SE431822B - FILTERING RESPIRATORY PROTECTION - Google Patents

Description

.800376-4-1 the filter surface by wrinkling. This enables the manufacture of a less obstructive respiratory mask with in some cases greater flexibility tet. While the previous filter materials worked entirely on the barrier principle, and consisted of fibers, usually cellulosic fibers with added, short glass fibers, or of paper made of glass fibers, or felt-like materials with varying efficiency, the new one consists generation of microfibre materials with both electrostatic and canic effect. These microfibers are normally enclosed between two sheets of sparsely woven material, mesh or the like, which have very low and does not normally affect the filtration but only the helps to protect and hold the microfibers together. The microfibers usually consists of PVC or polycarbonate. There are also on the market a material with similar effects and electrical properties.

The design of a breathing mask so that the improved efficiency The new materials come into their own, causing new problems.

As the filter material is relatively expensive, the material economy is a pri- more factor. Fortunately, this is offset by the fact that smaller materials it is therefore an aim to use such a small amount of material as possible to provide sufficient strength and durability.

The simplest respiratory protection is little more than a flat material pocket which is opened and placed over the wearer's face, but it has many neck-f parts, with a tendency to collapse on the wearer's face when inhaled. ning is not the slightest, and this can be unpleasant when the mask worn for a long time. This mask also makes it difficult to speak.

Simple masks of this kind tend to leak around the edge between lan face and the adjacent opening edge. Such a leak at the contact edge, the effectiveness of the respiratory protection deteriorates considerably According to the present invention there is now provided a filtering protection of flexible, filtering sheet material in the form of a pocket of generally truncated conical shape with an open edge at the truncated the wider end of the cone and a closed edge at the small of the truncated cone lare end, which is characterized by the closed end of the pocket is provided with first fold lines, which delimit a general four-sided area, which extends inwards into the pocket and consists of triangular yellow surfaces, which lie against each other and tilt in relation to each other.

Preferably, the fold line forming the common base is stiffened longitudinally to act as a reinforcement. The rest of them Soos7e4 ~ 1 the first fold lines may also be longitudinally stiffened.

Preferably, the flexible, filtering sheet material is weldable. with the first fold lines consisting of welds in the material as acts to stiffen the fold lines longitudinally. The first flat pocket can be made of a single blank format as two opposite, truncated cones with a common short side, where the two truncated cones superimposed and joined along the side edges of the pocket, e.g. pelvis by welding.

The open edge of the pocket can be provided with an inwardly directed sealing strip as described in published British patent application 7,911,595.

According to another aspect of the present invention, there is provided a flexible, filtering sheet material in the form of a plate pocket with truncated conical shape with opposite side walls, an open edge at the larger end of the truncated cone and a closed edge at smaller the end and a framework, which delimits a four-sided surface at the pocket closed end and consisting of two triangular surfaces, where the triangles has a common base and the tips that oppose the common base is located mainly at the corner of the closed end of the pocket. The common ba- extends in a direction perpendicular to the connecting lines of the corners and the triangular surfaces lie against each other and are in use leaning against each other.

The present invention will be described in more detail in connection with a working examples and with reference to the accompanying drawings.

Fig. 1 is a plan view of a sheet of filter material showing how to an embodiment of a filter mask according to the invention can be described ras ut.

Fig. 2 is a perspective view of the cut blanks of Fig. 1 at the end of the cut.

Fig. 3 is a plan view of a blank for carrying out a filtering device. the respirators according to the invention.

Figs. 4 (a) and (b) are schematic cross-sections through welds which can be used used in the manufacture of the masks.

Figs. 5-9 show steps in the manufacture of a mask of the blank in Fig. 3.

Figs. 10-12 show further steps in the manufacture of a mask. 8003764--1 Fig. 13 is a side view of the breathing mask open.

Fig. 14 is a front view of the mask of Fig. 13, also open.

Fig. 15 is a perspective view of the respirator of Figs. 13 and 14 of FIG use.

Fig. 16 is a schematic view showing the effect of the mask of Figs. 13-15.

