FIELD OF INVENTION

The present invention relates to a method for the repeated forming of a protective filter mask and the mask produced by this method.

BACKGROUND OF INVENTION

Disposable protective filter masks are now a standard element for protection of respiratory system against aerosol particulates. The masks are used not only in health care, but also when working in dusty environments such as, mines or when working with dusting particulate materials. After a day of use of these masks, they are replaced by a new one.

The masks are made of different kinds of nonwovens filter, in different shapes and with different fastening means on the face. To properly fulfill their task, masks should provide adequate filtration efficiency and proper adherence to face. In general, the mask should not cause too much breathing resistance to provide comfort for their use. To lower breathing resistance, suitable disposable masks are as large as possible, developed surface. One method of developing the surface of protective mask is pleated surface.

Polish application, P.288841 discloses process for making masks for respiratory protection against aerosol particles, protecting against hydrofluoric acid mist and against polycyclic aromatic hydrocarbons. The essence of the invention is the use of needled nonwoven fabric layers appropriately selected basis weight, impregnated with an impregnating solution. From the air inlet side, the first layer is needled nonwoven impregnated layer, and the second layer - pneumotermic melt blown nonwoven fabric.

P.321771 relates to filter-adsorption mask for a single use, where the compounds of lead and sulfuric acid mist are present. The essence of this semi-mask is that the trapezoid-shaped canopy consists of five nonwovens layers permanently joined together in a known manner, arranged so that to the middle layer of impregnated nonwoven adsorbing-sorbing material, from both sides the layers of the electret melt blown nonwoven fabric are adjacent. To these layers on the outer side of the nonwoven layer a thermoplastic particle absorbing nonwoven material is adjacent, and from the inner side of the mask a layer of nonwoven fabric protective thermoplastic is adjacent, wherein the middle layer is a nonwoven fabric impregnated with substances having physico-chemical affinity for the compounds of lead and sulfuric acid.

Polish application No. P.355237 discloses a protective mask, comprising a nonwoven layer filter having pleats, nasal clip and the harness straps, wherein the at least one pleat is formed in the central portion of the filter material through the geometric mesh of rectangular shape with inclined notches made on the long edges, and the depth of the pleats is less than the width of the folded respirator, wherein the notches after bent are folded by the longitudinal welding and the edges of the pleats are preferably welded transversely. Also described is a method for producing a protective respiration mask, the method comprising making pleats of surface of the mask, wherein pleats are made in the central portion of the respirator, then folded and combined by sealing the edges of the longitudinal notches, preferably with the binder or discs, and then preferably the edges of pleats are welded transversely spaced at preset dimensions as required for the mask with all the layers. It should be noted that the mask is the subject of the application P.355237 has a shape similar to the anatomical.

US 6474336 B1 describes a mask comprising a mini-tabs which are of such a size and structure that form a kind of fixed pattern, which due to its structure defines a chamber to breathe when the mask is placed on the wearer's face.

The solution described in JP2012035006 is a new apparatus for the mask production, and a new mask maintaining while wearing pleated body, wherein the three- dimensional shape of the folds of the mask body is elongated and forms a mask. The document JP2012035006 also describes a device for the production of masks, including the pleated mask body and ear mounting portion connected to each side of the mask body comprising: wherein said device comprises means providing pleating, which pleat mask body that comprises a plurality of nonwoven fabric layers and apparatus for welding a three-dimensional shape, which seal distal portion or all of the nonwoven layers, such that the first weld is repeatedly or intermittently aligned in a direction extending transverse to the fold to form a first weld line in the middle of the mask body in a state in which the corrugations in the central portion extended.

JP2004242905 shows a disposable dust mask, easy to manufacture and designed so as to achieve stabilization of the mask, preventing it from collapsing. It also presents a method of producing the mask. Disposable dust mask filter element comprises a cup-shaped supporting member contacting with the face, the straps and the retaining element stripes. The inner surface of the filter element is lined with a supporting material comprising square shaped structure. Shape-retaining material is made of synthetic resin whose melting point is lower or the same as the melting point of the synthetic fibers constituting the filter element. Shape-retaining material is subjected to melting and solidification of a portion of the peripheral edge of the filter element to become thin and able to move through the regions of the retaining strips piercing element to connect the filter element with an element-contacting with the face.

