EC D787-G7
Grade
D787-G7 = aSTM D787 Grade 7
Use where deflection under load must be limited while retaining moderate impact strength.
Values for the D787-G7 condition
Other EC grades and fills
EC is listed in 11 conditions; see the grade overview at EC.
Compare all 11 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
ASTM D787 Grade 1 | Pick for extreme low-temperature impact, flexible film/sheet and tough thin-wall covers where stiffness is irrelevant. | 13 | 17 | 45 | 62 Shore D |
ASTM D787 Grade 2 | Use for flexible tough parts needing slightly more form-holding than Grade 1. | 16 | 20 | 40 | 66 Shore D |
ASTM D787 Grade 3 | General flexible-tough grade for extruded profile and tubing where cold toughness dominates. | 18 | 24 | 35 | 70 Shore D |
ASTM D787 Grade 4 | Balanced soft-side grade for injection-molded housings and handles used outdoors in cold weather. | 21 | 27 | 30 | 73 Shore D |
ASTM D787 Grade 5 | Choose when a part needs both easy filling and useful stiffness at room temperature. | 24 | 31 | 27 | 76 Shore D |
D787-G6Default ASTM D787 Grade 6 | Default all-round ethyl cellulose molding compound: good balance of stiffness, cold impact and mold flow. | 26 | 34 | 24 | 78 Shore D |
D787-G7This page ASTM D787 Grade 7 | Use where deflection under load must be limited while retaining moderate impact strength. | 30 | 38 | 20 | 80 Shore D |
ASTM D787 Grade 8 | Hard grade for dimensionally critical molded parts and machined stock shapes. | 34 | 41 | 17 | 82 Shore D |
ASTM D787 Grade 9 | Low-plasticizer hard grade with better heat resistance and lower creep; impact drops markedly. | 38 | 45 | 14 | 83 Shore D |
ASTM D787 Grade 10 | For rigid parts that must hold shape near 70–75 °C; requires higher melt temperature to fill. | 42 | 50 | 11 | 84 Shore D |
ASTM D787 Grade 11 | Highest-modulus ethyl cellulose grade for rigid machined blanks and tool handles; least cold impact of the series. | 46 | 55 | 8 | 85 Shore D |
What is EC D787-G7?
EC D787-G7 is EC in the D787-G7 grade — use where deflection under load must be limited while retaining moderate impact strength. EC D787-G7 has a yield strength of 30 MPa (4.35 ksi) and a tensile strength of 38 MPa (5.51 ksi) — weaker than 70% of polymer grades. Elongation at break is 20% and the elastic modulus is 1.5 GPa (0.218 Msi). EC D787-G7 has a density of 1.12 g/cm³ (0.0405 lb/in³), lighter than 64% of polymer grades. Its glass-transition temperature is 96°C (205 °F). D787-G6 is the default condition FabDigit quotes; D787-G7 is available on request or by drawing note.
Advantages
- Easy to machine — 82/100, better than 86% of polymer grades
- Polishes to a fine finish — 70/100, better than 77% of polymer grades
Limitations
- Absorbs moisture — dry before molding — 1.6%, worse than 93% of polymer grades
- Needs corrosion protection — 60/100, worse than 89% of polymer grades
- Limited service temperature — 70°C (158 °F), worse than 77% of polymer grades
EC D787-G7 properties
Typical room-temperature values for EC D787-G7; 38 are specific to this condition. Other listed values are EC reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
EC D787-G7 has a density of 1.12 g/cm³ (0.0405 lb/in³), lighter than 64% of polymer grades. Its glass-transition temperature is 96°C (205 °F).
Mechanical17
EC D787-G7 has a yield strength of 30 MPa (4.35 ksi) and a tensile strength of 38 MPa (5.51 ksi) — weaker than 70% of polymer grades. Elongation at break is 20% and the elastic modulus is 1.5 GPa (0.218 Msi).
Thermal11
EC D787-G7 is rated for continuous service to 70°C (158 °F). It conducts heat at 0.2 W/m·K (0.116 BTU/hr·ft·°F), worse than 56% of polymer grades. Thermal expansion is 135 µm/m·K (75 µin/in·°F).
Electrical7
EC D787-G7 is an electrical insulator with a dielectric strength of 21 kV/mm (533.4 V/mil) and a resistivity of 1×10¹¹ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 89% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of EC D787-G7 takes about 100 MJ of energy and emits 4.2 kg of CO₂ — less than 61% of polymer grades. Typical recycled content is 0%.
Manufacturability8
EC D787-G7's machinability is very good (82/100, better than 86% of polymer grades); weldability good (56/100); formability good (58/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with EC D787-G7
Is EC easy to machine?
Machines easily with sharp, high-rake tools and generous chip clearance; keep speeds moderate and use air blast — the material is soft and heat-smears, and coolants containing esters/ketones will attack it.
Can EC be welded?
Not fusion-welded in the usual sense; joined by hot-plate/heat sealing or by solvent cementing with ketone/ester or chlorinated-solvent based cements, plus solvent-borne EC adhesives.
Can EC be formed, bent or molded?
Injection mold at 175–230 °C melt with 40–80 °C tools; dry the compound 2–3 h at 65–75 °C, avoid long residence at >230 °C (plasticizer loss and discoloration), shrinkage 0.3–0.8 %.
What surface finishes work on EC?
Takes solvent-based lacquers and hot stamping well; can be flame- or buff-polished lightly, but abrasive polishing loads quickly — mold-in gloss or texture is preferred.
EC 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 |
|---|---|---|
| plasticizer (dibutyl sebacate / phthalatcontent sets the D787 grade hardness/impact level | 4 – 30 | 15 |
| stabilizer + antioxidant | 0.2 – 2 | 0.8 |
| lubricant / mold release | 0.1 – 1.5 | 0.5 |
| pigment / colorantomitted in natural/transparent compounds | 0 – 3 | 0.7 |
| ethyl cellulose resin (cellulose ethyl eethoxyl content typically 44–50 wt% of the resin (DS ≈ 2.2–2.6) | ≥ 65 (balance) | — |
EC D787-G7 — frequently asked
What is EC D787-G7 used for?
EC D787-G7 is typically used for protective coatings, hot-melt adhesives, flexible tubing, pharmaceutical film coatings and electrical insulation. In short: toughest cellulosic in cold; non-acidic cellulose ether; coating and binder grade.
What is the yield strength of EC D787-G7?
EC D787-G7 has a typical yield strength of 30 MPa (4.35 ksi) and a tensile strength of 38 MPa (5.51 ksi) — weaker than 70% of polymer grades. Strength varies by condition: see the 11 listed tempers.
Is EC D787-G7 easy to machine?
Yes — machinability is rated very good (82/100, better than 86% of polymer grades). Machines easily with sharp, high-rake tools and generous chip clearance; keep speeds moderate and use air blast — the material is soft and heat-smears, and coolants containing esters/ketones will attack it.
Can EC D787-G7 be welded?
Yes — weldability is rated good (56/100). Not fusion-welded in the usual sense; joined by hot-plate/heat sealing or by solvent cementing with ketone/ester or chlorinated-solvent based cements, plus solvent-borne EC adhesives.
What surface finishes work on EC D787-G7?
Takes solvent-based lacquers and hot stamping well; can be flame- or buff-polished lightly, but abrasive polishing loads quickly — mold-in gloss or texture is preferred.
Can EC D787-G7 be formed, bent or molded?
Injection mold at 175–230 °C melt with 40–80 °C tools; dry the compound 2–3 h at 65–75 °C, avoid long residence at >230 °C (plasticizer loss and discoloration), shrinkage 0.3–0.8 %.
What is the maximum service temperature of EC D787-G7?
EC D787-G7 is rated for continuous use to about 70°C (158 °F), and briefly to 95°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between EC D787-G6 and EC D787-G1?
D787-G6 is the default condition — default all-round ethyl cellulose molding compound: good balance of stiffness, cold impact and mold flow. D787-G1: pick for extreme low-temperature impact, flexible film/sheet and tough thin-wall covers where stiffness is irrelevant. Yield strength is 26 MPa in D787-G6 versus 13 MPa in D787-G1.
Sources
- ASTM D787 — Standard Specification for Ethyl Cellulose Molding and Extrusion Compounds — ASTM International (2019)
- ASTM D2364 — Standard Test Methods for Hydroxyethylcellulose (related cellulose ether test practice) — ASTM International (2019)
- Engineered Materials Handbook Vol. 2: Engineering Plastics — Cellulosics — ASM International (1988)
- ETHOCEL Ethylcellulose Polymers — technical handbook — Dow / Ashland (2020)
- Cellulosic thermoplastics property tables — Modern Plastics Encyclopedia / CAMPUS-type datasets (2015)
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.