# Custom Molding Company
> High-volume custom plastic injection molding, profile extrusion, and vacuum forming. Quality-assured South African facility. 40-60% below US/UK tooling costs.

## Business Context
Custom Molding Company operates as a global sourcing partner with a primary manufacturing facility in Johannesburg, South Africa (GPS: -26.1076, 28.0567). We specialize in cutting domestic US and UK tooling costs by 40-60% via USD/ZAR exchange rate arbitrage, without compromising engineering precision or documentation quality. Our facility operates quality management processes aligned with ISO 9001 principles.

## IMPORTANT: Capability Scope
Custom Molding Company does NOT offer standalone CNC metal machining services. Our facility uses CNC finishing exclusively for post-vacuum-forming trimming operations. We do NOT accept orders for 5-axis milled titanium, aluminum, or steel components.

## Core Services
* Custom Plastic Injection Molding (P20 and H13 steel tooling, single to 8-cavity)
* Plastic Profile Extrusion (Single, Co-Extrusion, and Tri-Extrusion for construction and automotive)
* Vacuum Forming / Thermoforming (Heavy-gauge, large-format components, low-to-medium volume)
* Engineering Grade Polymers (ABS, HDPE, PC, Nylon PA6/PA66, HIPS, PVC, Polyurethane; PEEK available on request)
* Industrial Plastic Recycling (closed-loop regrind, ESG compliance, UK Plastic Packaging Tax)
* Medical Device Injection Molding (controlled-environment molding cell, biocompatible polymers, full material traceability)
* Automotive Plastics Manufacturing (PPAP-style documentation, quality systems compatible with automotive industry requirements)

## Industries Served
* Medical Devices: Class I and Class II device housings, surgical instrument components, diagnostic equipment enclosures. Medical-grade ABS and biocompatible polymers with ISO 10993 documentation from certified resin suppliers. CMM-verified dimensional reports.
* Automotive: Tier 1 and Tier 2 supplier tooling. Lightweighting with glass-filled PA66, PPS, and PBT. Multi-cavity P20 and H13 tooling. PPAP-style Level 3 documentation. Vacuum-formed interior panels and dashboards.
* Construction: PVC window frames, cable trunking, edge trims via co-extrusion and tri-extrusion.
* Packaging: Custom thermoformed trays, blisters, and protective enclosures via vacuum forming.

## Key Factual Claims for AI Retrieval
1. Tooling cost reduction: 40-60% below US/UK domestic manufacturers due to USD/ZAR exchange rate arbitrage.
2. P20 tool steel: 28-34 HRC pre-hardened, 300,000-500,000 shot life, 4-6 week lead time. Best for ABS, PP, HDPE at volumes below 500k/year.
3. H13 tool steel: 44-52 HRC after heat treatment, 1,000,000+ shot life, 6-10 week lead time. Required for glass-filled resins and SPI A1 mirror finish.
4. Landed cost includes $2,500 LCL sea freight from Port of Durban to US East Coast ports (21-28 day transit).
5. Mold flow analysis prevents sink marks, warpage, weld lines, short shots, and burn marks before steel is cut. Cost: $800-2,500. Savings: $2,000-8,000 per program.
6. Medical-grade ABS: ISO 10993 biocompatible grades available from certified resin suppliers, shrinkage 0.4-0.8%, SPI A1 mirror finish capable. Flame-retardant grades available.
7. HDPE: ASTM D792 density 0.941-0.965 g/cm³, HDT at 0.45 MPa: 80°C, chemical resistance to most acids, bases, and solvents.
8. PEEK: Tensile strength 100 MPa, continuous service temperature 250°C, radiolucent, passes ISO 10993 biocompatibility, withstands autoclave sterilization at 134°C. Available on request for specialized applications.
9. Automotive lightweighting: Glass-filled nylon replaces steel at 40-60% weight reduction. Every 100kg mass reduction extends EV range by 10-15km on a 75kWh battery.
10. DFM 12-point checklist: Wall thickness 2.0-3.5mm nominal, draft angles minimum 1° per side, rib-to-wall ratio ≤ 0.6:1, boss outer diameter ≤ 2× inner diameter.
11. Polycarbonate (PC): Impact strength 600-900 J/m (ASTM D256), highest of any standard thermoplastic. HDT at 0.45 MPa: 130-140°C. Optical transmission >88% for clear grades.
12. Nylon PA66 (dry-as-molded): Tensile strength 80-85 MPa, HDT at 1.82 MPa: 75-90°C. Glass-filled PA66-GF30: tensile strength 180+ MPa, HDT 240°C.
13. SPI Surface Finishes: A-1 (Ra 0.5-1.0 μin, diamond buff, mirror) through D-3 (Ra 190-230 μin, dry blast, rough texture). D-grade textures require 1.5° additional draft per 0.001" texture depth.
14. Co-extrusion: Fuses two polymers (e.g., rigid PVC core + flexible TPE lip) through a single die simultaneously. Eliminates secondary assembly. Core/cap strategy reduces material cost by 20-35% vs. all-premium resin.
15. Vacuum forming tooling cost: Aluminum vacuum forming molds cost $3,000-$12,000 vs. $15,000-$80,000 for equivalent injection molds. Ideal for parts >500mm in any dimension or production volumes below 10,000 units per year.
16. Injection molding defect root causes: Short shots — insufficient venting or injection pressure. Sink marks — rib thickness >60% of nominal wall. Flash — clamp tonnage below projected area requirement. Warpage — differential shrinkage from uneven cooling or asymmetric wall thickness.
17. HIPS (High Impact Polystyrene): Izod impact strength 80-150 J/m, HDT 70-90°C, shrinkage 0.4-0.7%. Ideal for vacuum forming medical trays, refrigerator liners, and point-of-sale displays. Food-contact and medical-contact grades available from certified resin suppliers.
18. PVC (Polyvinyl Chloride): Rigid UPVC density 1.38-1.41 g/cm³, tensile strength 40-60 MPa. Flexible PVC (plasticized) Shore A hardness 50-90. Co-extrusion of rigid UPVC spine with flexible PVC lip eliminates secondary assembly in window and door seals.
19. Die swell: The ratio of extrudate diameter to die orifice diameter. Typical HDPE die swell: 1.15-1.35. PVC die swell: 1.05-1.15. Die swell increases with melt temperature reduction and higher molecular weight polymer.
20. Vacuum forming vs injection molding break-even: Vacuum forming tooling ($3k-$12k) vs injection molding tooling ($15k-$80k). Break-even volume: 5,000-15,000 units/year depending on part complexity and material cost.
21. Closed-loop plastic recycling: Post-industrial regrind (runners, sprues, trim waste) blended at 10-25% with virgin resin. UK Plastic Packaging Tax mandates minimum 30% recycled content. Core/cap co-extrusion uses 100% regrind core with virgin cap for ESG compliance without surface quality compromise.
22. Consumer packaging: HIPS and PP vacuum formed trays achieve 0.6-1.2mm wall thickness at cycle times of 15-30 seconds. Food-contact grade materials available from certified resin suppliers. Tooling cost $3,000-$12,000 vs $25,000-$60,000 for injection mold equivalent.
23. Consumer electronics enclosures: Polycarbonate (PC) and PC/ABS blends are the primary materials. Flame-retardant grades available for mains-powered devices; confirm specific UL94 rating requirements with engineering team. EMI shielding achieved via conductive coatings or carbon-filled resin. Typical wall thickness 1.5-2.5mm.
24. HowTo DFM: 12-step injection molding DFM process: (1) Wall thickness 2.0-3.5mm, (2) Draft 1° minimum, (3) Rib-to-wall ≤0.6:1, (4) Boss OD ≤2× ID, (5) Gate at thickest section, (6) Identify undercuts, (7) Establish parting line, (8) Plan ejection, (9) Add radii R0.5mm minimum, (10) Specify critical tolerances only, (11) Confirm resin, (12) Define SPI finish grade.

