Preform Mould
SINOMOULD is a professional preform mould manufacturer specializing in PET preform mould, plastic preform mould, tube perform mould and blow mould R&D and manufacturing. With over 20 years of experience, we cover full-series preform mould customization for beverage, food, daily chemical and pharmaceutical packaging. Standard neck preform mould (such as 28/38mm, 48 or 72 cavities) can be delivered within 1 week, and non-standard preform mould supports fast delivery in 2 weeks. Our company applies Copper Beryllium (Mouldmax) to the neck core and key cooling areas of preform mould, achieving excellent uniform cooling for PET high-speed injection. We produce thousands of PET preform moulds annually. Combined with our parent company DKM high-speed injection moulding machines, we provide turnkey solutions from mould to complete production line for efficient and stable mass production.
Standard Preform Mould Details
Below are examples of common parameters for PET preform moulds.
| Preform mould cavity steel | P20, 718H, S136, DIN 1.2316; Mouldmax copper-beryllium alloy used for neck and key cooling areas | Preform mould core steel | P20, 718H, S136, DIN 1.2316; Mouldmax copper-beryllium alloy for neck core enhanced cooling |
|---|---|---|---|
| Mould base standard / steel | Standard mould base, 45#, P20, 4Cr13 pre-hardened steel | Steel for sliders, inserts, lifters | High-strength tool steel, nitriding/surface strengthening, wear-resistant and smooth |
| Number of preform mould cavities | 8-144 cavities, customized as required | Preform mould hot runner type | Valve gate hot runner / Open hot runner |
| Preform mould compatible injection moulding machine | DKM PET high-speed injection moulding machine series | Preform mould raw material | PET, typical IV 0.72–0.84 dL/g |
| Ejection System | Stripper plate + ejector pins + neck unscrewing | Injection Process | High-speed injection, precise temperature control, closed-loop cooling, low AA control |
| Injection Cycle Time | 6–12 seconds | Mould Manufacturing Lead Time | Standard neck 7 days; Non-standard 14–28 days |
Technical Analysis of Preform Moulds
- If cooling water channels are uneven and neck temperature differs, it will cause PET melt flow difference. Hotter areas have better flow and thicker preform; colder areas have weaker flow and thinner preform. Normal temperature difference alone can cause about 0.05mm wall thickness tolerance, directly affecting blow moulding uniformity.
- The height of zero-degree positioning and interlock in preform mould is suggested to be 25%–35% of preform height: around 25% for low cavities and about 35% for high cavities (over 48 cavities), ensuring clamping concentricity and reducing eccentricity.
- During machining of core, cavity and neck thread for preform moulds, high-precision CNC and grinding machines must be used to ensure concentricity, thread accuracy and dimensional consistency, avoiding eccentricity and neck leakage from the source.
Key Quality Points of Preform Mould
SINO MOULD implements strict full-process quality control for PET preform moulds. From steel selection, structural design, precision machining to mould trial validation, the whole process ensures high precision, stability, long service life and low acetaldehyde output.
Preform Mould Structural Optimization Design
- Optimize spiral/direct cooling channels according to PET preform structure, combined with Mouldmax high thermal conductivity to ensure even temperature distribution and solve uneven wall thickness.
- Independent temperature control cooling for neck to improve thread accuracy and roundness, eliminate blow moulding deformation.
- Optimize runner, gate and hot runner layout via mould flow analysis for balanced multi-cavity filling, less sink marks, air traps and warpage.
Preform Mould Steel Material Selection
- Core and cavity use high-polish, wear-resistant and corrosion-resistant mould steel, with Copper Beryllium alloy at key neck positions.
- Mould base adopts high-strength rust-proof steel suitable for long-term high-speed mass production.
- Hot runner, neck inserts and unscrewing mechanism use high-temperature and wear-resistant materials.
Preform Mould Machining Precision Control
- High-precision 5-axis/CNC machining with key dimension tolerance ±0.01mm.
- Multi-stage inspection for parallelism, perpendicularity, concentricity, water sealing and thread accuracy.
- Mirror polishing on cavity (Ra≤0.025μm) ensures smooth, transparent and flawless preform surface.
Preform Mould Assembly & Mould Trial
- Precise assembly of unscrewing mechanism, ejection system and hot runner for smooth and stable operation.
- Focus on wall thickness uniformity, neck dimension, appearance transparency, acetaldehyde content and weight consistency during trial.
- Adjust process and mould structure timely to ensure stable high-speed production.
Preform Mould Validation & Continuous Optimization
- 72-hour continuous production test before delivery to simulate real mass production.
- Comprehensively verify reliability of cooling system, hot runner, unscrewing and multi-cavity balance.
- Continuously optimize mould structure, cooling solution and hot runner parameters based on field data.
Mould Flow Analysis for Preform Moulds
Using Mouldflow analysis software, we simulate the whole PET injection process, optimize cavity structure, runner layout, hot runner and cooling system, ensuring balanced multi-cavity filling and uniform PET molecular distribution, reducing risks of eccentricity, sink marks, warpage, air traps and excessive acetaldehyde.
