PVC (Type 1) Rigid Sheet Technical Spec
Comprehensive technical specification for rigid PVC (Type 1) sheet stock, covering Canadian standard sizing, machining parameters, common defects, and storage guidelines for fabrication and machining operations.
Material Overview & Common Uses
Rigid PVC (Polyvinyl Chloride) Type 1 (unplasticized, high-impact grade) is a versatile thermoplastic sheet widely used in Canadian industrial fabrication, signage, chemical processing, and architectural millwork. It offers excellent chemical resistance, good dimensional stability, and self-extinguishing flammability characteristics. Common applications include: chemical tank linings, fume hoods, ductwork, machine guards, jigs and fixtures, point-of-purchase displays, and outdoor signage. Type 1 PVC is preferred for its balance of stiffness, impact strength, and machinability compared to Type 2 (high-impact) or cellular PVC.
Core Technical Properties & Sizing
| Property & Standard Sizes | Value / Specification | Standard / Method |
|---|---|---|
| Density | 1.40 – 1.45 g/cm³ | ASTM D792 |
| Tensile Strength | 6,500 – 8,000 psi (45 – 55 MPa) | ASTM D638 |
| Flexural Modulus | 350,000 – 450,000 psi (2.4 – 3.1 GPa) | ASTM D790 |
| Impact Strength (Izod, notched) | 0.5 – 1.5 ft-lb/in (27 – 80 J/m) | ASTM D256 |
| Heat Deflection Temp (HDT) @ 264 psi | 155 – 175°F (68 – 79°C) | ASTM D648 |
| Coefficient of Linear Thermal Expansion | 3.0 – 5.0 × 10⁻⁵ in/in/°F (5.4 – 9.0 × 10⁻⁵ mm/mm/°C) | — |
| Flammability Rating | UL 94 V-0 (self-extinguishing) | — |
| Water Absorption (24 hr) | 0.04 – 0.10% | ASTM D570 |
| Standard Sheet Sizes (Canadian Stock) | 48″ × 96″ (1220 × 2440 mm) and 60″ × 120″ (1525 × 3050 mm) | — |
| Thickness Range | 1/16″ (1.5 mm) to 2″ (50.8 mm) | Common: 1/8″, 1/4″, 3/8″, 1/2″, 3/4″, 1″ |
| Thickness Tolerance | ±10% (≤1/4″), ±8% (1/4″–1/2″), ±6% (1/2″–1″), ±5% (>1″) | ASTM D1784 |
| Flatness Tolerance | 1/8″ over 48″ length for ≤ 1/2″ thick; 1/16″ over 48″ for > 1/2″ thick | — |
| Surface Finish & Color | Glossy on both sides (standard); White, Grey, Black opaques | Custom colors available on special order |
Machinability, Tooling & Feeds
Rigid PVC Type 1 machines well with standard woodworking and metalworking equipment, but requires sharp tooling and proper chip evacuation to prevent melting or gumming. Refer to the table below for recommended parameters:
| Operation | Tooling Recommendation | Feeds & Speeds |
|---|---|---|
| Sawing | Carbide-tipped blade, 10–12 TPI (≤1/2″), 8–10 TPI (>1/2″) | 3,000–4,000 SFM (15–20 m/s), moderate feed rate |
| Routing | Single-flute or two-flute carbide bits, 1/4″–1/2″ diameter | 12,000–18,000 RPM, 100–200 IPM (2.5–5 m/min) |
| Drilling | HSS or carbide twist drills, 118° point angle | 2,000–3,000 RPM (1/8″–1/4″), 1,000–1,500 RPM (larger). Peck drill to clear chips. |
| Tapping | Roll-form taps (≤1/4-20), cut taps for larger threads | 500–1,000 RPM. Use wax or light oil lubricant. |
| Turning | Carbide inserts with positive rake geometry | 400–800 SFM (2–4 m/s), Feed: 0.005–0.015 IPR, Depth: 0.020–0.100″ |
| Edge Finishing | Sand with 180–320 grit abrasive paper | Flame polishing possible for clear grades (not typical for opaque) |
| Bonding | Solvent cements (IPS Weld-On 3, 4, or 16) | 24 hr cure at 70°F (21°C) for structural joints |
| Thermal Forming | Strip heaters or convection oven | 250–300°F (120–150°C). Cool under restraint to maintain shape. |
| Chip Control | Use vacuum or compressed air | Chips are non-toxic but can create slippery floors |
Common Defects & Quality Control
Incoming inspection and in-process quality checks should focus on the following parameters:
| Defect | Description | Acceptance Criteria |
|---|---|---|
| Surface Scratches | Fine linear marks from handling or packaging | ≤ 0.002″ deep; acceptable if not in critical aesthetic areas |
| Die Lines / Extrusion Marks | Longitudinal grooves from manufacturing | ≤ 0.001″ deep and spaced ≥ 1″ apart |
| Pits / Voids | Small circular depressions from trapped air | Maximum diameter 0.010″; ≤ 2 per sq ft |
| Warpage / Bow | Deviation from flatness | Rejectable if > 1/8″ over 48″ length (for ≤ 1/2″ thick) |
| Thickness Variation | Out-of-tolerance per ASTM D1784 | Rejectable if outside stated tolerances |
| Color Inconsistency | Streaks or mottling in opaque sheets | Compare to approved standard under D65 lighting |
| Edge Cracks / Delamination | Visible separation at cut edges | Reject if > 1/16″ deep |
| Contamination | Embedded foreign particles | Reject if visible to the naked eye |
| Storage Damage (Crazing) | White stress marks from cold bending or impact | Reject if surface integrity is compromised |
| QC Tools | Digital caliper, straightedge, feeler gauge, 10× loupe, gloss meter | Verify thickness, flatness, surface defects, and finish consistency |
Storage, Handling & Racking Guidelines
Proper storage and handling prevent damage and maintain material quality for fabrication.
| Parameter | Guideline |
|---|---|
| Temperature | Store at 60–80°F (15–27°C). Avoid direct sunlight and heat sources. |
| Humidity | No special requirement; PVC is not hygroscopic, but keep dry to prevent condensation. |
| Racking | Vertical in A-frame racks with padded supports. Max stack: 12 sheets (1/4″), 6 sheets (1/2″), 3 sheets (1″). |
| Lifting | Use suction cups or edge protectors for sheets > 4′ × 8′. Never drag sheets across each other. |
| Packaging | Keep original plastic wrap or interleave paper between sheets to prevent abrasion. |
| FIFO Rotation | Rotate stock; PVC has indefinite shelf life if stored properly, but older stock may yellow slightly. |
| Safety | PVC dust is a mild irritant. Use local exhaust ventilation when machining. Avoid smoking near PVC dust (toxic fumes). |
| Fire | Self-extinguishing, but emits hydrogen chloride (HCl) gas if burned. Store away from open flames. |