60 results about "Interconnected porosity" patented technology

The present invention relates to methods of making and using composites and scaffolds as implantable devices useful for tissue repair, guided tissue regeneration, and tissue engineering. In particular, the present invention relates to methods of making and using compression molded resorbable thermoplastic polymer composites which can be subsequently processed with non-organic solvents to create porous, resorbable thermoplastic polymer scaffolds or composite scaffold with interconnected porosity. Furthermore, these composites or scaffolds can be coated with an organic and/or inorganic material.

A porous bone fixation device has a body including non-porous areas that provide superior long term fixation and osteointegration performance. The porous areas provide an in-growth surface in strategic sections such as the threaded section of the fixation device that allow substantially more contact area between in-growth surface and bone. The in-growth material is a network of interconnected porosity in a matrix of bio compatible, preferably titanium. Examples of bone fixation devices include bone screws, bone anchors, dental implants, and similar devices used to provide a fixation point in bone.

Abrasive articles possessing a highly open (porous) structure and uniform abrasive grit distribution are disclosed. The abrasive articles are fabricated using a metal matrix (e.g., fine nickel, tin, bronze and abrasives). The open structure is controlled with a porosity scheme, including interconnected porosity (e.g., formed by leaching of dispersoid), closed porosity (e.g., induced by adding a hollow micro-spheres and/or sacrificial pore-forming additives), and/or intrinsic porosity (e.g., controlled via matrix component selection to provide desired densification). In some cases, manufacturing process temperatures for achieving near full density of metal bond with fillers and abrasives, are below the melting point of the filler used, although sacrificial fillers may be used as well. The resulting abrasive articles are useful in high performance cutting and grinding operations, such as back-grinding silicon, alumina titanium carbide, and silicon carbide wafers to very fine surface finish values. Techniques of use and manufacture are also disclosed.

The porous material of the present invention is produced by heating a dry powder mixture, containing mainly an organic solid binder and inorganic particles. The mixture is foamed while the organic binder is melted. Foaming comes from a foaming agent in the powder mixture. The solid foamed structure comprising inorganic particles embedded in an organic binder is then heated to eliminate the organic binder and finally to sinter the remaining inorganic tri-dimensional network into a rigid structure having interconnected porosity.

A processing device includes a plurality of walls defining an interior space configured to be exposed to plasma and a surface coating on the interior surface of at least one of the plurality of walls. The surface coating includes pores forming interconnected porosity. The processing device further includes a sealant residing in at least a portion of the pores of the surface coating. In an embodiment, the sealant can be a thermally cured sealant having a cure temperature not greater than about 100° C. In another embodiment, the sealant can be an epoxy sealant having a viscosity of not greater than 500 cP in liquid precursor form. In yet another embodiment, the sealant can be a low shrinkage sealant characterized by a solidification shrinkage of not greater than 8%.

A bonded abrasive tool, having a structure permeable to fluid flow, comprises sintered agglomerates of a plurality of abrasive grains and a binding material, the binding material being characterized by a melting temperature between 500 and 1400° C., and the sintered agglomerates having a loose packing density of ≦1.6 g/cc and three-dimensional shape; a bond material; and about 35-80 volume % total porosity, including at least 30 volume % interconnected porosity. Methods for making the sintered agglomerates and abrasive tools containing the sintered agglomerates are described.

Techniques, mixtures and improved porous materials (interconnected porous constructs) that are capable of maintaining a sufficient porosity while conferring improved mechanical and physical strength to the final construct. A sacrificial construct (for example, a sacrificial material such as polymethyl methacrylate (PMMA)) is used to obtain an inverse porosity of the construct it was molded into. The process provides a less porous end material that may be used as an arthroplasty device or surgical implant (for example, an interference screw of suture anchor) among many other applications. The process employs a sacrificial material to reduce the porosity of the final construct to about 35%.

