A method of fabricating a high-altitude balloon. The method includes coextruding at least two adjacent continuous layers of extrudate, extrusion-bonding the layers of extrudate to one another along an edge of the sheets of extrudate to form a seam, and cooling the extrudate.

A high altitude balloon. A plurality of layers of coextruded extrudate are formed in a seamless sheet in a shape that defines a balloon envelope. Delaminator layers may be interposed between two or more of the layers of extrudate.

Co-extruded and extruded high-altitude balloons and apparatus and methods for manufacture. A high-altitude balloon has a plurality of layers of coextruded balloon panel extrudate, a first one of the layers extrusion-bonded to a second one of the layers along a first edge, the second one of the layers extrusion-bonded to a third one of the layers along a strip spaced apart from the first edge, extrusion-bonding of successive layers alternating between the first edge and the strip, the first one of the layers and the last one of the layers extrusion-bonded together along a second edge.

The present invention provides methods of preparing peelable seal layers, methods of preparing multilayer films, peelable seal layers made therefrom, and multilayer films made therefrom. In one aspect, a method of preparing a peelable seal layer comprises (a) providing a first blend comprising (i) from 5 to 98 percent by weight of a reactor grade propylene based plastomer or elastomer having a molecular weight distribution of less than 3.5 and a density of less than 0.89 g/cc and (ii) from 2 to 95 percent by weight of a second polymer selected from the group consisting of polyethylene, polybutylene, and styrenic polymer and mixtures thereof; (b) providing at least one linear low density polyethylene; (c) blending the first blend with the at least one linear low density polyethylene to obtain a second blend; and (d) extruding the second blend to form a peelable seal layer, wherein the peelable seal layer has a heat seal initiation temperature less than 120 C. when sealed at a bar pressure of 40 psi with a dwell time of 0.5 seconds.

The present invention provides methods of preparing peelable seal layers, methods of preparing multilayer films, peelable seal layers made therefrom, and multilayer films made therefrom. In one aspect, a method of preparing a peelable seal layer comprises (a) providing a first blend comprising (i) from 5 to 98 percent by weight of a reactor grade propylene based plastomer or elastomer having a molecular weight distribution of less than 3.5 and a density of less than 0.89 g/cc and (ii) from 2 to 95 percent by weight of a second polymer selected from the group consisting of polyethylene, polybutylene, and styrenic polymer and mixtures thereof; (b) providing at least one linear low density polyethylene; (c) blending the first blend with the at least one linear low density polyethylene to obtain a second blend; and (d) extruding the second blend to form a peelable seal layer, wherein the peelable seal layer has a heat seal initiation temperature less than 120 C. when sealed at a bar pressure of 40 psi with a dwell time of 0.5 seconds.

Multilayered polymer films are configured so that successive constituent layer packets can be delaminated in continuous sheet form from the remaining film. The new films are compatible with known coextrusion manufacturing techniques, and can also be made without the use of adhesive layers between layer packets that are tailored to be individually peelable from the remainder of the film. Instead, combinations of polymer compositions are used to allow non-adhesive polymer layers to be combined in such a way that delamination of the film is likely to occur along a plurality of delamination surfaces corresponding to interfaces between particular pairs of layers for which the peel strength is reduced relative to the peel strength at other layer interfaces within the film. The absence of an adhesive between peelable layer packets results in the delamination being irreversible.

Multilayered polymer films are configured so that successive constituent layer packets can be delaminated in continuous sheet form from the remaining film. The new films are compatible with known coextrusion manufacturing techniques, and can also be made without the use of adhesive layers between layer packets that are tailored to be individually peelable from the remainder of the film. Instead, combinations of polymer compositions are used to allow non-adhesive polymer layers to be combined in such a way that delamination of the film is likely to occur along a plurality of delamination surfaces corresponding to interfaces between particular pairs of layers for which the peel strength is reduced relative to the peel strength at other layer interfaces within the film. The absence of an adhesive between peelable layer packets results in the delamination being irreversible.

The disclosure relates to forming shaped thermoplastic articles having smooth peripheries. Many thermoplastic articles have sharp edges formed upon molding or cutting the article from a feedstock sheet. Such sharp edges can damage thin plastic films or flesh which they contact, and smoothing the edges is desirable. Described herein are methods of forming a smooth periphery for such sharp-edged articles by rolling over the sharp edge. The smoothing operation is performed by forming a deflectable flange including a bend region separated from the potentially sharp peripheral edge by a spacer, deflecting a portion of the deflectable flange, and softening at least one bent portion of the deflectable flange to yield a smooth periphery upon cooling. A liner sheet may be attached to the feedstock sheet prior to, during, or after forming and can be peelable therefrom.

An example medical device includes a balloon that is inflatable to an inflated configuration. The balloon includes a non-compliant layer coextruded on an inner layer, and an outer layer coextruded on the non-compliant layer. The non-compliant layer is configured to delaminate from the inner and the outer layers in the inflated configuration. The non-compliant layer may be configured to rupture in the inflated configuration. An example technique includes inflating the balloon to a predetermined pressure sufficient to rupture the non-compliant layer and insufficient to rupture both the inner and outer layers. The example technique further includes deflating the balloon, and introducing the balloon into a vasculature. Another example technique includes coextruding a non-compliant layer on an inner layer, coextruding an outer layer on the non-compliant layer, and forming a balloon from the inner layer, the non-compliant layer, and the outer layer.

An example medical device includes a balloon that is inflatable to an inflated configuration. The balloon includes a non-compliant layer coextruded on an inner layer, and an outer layer coextruded on the non-compliant layer. The non-compliant layer is configured to delaminate from the inner and the outer layers in the inflated configuration. The non-compliant layer may be configured to rupture in the inflated configuration. An example technique includes inflating the balloon to a predetermined pressure sufficient to rupture the non-compliant layer and insufficient to rupture both the inner and outer layers. The example technique further includes deflating the balloon, and introducing the balloon into a vasculature. Another example technique includes coextruding a non-compliant layer on an inner layer, coextruding an outer layer on the non-compliant layer, and forming a balloon from the inner layer, the non-compliant layer, and the outer layer.