DE1097282B - Filter insert made of soft fiber to trap fine dust or suspended matter from the air you breathe - Google Patents

Description

GERMAN

The invention relates to a filter insert made of soft fibrous material for catching fine dust or suspended matter from the breathing air, the edge of which is clamped airtight between the filter housing and a filter cover is.

When catching fine dust or suspended matter from the air it is important to use the filter insert to form as fine-pored as possible and to give it such a structure that the air flowing through it together with the particles contained in it is repeatedly deflected in other directions to the particles on the longest possible way through the filter insert to give yourself the opportunity to get into the branches to fix. The filter body, which z. B. used as an insert in a filter capsule of a respirator consist of fibers of various types. Cotton, cotton linters, Cellulose and other fibers, either by sludging in air and water in one more or less thick layer or to be deposited into a fleece. But there are also fiber mixtures well proven, made from a mixture of the aforementioned fibers with finely divided asbestos, Plastic fibers or the like exist, which become matted with the other fibers during the deposition process and which gives the filter insert additional electrostatic properties. For the manufacturer of such filter inserts The first task is to create a fiber body with the greatest possible pore fineness and as branched as possible Produce structure, but then also to train this body so that it is as small as possible The impingement surface offers as little resistance as possible to the breathed air. Are If the pores in the filter are narrow, there is, on the one hand, a blockage when the filter is used in dusty air of the pores by the fine trapped particles and, on the other hand, contamination of the exposed Surface that increases the filter resistance so that it is difficult to breathe deeply.

It has now become known to remove the filter inserts externally or by brushing the surface can also be cleaned internally by tapping and / or sucking through with strong air currents. With these However, there is a risk that the structure of the filter and the filter effect will be adversely affected is questioned when re-used.

It therefore arises for the manufacturers of such filter inserts the further task of training the filter insert so that it can be used after a certain period of use can be removed from the filter container and replaced with a new insert. According to this requirement trained filter inserts are also already known. They consist e.g. B. from a folded paper-like Filter belt that runs through the side of a comb-like filter insert made of soft fiber

for catching fine dust
or suspended matter from the air we breathe

Applicant:

Auergesellschaft GmbH,
Berlin N 65, Friedrich-Krause-Ufer 24

Dieter Gohde, Berlin-Zehlendorf,
has been named as the inventor

holding devices engaging the folds is grasped and sealed. It has also become known to clamp the edges of a round filter body between the lid and the lower part of the filter container and thereby to produce an edge seal. However, the edge sealing is difficult to carry out, because the relatively loose filter structure can easily be destroyed when jammed. These On the other hand, there is no danger in the case of known filters which, in contrast to those described above, consist of Cardboard-like thick filter discs exist as they are z. B. used in the known chamber filters will.

The difficulties outlined arise with a filter insert made of soft fiber material with a short period of use (Disposable filter) eliminated according to the invention in that at least the edge of the filter insert provided with a coating of thermoplastic material or with thermoplastic material is impregnated and is shaped by means of pressure and heat in such a way that its shape follows the shape of the filter housing and the edge of the lid adjusts in their sealing area. Since these filter inserts because of their loose structure may tend to sag or dent when the air is sucked through Another feature of the invention is the surface of the entire filter insert or parts thereof solidified by sprayed thermoplastic masses. This does not make the breathing resistance significant elevated. The thermoplastic mass sprayed on to solidify the surface can consist of thread-pulling Plastics, so-called spinning varnishes, exist. These threads cover the entire surface the filter insert in the form of a fine mesh and give the filter insert strength and dimensional stability without a noticeable increase in resistance.

009 698/46

The drawing shows some exemplary embodiments of the invention.

In Fig. 1, the filter housing of a respirator 1 is shown. The housing consists of the Lower part 2, which is designed so that you can also arrange filter materials of other types in it, for. B. activated carbon or the like. A central opening 3, provided with an inhalation valve 4, connects the filter housing with the inside of the mask. The outer edge 5 of the filter housing is bent over. The bent edge ίο lies on it 14 of the filter cover 6, the one with through openings? is provided. The lid is hinged hinged to the filter housing. On the opposite side there is a rubber band 9 that is unbuttoned under tension on a button 10 and thereby the edge of the lid with light pressure against the edge 5 of the filter housing presses. Is between the edge 5 and the bent edge 14 of the lid the filter insert 11 clamped, which is shown enlarged in Fig. 2. The edge zone of this deposit is provided on one or both sides with a coating 12 made of thermoplastic material and through Pressure and heat shaped so that it adapts to the shape of the filter housing and the lid edge and A good seal is created there. Due to its solidified bent edge, the filter insert 11 only take a certain, centered position when inserting and not to the side under formation move from leaks.

Figs. 3 and 4 show embodiments of filter inserts, the surface of which is also outside the Edge area is solidified. Just as it is possible to cover the entire surface with solutions of thermoplastics spraying, in order to make them dimensionally stable, can also be done, as Fig. 3 shows, for example Attach star-shaped narrow thermoplastic layers 13 that prevent the filter from flexing during ventilation impede. In Fig. 4 it is shown how the entire surface of the filter with filiform Thermoplastics 15 is secured against change in shape and bending.

Claims (3)

Patent claims: 1. Filter insert made of soft fiber to trap fine dust or suspended matter from the Breathing air, the edge of which is clamped airtight between the filter housing and a filter cover, characterized in that at least the edge of the filter insert (11) has a coating (12) thermoplastic material is provided or impregnated with thermoplastic material and means Pressure and heat is shaped so that its shape is the shape of the filter housing and the Adjusts the lid edge (5,14) in their sealing area. 2. Filter insert according to claim 1, characterized in that the surface of the entire Filter insert (11) or parts thereof is solidified by sprayed-on thermoplastic masses. 3. Filter insert according to claim 2, characterized in that the solidification of the surface sprayed on thermoplastic mass made of stringy plastics, so-called spinning varnishes, consists. Considered publications:
German patents No. 693 390, 698 043,
257, 1019913. 1 sheet of drawings © 009 698/46 1.61