A method of manufacturing a core stiffened structure includes orienting the plurality of core wafers in a non-uniform pattern onto a first face sheet, the non-uniform pattern producing non-uniform spacing between adjacent core wafers; assembling a second face sheet onto the plurality of wafers; and curing an adhesive to create a bond between the plurality of wafers, the first face sheet, and the second face sheet.

A method of manufacturing a core stiffened structure includes orienting the plurality of core wafers in a non-uniform pattern onto a first face sheet, the non-uniform pattern producing non-uniform spacing between adjacent core wafers; assembling a second face sheet onto the plurality of wafers; and curing an adhesive to create a bond between the plurality of wafers, the first face sheet, and the second face sheet.

A method for manufacturing a plastic fuel tank including: a) inserting a plastic parison including two distinct parts into an open two-cavity mold; b) inserting a core, bearing at least part of a reinforcing element configured to create a link between the two parison parts, inside the parison; c) pressing the parison firmly against the mold cavities, for example by blowing through the core and/or creating suction behind the cavities; d) fixing the part of the reinforcing element to at least one of the parison parts using the core; e) withdrawing the core; f) closing the mold, bringing its two cavities together to grip the two parison parts around their periphery to weld them together; g) injecting a pressurized fluid into the mold and/or creating a vacuum behind the mold cavities to press the parison firmly against the mold cavities; and h) opening the mold and extracting the tank.

A method for manufacturing a plastic fuel tank including: a) inserting a plastic parison including two distinct parts into an open two-cavity mold; b) inserting a core, bearing at least part of a reinforcing element configured to create a link between the two parison parts, inside the parison; c) pressing the parison firmly against the mold cavities, for example by blowing through the core and/or creating suction behind the cavities; d) fixing the part of the reinforcing element to at least one of the parison parts using the core; e) withdrawing the core; f) closing the mold, bringing its two cavities together to grip the two parison parts around their periphery to weld them together; g) injecting a pressurized fluid into the mold and/or creating a vacuum behind the mold cavities to press the parison firmly against the mold cavities; and h) opening the mold and extracting the tank.

A reinforcing element, having a cross section with a flattened overall shape and extending in a main direction and comprising at least one lateral edge made of a polymeric composition comprising a thermoplastic polymer, the lateral edge extending in a general direction substantially parallel to the main direction is treated by heating at least a part of the lateral edge, during which at least a part of the lateral edge is subjected to a plasma flow so as to raise the temperature of the part of the lateral edge above the melting point of the thermoplastic polymer.

A multilayer permeation resistant article, such as a fuel transfer hose, includes an elastomeric layer and a polyketone (PK) barrier layer. The elastomeric layer may be directly bonded to the PK barrier layer without an intervening adhesive layer. To facilitate such direct bonding, the elastomeric layer may be formed from a composition including one or more ethylene vinyl acetate elastomer(s). The elastomeric composition may include additional elastomer(s), such as chlorinated polyethylene (CPE), acrylonitrile butadiene rubber (NBR), hydrogenated nitrile rubber (HNBR), or chlorosulfonated polyethylene (CSM). The barrier layer may exhibit a permeation rate of less than 10 g/m.sup.2/day. The bonding performance of the elastomeric layer to the PK barrier layer may be characterized by an average load per width of 10 lbf/in or greater.

An embodiment relates to a method for producing a self-assembly polymer membrane by non-solvent induced film formation (NIFF), the method including: (a) preparing a polymer solution by mixing an ionized polymer with an organic solvent, (b) preparing a substrate on which a polymer solution coating layer is formed by coating the polymer solution on a substrate and (c) forming an ionized polymer membrane by immersing the substrate on which the polymer solution coating layer is formed in a non-solvent without going through a drying process under elevated temperature conditions. Accordingly, it is possible to produce a nonporous, dense polymer membrane in an efficient way that saves time and energy.

The present invention relates to fiber composite plastic (11, 13) comprising a polymer (40, 41) and at least one textile (50), which has at least one palpably inhomogeneous surface (60, 61) with a textile structure and is entirely surrounded by polymer (40, 41), wherein the fiber composite plastic (11, 13) has at least one palpably inhomogeneous surface (60, 61), wherein inhomogeneities of this fiber composite plastic surface are caused by the textile structure, and a method for producing the fiber composite plastic (11, 13).

In one instance a semicrystalline polyketone powder useful for additive manufacturing is comprised of a bimodal melt peak determined by an initial differential scanning calorimetry (DSC) scan at 20 C./min and a D.sub.90 particle size of at most 300 micrometers and average particle size of 1 micrometer to 150 micrometers equivalent spherical diameter. In another instance, A composition is comprised of a semicrystalline polyketone powder having a melt peak and a recrystallization peak, wherein the melt peak and recrystallization peak fail to overlap.

A polyacetal resin composition; a metal resin composition; and a method for producing a polyacetal resin composition are provided. The polyacetal resin composition contains 100 parts by weight of a polyacetal resin (A) and 0.1 to 0.9 part by weight of a fatty acid metal salt (B) having a weight loss rate of 20% by weight of more, the weight loss rate being the ratio of weight loss after the fatty acid metal salt is heated from room temperature to 200 C. at a rate of 200 C./minute in the air at atmospheric pressure and is subsequently held at 200 C. for 60 minutes.