Disposable, Compostable Surgical/Medical Masks and Methods of Production Therefor
20240349826 ยท 2024-10-24
Inventors
Cpc classification
A41D13/11
HUMAN NECESSITIES
International classification
Abstract
Disclosed are disposable, compostable surgical/medical masks comprising (i) a 3-ply face-mask component wherein the two outer layers are a spunbond PLA textile and the third center layer is a meltblown PLA textile, (ii) a deformable nose bar formed from a PLA extrudate, and (iii) a pair of elongate narrow-width 3-ply stretchable soft ear loop strips wherein the two outer strips are spunbond PLA textile and the third middle layer is a compostable elastic film. Some embodiments relate to 4-ply disposable, compostable surgical/medical masks comprising two outer layers each comprising a spunbond PLA textile and two middle layers comprising meltblown PLA textile. Some embodiments relate to 4-ply disposable, compostable surgical/medical masks comprising two outer layers each comprising a spunbond PLA textile, a middle layer comprising a spunbond PLA textile, and a middle layer comprising a meltblown PLA textile.
Claims
1. A disposable, compostable pleated surgical/medical mask, comprising: a mask assembly having, (i) an outward-facing first outer layer consisting of a spunbond polylactic acid (PLA) textile, (ii) an inward-facing second outer layer consisting of a spunbond PLA textile, (iii) an intermediate layer(s) consisting of a meltblown PLA textile disposed between the first outer layer and the second outer layer, and (iv) a deformable nosebar disposed between the meltblown PLA layer and one of the first outer layer and the second outer layer about an upper linear edge of the assembly, wherein the mask assembly is pleated with (v) a bottom linear edge of the mask assembly ultrasonically welded together with a first plurality of spaced-apart rows of welds, (vi) the top linear edge of the mask assembly ultrasonically welded together with a second plurality of spaced-apart rows of welds whereby the PLA nosebar is disposed between a pair of the second plurality of spaced-apart rows of welds, and (vii) opposing side edges of the mask assembly ultrasonically welded together with a pair of a third plurality of spaced-apart rows of welds; and a pair of wherein each of the pair of the ear loop strips is formed from a soft-resilient textile wherein the first layer is a spunbond PLA textile, the second layer is a compostable elastic film, and the third layer is a spunbond PLA textile, said soft-resilient textile laminated together by a heat-embossing process, said soft-resilient textile having a stiffness in a machine direction and a resilience in a cross direction; wherein opposing ends of each one of the pair soft-resilient ear loop strips are ultrasonically welded to an upper corner and a bottom corner of the opposing side edges of the mask assembly.
2. The disposable, compostable pleated surgical/medical mask of claim 1, wherein the deformable nosebar is formed from an extruded PLA material.
3. The disposable, compostable pleated surgical/medical mask of claim 1, wherein the deformable nosebar is an aluminum strip.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0022] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more embodiments of the invention and are not to be construed as limiting the invention. In the drawings:
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DETAILED DESCRIPTION OF THE INVENTION
[0042] The embodiments of the present disclosure generally relate to disposable, compostable surgical/medical masks comprising assemblies of a plurality of components wherein each of the components has been fashioned from polylactic acid (PLA) materials.
[0043] An embodiment of an example of a disposable, compostable 3-ply surgical/medical mask 10 disclosed herein is shown in
[0044] The deformable nose bar 35 may be produced by extrusion of an extrusion-grade PLA through an extruder fitted with a die with round bores therethrough to produce elongate solid round PLA bars or alternatively, through a die having elongate slits therethrough to produce solid rectangular PLA strips. According to an aspect, elongate solid round PLA bars may be corrugated around their linear axis. According to an aspect, elongate solid rectangular PLA bars may be corrugated around their linear axis. According to another aspect, the deformable nose bar may be a deformable aluminum strip.
