Impact strength
The flexible segments between carbonyl and ethylene units dissipate energy under impact. Notched impact is 230% higher than Nylon and PBT.
IMPACT +230%
MATERIAL SCIENCE
POK: an engineering plastic built from carbon monoxide
POKETONE is the aliphatic polyketone Hyosung commercialised first in the world. Understand the molecular structure and you understand why it leads on hydrolysis resistance, wear and barrier at the same time.
DEFINITION
What is POK
POKETONE is a highly crystalline aliphatic polyketone — Polyketone, POK — made by alternating copolymerisation of carbon monoxide (CO) and olefins. Every other carbon in the backbone carries a carbonyl group (C=O). That regular carbonyl sequence lets the chains pack tightly into a highly crystalline structure, and that is where the strength, wear resistance and barrier come from.
Two families exist, depending on the comonomer. The binary alternating copolymer of CO and ethylene goes mainly into high-strength fibre. Add propylene and you get the terpolymer — slightly lower melting point, wider processing window, and the form that dominates engineering-grade POK.
From a feedstock point of view, POK consumes carbon monoxide — an industrial emission — turning an air pollutant into a polymer. That is why it is often called a green engineering plastic.
Hyosung’s published POK repeat unit — carbonyls strictly alternating, n ethylene units and m propylene units.
Natural pellets are near ivory — light-coloured parts can run without masterbatch.
PROPERTIES
Where the six properties come from
Every property traces back to a structural feature — this is not marketing copy. Understand the mechanism and you can judge at drawing-board stage whether POK fits.
Hydrolysis resistance
A carbon–carbon backbone with no hydrolysable ester or amide links, so molecular weight holds up under prolonged immersion or high humidity. Certified to KTW and W270.
NO HYDROLYSIS
Chemical resistance
High crystallinity blocks solvent and chemical ingress. Outstanding acid and alkali resistance — second only to PPS.
NEAR PPS
Wear & self-lubrication
Dense crystalline structure and low friction. Standard grades wear three times better than POM; modified grades reach 10× or more.
×3 — ×10+ POM
Gas barrier
Polar carbonyl groups pack the chains tightly and resist hydrocarbon permeation. In petrol at 93°C over 15 days it beats PTFE and matches EVOH.
≈ EVOH
Low-carbon footprint
Carbon monoxide as comonomer, no harmful plasticisers or formaldehyde, recyclable — suitable for food contact and children’s products.
CO-BASED
COMPARISON
How it sits against mainstream engineering plastics
POK is not positioned as a cheaper PA66. It refuses to compromise on hydrolysis resistance, wear and barrier at the same time — and when a duty demands all three, it is often the only answer.
| Property | POK | PA66 | POM | PBT |
|---|---|---|---|---|
| Hydrolysis | ●●●●● | ●●○○○ | ●●●○○ | ●●●○○ |
| Chemical media | ●●●●● | ●●●○○ | ●●●○○ | ●●●○○ |
| Wear / self-lubrication | ●●●●● | ●●●○○ | ●●●●○ | ●●○○○ |
| Gas barrier | ●●●●● | ●●●○○ | ●●○○○ | ●●●○○ |
| Fuel resistance | ●●●●● | ●●●○○ | ●●○○○ | ●●●○○ |
| Impact strength | ●●●●● | ●●●○○ | ●●○○○ | ●●○○○ |
| Dimensional stability | ●●●●○ | ●●●○○ | ●●●●○ | ●●●●○ |
| Processing window | ●●●○○ | ●●●●○ | ●●●●○ | ●●●●● |
* Qualitative comparison compiled from Hyosung POKETONE literature. On processing window, POK demands tighter drying and mould-temperature control — see Technical Support.
KEY DATA
Six numbers you can design against
These figures come from Hyosung published data. They are not peak values but what standard grades hold consistently — which matters more in selection than a headline number.
