What aspects should be considered when determining the overall layout of the cavity

Update:25 Dec 2018
Summary:

What aspects should be considered when determining the […]

What aspects should be considered when determining the overall layout of the cavity and selecting the parting surface?

Answer: (1) Pay attention to the overall layout of the cavity

a) Balance as much as possible to form a balanced gating system to ensure uniformity and stability of the quality of the part.

b) The cavity arrangement and the gate opening are stress-symmetrical, so as to prevent the mold from being subjected to eccentric load and causing flash.

c) Try to arrange the cavities to be compact so as to reduce the overall dimensions of the mold.

(2) Partition surface selection principle

a) The selection of the parting surface should facilitate the demolding of the plastic part and simplify the structure of the mold. The parting surface should be selected as much as possible to leave the moving part in the moving mold when the mold is opened.

b) The parting surface should be selected as far as possible without affecting the appearance, and the resulting flash edge can be easily eliminated or trimmed.

c) The selection of the parting surface guarantees the dimensional accuracy of the plastic part.

d) The parting surface selection should be beneficial to the exhaust.

e) The selection of the parting surface should facilitate the processing of the mold parts.

f) The selection of the parting surface should take into account the technical specifications of the injection machine.

3. What are the structural design methods for punches, dies, and threaded cores and threaded rings, and their characteristics are briefly described.

Answer: (1) Punches can be divided into integral and combined

a) The integral punch, the punch and the template are made in one piece, the structure is firm, the molding quality is good, but the steel consumption is large, and it is suitable for a small punch with a simple inner surface shape.

b) The combined punch is made of different materials and heat treated with the punch and the fixed plate, and then joined together. It is used when the shape of the inner surface of the plastic part is complicated and is not convenient for machining, or the shape is not complicated, but in order to save high quality steel and reduce the amount of cutting processing