| 摘要 |
A method for helmet construction by applying vacuum and fluid-pressure technologies is disclosed. Different types and sizes of exterior and interior helmet shells are press-formed from general engineering plastics. Conventional adhesive is applied on the inside surface of the exterior shell for fastening the interior and exterior shells together to form an integral shell unit. The shell unit is set on the base of a vacuuming apparatus moulded to adapt and to receive the inside surface contour of the interior shell. The vacuuming apparatus and the shell unit setting thereon are placed inside a conventional plastic film bag for vacuuming clear of any air pockets in the space between the two shell layers. The vacuumed film bag containing the vacuuming apparatus and the shell unit is then submerged under heated fluid contained in an airtight and pressure-resistant vessel. Pressure is subsequently applied to the vessel to further pressurize and complete the fastening process of the interior and exterior shells. Helmet construction according to this method requires low operating temperature and low operating pressure, thus enabling the use of relatively inexpensive and easily sourced raw materials.
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