An earplug assembly and method of forming the same is described. The method includes uniaxially stretching a cord formed of copolymer including ethylene segments and vinyl acetate segments to form a cold-drawn cord. The cold drawn cord has an elongation to break of 250% or less. The method then includes fixing the cold drawn cord to an earplug.

Embodiments of the disclosure are generally directed to systems and methods for switchable electroactive devices for head-mounted displays (HMDs). In particular, a method may include (1) applying an electric field to an electroactive element of an electroactive device via electrodes of the electroactive device that are electrically coupled to the electroactive element to compress the electroactive element, which comprises a polymer material defining nanovoids, such that an average size of the nanovoids is decreased and a density of the nanovoids is increased in the electroactive element, wherein the electroactive device is positioned at a distance from a user's eye, and (2) emitting image light from an emissive device positioned such that at least a portion of the image light is incident on a surface of the electroactive device facing the user's eye.

A low shrinkage low oligomer polyester film and a method for manufacturing the same are provided. The method includes forming at least one polyester composition into an unstretched polyester thick film and stretching the unstretched polyester thick film in a machine direction (MD) and a transverse direction (TD) at a stretch ratio of two to six times. The polyester composition includes 94% to 99.974% by weight of a polyester resin, 0.01% to 1% by weight of a primary antioxidant, 0.01% to 1% by weight of a secondary antioxidant, 0.003% to 2% by weight of a nucleating agent, and 0.003% to 2% by weight of a flow aid. The polyester resin has an intrinsic viscosity between 0.60 dl/g and 0.80 dl/g.

A matte film for hot pressing and a manufacturing method thereof are provided. The manufacturing method includes steps of forming at least one polyester composition into an unstretched polyester thick film and stretching the unstretched polyester thick film in a machine direction (MD) and a transverse direction (TD). The polyester composition includes 81% to 97.9497% by weight of a polyester resin, 0.02% to 2% by weight of an antioxidative ingredient, 0.0003% to 1% by weight of a nucleating agent, 0.01% to 2% by weight of a flow aid, 0.01% to 2% by weight of a polyol ester based polyester modifier, 0.01% to 2% by weight of an inorganic polyester modifier, and 2% to 10% by weight of silica particles. The polyester resin has an intrinsic viscosity between 0.60 dl/g and 0.80 dl/g.

A polyolefin porous separator includes a first surface and a second surface corresponding to the first surface. The surfaces of the polyolefin porous separator contain dendritic crystals and micropores, the dendritic crystals intersect with the micropores on the first surface or/and the second surface, and the dendritic crystals penetrate through the second surface from the first surface. A preparation method of the polyolefin porous separator includes: (1) a mixed melting of polyethylene resin and a mineral oil; (2) an extrusion of the mineral oil/polyethylene resin molten mixture; (3) a stretching of a thick sheet in a machine direction (MD); (4) a stretching of the separator in a transverse direction (TD); (5) immersing the separator into a solvent to extract the mineral oil; (6) a secondary stretching of the separator in the TD; and (7) subjecting the separator having the longitudinal crystals to a heat-setting treatment and then rolling up.

An example device includes a nanovoided polymer element, which may be located at least in part between the electrodes. In some examples, the nanovoided polymer element may include anisotropic voids, including a gas, and separated from each other by polymer walls. The device may be an electroactive device, such as an actuator having a response time for a transition between actuation states. The gas may have a characteristic diffusion time (e.g., to diffuse half the mean wall thickness through the polymer walls) that is less than the response time. The nanovoids may be sufficiently small (e.g., below 1 micron in diameter or an analogous dimension), and/or the polymer walls may be sufficiently thin, such that the gas interchange between gas in the voids and gas absorbed by the polymer walls may occur faster than the response time, and in some examples, effectively instantaneously.

Provided are a retardation film that has a high heat resistance, has excellent formability and handleability even in a single-layer structure, has a negative thickness-direction retardation Rth value, and is suitable as a negative A-plate or a positive C-plate and a method for producing the film. The retardation film is formed of a stretched film of a polyester resin, contains a unit (A1) represented by the formula (1) as a diol unit (A) and a unit (B1) represented by the formula (2a) or (2b) as a dicarboxylic acid unit (B), and is a negative A-plate or a positive C-plate.

##STR00001##

In the formulae, Z.sup.1 and Z.sup.2 represent an aromatic hydrocarbon ring, R.sup.1, R.sup.2a, R.sup.2b, R.sup.3a and R.sup.3b represent a substituent, k, p1 and p2 denotes an integer of 0 to 8, q denotes an integer of 0 to 4, m1, m2, n1 and n2 denotes an integer of not less than 0, A.sup.1a and A.sup.1b represents an alkylene group, and A.sup.2a, A.sup.2b and A.sup.3 represents a divalent hydrocarbon group.

An oriented film including poly(ethylene-2,5-furandicarboxylate) is produced in a process by preparing a sheet from a poly(ethylene-2,5-furandicarboxylate) resin by heat processing, which sheet has a thickness of at most 2.5 mm; allowing the sheet to cool; and stretching the cooled sheet in at least one direction with a stretch ratio of at least 4/1 at a temperature in the range of 90 to 130° C., yielding an oriented film. The oriented film has a thickness of 1 to 400 μm and a tensile strength at break of at least 100 MPa.

The invention relates to a process for the production of a non-fibrous drawn polymer tape, said process comprising the steps: a) compacting a polymer powder in a press to form a compacted polymer bed; b) calendering said compacted polymer bed to form an oriented polymer tape; and c) drawing said oriented polymer tape to form a highly oriented polymer tape; characterized in that step a) comprises compacting the polymer powder at a temperature and pressure such that from 0.1 to 20 wt. % of the polymer powder as measured by DSC is melted. The invention also relates to a tape obtainable by the above process, and a monolayer, multilayered material sheet and ballistic resistant article comprising such a tape.

Improved battery separators, base films or membranes, batteries, cells, devices, systems, vehicles, and/or methods of making and/or using such separators, films or membranes, batteries, cells, devices, systems, vehicles, and/or methods of enhancing battery or cell charge rates, charge capacity, and/or discharge rates, and/or methods of improving batteries, systems including such batteries, vehicles including such batteries and/or systems, and/or the like; biaxially oriented porous membranes, composites including biaxially oriented porous membranes, biaxially oriented microporous membranes, biaxially oriented macroporous membranes, battery separators with improved charge capacities and the related methods and methods of manufacture, methods of use, and the like; flat sheet membranes, liquid retention media; dry process separators; biaxially stretched separators; dry process biaxially stretched separators having a thickness range between about 5 μm and 50 μm, preferably between about 10 μm and 25 μm, having improved strength, high porosity, and unexpectedly and/or surprisingly high charge capacity, such as, for example, high 10 C rate charge capacity; separators or membranes with high charge capacity and high porosity, excellent charge rate and/or charge capacity performance in a rechargeable and/or secondary lithium battery, such as a lithium ion battery, for high power and/or high energy applications, cells, devices, systems, and/or vehicles, and/or the like; single or multiple ply or layer separators, monolayer separators, trilayer separators, composite separators, laminated separators, co-extruded separators, coated separators, 1 C or higher separators, at least 1 C separators, batteries, cells, systems, devices, vehicles, and/or the like; improved microporous battery separators for secondary lithium batteries, improved microporous battery separators with enhanced or high charge (C) rates, discharge (C) rates, and/or enhanced or high charge capacities in or for secondary lithium batteries, and/or related methods of manufacture, use, and/or the like, and/or combinations thereof are disclosed or provided.