220℃
Melting point
Around 220°C — roughly 40°C below PA66, which pays off in energy and cycle time
200℃
Heat deflection
Sustained high-temperature service, covering most under-hood and electronic duties
+230%
Impact strength
Improvement over Nylon and PBT, holding in notched and low-temperature conditions
14×
Wear resistance
Multiple versus POM: about 3× for standard grades, up to 14× when modified
≈EVOH
Gas barrier
Barrier level against moisture and hydrocarbons, close to dedicated barrier resins
100%
Carbon backbone
An all-carbon backbone with no ester or amide links — the root of its hydrolysis resistance
GRADE SYSTEM
Nine series, sorted by flow and melting point
Hyosung divides POKETONE by melt index and melting point into six main series and three special ones. The first selection question is not strength — it is which flow and melting band you need.
| Series | Flow & melting | Typical position | Grades in stock |
|---|---|---|---|
| M130 | Very high flow | Thin walls, long flow paths, small precision parts; structures sensitive to injection pressure; food contact applications | M130F |
| M330 | High flow | General injection mouldings, thin-wall housings, multi-cavity tools | M330AM330A-UVM330FM330F-SM330S |
| M530 | Medium flow | Medium and thick-wall parts, fittings — balanced between M330 flow and M630 impact | M530F |
| M630 | Medium flow · high impact | The most balanced series — impact and stiffness together, and our highest-volume family | M630AM630FM630V |
| M730 | Low flow | Thick sections and where high melt strength matters; better creep resistance | M730RM730F |
| M710 | Low flow · low melting | Parts sensitive to thermal history — run cooler to cut degradation risk | M710F |
| M410 | Monofilament · low melting | Monofilament, fibre and continuous forming that needs high draw orientation; the low-bloom version suits food contact | M410F-S |
| M640 | Low-temp impact · high melting | Cold climates and low-temperature impact, with heat resistance kept | M640A |
| E700 | PK compound for EVOH blends | Blended with EVOH to improve retort performance and barrier — packaging and pipe | On request |
* Series classification per Hyosung. The stock column reflects our current grade list; colour variants of the same grade (natural, black, white, grey and so on) are not listed separately. Flow and suitable processes follow the individual TDS, available on request.
PROCESSING
Processing: a narrower window than PA or POM
This is where new projects get caught. The five points below are what we see most often on the floor; for production parameters, follow the grade TDS and your own mould trials.
| Stage | What to do | What goes wrong |
|---|---|---|
| Drying | Hot-air dry at 80–100°C for 3–4 hours; a dew point below −20°C is better still | Under-drying gives silver streaks, bubbles and lower impact strength |
| Melt temperature | Typically 220–260°C depending on grade; avoid long residence time | Overheating or dwell causes degradation — yellowing and odour |
| Mould temperature | 60–90°C recommended; a hotter mould completes crystallisation | A cold mould raises shrinkage and destabilises dimensions |
| Screw | Medium speed, medium pressure and back pressure; avoid high shear | High shear causes melt fracture and local overheating |
| Regrind | Usable in moderation, with the ratio controlled and the regrind re-dried | Too much regrind accumulates degradation and hurts long-term properties |
CERTIFICATION
The paperwork that gets you into regulated markets
Most POK applications sit in food contact, drinking water or children’s products — where the compliance file matters more than the data sheet. Native grades hold the certifications below, and we supply the matching batch documents with the goods.
FDA (FCN)
US food contactFood Contact Notification covering repeated-use articles
EU 10/2011
EU food contactIncluding the (EU) 2020/1245 amendment for plastic food contact materials
GB 4806
China food contactMeets Chinese requirements for food contact materials and articles
NSF/ANSI 51
Food equipmentSanitation standard for materials in commercial food equipment
NSF/ANSI 61
Drinking waterHealth effects of drinking water system components
KTW · W270
Germany, waterHygienic assessment of plastics in contact with drinking water
WRAS BS6920
UK water regulationsMaterial approved under the UK water regulations scheme
ACS
France, waterFrench sanitary compliance for drinking water contact materials
GB/T 17219
China, waterSafety evaluation for equipment and protective materials in drinking water supply
DIN 8077 / 8078
German pipe standardDimensions and quality requirements for pipes and fittings
USP Class VI
Medical, biocompatibilityBiological evaluation of materials for medical devices
ISO 10993
Medical, biocompatibilityThe ISO series for biological evaluation of medical devices
ISO 9001 / 14001
Quality & environmentUpstream production and quality management system certification
RoHS · REACH
Restricted substancesFree of harmful plasticisers, bisphenol A, phthalates and heavy metals
How to get the compliance file
Base certifications for native grades are issued by Hyosung. Whether the finished article can claim compliance also depends on masterbatch, additives and processing. We supply the original COA, compliance declarations and migration testing support to help you file.
* Applicability depends on grade and end use. Ask us for the relevant certificate copy — the document governs.
