Improved ventilation piece

Abstract

A vent is provided that includes a film and a first layer disposed on a first side of the film, the first layer defining an aperture such that the film is exposed through the aperture, the aperture having a primary dimension and a secondary dimension, where the film has a machine direction and a transverse direction, and the primary dimension of the aperture of the first layer is oriented at an angle of less than 90 degrees with respect to the machine direction of the film.

Description

Technical Field

[0001] This disclosure relates to the field of acoustic ventilation components, and more specifically to improved acoustic ventilation components and electronic devices including such ventilation components. Background Technology

[0002] Electronic devices that include acoustic transducers such as speakers and microphones typically include vents or vent assemblies that protect these transducers from contaminants such as particulate matter or liquids. These vents or vent assemblies usually shield openings in the housing of the electronic device through which sound is transmitted from the speaker or microphone, respectively.

[0003] The materials used to construct ventilation components or ventilation assembly need to resist the passage of particulate matter and liquids, especially liquid water, while also maximizing the propagation of sound through them.

[0004] However, it has been found that typical materials that meet these stringent requirements are sometimes prone to wrinkling of the membrane during manufacturing or assembly. This wrinkling can affect the acoustic properties of the membrane and also the visual appearance of the ventilation components and any devices on which they are installed.

[0005] Therefore, there is still a need for improved ventilation components and ventilation assemblies with improved acoustic performance and improved visual appearance.

[0006] This disclosure is intended, at least in part, to address at least one of these problems. Summary of the Invention

[0007] According to a first aspect, a ventilation element is provided, comprising a membrane and a first layer disposed on a first side of the membrane, the first layer defining an aperture through which the membrane is exposed, the aperture having a primary dimension and a secondary dimension, wherein the membrane has a machine orientation and a transverse orientation, and the primary dimension of the aperture of the first layer is oriented less than 90 degrees relative to the machine orientation of the membrane.

[0008] As used herein, the term "machine orientation" refers to the dominant dimension along which the membrane is processed during the manufacture of the ventilation component. For example, machine orientation can be the direction in which the membrane is removed from the roll and passes through rollers during ventilation component manufacturing. The term "lateral orientation" as used herein refers to a direction or dimension that is 90 degrees from the machine orientation.

[0009] Typically, as measured using the methods described herein, the machine orientation corresponds to the dimension of the membrane with the highest stiffness. Therefore, the machine orientation of the membrane can be extended along the rigid dimension of the membrane.

[0010] The membrane can be an expansion membrane.

[0011] The membrane may include fibrous materials. Therefore, the membrane may include materials comprising fibrous microstructures. The fibers may be interconnected at nodes, thus the microstructure can be a node-and-fiber structure.

[0012] The membrane comprises materials selected from the group consisting of: polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), polyvinylidene fluoride (PVDF), polyethylene (PE), polyether ketone ketone (PEKK), polyether ether ketone (PEEK), poly(tetramethyl-p-silylphenylene siloxane) (PTMPS), polydimethylsiloxane (PDMS), poly(p-xylene) (PPX), polyamide 6, polyurethane, thermoplastic polyurethane, polypropylene, polyimide (PI), or polyacrylonitrile (PAN), or combinations thereof.

[0013] In some embodiments, the membrane may include a material selected from the group consisting of PTFE, PE, PI, or PEKK.

[0014] In examples where the membrane includes an expanding material, the expanding material may be selected from the group consisting of: expanded PTFE (ePTFE), expanded FEP (eFEP), expanded PVDF (ePVDF), expanded polyethylene (ePE), expanded PEKK (ePEKK), expanded PEEK (ePEEK), expanded PTMPS (ePTMPS), expanded polydimethylsiloxane (ePDMS), expanded PPX (ePPX), expanded polyamide 6, expanded polyurethane, expanded thermoplastic polyurethane, expanded polypropylene, expanded polyimide, or expanded polyacrylonitrile (PAN), or combinations thereof.

[0015] The membrane may include an expansion material selected from the group consisting of ePTFE, ePE, or ePEKK.

[0016] Typically, the hole has an elongated shape, with a first dimension larger than a second dimension orthogonal to it. The primary dimension of the hole can be the first dimension, and the secondary dimension can be the second dimension. Therefore, the hole can have an aspect ratio (“AR”) greater than 1.

[0017] The hole can have a regular shape. The hole can have at least one plane of symmetry. The hole can have a principal axis extending along at least one plane of symmetry. The principal dimension can extend along the principal axis. The hole can have a second plane of symmetry. The hole can have a secondary axis extending along the second plane of symmetry. The secondary dimension can extend along the secondary axis. The hole can have a shape selected from ellipse, stadium, trapezoid, or rectangle. A stadium shape can also be called a lozenge. The hole can have a shape with two orthogonal planes of symmetry. For example, the hole can have a shape selected from an elongated hexagon or an elongated octagon.

[0018] The hole can have an irregular shape. For example, the hole can be generally elliptical, stadium-shaped, trapezoidal, or rectangular, but its edges can be serrated or irregular.

[0019] In some examples, the main size of the aperture can be oriented at an angle of less than 45 degrees relative to the machine orientation of the membrane. The main size of the aperture can be oriented at an angle of less than 25 degrees relative to the machine orientation of the membrane. The main size of the aperture can be oriented at an angle of less than 10 degrees relative to the machine orientation of the membrane.

[0020] The main dimension of the aperture can be oriented at an angle from 0 to 89 degrees relative to the membrane's machine orientation. The main dimension of the aperture can be oriented at an angle from 0 to 45 degrees relative to the membrane's machine orientation. The main dimension of the aperture can be oriented at an angle from 0 to 30 degrees relative to the membrane's machine orientation. The main dimension of the aperture can be oriented at an angle from 0 to 20 degrees relative to the membrane's machine orientation. The main dimension of the aperture can be oriented at an angle from 0 to 10 degrees relative to the membrane's machine orientation. The main dimension of the aperture can be oriented at an angle from 0 to 5 degrees relative to the membrane's machine orientation.

[0021] To avoid ambiguity, the range provided above is intended to include the endpoints of the range.

[0022] The main dimensions of the aperture can be oriented substantially parallel to the machine orientation of the membrane. That is, the main dimensions of the aperture can be oriented at an angle of 0 degrees or 0 to 2 degrees relative to the machine orientation of the membrane.

[0023] In some examples, the hole can have an aspect ratio (AR) greater than 1 (major dimension to minor dimension). The hole can have an AR greater than 1.1. The hole can have an AR greater than 1.2. The hole can have an AR greater than 1.4.

[0024] The hole can have an AR of 1.1 to 3.0. The hole can have an AR of 1.2 to 1.9. The hole can have an AR of 1.2 to 1.7.

[0025] To avoid ambiguity, a hole with AR of 1 has a "major" dimension equal to the "minor" dimension. In other words, all dimensions of a hole with AR of 1 are equal. For example, a hole with AR of 1 can be circular or square. The terms "major" and "minor" are used for comparison purposes and are given their standard meaning for holes with AR greater than 1.

[0026] The first layer may include an adhesive material. The first layer may include a pressure-sensitive adhesive. The first layer may include an acrylic adhesive. The first layer may include a heat-activated film adhesive. The first layer may include a polymeric material, such as rubber. The first layer may include a rubber gasket. The first layer may include a layer configured to constrain the film to the first layer, for example, at the boundary of an aperture. In this context, "constraint" can be understood to include at least the following methods: clamping, pinning, and bonding. The first layer may include an adhesive supported on a film support. The film support may include polyester.

