Technical Questions

The opening specification should consider the sand grain fineness used in the process. As a practical reference, the finer the sand, the smaller the vent opening should be, reducing the passage of grains into the venting passages and contributing to higher clogging resistance.
For slotted vents, the specification should be treated as slot width. For lines based on a screen-type or perforated-style concept, selection should consider the opening size and the internal venting geometry.
These specifications should be used as an initial guideline. Final vent selection should also consider the molding or core-making process, sand type, AFS grain fineness, resin or binder concentration, fines percentage, core box geometry, and actual operating conditions. Ventistamp recommends validating the selection in the customer’s real process or contacting our technical team.

The opening size for aluminum processes should consider two main factors: the process type, low-pressure or gravity casting, and the tooling area where the vent will be applied.

When the vent is in direct contact with aluminum, the opening size should be smaller, helping reduce aluminum penetration into the vent. In areas where the vent is not in direct contact with aluminum and operates over the sand core, larger openings may be used according to the required venting capacity.

These specifications should be used as an initial guideline. Final selection depends on the aluminum alloy, operating temperature, cooling system, permanent mold geometry, vent position, and actual production conditions. Ventistamp recommends validating the selection in the customer’s real process or contacting our technical team.