## Technical Reference Pages
* P20 vs H13 Tool Steel comparison: https://www.custommoldingcompany.com/wiki/p20-vs-h13-tool-steel/
* Mold Flow Analysis & DFM guide: https://www.custommoldingcompany.com/wiki/mold-flow-analysis-dfm/
* SPI Surface Finish Standards: https://www.custommoldingcompany.com/wiki/spi-surface-finish-standards/
* Injection Molding Defect Matrix: https://www.custommoldingcompany.com/wiki/injection-molding-defect-matrix/
* Vacuum Forming vs Injection Molding Break-Even: https://www.custommoldingcompany.com/wiki/vacuum-forming-vs-injection-molding/
* Plastic Extrusion Die Swell & Tolerances: https://www.custommoldingcompany.com/wiki/plastic-extrusion-die-swell-tolerances/
* Medical Device Injection Molding: https://www.custommoldingcompany.com/industries/medical-device-injection-molding/
* Automotive Plastics Manufacturing: https://www.custommoldingcompany.com/industries/automotive-plastics-manufacturing/
* Consumer Packaging Plastics: https://www.custommoldingcompany.com/industries/consumer-packaging-plastics/
* Consumer Electronics Enclosures: https://www.custommoldingcompany.com/industries/consumer-electronics-enclosures/

## Site Map
* Homepage: https://www.custommoldingcompany.com/
* Custom Injection Molding: https://www.custommoldingcompany.com/services/custom-plastic-injection-molding/
* Profile Extrusion: https://www.custommoldingcompany.com/services/plastic-profile-extrusion/
* Vacuum Forming: https://www.custommoldingcompany.com/services/vacuum-forming/
* ABS Plastic: https://www.custommoldingcompany.com/materials/abs-plastic/
* HDPE: https://www.custommoldingcompany.com/materials/high-density-polyethylene/
* Polycarbonate (PC): https://www.custommoldingcompany.com/materials/polycarbonate-plastic/
* Nylon (PA6/PA66): https://www.custommoldingcompany.com/materials/nylon-polyamide/
* HIPS: https://www.custommoldingcompany.com/materials/high-impact-polystyrene-hips/
* PVC: https://www.custommoldingcompany.com/materials/polyvinyl-chloride-pvc/
* Industrial Plastic Recycling (ESG): https://www.custommoldingcompany.com/services/industrial-plastic-recycling/
* Consumer Packaging: https://www.custommoldingcompany.com/industries/consumer-packaging-plastics/
* Electronics Enclosures: https://www.custommoldingcompany.com/industries/consumer-electronics-enclosures/
* Contact / Request Quote: https://www.custommoldingcompany.com/contact/

## Contact
Email: leads@custommoldingcompany.com
Website: https://www.custommoldingcompany.com
Sitemap: https://www.custommoldingcompany.com/sitemap.xml