Mold having air-venting grooves

A mold includes a parting surface, runners, mold cavities, gates and primary air-venting grooves defined in the parting surface. The gates connect the respective runners to the corresponding mold cavities. Each primary air-venting groove includes an air-receiving groove portion and an air-venting groove portion in communication with the air-receiving groove portion. The air-receiving groove portion communicates with the gate and surrounds the corresponding mold cavity. The air-venting groove portion extends to and terminates at a corresponding edge of the parting surface.

BACKGROUND

1. Technical Field

The present disclosure relates to molds having air-venting grooves.

2. Description of Related Art

Generally, in an injection molding process, a mold is used. The mold defines a plurality of runners and a plurality of mold cavities communicating with the runners to form a plurality of plastic articles. During the injection molding process, molten material fills the runners and the mold cavities and then is cooled to form the plastic articles. However, air may remain in the runners and the mold cavities in a typical mold, and may deteriorate the plastic articles.

Therefore, what is needed is a mold, which can overcome the limitations described.

DETAILED DESCRIPTION

Referring toFIG. 1, a mold10, according to an exemplary embodiment, includes a parting surface100, a sprue110, and a plurality of cooling channels101. Eight runners102, eight mold cavities103, eight gates104, eight primary air-venting grooves105and four secondary air-venting grooves106are defined in the parting surface100.

The cooling channel101is configured for introducing a coolant, such as water or oil to cool the mold10. The sprue110is in communication with the runners102and a joint111is formed at a joining portion between the sprue110and the runner102. The gate104connects the runner102and the mold cavity103.

The air-receiving groove portion151is in communication with the air-venting groove portion152and the outer air-venting groove portion153. The air-receiving groove portion151communicates with the gate104and surrounds the corresponding mold cavity103. In this embodiment, the air-receiving groove portion151and the mold cavity103are substantially round, and the air-receiving groove portion151is internally tangent to the mold cavity103. In this way, air from the mold cavity103can smoothly flow into the air-receiving groove portion151. The gate104connects the mold cavity103at the tangent portion of the air-receiving groove portion151and the mold cavity103.

The air-venting groove portion152connects the air-receiving groove portion151and the outer air-venting groove portion153. The air-venting groove portion152extends to and terminates at a corresponding edge of the parting surface100. In this embodiment, the air-venting groove portion152is substantially strip-shaped. The outer air-venting groove portion153partially surrounds the air-receiving groove portion151and connects the air-receiving groove portion151to the air-venting groove portion152. A depth of the air-venting groove portion152is substantially equal to that of the outer air-venting groove portion153and is greater than that of the air-receiving groove portion151, as shown inFIG. 3. In this embodiment, the depths of the air-venting groove portion152and the outer air-venting groove portion153are about 0.1 millimeters, and the depth of the air-receiving groove portion151is about 10 micrometers.

The secondary air-venting groove106connects the joint111to the air-venting groove portion152. The secondary air-venting groove106is line-with-arrow-shaped. An arrow portion161of the secondary air-venting groove106interconnects two adjacent air-venting groove portions152so that air can be quickly repelled. A depth of the arrow portion161is the same as that of the air-receiving groove portion151.

When in use, molten material (not shown) is injected in the mold10through the sprue110and flows into the runner102and the gate104in such order to fill into the mold cavity103. During the above process, air in the mold10is repelled through a first channel of the secondary air-venting groove106to the air-venting groove portion152of the primary air-venting groove105, and through a second channel of the runner102, the gate104, the mold cavity103, the air-receiving groove portion151, the air-venting groove portion152and the outer air-venting groove portion153. The two channels increases air venting out of the mold10. Thus, air in the mold10can be repelled completely and yield of plastic articles made by the mold10increases.