[0045] The disposable, compostable surgical/medical mask 10 shown in
[0046] In the example embodiment shown in
[0047] The next step after the upper and lower edges of the flat pleated 3-ply assembly comprising the inward-facing spunbond PLA textile layer 20, the middle meltblown PLA textile layer 30, the outward-facing meltblown PLA textile layer 40 and ultrasonically welded to form the welded top strip 21 and the welded bottom strip 22, the side edges 23a, 23b of the mask 10m wherein the mask 10 has upper corners 24a, 24b, and bottom corners 25a, 25b.
[0048] The 3-ply disposable, compostable soft ear loop strips 50 may be produced by concurrently unspooling a first spunbond PLA textile with a compostable elastic polymeric resin film and a second spunbond PLA textile to thereby form a 3-ply layered assembly comprising the compostable elastic film sandwiched between the first and second spunbond PLA textile layers. The 3-ply layered assembly may then be bonded together by a heat embossing process to produce a continuous intermediate 3-ply laminate textile. The continuous intermediate textile may then be activated by conveyance through one or more stages of rollers having circumferential grooves of generally rectangular or triangular form that closely mesh together to thereby stretch the two outer inelastic layers and cause a permanent elongation in the 3-ply laminate textile in the cross direction (CD) that does not exceed the elastic limit of the elastic film layer sandwiched between the two outer spunbond PLA textile layers. The elongation of two outer spunbond PLA textile layers caused by conveyance through the rollers activates the 3-ply laminated textile and to thereby provide a soft resilience that enables the textile to be stretched and then return to its original shape in the cross direction (CD) while maintaining stiffness in the machine direction (MD). The activated 3-ply stretchable textile may then be cut into elongate strips along the cross-direction axis of the activated 3-ply stretchable textile to thereby form 3-ply stretchable soft ear loop strips 50.
[0049] The disposable, compostable surgical/medical masks 10 may be assembled by ultrasonically welding of the ends of a first 3-ply stretchable soft ear loop strip 50 about the top corner 24a and bottom corner 25a of one side edge 23a of the laminated 3-ply face-mask component, and then ultrasonically welding of the ends of a second. 3-ply stretchable soft ear loop strip 50 about the top corner 24b and bottom corner 25b of the opposite side edge 23b of the laminated 3-ply face-mask component to thereby produce a disposable, compostable surgical/medical mask 10 according to this disclosure. After the mask assembly 20, 30, 40 and the soft resilient ear loops 50 have been completely welded together, the continuous mask assemblies may be separated by cutting bars into individual disposable, compostable pleated surgical/medical masks 10.
[0050] According to an aspect, the disposable, compostable, surgical/medical masks 10 may be assembled by ultrasonically welding of the ends of a first 3-ply stretchable soft ear loop strip 50 about the top corners 24a, 24b, and then ultrasonically welding of the ends of a second 3-ply stretchable soft ear loop strip 50 about the bottom corners 25a and bottom corner 25b of the opposite side edge 23b of the laminated 3-ply face-mask component to thereby produce another embodiment of a disposable, compostable surgical/medical mask according to this disclosure.
[0051] According to an aspect, a suitable compostable elastic film for use in preparing the soft-resilient ear loops disclosed herein, may be prepared from one of TERRATEK FLEX FX2200, TERRATEK FLEX FX1515, TERRATEK FLEX GDH-B1FA, all available from Green Dot Bioplastics Inc. Emporia, KS, USA (TERRATEK is a trademark owned by Green Dot Bioplastics LLC, Cottonwood Falls, KS, USA), and the like.
[0052] According to an aspect, the first and second PLA textiles used to produce a 3-ply stretchable textile suitable to produce stretchable soft ear loop strips may be meltblown PLA textiles. According to another aspect, the 3-ply layered laminate assembly may be bonded together by passage through a hot-roll calendaring apparatus. According to another aspect, 3-ply layered laminate assembly may be bonded together by adhesive bonding.
