Archive for the Applications and uses Category

Liquid Extrusion Porosimetry and the Measurement of Pore Size and Volume in Nonwovens

Nonwoven fabric is the name given to fabric-like materials that are made from long fibers (continuous long) and staple fiber (short) bonded together by mechanical treatment, heat, solvent or other chemical application. This method of production distinguishes non-woven materials from woven and knitted fabrics. Fibres may be oriented in one direction or deposited randomly to produce one or more fibre layers. The resulting products are flexible and porous. Felt is probably the most commonly known nonwoven material but the term also includes plastics like nonwoven polypropylene. A variety of manufacturing processes can be used, including spunlaid, staple nonwoven, flashspun and airlaid paper, to produce nonwovens.

Nonwovens have many applications in a wide variety of industries such as healthcare, biotechnology, paper, filtration as well as household uses. When in use they are subjected to compressive stress and the performance of nonwovens in such applications is largely determined by their pore structure. In order to assess this vital property it is important to characterise pore size, pore volume and pore volume distribution of nonwovens under compressive stress.nonwoven

The development of instruments that can measure such pore structure characteristics became a priority in the field and research developed the use liquid extrusion porosimetry to measure pore volume and pore diameter of a nonwoven under compressive stresses. The method uses a wetting agent, a liquid that can spontaneously flow into the pores of a sample. This is possible because the solid/wetting liquid interfacial free energy is less than the solid/gas interfacial free energy. Filling of the pores of the nonwoven sample with the wetting liquid therefore reduces the free energy of the system.

Continue reading Liquid Extrusion Porosimetry and the Measurement of Pore Size and Volume in Nonwovens

Mercury Porosimetry For Porous Structures – PASCALL Porosimeter

The mercury porosimetry technique is one of the most useful methods to investigate the porous structure of solid samples in a quantitative way. It provides reliable information about pore size/volume distribution, particle size distribution, bulk (envelope) density and specific surface for most porous solids.Porosimeter

Pressurization by Automatic Speed-up and Continuous Adjustment Logic, or, in short Pascal, is a special operating principle developed by Thermo Fisher Scientific and used in the new generation of automatic mercury porosimeters the Pascal Range, which reduces run times by up to 30%. Providing fast automated measurements with selectable intrusion/extrusion speed rates to minimise hysteresis effects, the PASCAL range provides maximum resolution in minimum time.  Continue reading Mercury Porosimetry For Porous Structures – PASCALL Porosimeter

Biotechnology and Healthcare

One industry sector that increasingly demands precise information on pore size and related characteristics is biotechnology and healthcare. Considering the number of porous materials now used in this branch of science, in such a variety of advanced applications, it is not surprising that there is much interest in the instruments described on this website. Continue reading Biotechnology and Healthcare

Batteries and Battery Separators

Batteries and separators

The porous nature of various elements in the structure of a battery has a crucial effect on its performance and is the subject of much material characterisation work using PMI instruments. Materials used to separate the cells in a battery are of particular concern, but so too are a number of other key components. Continue reading Batteries and Battery Separators

Pore Size in Automotive Components

automotive

The automotive industry is just one of the many sectors that regularly make use of instruments for the measurement of pore size and other pore characteristics. Perhaps the most obvious components for which information on pore structure is needed – but not the only ones – are the various filters that play vital roles in the functioning of a vehicle. Continue reading Pore Size in Automotive Components

What Is a Porosimeter?

Liquid extrusion porosimeter from PMI

Liquid extrusion porosimeter

While exploring the topic of pore size and other characteristics of porous materials, the instruments we come across most regularly are the many and varied porometers and permeameters. Occasionally on this pore size website we have touched upon porosimeters, and for clarity I would like to return briefly to that subject today. Continue reading What Is a Porosimeter?

Porometry Made Simple

PMI porometer

Among the many pore characterisation products currently described on the PMI website is a ‘Simple Porometer’. It reminds me that now might be a good time to go back to basic principles and tell new visitors to Pore Size about what a porometer is and why it is so useful. Continue reading Porometry Made Simple

Fuel Cell Porometer

Fuel cell

Designed for use by manufacturers of fuel cell components, Meritics considers the Fuel Cell Porometer from PMI to be an exceptionally versatile instrument. Its fully automated analysis includes measurement of pore ‘throat’ diameters, the size distribution of the pores, the mean diameter of the flow pores and the surface area – or envelope surface area – of the through pores. It can also be used to determine the material’s liquid and gas permeability. Continue reading Fuel Cell Porometer

Permeability in Battery Components

Battery

Components used in the construction of a battery or fuel cell may be exposed to strong chemicals, high pressures and raised temperatures. In developing new and better products, it is essential to study the behaviour of components under different conditions – and component permeability is a key factor. To measure permeability of components in batteries the developers use liquid permeameters and gas permeameters. Continue reading Permeability in Battery Components

Capillary Flow Porometry in the Study of Filter Media

Filter

If I was to ask you to name something whose porous nature people might want to investigate, I bet that ‘filters’ would be a popular answer – if not the very top response. Today I’d like to have a look at filter media and what a porometer can tell us about them. Continue reading Capillary Flow Porometry in the Study of Filter Media