WO2012097762 discloses the inhalation mask against biological and mechanical impurities, wherein said mask comprise an inner textile layer and an outer layer of fabric. Between those two layers the filter layer of polymeric nanofibres and/ or active layer of polymeric nanofibers is placed, which in their structure contain a biocide(s). The outer and the inner textile layer are made of microfibers, while at least the outer textile layer and its adjacent layers: a filter or active layer from the polymer nanofibers are hydrophobic, and all the layers are connected to each other via the backhaul network, which prevents them mutual mobility and reduce the permeability of the mask only slightly. The inner textile layer on the periphery of the mask is provided with an adhesive layer for securing the mask to the face of the user. This method of fixing the mask to the face mask provides excellent adhesion to the skin, thus preventing unfiltered air breathing. This document also describes a method for producing such a mask.

The methods for mask production provides mostly mask, in which the flat filter layers of different filtering non-woven materials and non-woven protective material are successively assembled and cut to the desired shape, then heat-sealed on their sides and drawstring are fixed, breathing valves and sealing elements mounted. These activities carried out successively preventing the formation of substantial filtering layer in the form of pleats to increase the working surface of the mask.

It was difficult to operate a pre-creased, elastic fabric because of its tendency to expansion. Research on production of disposable masks unexpectedly enabled the development of a repeated process for forming such masks.

In a new solution, the production of masks is performed repeatedly. Such an approach to the production of the masks turned out to be a breakthrough and allowed the simultaneous solution of all problems associated with manual production of masks.

In a repeated process a substantial flat filter layer mask is taken from the spool on a special roller system suitable for moving the shape of the tabs (pleats). Creased filter layer is further combined with successive layers of masks: prefilter layer and shall layers, drawstring fastening and rubber bands are fixed, then the mask is pressed and cut into the desired shape while welding, which combines all the elements of the mask.

The entire production process of mask production is executed in a special automated line. There is no need to carry another mask intermediates between different workstations, where subsequent forming operations of the product were made. This solution enables manufacturing process able to obtain many advantages. Masks can be produced from cheaper raw materials because now these materials can be pleated in order to develop the surface and in result the breathing resistance of the pleated mask is reduced.

Masks are produced in a controlled and reproducible manner, productivity has got multiplied and human errors associated with the manual fixing and combining masks was eliminated. In addition, costs of production and raw material efficiency were significantly reduced. New technological solution was created by solving the problem of synchronizing the movement advancing ribbon mask material and various cutting and joining operations that have been performed in stationary devices. Furthermore it was possible to master the technique of primarily controlled pleating of a moving flat band of filter material, together with maintaining the shape of the pleated material until its fixation in the process of welding the edges of the mask. The use of new production technology of the disposable masks now creates great opportunities to compose a variety of masks, filter materials and auxiliaries and filling production line in the future with additional operations.

The present invention relates to a method for the repeated forming of a protective filter mask, characterized in that the flat filter material is delivered from the spool and the longitudinal creases (pleats) are folded with a special arrangement of rollers, then the creased, flat, filter material is flattened and connected to optional layers of the mask: pre-filter layer and shell layers, then the edges of the band are welded longitudinally and it follows that the transverse welds on the band are carried out by the cut of a band at the point of the weld, and the drawstrings (mounting straps) are fixed.

Preferably, the method of the invention comprises the additional step of introducing a lower and/or upper layer of fleece. Furthermore the transverse welding of the band includes mounting drawstrings (mounting straps). In a particularly preferred method, a the mask is produced from two layers of nonwoven filter fabric, the outer layer is a pre-filter layer lying underneath the main filter, which are taken from two separate reels of the filter material and from which a pressure roll arrangement forms a pleated filter composite layer, the composite nonwoven band moves further and enters the ultrasonic welder that performs welds along the edges of non-woven bands and then enters the cutter, which cuts holes cyclically on one part of the non-woven belt, after which the mask is provided with an aluminum strip to the facial fixing of the mask on the ridge of the nose, then the edges of the nonwoven fabric are pressed and pulled, both layers, joned in the previous step, are folded in half by placed on the way of band a wedge-like element which breaks in half the nonwoven fabric , the nonwoven belt folded in half and set the back upwardly moves further under element of an ultrasonic welder which welds the surfaces forming the oblique sides of the trapezoidal shape of the face mask, in a further step, a valve is introduced, then the nonwoven material band is straightened and the unnecessary portion of the nonwoven fabric is periodically removed by knives.