[0027] In some examples, the vent may include a second layer disposed on a second side of the membrane. The second side of the membrane may be on the side opposite to the first side of the membrane. The second layer may define an aperture through which the membrane is exposed. The aperture may have a primary dimension and a secondary dimension. The primary dimension of the aperture in the second layer may be substantially aligned with the primary dimension of the aperture in the first layer. The aperture defined by the second layer may have the same shape as the aperture defined by the first layer. The aperture defined by the second layer may have the same size as the aperture defined by the first layer.

[0028] The second layer may include an adhesive material. The second layer may include a cured adhesive material. The second layer may include a pressure-sensitive adhesive. The second layer may include an acrylic adhesive. The second layer may include an adhesive supported on a film support. The second layer may include a polyester film.

[0029] The ventilation component of this invention is less prone to wrinkling of the ventilation membrane. The ventilation component of this invention can substantially resist wrinkling of the ventilation membrane. During manufacturing, the membrane can substantially resist wrinkling. During use, the membrane can substantially resist wrinkling. For example, when the ventilation component is installed inside the housing of an electronic device, the membrane can substantially resist wrinkling during use.

[0030] As used herein, the term "wrinkling" refers to membrane deformation, which includes undulations within the pore defined by a first pore, and, where a second pore is present, undulations within the pore defined by a second pore. Therefore, a "wrinkled" membrane comprises a series of peaks and troughs (or "ripples"), and the degree of wrinkling or "wavyness" of the membrane can be characterized by measuring the average peak height (Wc) of the membrane undulations and the root mean square height (Wq) of these undulations. Larger Wc or Wq values ​​correspond to membranes with higher wrinkling / greater wavyness, while smaller Wc or Wq values ​​correspond to membranes with lower wrinkling / less wavyness.

[0031] Using the method described herein, the membrane can have at least a reduced average peak height (Wc) compared to a ventilator whose main dimension is oriented 90 degrees relative to the machine direction of the membrane.

[0032] The Wc of this membrane can be smaller than the Wc of a membrane in a ventilation device having orifices with an aspect ratio of 1. The Wc of this membrane can be smaller than the Wc of a membrane in a ventilation device having orifices with the same cross-sectional area and an aspect ratio of 1.

[0033] The membrane can have a Wc of less than 1.5 µm. The membrane can have a Wc of less than 1.2 µm. The membrane can have a Wc of less than 1 µm.

[0034] Compared to a ventilator membrane whose main dimensions are oriented 90 degrees relative to the machine orientation of the membrane, as measured using the method described herein, this membrane can have at least a reduced root mean square height (Wq).

[0035] The membrane can have a smaller Wq than the membrane of a ventilator with orifices having an aspect ratio of 1. The membrane can have a smaller Wq than the membrane of a ventilator with orifices having the same cross-sectional area and an aspect ratio of 1.

[0036] The membrane can have an improved sound pressure level (SPL, dB), as measured using the methods described herein. The membrane can have an SPL greater than that of a membrane with an aperture of the same cross-sectional area and an aspect ratio of 1, as measured using the methods described herein. The membrane can have an SPL greater than that of a membrane with an aperture of the same cross-sectional area and an aspect ratio of 1 in the frequency range of 100 Hz to and including 20 kHz, as measured using the methods described herein. The membrane can have an SPL greater than that of a membrane with an aperture of the same cross-sectional area and an aspect ratio of 1 at a frequency of 1 kHz, as measured using the methods described herein. The membrane can have an SPL greater than that of a membrane with an aperture of the same cross-sectional area and an aspect ratio of 1 in the frequency range of 100 Hz to 2.5 kHz, as measured using the methods described herein. The membrane can have a higher SPL (Spectrum of Particle Size) than a membrane with an aperture of the same cross-sectional area and an aspect ratio of 1 in the frequency range of 100 Hz to 2 kHz, as measured using the methods described herein. The membrane can have a higher SPL than a membrane with an aperture of the same cross-sectional area and an aspect ratio of 1 in the frequency range of 100 Hz to 10 kHz, as measured using the methods described herein. The membrane can have a higher SPL than a membrane with an aperture of the same cross-sectional area and an aspect ratio of 1 in the frequency range of 100 Hz to 5 kHz, as measured using the methods described herein. The membrane can have a higher SPL than a membrane with an aperture of the same cross-sectional area and an aspect ratio of 1 in the frequency range of 100 Hz to 1 kHz, as measured using the methods described herein. The membrane can have a higher SPL than a membrane with an aperture of the same cross-sectional area and an aspect ratio of 1 in the frequency range of 500 Hz to 10 kHz, as measured using the methods described herein. The membrane can have a higher SPL (Spectral Power Per Dimension) than a membrane with an orifice of the same cross-sectional area and an aspect ratio of 1 in the frequency range of 100 Hz to 2 kHz, as measured using the methods described herein. The membrane can have a higher SPL than a membrane with an orifice of the same cross-sectional area and an aspect ratio of 1 in the frequency range of 100 Hz to 1.5 kHz, as measured using the methods described herein. The membrane can have a higher SPL than a membrane with an orifice of the same cross-sectional area and an aspect ratio of 1 in the frequency range of 500 Hz to 1 kHz, as measured using the methods described herein.

[0037] This membrane can have a higher SPL compared to a membrane whose machine orientation is 90 degrees relative to the main size of the aperture with the same aspect ratio. The difference in SPL can be calculated as SPL(0 degrees) minus SPL(90 degrees). This membrane can have an SPL at least 0.25 dB higher than a membrane whose machine orientation is 90 degrees relative to the main size of the aperture with the same aspect ratio. This membrane can have an SPL at least 0.5 dB higher than a membrane whose machine orientation is 90 degrees relative to the main size of the aperture with the same aspect ratio.

[0038] When measured at 1 kHz, this membrane can have an SPL at least 0.25 dB higher than a membrane whose machine orientation is oriented 90 degrees relative to the principal size of the aperture with the same aspect ratio. When measured at 1 kHz, this membrane can have an SPL at least 0.5 dB higher than a membrane whose machine orientation is oriented 90 degrees relative to the principal size of the aperture with the same aspect ratio.

[0039] When measured in the 100Hz to 10kHz range, this film can have an SPL at least 0.25dB higher than a film whose machine orientation is oriented 90 degrees relative to the principal size of the aperture with the same aspect ratio. When measured in the 100Hz to 10kHz range, this film can have an SPL at least 0.5dB higher than a film whose machine orientation is oriented 90 degrees relative to the principal size of the aperture with the same aspect ratio.

[0040] Compared to a comparative ventilator having an aperture defined in the first layer with an aspect ratio of 1 for the major and minor dimensions, the membrane may have a percentage change in SPL of at least 0.1% (%δSPL), as measured using the methods described herein. Compared to a comparative ventilator having an aperture defined in the first layer with an aspect ratio of 1 for the major and minor dimensions, the membrane may have a percentage change in SPL of at least 0.2%, as measured using the methods described herein. Compared to a comparative ventilator having an aperture defined in the first layer with an aspect ratio of 1 for the major and minor dimensions, the membrane may have a percentage change in SPL of at least 0.3%, as measured using the methods described herein. Compared to a comparative ventilator having an aperture defined in the first layer with an aspect ratio of 1 for the major and minor dimensions, the membrane may have a percentage change in SPL of at least 0.4%, as measured using the methods described herein. Compared to a contrasting ventilator having orifices defined in the first layer with an aspect ratio of 1 for the primary to secondary dimensions, the membrane may have at least 0.5% %δSPL, as measured using the methods described herein.