Fig. 17 (a) - (e) show different steps in the manufacture of a modification of the mask in Figures 13-15.

Fig. 18 is a side view of another embodiment of a respirator according to present invention in the open state.

Fig. 19 is a view of the mask of Fig. 18, also open and seen from the open edge.

Fig. 20 is a view similar to Fig. 19, but during the opening of the mask.

Fig. 21 shows a step in the manufacture of the mask of Fig. 18 and Figures 22 and 23 are plan views of the mask of Figure 18 folded flat.

The breathing mask in Figs. 13-15 is made of flexible, sheet-shaped filter material, for example, as described above, and is originally gene in the form of a flat pocket 1, shown in Fig. 5, with generally truncated conical shape with a closed end 2 along the smaller end of the truncated cone, closed side edges 3 and an open edge 4 at the larger end of the truncated cone. For the sake of simplicity, more pocket 1 below to be described with an upper wall 5, which when used lies above the wearer's nose, and a lower wall 6 which, in use, lies under the wearer's chin.

This flat pocket 1 is as described below the fold to form the closed end of the pocket, a four-sided surface consisting of two main substantially identical, triangular surfaces 7, where the triangles have a mensam base 8 and tips e, f, facing the base 8, adjacent the corners or ends of the closed end of the flat pocket 2. The common the same base 8 lies on a line perpendicular to the connecting line between the tips e, f, and the triangular surfaces 7 lie against each other. others, and leaning against each other in use.

The fold line which forms the common base 8 of the triangular the surfaces 7 are suitably extended at 9 and 10 on each wall of the can to the open edge of the pocket 4. 8003764-1 In addition to the above folding lines, the breathing mask is suitable fold lines 15 extending from the tips e, f on the upper wall of the pocket 5 to points on the edge 4 between the fold line 9 and the side edge 3. These fold lines 15 together with the fold line 9 form in it upper wall 5 an inverted V-shaped channel 16 which is placed on the carrier nose and thus positively adapts the upper wall 5 of the pocket to the but on the wearer's face and thus reduces the edge leakage around the nose and in the area between the nose and cheeks.

The respirator is held in place on the face by one or two neck straps 13, 14, attached to the pocket next to the edge 4. The neck straps can be attached to points A1, A2 and B1, B2 or both may be fixed put at C1, C2 at the ends of the side edges 3 or can a only straps be attached at points C1, C2.

The manufacture of a respirator as above will now be described from the beginning in connection with a sheet of filter material which is weldable, for example with high frequency welding, ultrasonic welding or heat welding ning. The mask is made of a blank 20, shown in Fig. 3, which consists of two truncated triangles with the smaller ends coinciding. The- The shape of the raw material has advantages from an economic point of view in from a sheet 21, Fig. 1, of the material, which is substantially wider than the raw material, e.g. 3 m wide and approximately 100 m long. In fig. 1 it appears that a plurality of blanks can be cut out of the sheet 21 with the blanks in continuous, long rows, and with the blanks in one row staggered in length half a substance length in relation to the substances in an adjacent horizontal row. The only material spillage occurs, then at sheet 2 edges. The blank can, for example, be 21 cm wide at the larger end on each truncated triangle, 9.5 cm wide at the smaller end of each je truncated triangle and approximately 19 cm long, so that the triangle tip angle is approximately 59 °.

A sheet 21 of filter material is passed continuously through a high speed cutting machine, which makes continuous, longitudinal zigzag inserts 22, which form side edges on the blanks. The machine may also be able to cross section 23 for the ends of the blanks. These cuts 23 do not go all over the width of each subject line so that the subject lines are certainly man-hanging to fit into the subsequent treatment. At at the end of the cutting machine, fold the blank rows into zigzags, as shown in Fig. 2. sover-1 The next step that can be combined with the cutting or only with the front the position of the cuts 23 is to make a pattern of on each blank welds as shown in Fig. 3. These welds are sealing welds 24 along the end edges of the blank to prevent abrasion of the material along these edges, a central longitudinal weld 25 forming folding lines 8, 9 and 10 and four welds 26, 27 forming folds lines 11, 12.

