POK applications share one pattern: heat, moisture, abrasion and chemical media usually arrive together. These six areas account for most of our shipments, each with typical parts and recommended grades.
Fuel systems, connectors and trim — where POK first reached volume.
Flame retardancy, tracking resistance and low warpage — the three gates for connectors.
Replacing POM and PA66 — the point is wear life and noise, not strength.
Compliance paperwork and CIP resistance decide the project more than mechanical data.
Stable after years under water — the core difference from PA and PBT.
Feel, gloss and impact — that is the whole brief in consumer goods.
Automotive parts have to resist fuel and heat while holding dimensions through years of vibration and thermal cycling. POK has no hydrolysable groups and absorbs far less moisture than PA66, so dimensions drift less when humidity changes. Its resistance to petrol, diesel, engine oil and most cleaning agents is better than PA11/PA12.
High crystallinity gives POK a high heat deflection temperature and stiffness, and with the right flame-retardant package it reaches V0. Compared with PBT it holds electrical properties more steadily in humid conditions, which suits connectors and switches where insulation resistance matters. Carbon-filled grades add conductivity and EMI shielding.
Low friction and a dense crystalline structure make standard POK wear three times better than POM; with silicone, PTFE or molybdenum disulphide that reaches 10× or more, with markedly lower running noise. For high-speed, high-load, long-life drives that means longer service intervals and less downtime.
POK contains no formaldehyde or harmful plasticisers and meets FDA and EU 10/2011 food contact requirements. It resists fats, weak acids and common cleaning agents, which suits food machinery parts that go through repeated CIP; its high gas barrier also allows use as a barrier layer in packaging.
PA66 and PBT hydrolyse in long-term hot-wet service, losing strength and changing dimensions. POK’s backbone is carbon–carbon with no ester or amide links, so hydrolysis resistance stands out. It is certified to KTW and W270 for drinking water contact, making it suitable for water treatment equipment and sanitary internals.
POK has a high-gloss surface and a warm touch, and it resists sweat and common cosmetic ingredients — a good fit for packaging and wearables. High-impact grades stay tough at low temperature, so they work in helmet, protective gear and sports equipment structures.
These five come up most often in Hyosung literature and in our own shipments. None of them is simply "better properties" — in each case the incumbent material fails at one specific point.
REPLACING POM · THE FORMALDEHYDE QUESTION
Food conveyor belts and water purifier parts have long been POM territory, but formaldehyde release — in processing and in long service — has pushed brand owners to look elsewhere. POK’s backbone contains no formaldehyde structure and it holds FDA, EU 10/2011 and Chinese food contact certifications. It also resists cleaning agents and impact, so it lasts noticeably longer under repeated CIP.
REPLACING PA66 / POM · MOISTURE SWELL
The classic PA66 gear problem is dimensional change after moisture uptake: the mesh clearance shifts, noise rises and tooth wear accelerates. POK absorbs little water and holds dimensions; it wears 14 times better than POM and runs quieter. For high-speed, long-life, low-noise drives this is the most direct substitution path.
REPLACING PA / PBT · LONG-TERM HYDROLYSIS
Wet parts must not degrade, leach or distort through alternating hot and cold water and years of immersion. The ester and amide links in PA and PBT hydrolyse; POK’s carbon–carbon backbone does not, so dimensions and strength hold. Certified to KTW, W270, NSF/ANSI 61, WRAS, ACS and GB/T 17219 — enough to support a whole-machine water path filing.
EMERGING · HIGH VOLTAGE MEETS CARBON ACCOUNTING
Male high-voltage connectors demand insulation, flame retardancy and long-term dimensional stability — and increasingly a carbon footprint the OEM can defend. POK covers the electrical and flammability side, and because one of its feedstocks is industrial carbon monoxide its production carbon is well below petroleum-based engineering plastics. That now counts in material selection scoring.
EXTRUSION · CORROSION AND PERMEATION
Metal corrosion in oilfield pipe and oxygen permeation in food packaging look unrelated but share a root: both need a material that stays impermeable in the face of chemical media. POK’s chemical resistance and oxygen barrier approach EVOH, so it serves as a downhole liner, the inner layer of reinforced thermoplastic pipe (RTP) and high-barrier food film. Blended with EVOH, E700 pushes retort performance further.
Temperature, media, load type, moulding process — four inputs, and we come back with a defensible grade recommendation plus the matching TDS.
HYOSUNG CHEMICAL · Distributor Authorization Certificate · 1 January 2024