[0041] The percentage change in SPL (%δSPL) can be calculated as follows: %δSPLAR=((SPLx-SPLAR1) / SPLAR1)x100, (1) SPLAR1 is the SPL measured for a membrane with orifices having an aspect ratio of 1, while SPLX is the SPL measured for the membrane in question at the same frequency and angle, with an aspect ratio AR > 1. Therefore, a positive %δSPLAR corresponds to an improvement in performance (i.e., the article in question has a higher SPL compared to a ventilator with orifices having an aspect ratio of 1 (AR1)), while a negative %δSPLAR corresponds to a decrease in performance.

[0042] This film exhibits improved %δSPLAR at 100 Hz. This film exhibits improved %δSPLAR at 500 Hz. This film exhibits improved %δSPLAR at 1 kHz. This film exhibits improved %δSPLAR at 2 kHz. This film exhibits improved %δSPLAR in the frequency range of 100 Hz to 2.5 kHz. This film exhibits improved %δSPLAR in the frequency range of 500 Hz to 2.5 kHz. This film exhibits improved %δSPLAR in the frequency range of 1 kHz to 2.5 kHz.

[0043] In a second aspect, a ventilation element is provided, comprising a membrane and a first layer disposed on a first side of the membrane, the first layer defining an aperture through which the membrane is exposed, the aperture having a primary dimension and a secondary dimension, wherein the membrane has a first dimension and a second dimension, the first dimension being orthogonal to the second dimension, and the membrane having a stiffness greater in the first dimension than in the second dimension, wherein the primary dimension of the aperture of the first layer is oriented at an angle of less than 90 degrees relative to the first dimension of the membrane.

[0044] This first direction typically corresponds to the machine direction defined in the first aspect above.

[0045] To avoid ambiguity, the optional features of the ventilation component in the first aspect are optional features of the second aspect, and the features in the first aspect corresponding to the machine direction of the membrane are applied to the first direction of the membrane in the second aspect.

[0046] In a third aspect, an electronic device is provided, comprising a housing, a ventilator as described in the first aspect, and an acoustic transducer, wherein the housing defines an aperture, and the ventilator transects the aperture such that the ventilator is positioned outside the housing and between the acoustic transducer.

[0047] An acoustic transducer can be a microphone or a speaker.

[0048] This electronic device can be a personal communication device.

[0049] According to the fourth aspect, a method for manufacturing a ventilation component according to the first or second aspect is provided, the method comprising the following steps: Provide one roll of film; Provide a first adhesive sheet defining multiple holes; A section of film unwound from the roll along the machine direction; A first adhesive sheet is applied to the film, such that multiple pores are oriented at an angle of less than 90 degrees relative to the machine direction, thereby forming a laminate; and The laminate is cut to form a ventilation element for the first or second aspect.

[0050] Typically, the holes in these multiple holes are elongated and have primary and secondary dimensions.

[0051] When the film is unwound, it can be stretched in the machine direction. The film and a first adhesive sheet can come into contact and be fed between a pair of rollers to form the laminate. Pressure can be applied to the film and the first adhesive sheet to form the laminate. The film of the ventilator formed by this method can have a strength direction corresponding to the machine direction. This strength direction can have a higher strength than the transverse direction that is right-angled or perpendicular to the machine direction or the strength direction.

[0052] The membrane of the ventilation component formed by the method of this aspect can have a higher Young's modulus in the machine direction than in the transverse direction. The membrane of the ventilation component formed by the method of this aspect can also have a higher tensile strength in the machine direction than in the transverse direction.

[0053] One hole in the adhesive sheet corresponds to the hole in the vent of the first aspect. For the avoidance of doubt, the characteristics of the hole in the first aspect are also the characteristics of the hole in the adhesive sheet of this aspect.

[0054] The membrane used in this aspect corresponds to the membrane of the ventilation component in the first aspect. For the avoidance of doubt, the characteristics of the membrane in the first aspect are the characteristics of the membrane in the method of this aspect.

[0055] The method may include the step of providing a second adhesive sheet defining a plurality of holes. The method may include the step of applying the second adhesive sheet onto the film such that the plurality of holes are oriented at an angle of less than 90 degrees relative to a machine direction, thereby forming a laminate. The step of applying the second adhesive sheet onto the film may be performed after the step of applying a first adhesive sheet onto the film. The step of applying the second adhesive sheet onto the film may be performed simultaneously with the step of applying the first adhesive sheet onto the film. The holes of the plurality of holes in the first adhesive sheet and the holes of the plurality of holes in the second adhesive sheet may be oriented at the same or substantially the same angle relative to the machine direction of the film.

[0056] Therefore, the laminate including the first adhesive sheet and the second adhesive sheet can be a sandwich laminate structure, wherein the film is disposed between the first adhesive sheet and the second adhesive sheet. Attached Figure Description

[0057] Embodiments of the invention will now be described by way of non-limiting example with reference to the accompanying drawings.

