A household vacuum sealer contains: a base, a lid, and a hot-melt sealing element. The base includes a receiving chamber for accommodating a control circuit and a vacuum pump. The base also includes a vacuuming chamber and an accommodation chamber. The hot-melt sealing element includes a holder, a mica slice, a laminated heating layer, the insulated composite layer, and a protective cap. The insulated composite layer includes multiple insulated tape layers. The laminated heating layer includes a high-temperature resistance tapes made of polyimide, a metal resistance tape, two electrical connection films, and two alternating current (AC) electrodes. The mica slice is parallelly fixed on a top of the holder. The laminated heating layer includes the two electrical connections. Furthermore, the protective cap is covered on the insulated composite layer and includes a hollowly elongated zone.

A formation method is provided during which a thermoplastic film is arranged on a fiber-reinforced thermoplastic skin. The thermoplastic film is configured from or otherwise includes thermoplastic material. A heating device is moved to a location along the thermoplastic film, where the thermoplastic film is disposed between the fiber-reinforced thermoplastic skin and the heating device. The thermoplastic film is heated with the heating device to melt the thermoplastic film and provide a melted thermoplastic film. The heating device is moved away from the melted thermoplastic film. A honeycomb core is pressed against the melted thermoplastic film to bond the honeycomb core to the fiber-reinforced thermoplastic skin with the thermoplastic material.

A method of forming a shaped article wherein said article comprises at least two parts which are chemically bonded, the method comprising: assembling at least two non chemically bonded parts in a weld cavity of a tool to form an assembly of the at least two parts, wherein said weld cavity is adapted to receive the assembly of at least two parts in the form of the shaped article; sealing the weld cavity of the tool; melting the assembly of at least two parts to chemically bond the at least two parts together to form the shaped article, wherein the shape of the weld cavity is matched to the outer circumference of the assembly of parts such that thermal expansion forces the polymer parts against the weld cavity surface and the pressure leads to full surface bonds between all parts, and wherein the tool forming the weld cavity comprises two halves forming a piston which fits into the bore of a bolster component and the plane of the split line between the two piston halves is parallel to the axis of the bore such that the pressure from the thermal expansion of the assembly of parts within the weld cavity is opposed by the surface of the bore preventing the weld cavity split line from opening and therefore preventing leakage of polymer from within the pressurised weld cavity volume, and wherein the two piston components are made from a dissimilar metal with higher coefficient of thermal expansion than the bolster component ensuring that at the welding temperature the piston is larger in diameter than the bore diameter of the bolster component leading to an interference fit which makes forces the weld cavity split line to close at the weld temperature but which still allows for a clearance gap between piston and bore at room temperature for the tool to be assembled and disassembled.