The entire welding pattern can be embossed in a single operation or it can It is made up of a number of straight welds.

The effect of these welds is as shown in Fig. 4 (a) that together press and flatten to the material in the area of the weld, and it has proved that this gives the weld seam a longitudinal stiffness. Through to use suitably shaped electrodes or by a subsequent the heating it is possible to profile such a weld seam e.g. as shown in Fig. 4 (b) to increase the longitudinal stiffness of the weld. This profiling can be done at least on the part of the weld 25 which constitutes the common base 8 on the triangular surfaces 7.

After this step, the blank is folded twice as shown in Fig. 5 to superimpose the two truncated triangles that possibly car-> the upper and lower walls 5, 6 of the respirator pocket and to form the closed end edge 2. After this folding, the side edges are welded 3 on the walls 5, 6 together to form the flat pocket, whose open edge 4 is formed by the welded edges 24. In the next step which As shown in Fig. 6, the pocket is opened by pulling on the ends n, m on it central weld seam 25 and at the same time the center point is pressed the weld 25 in to fold the blank along the welds 25, 26 and 27 and form the triangular surfaces 7 shown in Fig. 7. Further separation of points n and m join the triangular surfaces 7 as shown in Fig. 8. This creates triangular wings 30 which are then folded against point n to lie flat against the rest of the pocket as shown in Fig. 9. This operation gives the fold lines 15 which extend from the tips e, f to the open edge of the pocket 4. These fold lines 15 may, however, have been deformed by making corresponding welds on the original blank at the same time as the welds 24-27.

The mask shown in Fig. 9 is completely finished with the exception of the the placement of neckbands at the previously indicated points. 84303764--1 Another folding can be made as shown in Figs. 10-12. The triangular surfaces 7 are separated and folded downwards in opposite directions along the folding line 8 until they rest against the rest of the pocket as shown Fig. 11. This gives a rectangular, flat package which can be easily stopped. fit in the carrier's pocket, possibly in an envelope. The neck straps can be around the package as shown in Fig. 12.

A small, malleable metal strip 31, Fig. 14, can be attached to the top of the mask. re wall 5, so that it passes over the tip of the channel 16 next to the edge 4 to improve the seal across the bridge of the nose.

To use the mask, it is folded up to the shape shown in FIG. 9, and is then opened by pulling the ends of the side edges 3 apart, so that the mask has the shape shown in Figs. 13 and 14.

It should be emphasized that the shape of the mask described is housing advantageous in two important respects.

The shape of the upper wall 5 of the mask 5 with the channel 6 predestines respiratory the mask to sneak into the areas on both sides of the nose, which is so difficult to seal against leakage. Furthermore, the frame 31 is preformed into one U-shape by the folding up of the breathing mask, and is thus finished to squeeze the wearer's nose when placing the mask over the charged. No conscious action is required on the part of the wearer to shape the strip, although it may be necessary to readjust the strip sans shape until it fits comfortably on the nose. Although the face mask described above is stated to be made of weldable material, so that the fold lines 8, 9, 10, 11 and 12 can consists of welds, it should be pointed out that either the material is weldable or not, these fold lines can be provided on the nat way or simply be preformed pressed lines. A few or all of these fold lines may be reinforced, and reinforced the adjustments are made by applying reinforcing elements along the folds. lines, for example plastic strips, e.g. by injection molding or otherwise along the fold lines, and the plastic strips may be profiled or not and possibly keep the material in weight condition.

Other filter materials that can be used for respiratory protection are @ «m; e1- fabric with activated carbon arranged between two protective sheets to form 80-03764--1 a respirator capable of filtering gas and steam. The fabric with ak- activated carbon is activated charcoal in the form of a fabric made from scratch of woven, synthetic fibers, e.g. rayon. Charcoal impregnated filters materials can also be used. Alternatively, the charcoal fabric or it can charcoal impregnated filter material is combined with one or several layers of particulate filter material to provide a respirator with the ability to filter out particles as well as gas and vapors.