[0053] Alternatively, the 3-ply layered laminate assembly may be provided with a pair of resilient elastic ear loops 45 (
[0054] An embodiment of an example of a disposable, compostable 4-ply surgical/medical mask 60 disclosed herein is shown in
[0055] The 4-ply compostable, disposable surgical/medical mask 60 may be produced with conventional disposable mask production equipment known to those skilled in this art, by concurrently unspooling a first spunbond PLA textile 65 with two meltblown PLA textiles 75, 80 and a second spunbond PLA textile 85 onto a conveyer belt to thereby form a 4-ply layered assembly (
[0056] In the example embodiment shown in
[0057] The next step after the upper and lower edges of the flat pleated 4-ply assembly comprising the inward-facing spunbond PLA textile layer 85, the middle meltblown PLA textile layers 75, 80, the outward-facing meltblown PLA textile layer 65 are laminated with a deformable nosebar 70 placed near the top edges of two selected textile layers, is ultrasonically welding to form the welded top and bottom strips, followed by ultrasonically welding the side edges together, followed ultrasonically welding each of the pair of ear loops 90, 95
[0058] Another example embodiment relates to lamination of layered textile assemblies to provide 3-ply or 4-ply disposable, compostable face masks according to the present disclosure, that selectively may pass (i) level 1 of the ASTM F2100 Standard Specification for Performance of Materials used in Medical Face Masks for use in environments wherein there is low risk of fluid exposure (no splashes or sprays expected), or alternatively, (ii) level 2 of the ASTM F2100 Standard Specification for use in environments wherein there is moderate risk of fluid exposure (some occurrence of splashes or sprays expected), or alternatively (iii) level 3 of the ASTM F2100 Standard Specification for use in environments wherein there is a high risk of fluid exposure (likely occurrence of splashes or sprays expected).
[0059] Examples of suitable layers of spunbond PLA textiles that may pass a selected level of ASTM F2100 Standard Specification include single layers having a GSM value (weight in grams per square metre) from a range of about 20 to about 65, for example about 25 GSM, about 40 GSM, about 50 GSM. Also suitable are double layers of spunbond PLA textiles having a about 20/20 GSM or a about 25/25 GSM or a about 30/30 GSM.
[0060] Examples of suitable layers of meltblown PLA textiles that may pass a selected level of ASTM F2100 Standard Specification include single layers having a gsm value (weight in grams per square metre) from a range of about 20 to about 65, for example about 25 GSM, about 40 GSM, about 50 GSM. Also suitable are double layers of meltblown PLA textiles having a about 20/20 GSM or a about 25/25 GSM or a about 30/30 GSM.
[0061] It should be noted that doubled-layered meltblown PLA textiles and double-layered spunbond PLA textiles may pass a selected ASTM F2100 level may be thinner than single-layer meltblown and spunbond PLA textiles GSMs required to pass the same ASTM F2100 level. For example, a double-layered spunbond PLA textile with a GSM of about 25/25 may be thinner than a single-layer spunbond PLA textile having a GSM of about 40 or about 50.
[0062] Suitable 3-ply disposable, compostable masks configured to pass level 1 or alternative, level 2 or alternatively, level 3 of the ASTM F2100 Standard Specification, may comprise an outward-facing spunbond layer, a meltblown middle layer, and an inward-facing spunbond layer. It was found that this configuration was able to achieve the performance requirements for level 3 ASTM F2100 Standard Specification. The overall construction of the masks can be reduced in weight and therefore, in cost. Additionally, with two layers of meltblown, the barrier properties of one layer can be varied in relation to the other. This allows for a more optimal construction of the mask which results in exceeding the minimum performance requirements of the mask. Suitable 4-ply disposable, compostable masks configured to pass level 1 or alternative, level 2 or alternatively, level 3 of the ASTM F2100 Standard Specification, may comprise an outward-facing spunbond layer, two meltblown middle layers, and an inward-facing spunbond layer or alternatively, an outward-facing spunbond layer, a middle spunbond layer, a meltblown middle layer, and an inward-facing spunbond layer.
[0063] Samples of double-layer meltblown PLA textile and double-layer spunbond PLA textile were examined under a high-resolution large-chamber scanning electron microscope (SEM). Samples were prepared by gold sputtering, and then were examined with a JSM-IT700HR In TouchScope Field Emission SEM (Jeol USA Inc.).
