DE745525C - Use of fabrics, felts, fleeces or loose layers of synthetic threads for filtering purposes - Google Patents

Description

Use of fabrics, felts, fleeces or loose layers of synthetic threads for filter purposes The operational filtration of strongly acidic, alkaline or oxidizing solutions still cause technical difficulties, as for filter layers that are easy to manufacture and mechanically strong enough for this purpose, such as those in the form of fabrics or wadding made of natural fibers for neutral liquids are generally used, have not yet been available.

It is true that filter cloths made of nitrocellulose are used for acidic liquids, whose handling and storage is very uncomfortable and also in the Are only durable enough for a short period of time. Also tissues made from cellulose ethers have already been proposed for filtering purposes; however, these have Fabric only proven for alkaline liquids. Because of the lack of threads Such tissues are difficult to obtain for cellulose ethers on the market. For acidic liquids are also tissue and wadding made of glass wool and filter bodies that are baked made of glass fibers with ballistic resins have been used. The usage Such a filter is limited to cases in which either the contamination of the filter by glass fiber fragments does not matter or where the too filtering solution does not easily clog the fritted filter body. tissue made from asbestos are not very effective because of the strong swelling of the asbestos fibers and not mechanically robust enough.

It has also been suggested to use cotton-wool-like masses ordinary temperature resistant non-adhesive polyvinyl compounds Manufacture atomization of their solutions and these to rigid, corrosion-resistant filters or diaphragms to press. Such cotton wool-like masses could but are not further processed into textiles and deliver only a small amount of solid, rigid structures that are only capable of limited use.

As has now been found, this problem can be explained by a multifaceted usable and solid filter material for strongly attacking liquids remedy, by making fabrics, felts, fleeces or loose layers from endless or cut into stacks or broken synthetic threads made from polymeric hydrocarbons or their chlorine-containing derivatives or from copolymers with these substances became.

Such plastics are, for example, polystyrene, polyisobutylene, Polyvinyl ether, copolymers of styrene or polyisobutylene and vinyl ethers, also chlorocarbonus, polyvinyl chloride, post-chlorinated polyvinyl chloride or Copolymers of vinyl chloride with other polymerizable compounds, such as styrene, polyisobutylene, vinyl ethers and vinyl esters.

The manufacture of the fibers and threads from these plastics is essential known and is carried out on an industrial scale beretis. As filter layers Can be woven from threads, felts, fleeces or loose layers of endlessly spun or find use of cut or torn synthetic fibers in stacks.

The filter layers according to the invention are for acidic, alkaline. with an oxidizing effect and others with a destructive effect on the usual filter layers Liquids can be used equally well. Only for organic liquids which are on If the above plastics will dissolve, the filters cannot be used.

Claims (1)

PATENT CLAIM: Use of fabrics. Felt, fleece or loose Layers of endless or cut in stacks or otherwise synthetic threads that from polymeric hydrocarbons or their chlorine-containing derivatives or from copolymers are made with these substances in a manner known per se, as a filter. ~~~~~~~~~~~~ To distinguish the subject of the notification from the state of the art, the granting procedure the following publications have been considered: German patents ................ No. 664 679, 626 920, 425 770; French patent specification ................... - 758 454