The shape of the finished respirator and thus also its fit determined by the dimensions of the original raw material shown in Fig. 3. the blank and of the dimensions of the quadrilateral formed by the triangles 7 surface. If this quadrilateral surface is a square, it will be the result the face mask symmetrically about a center line parallel to the line X in Fig. 12. By making the fold lines 11 and 12 different lengths it is possible to vary the shape of the mask. The square surface can for example, being a rhomboid. Alternatively, the lines 11 can be made longer than the lines 12, i.e. the line connecting e and f in Fig. 3 is shorter than the connecting line between the tips g and h, and these lines do not intersect at their midpoints. The resulting but can be described as an upside down dragon and this leads to. that the respiratory protection seen from the side looks like in Fig. 12, where The fold line 12 is parallel to the center line X and the fold line 9 forms approximately 250 angles with the center line X. This becomes a close approximation to the classic cup shape on mouth and nose protection.

In one embodiment, the length of the line between the tips e and f is 8 cm, the length of the line between the tips g and h 10 cm and the lines intersect at a point 4 cm from the tip h and 6 cm from the tip g, so that the angle between the welds 25 and 26 becomes 450 and between welds 25 and 27 33.7 °.

To make manufacturing simple, however, the four-sided surface can be made square with the lines between the tips g and h as well as between e and f, both 9.5 cm long and with cuts in their midpoints.

Fig. 16 shows that the finished breathing mask can be considered as a frame bounded by fold lines 8, 9, 10, 11 and 12 between the the filter material extends. The fold lines 8, 9, 10, 11 and 12 can be likened to struts or struts under pressure which are joined together take at their ends. The welds along the side edges 3 are under tensile stress on exhalation and may be under pressure on inhalation, and therefore is 81003764-1 stiffness under load desirable. The support formed by the folding line 8 is particularly important as it stiffens the respiratory protection in direction. The effective point connections at the tips e, f can thus radiating around the strut 8 and giving a certain flexibility and similarity to the breathing mask, which can therefore be easily adapted to the plate or thin faces. When the wearer's lower jaw moves, for example at numbers, the tips e, f move and thereby relieves the load that otherwise it would lie on the bridge of the nose and cause the mask to fall off. Further prevents the mask from strengthening through the fold lines 8-12 that the mask collapses on the wearer's face, especially when it becomes clogged and therefore inefficient.

The face mask described above can be modified by providing inwardly extending sealing strips, for example as described in published British patent application 7,911,595. an inverted truncated triangle 35 is placed at each end of the blank, such as shown in Fig. 17 (a) and the end edges are curved inwardly into larger or smaller re extent. After folding lines 8-12 have been made, the blank is folded in the middle and welded along the side edges 3, as shown in Fig. 17 (b).

The flat pocket thus formed was then turned inside out as shown in FIG. 17 (c) and the additional parallel trapezoidal parts are folded inwards to form the inwardly directed sealing strip 3§, which can extend all or part of the way around the opening of the pocket, for example only in the areas of the ends at the edges 3, or in the areas of the ends of the edges 3 and over the nose but not under the chin, as described in the above-mentioned patent application.

It should be noted that the pocket must be turned inside out between the steps shown in Figs. 17 (b) and 17 (c) to ensure that the sealing the strip only gives a smooth surface to the face.

A further modification of the face mask of Figs. 13-15 is shown Figs. 18 and 19.

As can be seen, the mask corresponds exactly to the mask shown in Figs. ken, and the same reference numerals have been used for the corresponding parts. The difference is only the additional feature that in the lower edge 6 of the face mask, the fold lines 40 are made which delimit a triangular surface 41 in the middle of the fold line 10. A base on this triangular angular surface extends along the open edge of the pocket between the side edges and the tip opposite this base is located at or in the vicinity of 8003764--1 10 the tip of the tip g on the triangular surfaces 7.

As shown in Figs. 21 and 22, the triangular surface 41 is defined and the fold lines 40 are raised at the same time as the wings 30 are folded flat.

The fold lines 40 are made by pushing the point m inwards and folding together the adjacent parts of the wall 7.This creates two half- triangular surfaces that fold flat against each other and have a joint base along the fold line 13.

