Mold Components for
Packaging Manufacturing

PET preform molds operate at the highest temperatures and pressures in packaging — 80-300°C melt temperature, 150-200 MPa injection pressure, and extremely fast cooling requirements. The preform core pin determines the internal surface quality of the final blown bottle; any surface defect on the pin transfers to the preform and becomes amplified during blow molding. The pins also contain internal cooling channels (baffles or spiral bubblers) that must maintain efficient heat transfer throughout the tool life.

We manufacture PET preform core pins from ASP-23 (HRC 63-65) with mirror-polished OD surfaces (Ra <0.1μm) and precision-machined internal cooling geometry. The ASP-23 grade provides the abrasion resistance needed for the glass-like crystallization behavior of PET during cooling, while the powder metallurgy process ensures uniform hardness distribution — critical for pins with complex internal cooling geometries where conventional steels may have hardness variations near cooling channels.

Bottle caps require precise thread geometry for torque-to-open specification compliance and tamper-evident ring performance. The core pin that forms the internal thread must maintain thread profile accuracy within ±0.01mm over 5M+ shots — thread wear causes caps to cross-thread on the filling line, causing line stoppages and product waste. The unscrewing mechanism adds mechanical complexity, with each cavity containing a rack-and-pinion or hydraulic motor thread release system.

We supply thread core pins in DC53 (HRC 60-62) with CrN coating on the thread flanks. CrN reduces the coefficient of friction during unscrewing, lowering the motor torque requirement and reducing wear on both the pin thread and the molded cap thread. For beverage closures where food contact safety is paramount, our steel grades and coatings comply with EU 10/2011 and FDA food contact material regulations — documentation included with every shipment.

PET preform molds run at 10–15 shots per minute in 96–128 cavity configurations. Each core pin forms the internal preform shape and is subject to extreme thermal cycling (280°C melt temperature, 10°C cooling water). Pin concentricity within ±0.005mm is critical — even slight eccentricity creates wall thickness variation that causes blown bottles to fail drop tests.

We supply matched core pin sets in ASP-23 with TiAlN coating, achieving 10–15 million shot life. Block assemblies ensure ±0.002mm positional accuracy across all cavities. Recommended: Core Pins & Inserts.

Beverage cap molds run at 4–8 second cycle times with 32–64 cavities. The threaded core inserts must produce thread profiles within ±0.01mm over 5 million+ shots — thread wear causes caps to cross-thread on the filling line, triggering production stoppages. Unscrewing mechanism components experience high rotational loads at each cycle.

Our precision thread core inserts in DC53 with TiN coating deliver consistent thread profile accuracy. Unscrewing drive gears and cam followers in hardened tool steel resist the rotational wear. Recommended: Stepped Core Pins.

Thin-wall food containers (yogurt cups, deli containers) with 0.3–0.5mm walls require fill times under 0.3 seconds at injection pressures of 200+ MPa. At these extremes, gate insert wear accelerates dramatically — a worn gate changes the fill pattern, causing short shots. Venting is equally critical: air trapped in the thin cavity must escape in milliseconds.

We supply ASP-23 gate inserts with TiAlN coating for the extreme gate velocities, and precision-ground vent inserts with 0.02–0.03mm vent depth for PP and PS. Our support pillars ensure uniform clamp force distribution across the fast-cycling thin-wall mold. Recommended: Gate Inserts.

Premium cosmetic packaging (perfume caps, lipstick tubes, compact cases) demands SPI A-1 mirror finish with zero visible defects. These parts are molded in PMMA, SAN, or metallized ABS with chrome-look finishes. Any micro-pit, tool mark, or polishing scratch on the cavity surface transfers directly to the molded part — visible under retail store lighting.

We specify P21 (NAK80) cavity inserts for all mirror-grade cosmetic packaging. P21 achieves and maintains SPI A-1 finish through 1M+ shots without re-polishing. For metallized parts, our H6/h5 ejector clearances prevent witness marks. Recommended: Mirror-Grade Inserts.

Multi-layer barrier packaging (ketchup bottles, juice containers) uses co-injection technology with EVOH or nylon barrier layers sandwiched between PP structural layers. The co-injection nozzle and manifold components must maintain precise layer thickness control — too thin a barrier layer allows oxygen permeation that degrades product shelf life.

We supply precision co-injection nozzle tips and manifold inserts machined to ±0.005mm tolerance. All food-contact components meet FDA 21 CFR requirements with full material documentation. Recommended: Sprue Bushings.

Industrial pail and paint bucket handles are produced by insert molding wire bail handles into PP or HDPE grips. The wire locating core pins must position the metal insert within ±0.1mm while withstanding the impact loading of the over-molding process. Multi-cavity (8–16) configurations require consistent insert positioning across all cavities.

We supply precision wire-locating core pins with hardened V-groove features, and heavy-duty ejection systems for the thick-wall handle geometry. SKD61 material handles the impact loading of the insert molding process. Recommended: Ejector Pins.

Stackable milk crates and beverage crates are large-format (400–600mm) parts molded in PP or PP-GF15 with deep-draw side walls and complex interlock features on the base. The mold requires 8–12 slide mechanisms for the side wall undercuts and interlock features. Cycle times of 30–45 seconds on 1,500–2,500 ton presses create high cumulative wear.

Our heavy-duty slide core systems with oilless bronze guides handle the extended stroke lengths (80–120mm) required for crate side walls. DC53 slide bodies resist deformation under high extraction forces. Recommended: Slide Core Systems.