Disclosed are nano-engineered porous ceramic composite filtration media for removal of phosphorous contaminates from wastewater and other water or liquid sources. Such porous ceramic media has high surface area and an interconnecting hierarchical pore structure containing nano-iron oxide/oxyhydroxide compounds, as well as other nano materials, surfactants, ligands or other compounds appropriate for removing higher amounts of phosphorous or phosphorous compounds. The composite media can be modified with nano-phased materials grown on the high surface area and addition of other compounds, contains hierarchical, interconnected porosity ranging from nanometer to millimeter in size that provides high permeability substrate especially suited for removal of contaminants at the interface of the water or other fluids and the nanomaterial or surfactants residing on the surfaces of the porous structure.

Methods for cylindrical grinding a workpiece are disclosed. The method includes cylindrical grinding, with a bonded abrasive wheel having a permeable structure that includes interconnected porosity, a workpiece at a specific cutting energy of less than about 12 Hp/in³·min (29.7 J/mm³), and a material removal rate of at least about 1 in³/min·in (10.8 mm³/sec/mm)grinding. The bonded abrasive wheel may include at least about 3 volume percent of a filamentary sol-gel alpha-alumina abrasive grain having an average length-to-cross-sectional-width ratio of greater than about 4:1, or agglomerates thereof. In one embodiment, the workpiece is ground in the presence of a water soluble oil.

A composite material for storing thermal energy at various temperatures (30° C. to 450° C.) formed by an elastomer matrix into which a phase change material such as an inorganic salt is encapsulated. The material is characterized by a high volumetric thermal conductivity, a low density, a highly interconnected porosity and a relatively high modulus of elasticity. The significant properties of the matrices are: a large amount of energy involved in full melting/crystallization, a fairly low relative volume expansion upon melting and fairly low sub-cooling. The main advantages of the resulting composites are a very high energy density, a relatively low volume expansion, highly enhanced heat transfer, thermo adaptability, stability and insignificant hysteresis.

A method of repairing a component having interconnected porosity applies a material to the area of the porosity through a cold deposition process. Components repaired by this method are also claimed.

The present invention relates to a method of manufacturing a bioactive prosthetic device for reconstruction of bone tissue comprising the steps of: performing a CAT (Computed Axial Tomography) scan of a patient and obtaining the bone part and bone defect to be reconstructed (2) three-dimensional electronic model (1); produce a prototype resin model (3) of the bone region of the patient involved by prototyping to form a model (4) of the bone defect of the patient to be reconstructed; A spare sintered ceramic semi-finished product of controlled and interconnected porous structure manufactured to be slightly larger than the size and shape of the bone defect; machining and hand polishing of the sintered semi-finished product to obtain the exact size and shape of the bone defect, The invention also relates to a prosthetic device obtained using the method described above.

A process for producing a metal article containing at least 10% interconnected porosity, using a preform (11), comprising:

• • mixing an organic binder, a wetting agent and a granular material, to obtain a mouldable paste that combines 10 vol. pct. or more of said granular material, said material dissolving easily in a liquid solvent;
  • shaping the paste into an aerated preform and providing an open pore space to be infiltrated by the metal or alloy;
  • evaporating said wetting agent and baking said preform to a temperature sufficient to degrade the binder and create a network of interconnected open porosity in the preform;
  • filling said open pore space with the liquid metal or alloy.

All or part of the baked preform can be easily leached by a liquid solvent through the network of fine pores.

An open cell porous material and a method for producing it is provided. The porous material of the present invention is generally composed of particles of at least one inorganic material bonded together by a brazing agent, generally provided as inorganic brazing alloy particles. The porous material is produced by heating a mixture comprising inorganic brazing alloy particles having a first melting temperature, inorganic particles having a second melting temperature higher than the first melting temperature, a binding agent having a decomposition temperature lower than the first melting temperature and preferably a foaming agent. In practice, the mixture is heated to induce foaming thereof via the foaming agent. The solid foamed structure is then heated at the decomposition temperature to substantially eliminate the binder. The resulting foamed structure is then heated again at about the first melting temperature to melt the inorganic brazing alloy particles in order to bond together the remaining three-dimensional network of inorganic particles into a rigid structure having interconnected porosity.