The breathing mask opens in exactly the same way as the one described above mask, with the exception that when the ends of the side edges 3 have 'disassembled, the triangular surface 41 extends across the pocket opening as shown in Fig. 20. Then you only need to pull the the one on the fold line 12 outwards to flatten to the triangular surface 41. When the mask is placed on the face, this surface 41 lies the chin with the fold lines 40 along the edge of the lower jaw. The wonder the wall 7 of the mask is thus suitably adapted to the shape of the wearer on the chin and adjacent parts of the cheeks.

An additional advantage arising from the folding of the triangular learning part 41 is that the breathing mask in a flat, folded state, such as shown in Figures 22 and 23, has a generally rectangular shape as well fits in a pocket without having to do the additional folding described with reference to Figs. 10-12. It should point- ° Figs. 22 and 23 show the same face mask flat in the bay, but on Fig. 23, the mask is oriented for insertion into, for example, a breast pocket.

The face mask described above can be further enhanced by adding lay additional welding lines or plastic strips on the triangular ones the surfaces 7, where the additional welding lines or plastic strips stretch is parallel to the fold line 8 or at an angle opposite it, e.g. parallel to the fold lines 11 and 12.

It should be noted that the term "filter material" in this specification was used to denote a material which removes a or several undesirable components from a gas or vapor, whereby the component may be in the form of particles and / or molecules and may removed mechanically and / or electrostatically and / or absorbed and / or adsorbed by the filter material.

Claims (11)

u 8003764-1 EÉÉÉEÉÅÉÉÉX Filtering respiratory protection of flexible, filter-sheet material in the form of a pocket of generally truncated conical shape with an open edge at the wider end of the truncated cone and a closed edge at the narrower end of the stumbling cone, characterized in that it the closed end (2) of the pocket is provided with first folding lines (8, 11, 12) which delimit a generally four-sided area, which extends inwards into the pocket and consists of triangular surfaces (7) which lie against each other and are inclined relative to each other. A touch guard according to claim 1, characterized in that the two triangular surfaces (7) forming the quadrilateral region have a common base (8) perpendicular to the line connecting the tips (e, f) of the triangles located in the corner of the pocket at the closed end of the pocket. Face protection according to claim 1, characterized in that the folding line forming the common base (8) is longitudinally stiffened. 4. A face shield according to claim 1, characterized in that the first fold lines (8, 11, 12) forming the four-sided surface are stiffened longitudinally. Face protection according to claim 3 or 4, characterized in that the filtering sheet material is weldable and that the longitudinally stiffened folding lines (8, 11, 12) consist of a weld in the sheet material. Respiratory protection according to claim 3 or 4, characterized in that the longitudinally stiffened folding lines or lines consist of a stiffening element fixed to the sheet material. 7. Respiratory protection according to claim 6, characterized in that the reinforcing element is made of plastic material. Face protection according to one of the preceding claims, characterized in that the fold lines (8, 11, 12) which ßüêš fi šlïß-'I 1% delimit the generally four-sided area consist of a framework formed by the stiffened fold lines. 9. Face protection according to one of the preceding claims, characterized in that the generally four-sided area is similar. Respiratory protection according to one of Claims 1 to 8, characterized in that the opposite sides in the generally four-sided area are of equal length in pairs, and one pair of sides longer than the other. Respiratory protection device according to one of the preceding claims, characterized in that it is adapted to be used with the common base (8) in a generally vertical plane, with one of the side walls (5) on the pocket extending over the wearer's nose and with the other of the side walls (6) extending below the wearer's chin, a second folding line (9) being arranged in one side wall (5) and extending from the corresponding end of the folding line constituting the common base (8) to the open edge on the pocket and in use lies along the wearer's nose, and that a third folding line (10) is arranged in the second side wall (6) from the other end of the folding line which forms the common base (8) to the open edge of the pocket, and that this third fold line (10) in use goes under the wearer's chin, and that fourth fold lines (15) are arranged in the wall (5) and extend from the triangle tips (e, f) to the open end of the pocket on each side of the second fold line (9). ) to thereby b ild a generally V-shaped channel (16) for the wearer's nose.