| 摘要 |
In a method for the injection molding of a plastic blind rivet of the type essentially consisting of a shank and a rivet body such that an upward slide of the shank relative to the rivet body causes the leading end of the rivet body to expand outwardly and the outward expansion of the rivet body enables the rivet to be fastened to a panel, the improvement which comprises forming a ring gate in the lower end of the cavity of a second die used for molding a rivet body around a shank molded in advance in a first die, whereby the molten plastic material for the rivet body is allowed to flow through the ring gate into the rivet-body cavity of the second die with high uniformity, whereby the rivet body is produced free from a weld line and consequently from the possibility of sustaining cracks under the force exerted thereon when the shank is slid upwardly therein.
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