The present invention further provides a system for producing masks implemented in a repeated manner, comprising at least two spools of coils wounded separately with pre-filter material and primary filter material, pressure roller system forming a composite pleated filter layer, and an ultrasonic welder and cutter that repeatedly cuts holes for the valves in one part of the nonwoven band, belt systems of pressure- tensioning elements, an ultrasonic welder, which swings and aligns the sides of the nonwoven material, welding the layers forming oblique sides of a trapezoidal shape of the face mask, the curved guide moving the band of nonwoven material so that its goes back through the slit, which causes a spreading apart of the edges of the nonwoven material on the opposite side, and a rotary feeder inserting a valve into the cut hole at the same time and inserting to the split edges an inner pressure sleeve of the valve, a guide with a side surface of the cylinder with openings at the location of the valve, and blades approaching and moving away repeatedly from the nonwoven material.

The present invention further provides a mask filter consisting of a a layer of pleated filter material, which is welded on the sides, and the mask is equipped with a drawstring.

The subject of the invention is also filter mask produced by the process according to the invention.

The invention is illustrated in the drawing, in which:

Fig. 1 and Fig. 2 show a block diagram of a method for the manufacture of masks known in the art;

Fig. 3 shows a block diagram of a method for producing masks carried out in a repeated manner as described in Example 3;

Fig. 4 shows a block diagram of a method for producing masks carried out in a repeated manner as described in Example 4;

Fig. 5 shows a block diagram of a method for producing masks carried out in a repeated manner as described in Example 5;

The invention will be further illustrated in the examples whose purpose is merely a detailed presentation of preferred embodiments of the invention.

Examples

Example 1 (a multi-step, manual production, before using pleating)

The mask is made of two layers of nonwovens filter. The outer layer is a prefilter and below it is placed the main layer of non-woven filter. From two reels with pre-wound coils separately and in principle the filter material of the filter material the pressure roll arrangement forming a composite filter layer. Nonwoven web composite with a width of 16 cm moves on and gets under ultrasonic welding machine which performs the welds along the contour band nonwovens and which periodically cut holes in the valve on one part of the non-woven belt. As the two layers bonded are folded in half lengthwise axis of the strip nonwoven fabric and pass to the second ultrasonic welder, which moves together with a nonwoven material suitable mask seal takes the shape of a trapezium, while each in turn cuts off the molded part of the facial mask from the remainder of the nonwoven fabric. Facial parts are separated from the scrap, it moves to the second position where with the help of quick-setting glue stick them with a soft metal strip acting form of the pressure and the mask on the back of the nose. In the next post is pasted exhaust valve in the previously prepared hole in one of the trapezoidal walls of the facial mask. In the last post elastic straps are attached to opposite edges of the facial mask by translating them into the curled edge welding mask and its edge to form a loop.

Example 2 (automatic molding masks without pleating)

The mask as in Example 1 , is produced from two layers of nonwoven fabrics filtration The outer layer is a prefilter and below it is the main layer of non-woven filter. With two reels with pre-wound coils separately and in principle the filter material of the filter material the pressure roll arrangement forming a composite filter layer. Nonwoven web composite with a width of 16 cm moves on and gets under ultrasonic welding machine which performs the welds along the banks of non-wovens and contour band, which cuts down on the valve periodically holes on one part of the non-woven belt. A little further from the dispenser are placed on non-woven strips of aluminum covered on one side and fast drying glue pressed web to join her good. These strips are part of the facial seal the mask on the back of the nose. The edges of the nonwoven material are pressed and stretched by means of a pressure-belt tensioning elements. They provide a nonwoven web shifting and stacking is equal to the cameras performing subsequent forming operations masks. As the two layers bonded are folded in half at the point where the web by breaking the nonwoven wedge-like element. Composed in two non-woven belt, set up the ridge moves further into the ultrasonic welding element who, by aligning movements and non-woven approaching its surfaces are welded to form oblique sides of the trapezoidal shape of the facial mask.

