摘要:
Zeolites of type A wherein all the cationic sites of which occupied by sodium, calcium and/or magnesium, potassium and hydronium cations, which exhibit the advantage of having a water adsorption capacity≧23%, which do not adsorb and therefore cannot desorb nitrogen, and which, incorporated in polyurethane (PU) resins, make it possible to increase the potlife of the PU formulations in which they are incorporated. Such zeolites are prepared by a process comprising bringing into contact an aqueous suspension of zeolite 3A, 4A or 5A, an aqueous solution of calcium or potassium salt(s) or solutions of calcium and potassium salt(s), and an acid solution, simultaneously or otherwise and in any order; and in then filtering off and washing the solid obtained, and then drying and activating the zeolite.
摘要:
A viscoelastic material is extruded by kneading-and-conveying screws of different respective diameters positioned coaxially and telescopingly. A flight trough of a larger-diameter screw has radial orifices allowing a first space swept by the flight of the larger-diameter screw to communicate with a second space swept by a flight of a smaller-diameter screw. A fixed cylindrical tube arranged coaxially with the screws is disposed radially between the first and second spaces within the region in which the screws telescope. The tube has radial apertures therethrough to conduct material from the orifices to the second space. The first space is closed off at an axial end thereof by a wall where foreign substances accumulate that do not pass through the orifices. A passage through the wall can be opened to remove the accumulated substances without interrupting the extrusion operation.
摘要:
The invention relates to a zeolite of the faujasite X type having a low silica content, more precisely a zeolite LSX having a Si/Al atomic ratio lower than or equal to 1.15, having a high crystallinity rate and whereof the crystals have a controlled particle size distribution. The present invention also relates to the method for preparing said zeolite LSX.
摘要:
A device for continuously sheathing a ply of threads, said ply being formed by an array of approximately mutually parallel threads (F). The device comprises a thread guide (35), a coating chamber (31) into which a first feed channel (10) and a second feed channel (20) run, which are independent of each other, connected to a first feed means (13) and to a second feed means (23) respectively and capable of delivering a first material (A) and a second material (B) under pressure and with a defined flow rate, and the outlets (11, 21) of which channels are placed above and below the plane of the ply of threads (F), and an output die. Pressure-measuring means (12, 22), connected to a controller for controlling the pressure of each of the feed means (13, 23), are placed in the coating chamber (31) facing and in line with each other, on either side of the plane of the ply and in the immediate vicinity of the outlet for the feed channels (11, 21).
摘要:
A viscoelastic material is extruded by kneading-and-conveying screws of different respective diameters positioned coaxially and telescopingly. A flight trough of a larger-diameter screw has radial orifices allowing a first space swept by the flight of the larger-diameter screw to communicate with a second space swept by a flight of a smaller-diameter screw. A fixed cylindrical tube arranged coaxially with the screws is disposed radially between the first and second spaces within the region in which the screws telescope. The tube has radial apertures therethrough to conduct material from the orifices to the second space. The first space is closed off at an axial end thereof by a wall where foreign substances accumulate that do not pass through the orifices. A passage through the wall can be opened to remove the accumulated substances without interrupting the extrusion operation.
摘要:
This invention concerns an omega type zeolite of high thermal stability, present in the form of hexagonal prismatic monocrystals having scored or plane faces of 0.1 .mu.m in edge and 0.5 to 5 .mu.m in length, this zeolite being obtained through crystallization from a mother solution containing a silica source, alumina, metallic oxide, an organic cation and water, in which the alumina source is a crystalline aluminosilicate of which at least one part is in suspension in the mother solution. In its acid form this zeolite can be used as catalyst for hydration of olefins and isomeric change of xylenes.
摘要:
The present invention relates to an agglomerated zeolite adsorbent containing at least one polymer matrix that is greatly laden with at least one zeolite adsorbent. The invention also relates to the method for preparing such an adsorbent and to the uses thereof, particularly as an adsorbent of moisture, odors, volatile organic components, and the like.
摘要:
A method of the type in which a strip of rubber is moved continuously from a rubber-supplier device to a consumer device. During the continuous movement and prior to reaching the consumer device, a portion, referred to as the residue, is taken continuously from the strip of rubber. The residue is taken by continuously cutting the strip of rubber. For example, the supplier device includes upstream storage means for storing the strip of rubber from which the strip is moved toward the extruder, and downstream storage means in which the residue is stored. After the strip of rubber on the upstream storage means has been used up, the upstream and downstream storage means are swapped with each other.
摘要:
An extrusion device (1) for manufacturing a product based on a rubber mix, which comprises a rotary roller (5), an inlet orifice (15) for the rubber mix and a vault (6) partially circumferentially covering the external surface (51) of the roller (5), the rubber mix being driven from the inlet orifice (15) into the air gap situated between the vault (6) and the roller (5) towards an extrusion orifice (21) defining the profile of the product. The extrusion orifice is delimited by a wall (20) which cooperates with the external surface (51) of the roller (5), and the vault (6) carries on its internal surface oriented towards the roller projecting threads in order to delimit with the surface (51) of the roller a chamber for plasticization of the mix, at least two of the threads extending substantially axially of the roller.
摘要:
The invention concerns a superabsorbent composition containing a superabsorbent polymer powder, for instance polyacrylic and a zeolite powder exchanged with metal cations with bactericidal properties, in particular with silver ions. The hygiene articles incorporating them do not give off nor develop unpleasant smells though soaked with corporeal liquids.