Cast Acrylic Sheet IM
Grade
GB GB/T 7134-2008 Type 1 · ISO 7823-1
IM = impact-modified (high-impact) acrylic sheet
Rubber-toughened PMMA for glazing, machine guards and point-of-sale parts that must survive handling impact.
Values for the IM condition
Other Cast Acrylic Sheet grades and fills
Cast Acrylic Sheet is listed in 7 conditions; see the grade overview at Cast Acrylic Sheet.
Compare all 7 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
IMThis page Impact-modified (high-impact) acrylic sheet | Rubber-toughened PMMA for glazing, machine guards and point-of-sale parts that must survive handling impact. | — | 50 | 35 | 68 HRM |
Flame-retardant cast sheet | FR-additive cast sheet for transport interiors, lighting diffusers and building panels needing V-0 or DIN 4102 B1. | 60 | 62 | 3 | 88 Shore D |
Antistatic / static-dissipative cast sheet | Coated or compounded dissipative sheet for cleanroom enclosures, electronics workstation guards and semiconductor tooling. | 67 | 70 | 4 | 88 Shore D |
Extruded PMMA sheet | Cheaper, tighter-thickness extruded sheet; choose when cost and gauge tolerance matter more than solvent resistance or thermoforming detail. | — | 68 | 4.5 | 90 HRM |
Thick cast block / slab | Heavy-section cast slab for aquarium windows, submersible viewports and machined optical blocks; requires careful annealing. | 69 | 72 | 4 | 90 Shore D |
Colored / opal light-diffusing cast sheet | Pigmented, translucent or opal cast sheet for backlit signs, luminaire diffusers and decorative panels. | 70 | 73 | 4 | 90 Shore D |
Abrasion-/chemical-resistant hard-coated cast sheet | Siloxane hard-coated sheet for touch surfaces, machine windows and outdoor glazing where scratching is the failure mode. | 71 | 74 | 3.5 | 92 Shore D |
What is Cast Acrylic Sheet IM?
Cast Acrylic Sheet IM is Cast Acrylic Sheet in the IM grade — rubber-toughened PMMA for glazing, machine guards and point-of-sale parts that must survive handling impact. Cast Acrylic Sheet IM has a yield strength of 72 MPa (10.4 ksi) and a tensile strength of 50 MPa (7.25 ksi) — stronger than 82% of polymer grades. Elongation at break is 35% and the elastic modulus is 2.3 GPa (0.334 Msi). Cast Acrylic Sheet IM has a density of 1.17 g/cm³ (0.0423 lb/in³), lighter than 54% of polymer grades. Its glass-transition temperature is 108°C (226 °F).
Advantages
- Polishes to a fine finish — 95/100, better than 98% of polymer grades
- Good UV / weathering resistance — 90/100, better than 91% of polymer grades
- High strength — 72 MPa (10.4 ksi), better than 82% of polymer grades
Limitations
- Needs corrosion protection — 70/100, worse than 78% of polymer grades
- Low fracture toughness — 1.2 MPa·√m (1.09 ksi·√in), worse than 77% of polymer grades
Cast Acrylic Sheet IM properties
Typical room-temperature values for Cast Acrylic Sheet IM; 13 are specific to this condition. Other listed values are Cast Acrylic Sheet reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
Cast Acrylic Sheet IM has a density of 1.17 g/cm³ (0.0423 lb/in³), lighter than 54% of polymer grades. Its glass-transition temperature is 108°C (226 °F).
Mechanical17
Cast Acrylic Sheet IM has a yield strength of 72 MPa (10.4 ksi) and a tensile strength of 50 MPa (7.25 ksi) — stronger than 82% of polymer grades. Elongation at break is 35% and the elastic modulus is 2.3 GPa (0.334 Msi).
Thermal11
Cast Acrylic Sheet IM is rated for continuous service to 80°C (176 °F). It conducts heat at 0.19 W/m·K (0.11 BTU/hr·ft·°F), worse than 68% of polymer grades. Thermal expansion is 70 µm/m·K (38.9 µin/in·°F).
Electrical7
Cast Acrylic Sheet IM is an electrical insulator with a dielectric strength of 25 kV/mm (635 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 78% of polymer grades. UV resistance is excellent.
Sustainability4
Producing a kilogram of Cast Acrylic Sheet IM takes about 100 MJ of energy and emits 6 kg of CO₂ — less than 61% of polymer grades. Typical recycled content is 2%.