In the next step, moving the nonwoven strip is moved so that the ridge passes through the slit, a curved slide, which causes movement apart of the edges of the nonwoven on the opposite side. At this point, the carousel tray slides simultaneously breathing valve in place of the cutout is inserted into the valve and into the interior of the extended edges of inner non-woven pressure sleeve valve. When both valve means are located above the hole, the arms and carousel approaching the two parts of the valve coupled firmly by the presence of both of the valve banks of latches. Belt nonwoven straightens up and moves further on the side surface of the tubular guide holes at the site of the valves. At this element follows a circular cutting unnecessary portions of the fabric from using knives and cyclically upcoming dismissing the nonwoven fabric.

The result is a cut-out of individual elements of the facial mask and unnecessary portions of the nonwoven fabric belt. All cut parts fall into the storage tank from where it is distributed manually from waste fragments of nonwoven fabric. In a separate workstation to the edges of the mask are Trailed fastening drawstring hood on his head in the manner described in Example 1.

Example 3

The mask is fabricated from a single layer of filter cloth initially wound on the spool. Tape roller system pressure provides a nonwoven web to slide along the production line and its equal, flat orientation. The composite nonwoven web width 28 cm moves forward and gets between the arrangement of two sets of freely rotating discs. Plates in an amount of 5 pieces are embedded and penetrate the horizontal in such a way that the plane of the sets of plates for each axis converge on a straight line lying outside them. The axes on which the pivot plates are positioned relative to each other such that the plates are two shafts with each other and converge in the direction of the smallest distance between them. Non-woven belt is pulled between the two sets of plates. During this movement nonwoven initially falls flat on widely spaced plates, which are just beginning to delve into each other.

From that moment on a flat non-woven filter is refracted in such intervals that result from the adoption of the number and size of pleats. In the course of further movement between the plates and highlighting the pleats are closer to each other. On exit from between the plates is shaped nonwoven pleated web ready long. This web gets between the blades, which maintain its shape and to prevent the pleats of the secondary expansion by the action Of elastic forces nonwoven material. Ribbon pleats goes further between two rollers that gently collapsed and at the same time provide the tension and move the fabric. Non-woven gets crushed under the wheel next to prevent its expansion. The downstream sliding creased nonwoven web is tucked along the edges and welded using the ultrasonic probe along the circumference to form a thickened edge masks adhering better to face later. Nonwoven goes further into the ultrasonic welding machine that performs a wide 5 mm weld across the web. Next synchronized with the movement of the web cutter cuts the non-woven belt in the middle of the weld.

The result is a rectangular facepiece of five pleats of the edge length of 2 cm each. The cut parts fall into the storage tank. The last operation performed manually in a separate position is a combination of flexible retinacula on the banks of the masks. For this purpose, previously cut into equal segments elastic drawstring connected to an ultrasonic welder at the corners of the mask. As a result, gaining two drawstring hood for mounting it on the face for translating retinacula behind the ears.

Example 4 (mask, with pleated layer and smooth fleece on both sides)

The mask is performed as in Example 3 except that does not consist of one layer of filter cloth creased but the non-woven fabric after creased enclosed on both sides of the planar layers of loosely woven. In this case, when the creased nonwoven web extends between the guide disc is fed from the bottom of a nonwoven belt from its own spool. As they continued to press their pleats folding guides them to the ground and lower fleece is the gap between the sections of the guide is inserted into the second, upper belt fleece.

As a result of these operations is achieved creased nonwoven filter layer is essential sheathed on both sides of an additional layer of non-woven. The downstream sliding total creased nonwoven web is tucked along the edges and welded using the ultrasonic probe around the perimeter of the mask to form a thickened edge adjacent better later face, and bonding all three layers along both edges of the belt non-woven fabric. Further operations are carried out as in Example 4.

Example 5 (+ Auto, welding spool)

Forming operation of nonwoven sheathed on both sides with layers of nonwoven fabric to the date of the transverse welding is carried out as in Example 4. The cross seals combined nonwovens stabilize and protect them from expansion. No longer having to drag nonwoven under the pressure guide. Hand machine develops and I form a loop with the measured length of flexible material spool and applies it over the transverse seal near the edge of the web. At the same time sliding the ribbon in motion rotary ultrasonic welder welds loose ties with the nonwoven web. In the last operation ribbon is cut in half transverse weld with an automatic guillotine performing rocker moves over a moving non-woven belt. The intersection at this point also cuts loose ties at the point of junction with the mask to form independent loops on both sides of the mask. No special non-woven fabric scraps or waste.