Curing

-
Curing is a term in polymer chemistry and process engineering that refers to the toughening or hardening of a polymer material by cross-linking of polymer chains, brought about by electron beams, heat or chemical additives.


Comments

Post a Comment

Popular posts from this blog

Online, inline, atline and bypass (analysers)

-
Image
Inline : For inline analysis, a sensor can be placed in a process vessel or stream of flowing material to conduct the analysis. Online : Analysers which are connected to a process, and conduct automatic sampling, can be called online (or on-line) analysers or sometimes inline (or in-line) analysers. This means that online and inline analyses permit continuous process control. Offline and atline analyses, on the other hand, are characterized by manual sampling followed by discontinuous sample preparation, measurement and evaluation. The material properties can change during the time between sampling and the availability of the results, so direct process control is not possible. A bypass line is recommended in terms of process control to prevent a shutdown or lost product. If you have to clean, calibrate or validate ypour analyser a lot, then a bypass is the best solution.
Read more

Thermal conductivity detector (TCD)

-
Image
The thermal conductivity detector (TCD), also known as a Katharometer, is a bulk property detector and a chemical specific detector commonly used in gas chromatography.[1] This detector senses changes in the thermal conductivity of the column effluent and compares it to a reference flow of carrier gas. Since most compounds have a thermal conductivity much less than that of the common carrier gases of helium or hydrogen, when an analyte elutes from the column the effluent thermal conductivity is reduced, and a detectable signal is produced. The TCD consists of an electrically heated filament in a temperature-controlled cell. Under normal conditions there is a stable heat flow from the filament to the detector body. When an analyte elutes and the thermal conductivity of the column effluent is reduced, the filament heats up and changes resistance. This resistance change is often sensed by a  Wheatstone bridge  circuit which produces a measurable voltage change. The column ...
Read more

TDL - Tunable diode laser absorption spectroscopy

-
Image
Tunable diode laser absorption spectroscopy (TDLAS) is a technique for measuring the concentration of certain species such as methane, water vapor and many more, in a gaseous mixture using tunable diode lasers and laser absorption spectrometry.[citation needed] The advantage of TDLAS over other techniques for concentration measurement is its ability to achieve very low detection limits (of the order of ppb). Apart from concentration, it is also possible to determine the temperature, pressure, velocity and mass flux of the gas under observation. TDLAS is by far the most common laser based absorption technique for quantitative assessments of species in gas phase. A basic TDLAS setup consists of tunable diode laser light source, transmitting (i.e. beam shaping) optics, optically accessible absorbing medium, receiving optics and detector/s. The emission wavelength of the tunable diode laser, viz. VCSEL, DFB, etc., is tuned over the characteristic absorption lines of a species in ...
Read more