There are many types of inverted buckles for the flow channel locking shape of the point gate structure, and the type shown in Figure 1 is generally used.
The type in Figure 1 is a method in which a pull pin with an undercut shape on the head is arranged at the root of the main runner, and the runner and gate are forced to demold when the fixed template and the runner plate are opened.
The head of the pull pin is embedded in the gap of the runner plate, and is fixed on the fixed mold mounting plate by a pressing plate or an inner hexagonal screw plug.
In this way, if it is a thin-walled molded product or a resin with poor fluidity, the head of the pull pin narrows the passage in the flow channel, and a higher filling pressure and holding pressure are required in terms of molding conditions.
In this case, you can consider the method of sinking the pin part into the runner plate to fix it, as shown in Figure 2. With this method, it is necessary to process a tapered buckle shape on the runner plate, so the production cost of the mold will increase, but the pressure loss during forming can be improved.
If you want to shorten the forming cycle, sometimes the head of the pull pin is made into a pointed cone shape, which can simultaneously reduce the glue position and fasten the runner, as shown in Figure 3. With this method, since the glue position in the center of the runner is removed, the cooling efficiency is improved, which is very effective in shortening the forming cycle.
