Molding hollow, spherical objects like medical bulb syringes presents unique challenges, particularly in preventing flash at the parting line. This article reveals the mold design techniques that ensure a clean, professional finish.
A medical bulb syringe is essentially a hollow sphere, which poses a significant challenge for mold design. The parting line, where the two mold halves meet, is a common location for flash—a thin, unwanted excess of material. On a bulb syringe, flash can disrupt the smooth surface needed for squeezing and can harbor bacteria, making its elimination critical.
TYM's approach to flash prevention starts with precision mold manufacturing. Our mold bases are machined with extremely tight tolerances for flatness and parallelism. The cavity and core halves are then finished to a high degree of accuracy, ensuring perfect alignment when closed. The parting line itself is meticulously designed with minimal clearance.
We employ advanced locking mechanisms within the mold to maintain this alignment under the high injection pressures of LSR. Furthermore, the mold design incorporates optimized venting. These vents are extremely thin (often less than 0.05mm) and strategically placed to allow air to escape without letting LSR through. Some designs might even use vacuum assist to pull the material into the cavity and ensure complete filling without overpacking. This combination of precise alignment, robust locking, and expert venting ensures that our bulb syringe molds consistently produce parts free of flash, meeting the exacting standards of the medical field.