[0058] Figure 1 A top view of a ventilation component according to one embodiment, wherein the machine orientation (MD) of the membrane of the ventilation component is aligned with the main dimension of the orifice; Figure 2 A top view of a ventilation component according to an embodiment, wherein the machine orientation (MD) of the membrane of the ventilation component is perpendicular to the main dimension of the orifice; Figure 3 A top view of a ventilation component based on existing technology; Figure 4 : A side sectional view of an example ventilation component; Figure 5 : A side sectional view of an example ventilation component; Figure 6 A top view of a ventilation component according to an embodiment, wherein the machine orientation (MD) of the membrane of the ventilation component is aligned with the main dimension of the orifice; Figure 7 A top view of a ventilation component according to an embodiment, wherein the machine orientation (MD) of the membrane of the ventilation component is perpendicular to the main dimension of the orifice; Figure 8 For ventilation components with expanded polyethylene film and stadium-shaped holes with an aspect ratio of 1.2 to 2.1, the %δSPLAR curve in the range of 100 to 10000 Hz is given when the main size of the hole is 90 degrees or 0 degrees relative to the machine direction. Figure 9 For ventilation components with an expanded polyethylene film and rectangular holes with an aspect ratio of 1.2 to 2.1, the %δSPLAR curve in the range of 100 to 10000 Hz is given when the main size of the hole is 90 degrees or 0 degrees relative to the machine direction. Figure 10 The graphs show the root mean square height (Wq) of a ventilation component with an expanded polyethylene film and a stadium-shaped orifice with an aspect ratio of 1.2 to 2.1, when the main dimension of the orifice is 90 degrees (solid circle) or 0 degrees (hollow circle) relative to the machine direction; and the graphs also show the root mean square height (Wq) of a ventilation component with an expanded polyethylene film and a rectangular orifice with an aspect ratio of 1.2 to 2.1, when the main dimension of the orifice is 90 degrees or 0 degrees relative to the machine direction. Figure 11The graphs show the average peak height (Wc) of a ventilation component with an expanded polyethylene film and a stadium-shaped orifice with an aspect ratio of 1.2 to 2.1 when the main dimension of the orifice is 90 degrees (solid circle) or 0 degrees (hollow circle) relative to the machine direction; and the graphs show the average peak height (Wc) of a ventilation component with an expanded polyethylene film and a rectangular orifice with an aspect ratio of 1.2 to 2.1 when the main dimension of the orifice is 90 degrees or 0 degrees relative to the machine direction. Figure 12 : A graph of ΔSPL (0 degrees minus 90 degrees) for a ventilation component with an expanded polyethylene film and rectangular holes with an aspect ratio of 1.2 to 2.1; Figure 13 : A graph of ΔSPL (0 degrees minus 90 degrees) for a ventilation component with an expanded polyethylene film and stadium-shaped openings with an aspect ratio of 1.2 to 2.1; Figure 14 The graph shows the average peak height (Wc) of a ventilation component with an expanded polyethylene film and rectangular holes with an aspect ratio of 1.2 to 2.1 when the main dimension of the hole is 90 degrees or 0 degrees relative to the machine direction. Figure 15 The graph shows the root mean square height (Wq) of a ventilation component with an expanded polyethylene film and rectangular holes with an aspect ratio of 1.2 to 2.1 when the main dimension of the hole is 90 degrees or 0 degrees relative to the machine direction. Figure 16 For ventilation components with a dense polyethylene film and rectangular holes with aspect ratios of 1.7 and 2.1, the %δSPLAR curve in the range of 100 to 10000 Hz is given when the main size of the hole is 0 degrees relative to the machine direction. Figure 17 : For ventilation components with expanded polytetrafluoroethylene (ePTFE) membranes and rectangular orifices with aspect ratios of 1.2 to 2.1, the %δSPLAR curve in the range of 100 to 10000 Hz is given when the principal dimension of the orifice is 90 degrees or 0 degrees relative to the machine direction. Figure 18: A graph of Wq for a ventilation component with an ePTFE membrane and rectangular holes with an aspect ratio of 1.2 to 2.1, when the main dimension of the hole is 90 degrees or 0 degrees relative to the machine direction. Figure 19 : A graph of Wc for a ventilation component with an ePTFE membrane and rectangular holes with an aspect ratio of 1.2 to 2.1, when the main dimension of the hole is 90 degrees or 0 degrees relative to the machine direction. Figure 20 : A graph of ΔSPL (0 degrees minus 90 degrees) for a ventilation component with an expanded polytetrafluoroethylene membrane and rectangular holes with an aspect ratio of 1.2 to 2.1; Figure 21 : For ventilation components with expanded polytetrafluoroethylene (ePTFE) membranes and rectangular orifices with aspect ratios of 1.2 to 2.1, the %δSPLAR curve in the range of 100 to 10000 Hz is given when the principal dimension of the orifice is 90 degrees or 0 degrees relative to the machine direction. Figure 22 : A graph of ΔSPL (0 degrees minus 90 degrees) for a ventilation component with an expanded polytetrafluoroethylene membrane and rectangular holes with an aspect ratio of 1.2 to 2.1; Figure 23 : A graph of Wc for a ventilation component with an ePTFE membrane and rectangular holes with an aspect ratio of 1.2 to 2.1, when the main dimension of the hole is 90 degrees or 0 degrees relative to the machine direction. Figure 24 : A graph of Wq for a ventilation component with an ePTFE membrane and rectangular holes with an aspect ratio of 1.2 to 2.1, when the main dimension of the hole is 90 degrees or 0 degrees relative to the machine direction. Figure 25 For a ventilation component with a PEKK membrane and rectangular holes with an aspect ratio of 1.2 to 2.1, the %δSPLAR curve in the range of 100 to 10000 Hz is given when the main dimension of the hole is 90 degrees or 0 degrees relative to the machine direction. Figure 26 : A graph of ΔSPL (0 degrees minus 90 degrees) for a ventilation component with a PEKK membrane and rectangular holes with an aspect ratio of 1.2 to 2.1; Figure 27 : A schematic side view of a pressure roller used to laminate an adhesive layer including multiple holes onto a film; Figure 28 The vibration measurement scan image shows the operational flexural shape of the high-frequency modal vibration of the (3,1) split mode pair for a rectangular hole with the machine orientation perpendicular to the main size of the hole; Figure 29 The vibration measurement scan image shows the operational flexural shape of the high-frequency modal vibration of a (3,1) split mode pair for a rectangular hole with the machine orientation parallel to the main size of the hole (at 0 degrees). Figure 30 The vibration measurement scan image shows the operational flexural shape of the high-frequency modal vibration for the (1,1) split mode pair of a circular aperture; Figure 31 : A schematic diagram of an exemplary stadium-shaped ventilation component with the dimensions indicated; Figure 32 : A schematic diagram of an exemplary rectangular ventilation component with the dimensions indicated; Figure 33 : A graph showing the ΔSPL curve for a ventilation component with an expanded polyethylene membrane and rectangular orifices having an aspect ratio of 1.2 to 2.1, within different angular ranges of the orifice's principal dimension relative to the membrane's machine orientation; and Figure 34 : A graph of ΔSPL for a ventilator with an electrospun polyimide membrane and rectangular holes with an aspect ratio of 1.2 to 2.1, over different angular ranges of the main size of the hole relative to the machine orientation / rigidity of the membrane. Detailed Implementation

[0059] Although various embodiments of the invention are discussed in detail below regarding their manufacture and use, it should be understood that the invention provides many applicable concepts that can be implemented in various specific contexts. The specific embodiments discussed herein are merely illustrative of particular ways of making and using the invention and do not define the scope of the invention.

[0060] To facilitate understanding of the invention, several terms are defined below. The terms defined herein have meanings as commonly understood by one of ordinary skill in the art related to this invention. Terms such as “a,” “an,” and “the” are not intended to refer to a single entity, but rather to encompass general categories that can be illustrated using specific examples thereof. The terms used herein are used to describe specific embodiments of the invention, but their use does not define the scope of the invention unless set forth in the claims.

[0061] Test methods

[0062] Measurement methods of Wc and Wq

[0063] Optical microscopic images were acquired at 80× magnification using a Keyence VR-3000 one-click 3D measurement microscope. Before evaluating waviness, the image files were post-processed and leveled (correcting any tilt of the sample relative to the stage) using the VR-3000 series analysis software. To evaluate waviness, the [Line R] function button was selected from the toolbar, and the measurement type was set to waviness. A two-point profile was drawn vertically, its span covering the entire length of the film. The cutoff filter value was set to the default value (none), and the evaluation length of the two-point vertical profile was automatically set by the Keyence post-processing software. Subsequently, the software automatically calculated the waviness parameters of interest, namely the average waviness height Wc and the root mean square waviness height Wq. The Keyence analysis software calculated the roughness and waviness parameters according to ISO 4287:1997 "Surface roughness—definitions".

[0064] Measurement method for the orientation of the membrane machine relative to the principal size of the pore

[0065] An adhesive template pre-made in AutoCAD is used to control the angle between the membrane's machine orientation and the main aperture size. This template is laser-cut with predefined aperture sizes, orientation angles, and aspect ratios. The membrane is then placed (in...) Figure 27 (Illustrated schematically) The unwinding rollers of a small laminating machine are fed between two pressure rollers. An adhesive template with a pre-cut inner diameter shape is inserted parallel to the film into the pressure rollers, and the two are laminated together. Another identical pre-cut template is placed on top of the film already laminated to the lower template to form a fixed component, with the film sandwiched between two layers of pressure-sensitive adhesive. A feed tray is used before the pressure rollers to maintain the alignment between the main axis of the hole in the template and the unwinding direction of the film as the two pass through the pressure rollers and are laminated. The orientation angle between the machine orientation of the polymer and the main dimension of the hole in the finished product is confirmed / measured by scanning laser Doppler vibration measurement.

