Empty hard capsules, as a critical dosage form in the pharmaceutical and health supplement industries, rely heavily on precision molds for their production. The quality and design of these molds directly determine the dimensional accuracy, surface smoothness, cap-body fit, and production efficiency of the capsules, making them core equipment in the capsule manufacturing process. Production molds for empty hard capsules are primarily classified based on the capsule forming process, with the dip-molding method being the most widely used. The mold systems for this method can be broken down into the following categories:
1. Dip-Molding Mold System
This is the mold system used in the mainstream hard capsule production process today, with core components including mold pins (or mold rods) and mold plates.
Mold Pins: These are crucial to capsule formation and are typically precision-machined from corrosion-resistant alloys such as stainless steel. Their surfaces are highly polished (mirror-grade) to ensure easy capsule release and a smooth finish. The size and shape of the mold pins strictly correspond to capsule specifications (such as 00#, 0#, 1#, 2#, 3#, 4#, 5#, etc.), and are divided into body pins and cap pins for forming the Body and Cap parts of the capsule, respectively. Parameters like the diameter, length, and taper of the pins must be precisely controlled, as they directly affect the capsule's wall thickness, volume, and the tightness of the cap-body closure.
Mold Plates: These are used to secure and support large numbers of mold pins, typically in long strip or circular plate structures. The plates are precision-drilled with matrix-patterned holes to ensure even spacing and accurate positioning of the pins. Mold plates must possess sufficient rigidity and stability to withstand mechanical and thermal stress during production, preventing pin deformation that could lead to dimensional inaccuracies in the capsules. The design of mold plates also incorporates cooling channel layouts to achieve rapid and uniform cooling and setting of the pins after they are dipped in the gelatin solution.
2. Auxiliary Molds and Tooling
In addition to the core forming molds, production lines also require supporting equipment such as demolding devices, cutting molds, and sorting molds. Demolding devices mechanically or pneumatically remove the set capsules from the pins; cutting molds are used to precisely trim the opening edge of the capsule body to ensure a smooth finish; and sorting molds are used to separate and arrange the finished capsules. These auxiliary molds also require high-precision machining to ensure continuous production and final product quality.
3. Mold Material and Process Requirements
Empty hard capsule molds are in long-term contact with acidic gelatin solutions, high-temperature steam, and frequent friction. Therefore, materials such as 316L stainless steel and titanium alloys are often chosen for their corrosion resistance and high wear resistance. Processes like precision CNC machining, electrolytic polishing, and surface coatings (such as Teflon) are applied to ensure mold longevity (which can reach millions of cycles) and the surface quality of the capsules.
In summary, the production molds for empty hard capsules are systems that integrate precision machinery, materials science, and process control. Their design and manufacturing level directly determine the quality and production cost of capsule products, representing a concentrated expression of technical sophistication in the field of pharmaceutical equipment. If there is any demands on empty capsules, welcome to contact KornnacCaps.
