Seamless hollow parts
injection molding
physically cannot make.
Rotational molding. Biaxial rotation inside heated steel molds. Stress-crack-resistant LLDPE, XLPE, and nylon — at tooling costs that make blow molding look like a luxury.
Why rotomolding wins
where others can't compete.
Three processes. One benchmark. Procurement engineers use this table to justify tooling decisions to finance — the numbers hold up under audit.
| Metric | RotomoldingThis facility | Blow Molding | Injection Molding | Note |
|---|---|---|---|---|
| Tooling Cost | $3K–$15K | $30K–$80K | $50K–$250K+ | Aluminum tooling vs. hardened steel |
| Part Size Range | 0.5L → 50,000L | 0.1L → 220L | < 50L practical | No practical upper volume limit |
| Wall Uniformity | ±0.3 mm | ±0.8–1.5 mm | ±0.1–0.5 mm | Seamless, no weld lines |
| Minimum Order Qty | 1 unit | 500–2,000 units | 2,000–10,000 units | Prototype to production, same tool |
| Stress-Crack Resistance | Excellent (XLPE) | Good | Moderate | Cross-linked PE eliminates ESC failure |
| Complex Geometry | High (undercuts OK) | Moderate | High (draft required) | No internal cores required |
| Cycle Time | 15–45 min | 30–120 sec | 15–90 sec | Justified by tooling economics |
▸ Data sourced from SPE Rotational Molding Division technical reports. Tooling costs reflect North American suppliers, 2025.
Three polymers.
Every application covered.
Material selection is the first engineering decision. These data sheets contain the values your stress analysis needs — not marketing claims.
The workhorse. 85% of our production volume. Proven in 10,000-litre agricultural tanks operating in -40°C Canadian winters.
LLDPE
Color: Natural / Pigmentable| Property | Value | Test Standard |
|---|---|---|
| Melt Flow Index | 3–7 g/10 min | ASTM D1238 |
| Density | 0.926–0.940 g/cm³ | ASTM D792 |
| Tensile Strength | 20–25 MPa | ASTM D638 |
| Impact Resistance | Excellent | Low-temp ductile |
| UV Stability | Carbon Black / UV8 | ≥ 10 yr outdoor |
| Operating Temp | -50°C to +80°C | Continuous service |
Specified when environmental stress cracking is the failure mode. Cross-linking occurs during the molding cycle — no secondary process.
XLPE
Color: Natural / Black| Property | Value | Test Standard |
|---|---|---|
| Cross-Link Density | ≥ 65% | ASTM D2765 |
| Melt Flow Index | 3.5–5 g/10 min | Pre-cross-link |
| Stress-Crack Resist. | > 1000 hr | ASTM D1693-F50 |
| Chemical Resistance | Class A | Acids, alkalis, solvents |
| UV Stability | Carbon Black | ≥ 15 yr outdoor |
| Operating Temp | -60°C to +110°C | Continuous service |
When LLDPE stiffness is insufficient. Nylon parts carry structural loads that polyethylene cannot. Specified for kayak hulls, industrial hoppers, and high-abrasion environments.
Nylon 6
Color: Natural / Black / Custom| Property | Value | Test Standard |
|---|---|---|
| Particle Size | 350–500 μm | Rotomolding optimized |
| Tensile Strength | 60–80 MPa | ASTM D638 |
| Flexural Modulus | 2.5–3.0 GPa | ASTM D790 |
| Continuous Use Temp | -40°C to +120°C | Dry conditions |
| Abrasion Resistance | Excellent | Sand/slurry service |
| FDA Compliance | 21 CFR 177.1500 | Food contact grade |
CAD receipt to crated shipment.
No ambiguity in the schedule.
First-time production parts in 25–37 days. Repeat orders from stock tooling ship in 5–10 days. Every phase has a deliverable — not a status update.
▸ Click any phase bar to expand deliverables and process details.
Request a DFM Review.
Design-for-Manufacturability review is complimentary on all qualified enquiries. We review your geometry and return a written assessment within 48 hours — tooling cost estimate included.
Download the Rotomolding Spec Guide
32-page technical reference covering wall thickness guidelines, draft angles, insert design, and material selection matrices. Used by 400+ engineers benchmarking processes.