[0066] Vibration measurement is used to visualize the vibrational modal shape of the inner membrane of a ventilation component, which can then be used to identify the orientation of the stiffest dimensional direction (typically the machine direction) in the polymer. For example, the machine direction of a polymer with a rectangular aperture is always orthogonal to the nodal lines of a high-frequency split mode pair (e.g., the (3,1) mode), as shown in example images. Figure 28 and Figure 29 As shown. For circular and rhomboid / stadium-shaped holes, nodal lines of high-frequency (1,1) vibration modes can be used, such as, for example... Figure 30 As shown.

[0067] for Figure 28 and Figure 29 In the example shown, the main dimensions of the holes in both cases are horizontal. However, Figure 28 The modal node lines extend horizontally, while Figure 29The modal node lines extend vertically. Therefore, the angle between the principal dimension of the hole and the machine direction is 90 degrees. For Figure 29 In this example, the angle between the main dimension of the aperture and the machine orientation is 0 degrees. In other words, the machine orientation of the membrane is aligned with the main dimension of the aperture.

[0068] Methods for measuring sound pressure level

[0069] The sound pressure level (SPL) of the example ventilation component is obtained by detecting it after an acoustic test signal passes through the ventilation component.

[0070] The acoustic response of the samples was measured in dB using a MEMS microphone fixture placed 6.5 cm from the internal speaker within a Bruel & Kjaer 4232 anechoic chamber. Output response curves were recorded using SoundCheck 5.0 software and AmpConnect hardware (both commercially available from Listen). A calibration sequence was generated using an SCM-3 reference microphone (Listen) and a calibrator (Bruel & Kjaer) before sample measurement. A sample fixture was designed to hold and secure the sample to be tested. The speaker performed a frequency sweep at a sound pressure level of 94 dB within a frequency range of 100 Hz to 10 kHz. The aforementioned measuring microphone measured the acoustic response as a sound pressure level in decibels within this frequency range. Typically, the dB SPL value at a given frequency can be compared to a predetermined baseline signal measured at the same 94 dB reference level without the sample, or to another sample prepared at a different angle or aspect ratio. At a given frequency, a larger dB SPL value corresponds to better acoustic performance.

[0071] General Example

[0072] See Figure 1 and Figure 4 The ventilation component 1 includes a membrane 2 and a first adhesive layer 4 (as a first layer), the first adhesive layer 4 defining an aperture 6 having a stadium shape. The aperture 6 has a primary dimension 8 and a secondary dimension 10. The membrane 2 is made of foamed polyethylene, and the machine orientation (MD) of the membrane 2 is parallel to the primary dimension 8 of the aperture 6. The first adhesive layer 4 includes a pressure-sensitive acrylic adhesive.

[0073] See Figure 2 The comparative ventilation element 20 includes a membrane 22 and a first adhesive layer 24 defining an opening 26 having a stadium shape. The opening 26 has a primary dimension 28 and a secondary dimension 30. The membrane 22 is composed of foamed polyethylene, and the machine orientation (MD) of the membrane 22 is perpendicular to the primary dimension 28 of the opening 26. The first adhesive layer 24 comprises a pressure-sensitive acrylic adhesive. See also... Figure 3The standard ventilation component 40 includes a membrane 42 and a first adhesive layer 44 (as a first layer), the first adhesive layer 44 defining an aperture 46 having a circular cross-sectional shape. Therefore, the aperture 46 has a diameter of 48 and an aspect ratio of 1 (i.e., the width dimension is equal to the length dimension). The membrane 42 comprises foamed polyethylene. The first adhesive layer 44 comprises a pressure-sensitive acrylic adhesive.

[0074] Figure 5 The cross-section of the alternative ventilation element 50 is shown, which corresponds to Figure 1 The example features a second adhesive layer 52 (as a second layer) provided on the second side of the membrane 2, which defines a hole 54, the shape and size of which are the same as those of the hole 6 defined in the first adhesive layer 4.

[0075] See Figure 6 The ventilation component 60 includes a membrane 62 and a first adhesive layer 64 (as a first layer) defining an orifice 66 having a rectangular shape. The orifice 66 has a primary dimension 68 and a secondary dimension 70. The membrane 62 comprises ePTFE, and the machine orientation (MD) of the membrane 62 is oriented parallel to the primary dimension 68 of the orifice 66. The first adhesive layer 64 comprises a pressure-sensitive acrylic adhesive.

[0076] See Figure 7 The comparative ventilator 80 includes a membrane 82 and a first adhesive layer 84 (as a first layer) defining an orifice 86 having a rectangular shape. The orifice 86 has a primary dimension 88 and a secondary dimension 90. The membrane 82 is made of ePTFE, and the machine orientation (MD) of the membrane 82 is oriented perpendicular to the primary dimension 88 of the orifice 86. The first adhesive layer 84 comprises a pressure-sensitive acrylic adhesive.

[0077] According to the exemplary method (100) for preparing a ventilation component disclosed herein, by Figure 27 A schematic diagram is shown. A first adhesive sheet 110 is provided as a template, in which holes 112 are defined. The first adhesive sheet 110 is formed of a double-sided pressure-sensitive adhesive sheet. In this example, the first adhesive sheet is 2 feet long and 4 inches wide. The specific adhesives used in each example are described in detail below. One side of the adhesive pad is removed and adhered to a low-tack PET release liner of similar size and 165 μm thickness. A drawing is created in AutoCAD that specifies the dimensions, shape, and orientation angles of the array of acoustic ventilation components to be cut. The AutoCAD drawing is then loaded into the laser control software, and the adhesive sheet is placed inside the laser processing cavity for cutting. This first round of cutting cuts out the effective area or interior of the component.

[0078] Next, the final release liner is removed from the adhesive sheet 110, and the adhesive sheet 100 is loaded into the feed tray 120 of the small laminator.

[0079] The first adhesive sheet 110 is inserted into the feed tray 120 and supplied to a pair of pressure rollers 130 (in the direction shown by arrow 115). The first adhesive sheet 110 can be oriented as needed to provide the required orientation of the holes 112 for forming the ventilation element of this disclosure (e.g., as described above in conjunction with...). Figures 1 to 7 As discussed.

[0080] Method 100 includes providing a roll of film 150 and unwinding a section of film 155 from the roll of film 150 in the machine direction MD. The section of film 155 is also fed to a pressure roller 130, where the film 155 contacts a first adhesive sheet 110, forming a laminate 160 at an output 140 from the pressure roller 130. A feed tray 110 aligns the first adhesive sheet with the film 155, which is placed on an unwind roller and fed into the pressure roller 130, where the film 155 is laminated onto the adhesive sheet 110. The resulting laminate 160 is then cut to form a ventilator according to the present disclosure, wherein a hole 112 in the first adhesive sheet 110 corresponds to a hole in the ventilator.

