchlässigkeit des Spektrums
0
10
20
30
40
50
60
70
80
90
100
0 1000 2000 3000 4000 5000 6000
W
ellenlänge (nm)
D
urchlässigkeit (%)
Spectral Transmittance
Wave length (nm)
Transmittance (%)
Wanddicke 1 mm
Wanddicke 2 mm
Wanddicke 5 mm
Wanddicke 9 mm
wall thickness 1 mm
wall thickness 2 mm
wall thickness 5 mm
wall thickness 9 mm
7
LABORATORY GLASSWARE
LABORGLAS
PRINCIPLES OF USING LABORATORY GLASSWARE SIMAX
. CLEANING
The laboratory glassware can be cleaned either manually or in alaboratory dish washer using usual cleaning and
disinfecting agents. It is recommended to wash the glass before the rst use.
Laboratory glassware which came into contact with infectious substances should be cleaned and sterilized with
hot air or steam. In this way, burning-on of impurities and damaging of glass by possibly adhered chemicals is
prevented.
A) Manual cleaning:
a) Laboratory glassware should be wiped and washed with acloth or asponge using acleaning solution.
b) Donot use abrasive washing agents as they can scratch the glass.
c) Avoid extended exposition to alkaline media at temperatures above °C as printing can be destroyed.
B) Washing in dish washers:
Washing of laboratory glassware in dish washers is more considerate than manual cleaning. The glass gets into
contact with acleaning solution for arelatively short time only during the phase of rinsing when the solution is
sprayed on the glass surface.
When inserting the glassware into adish waster care should be taken to prevent mutual impacts.
. SAFETY INSTRUCTIONS FOR USER
Never expose the laboratory glassware to sudden changes in temperature. Prevent taking hot glassware out
of adrier and putting it on acold or wet laboratory table. The warning is particularly applicable to athick-walled
glassware, such as suction fl asks or desiccators.
Before each evacuation or pressure stress of glass fl asks, make visual inspection of afaultless state (for heavy
scratches, impacts, etc.). Damaged glass fl asks must not be used for works under pressure or vacuum.
The laboratory glassware under pressure or vacuum should be handled with care (e.g. with suction fl asks,
desiccators).
Donot expose the glassware to sudden changes in pressure.
To prevent developing stress in the glass donot heat up glass fl asks under vacuum or pressure from one side or
with an open fl ame.
The laboratory glassware with fl at bottom (e.g. Erlenmeyer fl asks, fl asks with fl at bottom) should not be exposed
to pressure stress.
Chemical resistance of materials
Substance groups + 20°C PE PP PBT PTFE ETFE VMQ NR FKM N.K.
Alcohols ++ ++ ++ ++ ++ + + +
Aldehydes + + ++ ++ ++ + + +
Alkaline solutions ++ ++ +/– ++ ++ + +
Esters + + + ++ ++ +
Ethers + ++ ++ +
Aliphatic hydrocarbons ++ ++/+ ++ ++ ++
Aromatic hydrocarbons + ++/+ ++ ++ ++
Halogenated hydrocarbons + + ++ ++ ++
Ketones + + +/– ++ ++ ++
Diluted or weak acids ++ ++ ++ ++ ++ + ++ +
Strong acids ++ ++ + ++ ++ ++
Oxidizing acids + ++ ++ +
++ = very good resistance
+ = good resistance
= low resistance
8
LABORATORY GLASSWARE
LABORGLAS
LABORATORY BOTTLES SIMAX
Laboratory bottles are made of the borosilicate glass .. featuring excellent chemical properties and ahigh
thermal resistance. They are chemically resistant and stable. After completion with aplastic pouring ring, they
enable liquids to be easily poured out. All bottles of the volume ml and higher have the same thread size, the
screw cups can be mutually interchanged.
The bottle, pouring ring, and screw cup can be sterilized.
Handling instructions:
a) Freezing of substances
Freeze the bottle in askew position (about °) and fi lled up to max. / (volume expansion).
Temperature limit: – °C as plastic lids and pouring rings donot resist to lower temperatures.
b) Thawing of substances
Thawing of afrozen material can be carried out by submerging the bottle into aliquid bath (temperature
di erence should not exceed  °C). The frozen material will thus be heated up uniformly from all sides and the
bottle will not be damaged. Thawing can also be accomplished slowly from the top so that the surface is fi rst
liquefi ed and the material can expand.
c) Sterilization
During sterilization, the screw cup can only lightly be fi tted on the bottle (screwed with max. one rotation).
Pressures are not equalized when the bottle is closed. The pressure diff erence created in this way can result in the
bottle breakage.
d) Pressure resistance
The laboratory bottles are not suitable for works under pressure or vacuum.