Constant Pressure Extrusion
Constant Pressure Extrusion - Related Videos
11:35
Constant Pressure-controlled Extrusion Method for the Preparation of Nano-sized Lipid Vesicles
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Cited by 29 •
2012
This protocol describes an extrusion method for preparing lipid vesicles of sub-micron sizes with a high degree of homogeneity. This method uses a pressure-controlled system with controlled nitrogen flow rates for liposome preparation. The lipid preparation1,2, liposome extrusion, and size characterization will be presented herein.
03:02
Constant Pressure Calorimetry
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2020
Calorimetry is a technique used to measure the amount of heat involved in a chemical or physical process or to measure the heat transferred to or from a substance. The heat is exchanged with a calibrated and insulated device called the calorimeter. Calorimetry experiments are based on the assumption that there is no heat exchange between the insulated calorimeter and the external environment. The well-insulated calorimeters prevent the transfer of heat between the calorimeter and its external...
10:22
Demonstration of the Power Law Model Through Extrusion
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2023
Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA Polymer melts are often formed into simple shapes or "extrudates", such as cylindrical pellets, flat sheets, or pipe, using an extruder.1 Polyolefins are among the most common extrudable polymers. Extrusion involves transporting and melting solid feed, which is sometimes mixed with non-polymeric materials, and the pressure build-up and transport of the melt or mixture.
01:12
Fluid Pressure over Curved Plate of Constant Width
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2023
When a curved plate of constant width is submerged in a liquid, the pressure acting normal to the plate varies continuously both in magnitude and direction. Calculating the magnitude and location of the resultant force at a point is often challenging for such cases. One of the methods to determine the resultant force and its location involves separately calculating the horizontal and vertical components of the resultant force. This complex calculation can be simplified by representing the...
01:05
Fluid Pressure over Flat Plate of Constant Width
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2023
When a body is submerged in water, it experiences fluid pressure acting normal on its surface and distributed over its area. For better design structures, it is crucial to determine the magnitude and location of the resultant force acting on the surface. In the case of a rectangular plate of constant width submerged in water, the pressure increases with depth, resulting in a linearly varying trapezoidal pressure distribution from the upper to the lower edge of the plate. The resultant force...
FAQs
These variables determine how readily a bioink moves and how accurately it is deposited. Higher viscosity can resist flow, while nozzle geometry affects the passage available for the material. Printing speed must remain compatible with the delivered flow so the filament stays continuous and dimensionally consistent. Adjusting these factors together helps balance placement accuracy with practical extrusion performance.
Stable pressure supports a more uniform material flow instead of producing intermittent or fluctuating extrusion. That consistency can improve filament continuity and dimensional consistency across a printed construct. However, pressure cannot be increased without limit, because the selected pressure must also balance print fidelity, shear exposure, and the viability of cells contained in the bioink.
Pressure must be sufficient to move the bioink through the nozzle and support accurate placement, but excessive pressure can increase shear exposure. For cell-laden materials, this creates a direct need to balance extrusion performance with cell viability. The appropriate setting therefore depends not only on continuity and shape fidelity, but also on how the process affects the biological material.
Both approaches provide regulated pressure to drive bioinks through a nozzle, but they use different mechanisms to generate or maintain that driving force. Pneumatic systems use controlled pressure, whereas mechanically regulated systems apply pressure through a mechanical regulation approach. In either case, the relevant outcome is sustained control of flow for consistent placement of biomaterial.
A typical workflow begins by selecting a bioink, such as a hydrogel, and loading it into an extrusion system. The operator then regulates the driving pressure, directs the material through a chosen nozzle, and coordinates flow with printing speed. Continuous deposition follows, with adjustments made to preserve filament continuity, dimensional consistency, print fidelity, and cell viability.
This approach can be used to fabricate tissue-engineered scaffolds, cell-laden constructs, and other three-dimensional biological models. Its value comes from controlled placement of biomaterials while maintaining a continuous deposited filament or stream. Such control allows researchers to organize hydrogels and related bioinks into designed structures for studying or building engineered biological systems.
Evaluation should consider whether deposition remained continuous, whether the printed dimensions were consistent, and whether the material followed the intended placement. For cell-laden constructs, cell viability and shear exposure are also important outcomes. Interpreting these measures together reveals whether the selected pressure, viscosity, nozzle geometry, and printing speed provided an effective balance between fabrication quality and biological compatibility.