[0081] A second adhesive sheet can be provided to form such as Figure 5 The second adhesive layer 54 is shown. The second adhesive sheet can also be supplied to the pressure roller 130 and contact the section of film 155, such that film 155 is sandwiched between the first adhesive sheet 110 and the second adhesive sheet. The resulting laminate can be cut to form... Figure 5 50 ventilation components.

[0082] With two adhesive layers provided, the second adhesive layer (e.g., a 4-inch × 24-inch double-sided adhesive sheet) is adhered to a 5 μm thick PET layer (4 inches × 24 inches) and loaded into a laser processing chamber for cutting. Once cutting is complete, this layer is placed on top of a laminate 160 (i.e., film 155, which has been laminated to a first adhesive sheet 110 with pre-cut holes 112) to form a captive layer. The final stack assembly of the laminate 160 and the second adhesive sheet is loaded back into the laser, which performs the final cutting on the individual components in the array. Die-cutting can be used instead of laser cutting, and is used in Example 16 below.

[0083] The laminate structure of all finished components (including the low-tack liner underneath the component) is: 165μm thick low-tack PET release liner / double-sided adhesive / film / double-sided adhesive / 50μm thick PET.

[0084] Individual components are removed from the release liner and carefully adhered to a pre-cut FR4 specimen with a matching effective area and aspect ratio. For example, a rectangular component with an aspect ratio AR=1.7 is adhered to an FR4 specimen pre-cut with a rectangular opening at the center matching AR=1.7. A circular component with AR=1 is adhered to an FR4 specimen pre-cut with a circular opening of AR=1. The FR4 is commercially available from McMaster Carr (product number #1331T37) and laser-cut into specimens. The specimen is 381 μm thick and is used, for example, as a platform for mounting samples in acoustic testing.

[0085] Material

[0086] Figures 8 to 13 Analysis of ventilation components comprising Examples 1 to 12, including foamed polyethylene films, is shown. The method for preparing the polyethylene film is not particularly limited; any method known in the art may be used as long as the film possesses the desired properties. One method known in the art for producing porous polyethylene films is by a wet or gel process. In this process, polyethylene is mixed with a hydrocarbon liquid and other additives. The mixture is heated above the temperature at which the polymer melts and extruded into a sheet. The sheet can then be biaxially oriented before and / or after the extraction of the hydrocarbon liquid, thereby producing a microporous membrane. Various process details are known, such as those disclosed in US 5,248,461; US ​​4,873,034; US 5,051,183; and US 6,566,012; each of which is incorporated herein by reference in its entirety. Additional discussions include Casting and stretching of filled and unfilled UHMW-polyethylene films, Ir. FH Assinck, Centre for Polymers and Composites, Eindhoven University of Technology, November 1995; and Porous Biaxially, drawn UHMWPE Films, HM Fortuin, DSM Research BV, Department of Materials Technology – 5th International Conference on Environmental Ergonomics.

[0087] The polyethylene film disclosed herein can be prepared by a “gel process” for producing dense polyethylene films, a process described in numerous documents such as US 4,948,544. For example, the polyethylene film can be formed by: dissolving a polyethylene polymer in a solvent to form a solution; shaping the solution into a strip or sheet at a temperature above the dissolution temperature of the polyethylene polymer; cooling the strip or sheet to a temperature below the dissolution temperature to gel the strip or sheet; removing the solvent from the gelled strip or sheet; and biaxially stretching the gelled strip or sheet at a temperature above the melting temperature to form a dense polyethylene film.

[0088] According to the supplier, the molecular weight of the starting resin used to prepare the membrane is 4,300,000 g / mol. The membranes obtained in Examples 1 to 12 have a surface area mass of 2.63 g / m², a gas flow rate of 4.9 L / hr at 12 mbar and 2.99 cm², a thickness of 9.6 μm, an ultimate tensile strength of 76 MPa in the first direction, and an ultimate tensile strength of 65 MPa in the second direction (orthogonal to the first direction). These properties are also listed in Table 1. According to the supplier, the molecular weight of the starting resin used to prepare this membrane is 4,300,000 g / mol.

[0089] Used to form Figures 8 to 13 The adhesive used in the ventilation components (Examples 1 to 12) analyzed in this paper is a pressure-sensitive adhesive purchased from Nitto Denko, part number: Nitto Denko No. 5605R.

[0090] Figure 14 and Figure 15 Analysis results are shown for ventilation components comprising Examples 14 to 19, which have the properties listed in Table 1 and are manufactured according to the same method described above for Examples 1 to 12. The membrane is a gel-treated ultra-high molecular weight polyethylene (UHMWPE) membrane with a basis weight of 3.65 g / m², an air flow rate of 4 L / hr at 12 mbar and 2.99 cm², a thickness of 12 μm, an ultimate tensile strength of 78.4 MPa in a first direction, and an ultimate tensile strength of 63.3 MPa in a second direction (orthogonal to the first direction), and is used as a precursor in this example. According to the supplier, the starting resin used to prepare the membrane has a molecular weight of 4,300,000 g / mol. [The text then abruptly shifts to a description of forming...] Figure 14 and Figure 15 The adhesive used in the ventilation components analyzed (Examples 14 to 19) is a pressure-sensitive adhesive purchased from NittoDenko, part number: NittoDenko No. 5605R.

[0091] Figure 16 Analysis results are shown for a ventilation component comprising a densified foamed polyethylene membrane formed in accordance with the teachings of US 4,948,544, which is incorporated herein by reference in its entirety. The membrane possesses the properties listed in Table 1. [The following appears to be a separate, unrelated section:] Used for forming... Figure 16 The adhesive used in the ventilation components analyzed was a pressure-sensitive adhesive purchased from Nitto Denko, part number: NittoDenko No. 5605BRN.

[0092] Figures 17 to 20 Analysis results are shown for ventilation components, Examples 20 to 25, comprising an expanded polytetrafluoroethylene (ePTFE) membrane, obtained from WL Gore & Associates, part number GAW344, and manufactured according to the teachings of US 3,953,566, which is incorporated herein by reference in its entirety. Used for forming Figures 17 to 20 The adhesive used in the analyzed ventilation components was a pressure-sensitive adhesive purchased from Tesa SE, part number: Tesa 4972. The performance of the membrane is shown in Table 1.

[0093] Figures 21 to 24 Analysis results are shown for ventilation components comprising Examples 26 to 31 of expanded polytetrafluoroethylene (ePTFE) membranes, obtained from WL Gore & Associates, part number GAW337, and manufactured according to the teachings of US 3,953,566, which is incorporated herein by reference in its entirety. Used for forming Figures 17 to 20 The adhesive used in the analyzed ventilation components was a pressure-sensitive adhesive purchased from Tesa SE, part number: Tesa 4972. The performance of the membrane is shown in Table 1.

[0094] Figure 25 and Figure 26 Examples include polyetherketoneketone (PEKK) material (NovaSpire™ PEKK AM), whose mechanical properties are shown in Table 1. This material is commercially available from Solvay Specialty Polymers. Used for forming Figure 25 and Figure 26 The adhesive used in the ventilation components analyzed was a pressure-sensitive adhesive purchased from Nitto Denko, part number: Nitto Denko No. 5605R.

