I. Product Overview

The fine-pitch needle valve hot runner system is a high-end injection system developed specifically for micro-precision parts, high-density multi-cavity molds, and confined gate spaces. Due to structural limitations, traditional independent cylinder-type needle valve hot runners can only achieve a minimum gate center distance of 35 mm, which fails to meet the production demands of densely arranged molds with a high number of cavities.

This system abandons the single-nozzle, independent cylinder structure in favor of an integrated design featuring a synchronously driven push plate, micro-integrated hot nozzles, and a compact, balanced manifold. It achieves a minimum gate center distance of 16 mm, with ultra-micro integrated models capable of as low as 5–8 mm. It achieves precise mechanical seal closure within extremely limited mold cavity space while retaining the core advantages of needle-valve systems—no drooling, no stringing, and no gate marks—making it perfectly suited for the high-volume, high-consistency injection molding of precision small parts.

II. Core Technical Advantages (Distinguishing Features from Conventional Needle Valve Systems)

1. Extremely Compact Structure Enabling Ultra-High Cavity Density

By eliminating independent external cylinders and adopting a centralized push-plate drive structure, the system significantly reduces the lateral space occupied by the nozzles. For molds of the same size, it increases the number of cavities by more than 50%, significantly boosting per-machine output and reducing unit production costs, making it the optimal solution for multi-cavity precision molds.

2. Synchronized Pinch Pin Operation for Exceptional Molding Consistency

The integrated ejector plate, guided by high-precision guide pins, ensures all pinch pins open and close in perfect synchronization, with motion error controlled within ±0.02 mm. Melt pressure, flow rate, and filling time are highly uniform across all cavities, completely eliminating common mass-production issues such as weight deviations, inconsistent dimensional tolerances, localized short shots, and flash in micro-plastic parts.

3. Precision Mechanical Gate Sealing Ensures Flawless Product Appearance

By mechanically cutting off the gate with the valve pins, this design eliminates issues common in open hot runner systems—such as drooling, stringing, and cold material residue. After molding, the product surface is free of gate protrusions and scars, eliminating the need for manual sanding or post-processing. It directly meets the high-standard requirements for Grade A appearance, transparent parts, and medical-grade clean parts.

4. Short Runners and Low Shear: Compatible with High-End Plastic Materials

Combined with micro-mirror-finished balanced runners, the system features a short melt flow path, low pressure loss, and minimal shear stress, effectively preventing issues such as high-temperature decomposition, carbon buildup, and yellowing of plastics. It is widely compatible with various high- and low-viscosity engineering plastics, including PC, PMMA, LCP, PEEK, glass-fiber-reinforced materials, and medical-grade non-leaching materials.

5. Precise Zone-Based Temperature Control for Stable and Durable Operation

The independent zone-based temperature control architecture—featuring “one nozzle, one heater” and “one nozzle, one temperature sensor”—combined with an ultra-thin, full-coverage heating structure, resolves issues such as localized heat buildup and uneven temperature distribution caused by dense component arrangement. Temperature control accuracy reaches ±1°C, ensuring long-term mass production without material blockages, carbonization, or temperature-related defects.

III. Core System Structure

1. Synchronous Drive Mechanism

Features a single/dual-cylinder linked integral push-plate structure, paired with high-precision guide and limit components, to ensure vertical reciprocating motion of the valve pins and eliminate uneven wear and sticking. Pneumatic or electric servo drive options are available based on operating conditions, accommodating both standard production environments and medical cleanrooms without an air supply. The overall structure offers high rigidity and excellent synchronization, ensuring stable operation with high-cavity molds ranging from 8 to 64 cavities.

2. Micro Precision Needle Valve Hot Runner Assembly

Features a slender, one-piece precision nozzle body, paired with an ultra-thin, high-temperature-resistant heating ring and micro thermal insulation and sealing components. The core valve needle is made of nitrided SKD61 or cemented carbide, precision-ground to a diameter tolerance strictly controlled within 0.01 mm, ensuring wear resistance, deformation resistance, and high-temperature operation without jamming. The nozzle gate can be customized with micro-orifices ranging from 0.3 to 2 mm in diameter, enabling precise material injection for micro-sized plastic parts.

3. Compact Balanced Runner Plate

Constructed from high-quality H13/P20 hot-work die steel, it undergoes five-axis precision milling and mirror-finish polishing. The symmetrical, equal-length balanced runner design eliminates dead zones and material buildup, facilitating quick color changes and cleaning. Combined with floating thermal insulation support columns and a high-temperature sealing structure, it incorporates thermal expansion clearances to completely eliminate issues such as high-temperature compression deformation and material leakage in confined spaces.

4. Intelligent Temperature Control and Sequencing System

Equipped with a multi-channel PID intelligent temperature control cabinet that supports independent zone temperature control and features automatic alarms for over-temperature, open circuits, and short circuits. The upgradeable timing control module precisely adjusts the opening and closing delays of each group of valve pins, effectively eliminating weld lines in long-stroke molded parts and product warping, thereby improving molding yield.

IV. Core Product Specifications

Minimum gate center distance: Standard models 16–22 mm; ultra-compact integrated models 5–8 mm

Supported cavity count: 2–64-cavity high-density multi-cavity molds

Gate Diameter Range: 0.3 mm–2.0 mm (customizable)

Needle Actuation Accuracy: Synchronization error ≤ 0.02 mm

Temperature Control Accuracy: ±1 °C

Compatible Materials: General-purpose plastics, transparent optical plastics, high-temperature engineering plastics, glass-fiber-reinforced plastics, medical-grade plastics

V. Application Areas

Specializes in various types of micro, precision, and high-cavity molds