A melamine-formaldehyde foam manufactured by including a melamine-formaldehyde condensate that has a weight average molecular weight (Mw) in a range of 1000 to 10,000 g/mol, a solid content in a range of 60 to 80 percent by weight (wt %), and a viscosity in a range of 1000 to 10,000, and a method of manufacturing the melamine-formaldehyde foam. The melamine-formaldehyde foam can have a uniform cell structure, while exhibiting excellent mechanical properties such as tensile strength and elongation.

A semicrystalline poly ketone powder useful for additive manufacturing may be made by dissolving a polyketone having differential scanning calorimetry (DSC) monomodal melt peak, at a temperature above 50 C. to below the melt temperature of the polyketone, precipitating the dissolved polyketone by cooling, addition of a nonsolvent or combination thereof. The method may be used to form polyketones having a DSC melt peak with an enthalpy greater than the starting polyketone.

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 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.

This application describes methods of forming an object. The methods described include forming a mixture with i) one or more primary diamines, ii) one or more polymerizable monomers, iii) a formaldehyde-type reagent, and iv) a polymerization initiator; forming a gel by heating the mixture to a temperature of at least 50 C.; and curing the one or more polymerizable monomers by activating the polymerization initiator. The one or more primary diamines may include one or more amine functional oligomers and/or primary aromatic diamine small molecules. The one or more polymerizable monomers may include styrenics, acrylates, methacrylates, vinyl esters, unsaturated polyesters, and derivatives thereof. The gel is a polyhemiaminal (PHA), a polyhexahydrotriazine (PHT), and/or a polyoctatriazacane (POTA) polymer, and curing of the gel forms an interpenetrating network of the PHA/PHT/POTA and the polymer formed from the polymerizable monomers.

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.

There is provided a joined body in which two or more members Yi including a fitting hole are fastened, in which a fastening rod including reinforcing fibers and a thermoplastic resin is positioned in the fitting hole, the fastening rod is caulked by heat, and the members Yi are caulking-fastened.

There is provided a joined body in which two or more members Yi including a fitting hole are fastened, in which a fastening rod including reinforcing fibers and a thermoplastic resin is positioned in the fitting hole, the fastening rod is caulked by heat, and the members Yi are caulking-fastened.