[0095] Figure 34The ΔSPL results for an electrospun polyimide film are shown. This electrospun polyimide film was prepared as follows: A polycondensation reaction between a diamine monomer and a tetracarboxylic dianhydride was performed in a mechanically stirred reactor in a highly polar solvent. This process generated a copolymer polyimide spinning solution. Subsequently, the polymer solution was spun using an electrospinning apparatus, where a high voltage was applied to guide a jet at high speed toward another electrode, where a current collector was used to collect the fibers formed due to the force exerted on the electrospun solution. The spun mat was heat-treated to obtain an imidized copolymer polyimide mesh containing nanofibers.

[0096] The properties of the resulting polyimide nanofiber network are shown in Table 1 below.

[0097]

[0098] Table 1—The properties of the membranes used in the ventilation components of this disclosure example, listing: membrane material type, machine-direction Young's modulus (MD), transverse Young's modulus (TD), geometric mean modulus (abbreviated as GeoMean modulus) (which is calculated as the square root of the product of the Young's modulus along the polymer machine direction (MD) and the Young's modulus along the polymer transverse direction (TD): GeoMean modulus = √[(MD modulus) × (TD modulus)]), mass per unit area (MPa), thickness, and porosity.

[0099] Example

[0100] Table 2 compares the corrugation characteristics of example and comparative ventilators. The example ventilator includes an ePE membrane with its main dimensions oriented at 0 or 90 degrees relative to the machine direction, and has stadium-shaped orifices (Examples 2–6, denoted by L2 to L6 in the figures) or rectangular orifices (Examples 8–12, denoted by R2 to R6 in the figures). The comparative ventilator includes an ePE membrane with circular orifices (Example 1 (comparison), denoted by C1) and square orifices (Example 7 (comparison), denoted by S1). Dimensions according to the shape of the example ventilator are given in Table 6, using the same designations C1, S1, L2 to L6, and R2 to R6.

[0101] The parameters Wc and Wq are shown in Figure 10 and Figure 11 In the middle, the SPL data corresponding to these examples is shown in Figure 8 (%δSPLAR, Example 2–6) and Figure 9(%δSPLAR, Examples 8–12). As shown in the figure, compared to the vent with the main orifice oriented at 90 degrees relative to the machine orientation of the membrane (solid circle), the example with the main orifice oriented at 0 degrees relative to the machine orientation of the membrane (hollow circle) has both lower Wc and Wq parameters, indicating reduced membrane waviness or wrinkling, and a significantly improved percentage change in SPL relative to the comparative example with an aspect ratio of 1 (%δSPLAR).

[0102] ΔSPL (SPL0-SPL90) is shown in Figure 12 (Examples 8–12) and Figure 13 In (Examples 2–6), and compared to the 90-degree example, all examples with a machine orientation of 0 degrees relative to the main size of the hole showed a significant improvement in SPL.

[0103]

[0104] Table 3 – A comparison of the corrugation characteristics of an example ventilator and a comparative ventilator. The example ventilator includes an ePE membrane with its main dimensions oriented at 0 or 90 degrees relative to the machine direction of the membrane and has rectangular orifices (Examples 15–19). The comparative ventilator includes an ePE membrane with square orifices (Example 14 (Comparative)).

[0105] The parameters Wc and Wq are shown in Figure 14 (Wc) and Figure 15 In (Wq), it can be seen that, compared with the ventilator in which the main orifice size is oriented 90 degrees relative to the machine orientation of the membrane, the example in which the main orifice size is oriented 0 degrees relative to the machine orientation of the membrane has both lower Wc and Wq parameters, indicating that the membrane ripples or wrinkles are reduced.

[0106] The %δSPLAR of example ventilation components, including densely foamed polyethylene film and orifices with rectangular cross-sectional shapes (denoted by R4 and R6), is shown in [reference to image / image / data]. Figure 16 The data indicates that, compared to a ventilator with an aspect ratio of 1, orienting the main axis of the orifice relative to the machine direction of the membrane at 0 degrees improves the SPL of the ventilator.

[0107]

[0108] Table 4 – A comparison of the corrugation characteristics of an example ventilator and a comparative ventilator. The example ventilator includes an ePTFE membrane whose main dimensions are oriented at 0 or 90 degrees relative to the machine direction of the membrane and has rectangular orifices (Examples 21-25, denoted by R2 to R6). The comparative ventilator includes an ePTFE membrane and has square orifices (Example 20 (comparison), denoted by S1).

[0109] The data in Table 4 are shown below. Figure 18 and Figure 19 The example ventilator with the main orifice oriented at 0 degrees relative to the machine direction of the membrane is shown in the figure, compared to a ventilator with the main orifice oriented at 90 degrees relative to the machine direction of the membrane. This indicates that the membrane corrugation or wrinkling is reduced.

[0110] Furthermore, the %δSPLAR values ​​for these examples are shown in Figure 17 The example ventilator with a main orifice orientation of 0 degrees relative to the machine direction of the membrane is shown to have an improved %δSPLAR compared to a ventilator with the main orifice orientation of 90 degrees relative to the machine direction of the membrane.

[0111] ΔSPL (SPL0-SPL90) is shown in Figure 20 In addition, compared with the 90-degree example, all examples with a machine orientation of 0 degrees relative to the main size of the hole showed a significant improvement in SPL.

[0112]

[0113] Table 5 – A comparison of the corrugation characteristics of an example ventilator and a comparative ventilator. The example ventilator includes an ePTFE membrane whose main dimensions are oriented at 0 or 90 degrees relative to the machine direction of the membrane and has rectangular orifices (Examples 27-31, denoted by R2 to R6). The comparative ventilator includes an ePTFE membrane and has square orifices (Example 26 (comparison), denoted by S1).

[0114] The data in Table 5 are shown below. Figure 23 (Wc) and Figure 24 (Wq) shows an example ventilator with the main orifice oriented at 0 degrees relative to the machine direction of the membrane, compared to a ventilator with the main orifice oriented at 90 degrees relative to the machine direction of the membrane. This indicates that the membrane corrugation or wrinkling is reduced.

[0115] Furthermore, the %δSPLAR values ​​for these examples are shown in Figure 21 The example ventilator with the main orifice oriented at 0 degrees relative to the machine direction of the membrane is shown to have an improved %δSPLAR compared to a ventilator with the main orifice oriented at 90 degrees relative to the machine direction of the membrane.

[0116] ΔSPL (SPL0-SPL90) is shown in Figure 22 In addition, compared with the 90-degree example, all examples with a machine orientation of 0 degrees relative to the main size of the hole showed a significant improvement in SPL.

[0117] Furthermore, example ventilators, including PEKK membranes and orifices with rectangular cross-sectional shapes (corresponding to R2 to R6), also demonstrate that example ventilators with orifice main dimensions oriented 0 degrees relative to the membrane machine direction have an improved %δSPLAR compared to ventilators with orifice main dimensions oriented 90 degrees relative to the membrane machine direction. Figure 25 ).

[0118] ΔSPL (SPL0-SPL90) is shown in Figure 26 In addition, compared with the 90-degree example, all examples with a machine orientation of 0 degrees relative to the main size of the hole showed a significant improvement in SPL.

[0119] Table 6 lists the shapes and dimensions of the ventilation components in the examples and figures discussed above. Figure 31 and Figure 32 An exemplary ventilation component shape with relevant dimension markings is shown.