[0064] It should be noted that the performance of the single-layer and double-layer meltblown PLA textiles may be improved by corona charging of the meltblown PLA textiles with forward/reverse charging with negative ions. The corona charging process creates an electrostatic charge on the fibers of the meltblown textile and is used to increase the filtration efficiency of the media while allowing the pressure drop through the media to remain within the ASTM F2100 Standard Specification performance requirements of the mask specification. Corona charging typically takes place in the production environment using ambient air around the manufacturing site. Charging for typical filtration media utilizes negative corona charging ions (typically 30 kV-100 kV DC potential) and is applied to both surfaces of the filter media during production. An example of a suitable final charging process for a meltblown textile may be 30 kV top side, 30 kV bottom side, +60 kV top side. However, those skilled in these arts will know how to vary the process to obtain their desired results.
[0065] It should be noted that the hydrophobicity of the spunbond and meltblown PLA textiles may be increased by incorporation of selected additives during production of the textiles to modify the surface charge of the fibers and/or to modify the surface structure of the fibers. Some additives such as metallic soaps may bloom to the surface of the fibers during processing and thereby create a waxy coating that will increase the hydrophobicity of the textile. Other additives may include depositing nanospheres onto the fiber surfaces to thereby modify their surface structures and to increase their hydrophobic properties.
[0066] The pore size distributions in a single-layer meltblown PLA textile (
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[0068] Multivariable correlation analyses were done with 192 4-ply masks configured with an outward-facing spunbond layer, a middle spunbond layer, a meltblown middle layer, and an inward-facing spunbond layer (
[0069] The effects of different methods of corona charging on the hydrophobicity of a single-layer meltblown PLA textile were assessed with the ASTM F1862 Standard Test Method for Resistance of Medical Face Masks to Penetration by Synthetic Blood (Horizontal Projection of Fixed Volume at a Known Velocity) using a sessile drop test to measure the apparent contact angles and are shown in
[0074] The apparent contact angles determined with the sessile drop test, are measured between the tangent to the liquid-fluid interface and the solid surfaces of the of single-layer meltblown PLA textile treated with different corona charging processes. Assessment of the images
[0075] According to some embodiments of the present disclosure, the dimensions of the disposable, compostable, pleated surgical/medical masks at this according to this disclosure, may have a length selected from a range of about 12 cm to about 21 cm and therebetween, and a width selected from a range of about 6 cm to about 13 cm. The disposable, compostable, pleated surgical/medical masks disclosed herein suitable for use by toddlers and young children from the ages of 2 yrs old to 6 yrs old, may have a length selected from a range of about 12 cm to about 14 cm and a width selected from a range of about 6 cm to about 8 cm. The disposable, compostable, pleated surgical/medical masks disclosed herein suitable for use by children and young juveniles from the ages of about 6 yrs old to about 14 yrs old, may have a length selected from a range of about 13 cm to about 16 cm and a width selected from a range of about 7 cm to about 9 cm. The disposable, compostable, pleated surgical/medical masks disclosed herein suitable for use by young adults and adults, may have a length selected from a range of about 15 cm to about 21 cm and a width selected from a range of about 9 cm to about 13 cm. Particularly suitable dimensions for disposable, compostable, pleated surgical/medical masks disclosed herein for adults may have a length of about 17.5 cm and a width of about 10 cm.
[0076] A disposable, compostable, pleated surgical/medical mask configured as disclosed herein, may be easily mounted by a user onto their face and secured in place, by simply unfolding the pleats to form a 3-dimensional structure as shown in
[0077] Another advantage of the disposable, compostable, pleated surgical/medical masks disclosed herein, comprising PLA textiles, deformable nosebars, and soft-resilient PLA ear loops is that they can be simply and easily disposed by composting. For example, used disposed compostable masks configured as disclosed herein, may be collected in bulk and then conveyed to a composting site.
[0078] The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.
[0079] Note that in the specification and claims, about or approximately means within twenty percent (20%) of the numerical amount cited.
[0080] As used herein a, an, said or the means one or more unless otherwise indicated.
[0081] Although the invention has been described in detail with particular reference to these embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference.