CA HP
Other
HP = high-plasticizer CA (20–30% plasticizer), soft/tough
Pick when maximum toughness, easy flow and warm hand feel matter (eyewear frames, tool handles, cast sheet); heat resistance and stiffness drop.
Values for the HP condition
Other CA grades and fills
CA is listed in 3 conditions; see the grade overview at CA.
Compare all 3 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
HPThis page High-plasticizer CA (20–30% plasticizer), soft/tough | Pick when maximum toughness, easy flow and warm hand feel matter (eyewear frames, tool handles, cast sheet); heat resistance and stiffness drop. | 26 | 30 | 50 | 66 Shore D |
cast/block eyewear sheet (block-pressed, patterned) | Choose for eyewear fronts and temples where layered/patterned aesthetics, CNC milling and tumble polishing are required. | 32 | 42 | 35 | 75 Shore D |
Low-plasticizer CA (≤12% plasticizer), rigid/heat-resistant | Pick when stiffness, dimensional stability and higher HDT are needed (rigid housings, sheet, technical film); flow is poor and impact strength lower. | 52 | 58 | 18 | 83 Shore D |
What is CA HP?
CA HP is CA in the HP condition — pick when maximum toughness, easy flow and warm hand feel matter (eyewear frames, tool handles, cast sheet); heat resistance and stiffness drop. CA HP has a yield strength of 26 MPa (3.77 ksi) and a tensile strength of 30 MPa (4.35 ksi) — weaker than 72% of polymer grades. Elongation at break is 50% and the elastic modulus is 1.1 GPa (0.16 Msi). CA HP has a density of 1.28 g/cm³ (0.0462 lb/in³), heavier than 67% of polymer grades. Its glass-transition temperature is 78°C (172 °F).
Advantages
- Polishes to a fine finish — 85/100, better than 92% of polymer grades
- Forms and bends easily — 88/100, better than 85% of polymer grades
- Easy to machine — 80/100, better than 84% of polymer grades
Limitations
- Absorbs moisture — dry before molding — 4%, worse than 99% of polymer grades
- Needs corrosion protection — 55/100, worse than 94% of polymer grades
- Limited service temperature — 55°C (131 °F), worse than 91% of polymer grades
CA HP properties
Typical room-temperature values for CA HP; 27 are specific to this condition. Other listed values are CA reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
CA HP has a density of 1.28 g/cm³ (0.0462 lb/in³), heavier than 67% of polymer grades. Its glass-transition temperature is 78°C (172 °F).
Mechanical16
CA HP has a yield strength of 26 MPa (3.77 ksi) and a tensile strength of 30 MPa (4.35 ksi) — weaker than 72% of polymer grades. Elongation at break is 50% and the elastic modulus is 1.1 GPa (0.16 Msi).
Thermal11
CA HP is rated for continuous service to 55°C (131 °F). It conducts heat at 0.22 W/m·K (0.127 BTU/hr·ft·°F), better than 60% of polymer grades. Thermal expansion is 155 µm/m·K (86.1 µin/in·°F).
Electrical7
CA HP is an electrical insulator with a dielectric strength of 18 kV/mm (457.2 V/mil) and a resistivity of 1×10¹⁰ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 94% of polymer grades. UV resistance is fair.
Sustainability4
Producing a kilogram of CA HP takes about 100 MJ of energy and emits 4 kg of CO₂ — less than 61% of polymer grades. Typical recycled content is 2%.
Manufacturability7
CA HP's machinability is very good (80/100, better than 84% of polymer grades); weldability good (60/100); formability excellent (88/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CA HP
Is CA easy to machine?
Machines and routs cleanly with sharp positive-rake tools and high speed; avoid heat build-up (plasticizer sweats, edges soften) and use air blast rather than water-based coolant.
Can CA be welded?
Solvent bonding (acetone/methyl acetate/ethyl acetate mixes) and adhesive joints are standard; ultrasonic works on rigid low-plasticizer grades, hot-plate welding tends to scorch.
Can CA be formed, bent or molded?
Dry 2–4 h at 65–75 °C before molding; melt 175–230 °C with mold 35–75 °C, keep residence time short as CA degrades and releases acetic acid above ~240 °C; excellent thermoforming and bending in hot air or oil.
What surface finishes work on CA?
Barrel/tumble polishing with wood chips and wax gives the classic high-gloss eyewear finish; flame or vapor polishing works but must be brief, and hard coats or UV-stabilized lacquers are advised for outdoor use.
CA 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 (diethyl phthalate, triaceticontent sets the High/Low plasticizer grade split | 8 – 30 | 15 |
| heat/light stabilizer + antioxidant | 0.1 – 1 | 0.4 |
| residual free acetic acid / moisturemust be dried before molding | 0 – 0.5 | 0.2 |
| colorant / pearlescent pigment (optional | 0 – 3 | 0.5 |
| cellulose acetate polymer (acetyl contenwood pulp / cotton linter cellulose esterified with acetic anhydride | ≥ 70 (balance) | — |
CA HP — frequently asked
What is CA HP used for?
CA HP is typically used for eyeglass frames, tool handles, photographic film base, packaging film, toys and cosmetic packaging. In short: biobased high-gloss cellulosic; standard eyewear sheet material; easiest cellulosic to polish.
What is the yield strength of CA HP?
CA HP has a typical yield strength of 26 MPa (3.77 ksi) and a tensile strength of 30 MPa (4.35 ksi) — weaker than 72% of polymer grades. Strength varies by condition: see the 3 listed tempers.
Is CA HP easy to machine?
Yes — machinability is rated very good (80/100, better than 84% of polymer grades). Machines and routs cleanly with sharp positive-rake tools and high speed; avoid heat build-up (plasticizer sweats, edges soften) and use air blast rather than water-based coolant.
Can CA HP be welded?
Yes — weldability is rated good (60/100). Solvent bonding (acetone/methyl acetate/ethyl acetate mixes) and adhesive joints are standard; ultrasonic works on rigid low-plasticizer grades, hot-plate welding tends to scorch.
What surface finishes work on CA HP?
Barrel/tumble polishing with wood chips and wax gives the classic high-gloss eyewear finish; flame or vapor polishing works but must be brief, and hard coats or UV-stabilized lacquers are advised for outdoor use.
Can CA HP be formed, bent or molded?
Dry 2–4 h at 65–75 °C before molding; melt 175–230 °C with mold 35–75 °C, keep residence time short as CA degrades and releases acetic acid above ~240 °C; excellent thermoforming and bending in hot air or oil.
What is the maximum service temperature of CA HP?
CA HP is rated for continuous use to about 55°C (131 °F), and briefly to 90°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM D706 — Cellulose Acetate Molding and Extrusion Compounds — ASTM International (2019)
- ISO 20200 — Determination of degree of disintegration of plastic materials under composting conditions — ISO (2023)
- ASM Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
- Polymer Handbook, 4th ed. (cellulose esters section) — Wiley (1999)
- Cellulose ester molding compound and film technical literature (Eastman, Daicel, Mazzucchelli) — producers (2023)
- CAMPUS / UL Prospector cellulosic thermoplastic datasets — CWFG / UL (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.