[0120] Figure 31 A schematic diagram of a stadium-shaped ventilation component with dimensions h, h', L, and L' is shown, where h = secondary axis dimension of the membrane, h' = secondary axis dimension of the ventilation component including the membrane and an adhesive boundary around the membrane, L = primary axis dimension of the membrane, and L' = primary axis dimension of the ventilation component including the membrane plus the adhesive boundary around the membrane. Furthermore, a stadium shape (or rhombus) is a rectangle with a base length and a top length of a, and both ends are closed by semicircles of radius r. The effective area of ​​this shape is calculated as πr² + 2ra. When a = 0, the membrane is circular. The adhesive wall width corresponds to (L' - L) / 2 = (h' - h) / 2. The relevant dimensions for C1 (circular ventilation component) and L2 to L6 (stadium-shaped ventilation components) are listed in Table 6.

[0121] Figure 32 An exemplary rectangular ventilator with dimensions A, A', B, and B' is shown, where A = the main axis of the membrane with rectangular holes, A' = the main axis of the ventilator with rectangular holes (ventilator = membrane + adhesive boundary surrounding the membrane), B = the secondary axis of the membrane with rectangular holes, and B' = the secondary axis of the ventilator with rectangular holes. A square boundary will exist when A = B. The adhesive wall width corresponds to (A' - A) / 2 = (B' - B) / 2. The effective area is calculated as AB. The relevant dimensions S1 (square ventilator) and R2 to R6 are shown in Table 6.

[0122]

[0123] Table 6 – Dimensions and specifications of ventilation component shapes according to examples of this disclosure.

[0124] Further examples use the same expanded polyethylene membrane as in Examples 1–12 in the ventilator, wherein the main dimensions of the ventilator are at angles of 0, 2, 5, 10, 20, 45, and 90° relative to the machine orientation of the membrane, and have rectangular orifices.

[0125] Figure 33 The following further examples are shown, with aspect ratios of 1.0 (i.e., square holes in the comparative ventilator) and ventilator holes of 1.2, 1.4, 1.7, 1.9 and 2.1, illustrating the effect of the angle of the ventilator's main dimension relative to the membrane's machine orientation on ΔSPL.

[0126] It can be seen that a significant increase in ΔSPL is observed at all angles between 0 and 45°.

[0127] Figure 34 The effect of the angle between the main dimension of the vent and the film dimension with the highest modulus on ΔSPL is shown for the electrospun polyimide film described in Table 1 above. It can be seen that the effect of ΔSPL is small for most aspect ratios, while a slight improvement is observed for the vent with an aspect ratio of 1.4.

[0128] While approved embodiments of the invention have been described above, it will be apparent that many and various changes and modifications in form, design, structure, and component arrangement can be made to other embodiments without departing from the invention, and it will be understood that all such changes and modifications are contemplated as embodiments of the invention as defined in the appended claims.

Claims

1. A vent comprising a membrane and a first layer disposed on a first side of the membrane, the first layer defining apertures such that the membrane is exposed through the apertures, the apertures having a major dimension and a minor dimension, wherein the membrane has a machine direction and a cross direction, and the major dimension of the apertures of the first layer is oriented at an angle of less than 90 degrees relative to the machine direction of the membrane.

2. The vent of claim 1, wherein, the major dimension of the apertures is oriented at an angle of less than 45 degrees relative to the machine direction of the membrane.

3. The vent of claim 2, wherein, the major dimension of the apertures is oriented at an angle of less than 25 degrees relative to the machine direction of the membrane.

4. The vent of claim 3, wherein, the major dimension of the apertures is oriented at an angle of less than 10 degrees relative to the machine direction of the membrane.

5. The vent of claim 4, wherein, the major dimension of the apertures is oriented such that it is substantially parallel to the machine direction of the membrane.

6. A vent according to any preceding claim, characterised in that, the aspect ratio of the major dimension to the minor dimension of the apertures is 1.1 to 3.

0.

7. The vent of claim 6, wherein, the aspect ratio of the major dimension to the minor dimension of the apertures is 1.2 to 1.

9.

8. The vent of claim 7, wherein, the aspect ratio of the major dimension to the minor dimension of the apertures is 1.2 to 1.

7.

9. A vent according to any preceding claim, characterised in that, the membrane is an expanded membrane.

10. A vent according to any preceding claim, characterised in that, the membrane comprises a fibrous material.

11. A vent according to any preceding claim, characterised in that, the membrane comprises a material selected from the group consisting of: polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), polyvinylidene fluoride (PVDF), polyethylene (PE), polyether ketone ketone (PEKK), polyether ether ketone (PEEK), poly(tetramethyl-p-phenylsilsesquioxane) (PTMPS), polydimethylsiloxane (PDMS), poly(p-xylylene) (PPX), polyamide 6, polyurethane, thermoplastic polyurethane, polypropylene, polyimide (PI), or polyacrylonitrile (PAN), or combinations thereof.

12. The vent of claim 11, wherein, the membrane comprises a material selected from the group consisting of: PTFE, PE, PI, or PEKK.

13. A vent according to any preceding claim, characterised in that, the first layer comprises an adhesive.

14. A vent according to any preceding claim, characterised in that, further comprising a second layer disposed on a second side of the membrane.

15. The vent of claim 14, wherein, the second layer defines apertures such that the membrane is exposed through the apertures.

16. The vent of claim 15, wherein, the apertures have a major dimension and a minor dimension, and the major dimension is aligned with the major dimension of the apertures of the first layer.

17. A vent according to any preceding claim, characterised in that, the membrane has at least a reduced wrinkling compared to a membrane of a vent having apertures with a major dimension oriented at 90 degrees relative to the machine direction of the membrane, the wrinkling measured by average peak height (Wc) and / or root mean square height (Wq) measured using the methods described herein.

18. A vent according to any preceding claim, characterised in that, the membrane has improved acoustic performance, the acoustic performance measured by sound pressure level (SPL, dB) measured using the methods described herein.

19. The vent of claim 18, wherein, the membrane has improved SPL compared to a comparative vent having apertures defined in a first layer with the same cross-sectional area and an aspect ratio of major dimension to minor dimension of 1.

20. The vent of claim 19, wherein, the percent change in SPL of the membrane is less than -0.1% relative to a comparative vent having apertures defined in a first layer with an aspect ratio of major dimension to minor dimension of 1, as measured using the methods described herein.

21. A vent comprising a membrane and a first layer disposed on a first side of the membrane, the first layer defining an aperture such that the membrane is exposed through the aperture, the aperture having a major dimension and a minor dimension, wherein, The membrane has a first dimension and a second dimension, the first dimension being orthogonal to the second dimension, and the membrane having greater stiffness in the first dimension than in the second dimension, wherein the principal dimension of the pores in the first layer is oriented at an angle of less than 90 degrees relative to the first dimension of the membrane.

22. An electronic device comprising a housing, a ventilator according to any of the preceding claims, and an acoustic transducer, the housing defining an aperture, and the ventilator spanning the aperture such that the ventilator is positioned outside the housing between the acoustic transducer and the acoustic transducer.

23. The electronic device of claim 22, wherein, The acoustic transducer is a microphone or a speaker.

24. A method for manufacturing a ventilation component according to any one of claims 1 to 21, the method comprising the following steps: Provide one roll of film; Provide a first adhesive sheet defining multiple holes; Unwind a section of film from the roll along the machine direction; The first adhesive sheet is applied to the membrane such that the plurality of holes are oriented at an angle of less than 90 degrees relative to the machine direction, thereby forming a laminated sheet; as well as The laminated sheet is cut to form a ventilation element as described in any one of claims 1 to 21.

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