| Mould Type | Single-colour injection mould; direct-injection shoe mould; two-colour or multi-colour mould; compression mould; rotational mould. | The correct mould structure depends on the shoe construction, PVC formulation, outsole geometry, production volume, and required surface finish. | Request samples showing the same sole profile, material hardness, colour arrangement, and production process. | Direct injection and multi-colour designs remain relevant where manufacturers seek fewer assembly steps and more integrated footwear designs. |
| Typical Mould Material | P20 pre-hardened steel is commonly used for general production; H13 hot-work steel is used for higher thermal and wear resistance; 420 stainless steel is selected where corrosion resistance and polished surfaces are important; aluminium is used mainly for prototypes or short runs. | Material selection affects mould life, polishing quality, dimensional stability, corrosion resistance, machining time, and total cost. | Ask for the actual material grade, hardness report, heat-treatment record, and certificate traceable to the mould components. | Buyers increasingly compare lifecycle cost rather than only the initial mould quotation, especially for repeat production and export orders. |
| PVC Processing Temperature | PVC injection processing is formulation-dependent; many rigid and flexible PVC applications are processed within an approximate melt-temperature range of 160–210 °C. | PVC is sensitive to overheating and prolonged residence time. Excessive temperature can cause degradation, discoloration, gas generation, and surface defects. | Check whether the mould design includes balanced filling, adequate venting, and cooling suitable for the selected PVC compound. | Energy control, stable processing windows, and reduced scrap are important purchasing criteria as production costs remain under pressure. |
| Mould Surface Finish | Common finishes include high polish, matte texture, leather grain, fabric grain, anti-slip texture, logo relief, and decorative engraving. | Surface texture directly influences appearance, grip, demoulding behaviour, and the visibility of flow or weld marks. | Approve a physical texture sample or master pattern before final machining and confirm the allowable texture deviation. | Functional outsole textures and visually distinctive patterns continue to support product differentiation without changing the basic PVC process. |
| Cavity Configuration | Typical configurations include one cavity for sampling, two to four cavities for flexible production, and higher cavity counts for large-volume standardised products. | More cavities can increase output but also raise requirements for filling balance, temperature control, mould alignment, maintenance, and machine capacity. | Verify cavity-to-cavity weight variation, dimensions, colour consistency, and the required injection-machine tonnage. | Flexible cavity planning is useful because footwear demand can change by season, size range, colour, and export destination. |
| Mould Cooling System | Water channels are normally arranged around thicker sections and high-heat areas; baffles, bubblers, or conformal cooling may be used where conventional drilling is insufficient. | Uniform cooling helps reduce cycle-time variation, shrinkage differences, warpage, and inconsistent sole dimensions. | Request a cooling-layout drawing and confirm pressure testing, accessibility for cleaning, and leak prevention. | Shorter and more stable cycles are increasingly valued because they improve output per machine and reduce energy consumption per pair. |
| Venting and Gas Control | Vents are placed at likely air-trap locations, including the toe, heel, tread ends, deep textures, and parting-line areas. | Insufficient venting may cause burn marks, short shots, flow marks, trapped gas, and incomplete detail transfer. | Inspect vent dimensions, vent-cleaning access, and trial-run records using the intended PVC compound. | Consistent appearance and lower rejection rates are important indicators of process maturity in export-oriented footwear production. |
| Dimensional Control | Critical dimensions normally include outsole length, width, heel height, tread depth, wall thickness, parting-line position, and fitting features. | Accurate dimensions support consistent sizing, fit, assembly, packing, and interchangeability between production batches. | Require a dimensional inspection report based on an agreed drawing, 3D model, tolerance table, or approved master sample. | Digital inspection, 3D scanning, and documented first-article approval are increasingly used to reduce communication errors across borders. |
| Expected Mould Service Life | Service life varies widely with steel grade, PVC additives, mould maintenance, cycle conditions, surface treatment, and production volume; it should be specified as an agreed shot or cycle target rather than a generic promise. | PVC formulations containing abrasive fillers or pigments can accelerate wear, while poor cleaning and corrosion can shorten usable life. | Ask for a written maintenance schedule, spare-part policy, repair procedure, and measurable life guarantee. | Total cost of ownership, repairability, and after-sales technical support are stronger trust indicators than a low initial price alone. |
| Quality Documentation | Useful documents include approved drawings, 3D files, steel certificates, hardness results, trial reports, inspection records, packing lists, and maintenance instructions. | Complete documentation improves repeatability, troubleshooting, ownership transfer, and future modification work. | A trustworthy supplier should provide controlled revision numbers and retain records for mould changes and corrective actions. | Traceability and transparent quality evidence are increasingly important for international buyers managing multi-site production. |
| Trust and Procurement Criteria | Relevant indicators include technical response quality, sample approval accuracy, realistic lead-time planning, inspection transparency, secure packaging, spare-part availability, and clear warranty terms. | These factors reveal whether a supplier can support the complete mould lifecycle rather than only manufacture a one-time tool. | Use a technical checklist, signed specifications, staged approval, trial samples, and acceptance criteria before final payment. | In 2024, supplier selection increasingly emphasised reliability, delivery visibility, production efficiency, sustainability-related requirements, and responsive technical service. |