Manufacturability4
Cast Acrylic Sheet IM's machinability is very good (70/100, better than 74% of polymer grades); weldability good (60/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Cast Acrylic Sheet IM
Is Cast Acrylic Sheet easy to machine?
Use sharp, high-rake carbide or single-flute router bits, high spindle speed with moderate feed and air/mist cooling; anneal at 80 °C before and after heavy machining to prevent crazing at cut edges.
Can Cast Acrylic Sheet be welded?
Joined by solvent cementing (dichloromethane, MMA-based cements) or two-part acrylic adhesive rather than fusion welding; hot-gas/ultrasonic welding is possible but rarely used on cast sheet.
Can Cast Acrylic Sheet be formed, bent or molded?
Thermoform or line-bend at 150–190 °C after drying 2–4 h at 80 °C; cast sheet shrinks ~2 % in the casting direction on reheat, so allow for orientation shrinkage in tooling.
What surface finishes work on Cast Acrylic Sheet?
Edges are diamond-polished, buffed or flame-polished to optical clarity; surfaces accept screen/UV printing, vinyl, laser engraving and siloxane hard or anti-reflective coatings.
Cast Acrylic Sheet chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| methyl acrylate / ethyl acrylate comonomoptional comonomer for thermal-processing latitude | 0 – 4 | 1 |
| peroxide/azo initiator + chain-transfer residuals from polymerization | 0.01 – 0.5 | 0.2 |
| UV absorber / stabilizerpresent in UV-filtering and outdoor grades | 0 – 1 | 0.3 |
| residual MMA monomerlower in cast than in extruded sheet | 0.1 – 1.5 | 0.7 |
| poly(methyl methacrylate) (MMA units)cell-cast from MMA monomer/syrup; very high molecular weight (Mw > 10⁶), essentially non-melt-processable | ≥ 95 (balance) | — |
Cast Acrylic Sheet IM — frequently asked
What is Cast Acrylic Sheet IM used for?
Cast Acrylic Sheet IM is typically used for display cases, aquariums, signage, skylight domes and point-of-purchase displays. In short: better solvent resistance than extruded; polishes to optical clarity; machines and laser-cuts cleanly.
What is the yield strength of Cast Acrylic Sheet IM?
Cast Acrylic Sheet IM has a typical yield strength of 72 MPa (10.4 ksi) and a tensile strength of 50 MPa (7.25 ksi) — stronger than 82% of polymer grades. Strength varies by condition: see the 7 listed tempers.
Is Cast Acrylic Sheet IM easy to machine?
Yes — machinability is rated very good (70/100, better than 74% of polymer grades). Use sharp, high-rake carbide or single-flute router bits, high spindle speed with moderate feed and air/mist cooling; anneal at 80 °C before and after heavy machining to prevent crazing at cut edges.
Can Cast Acrylic Sheet IM be welded?
Yes — weldability is rated good (60/100). Joined by solvent cementing (dichloromethane, MMA-based cements) or two-part acrylic adhesive rather than fusion welding; hot-gas/ultrasonic welding is possible but rarely used on cast sheet.
What surface finishes work on Cast Acrylic Sheet IM?
Edges are diamond-polished, buffed or flame-polished to optical clarity; surfaces accept screen/UV printing, vinyl, laser engraving and siloxane hard or anti-reflective coatings.
Can Cast Acrylic Sheet IM be formed, bent or molded?
Thermoform or line-bend at 150–190 °C after drying 2–4 h at 80 °C; cast sheet shrinks ~2 % in the casting direction on reheat, so allow for orientation shrinkage in tooling.
What is the maximum service temperature of Cast Acrylic Sheet IM?
Cast Acrylic Sheet IM is rated for continuous use to about 80°C (176 °F), and briefly to 100°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D4802 — Poly(Methyl Methacrylate) Acrylic Plastic Sheet — ASTM International (2021)
- ISO 7823-1 — Plastics: Poly(methyl methacrylate) sheets, cast sheets — ISO (2003)
- PLEXIGLAS GS cast sheet technical data — Röhm GmbH (2023)
- ACRYLITE / Chi Mei ACRYREX cast sheet property tables — Röhm / Chi Mei Corporation (2022)
- Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
- CAMPUS plastics database — PMMA sheet and molding grades — CWFG (2024)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.