High-Performance Polymers

Junkosha focuses its innovations within the category "High-Performance Polymers". Those polymers are clearly distinguished by their excellent properties relative to other polymers.
Based on a deep understanding of each High-Performance Polymer, Junkosha applies its manipulating techniques to provide the best solution. 

Fluoropolymer Characteristics

Among high-performance polymers, Junkosha utilizes a material family known as fluoropolymers in its key products. Its fundamental C-F (carbon-fluorine) structure has a high binding energy and low polarizability, meaning that it exhibits many excellent properties such as the following:

Heat and Cold Resistance

Fluoropolymers exhibit the widest operating temperature range among polymers.
Service temperature: PTFE, -250℃~+260℃ 


Fluoropolymers are non-incendive, incombustible and do not emit smoke.

Weathering Resistance

Fluoropolymers are not affected by factors such as ultraviolet radiation and oxidizing gas. As such, they can withstand defects or discolouration for more than 30 years.

Electrical Properties

Fluoropolymers have the lowest dielectric constant (permittivity) and dielectric loss tangent among polymers. As such, they are the best dielectric material for high-frequency, high-speed, signal transmission applications.
Fluoropolymers are characterized as excellent insulation materials due to having the highest volume and surface resistivity among polymers.

Chemical Resistance Properties

Fluoropolymers are very stable and retain their mechanical properties even during long-term contact with the majority of chemicals and solvents (excluding alkali metals such as metallic sodium or fluorine gas under high pressure and high temperature).

Low Friction

Fluoropolymers exhibit extremely low friction and non-stick features.


Fluoropolymers do not contain any additive and volatile oligomers. As such, they are free from contamination by solvent extraction and out-gas generation.

Types of Fluoropolymers

PTFE Polytetrafluoroethylene

Features an extremely high molecular weight and also ultra-high melt-viscosity, so that the melt process is not appliable. Has the lowest dielectric constant, dielectric loss tangent, and friction coefficient among polymers.

FEP Perfluoroethylene propylene copolymer

A copolymer of tetrafluoroethylene and hexafluoropropylene with similar excellent electrical properties, chemical resistance properties, and weathering resistance to PTFE. This fluoropolymer is capable of undergoing melt-processing.

PFA Perfluoroalkoxy alkane
RF; Perfluoroalkyl

A copolymer of tetrafluoroethylene and perfluoro alkyl vinyl ether with extremely similar properties to PTFE. This fluoropolymer is also melt-processable (extrusion, transfer and injection-molding).

ETFE Ethylene tetrafluoroethylene copolymer

Copolymer of tetrafluoroethylene and ethylene with excellent mechanical, creep, and impact resistance properties. This fluoropolymer is capable of undergoing melt processing.

Other High-Performance Polymers

This refers to polymers which have excellent chemical resistance and weathering resistance, retaining their mechanical strength and resisting thermal deformation even in high-temperature environments of over 150℃.

PEEK Polyetheretherketone

PEEK belongs to the PAEK (Polyaryletherketone) family. Its rigid structure comprises of aromatic rings linked by ketone and the ether group, which offers extraordinary mechanical properties and thermal stability. In addition, its excellent radiation resistance expands its application into the space and nuclear power plant sectors.

PPS Polyphenylene sulfide

This polymer is comprised of relatively simple repeated units, with high strength, stiffness, dimensional stability, and heat durability. It has strong chemical and solvent resistance, and the PPS mold parts are often used together with fluoropolymer parts.

PES Polyethersulfone

As a polymer family, comprising of aromatic rings linked by ether and the sulfone group, PES, PSU and PPSU are well known and commercialized. One of the PES chemical structures is exemplified above. These polymers are transparent, amorphous and include excellent thermal stability, chemical and radiation resistance.

LCP Liquid crystal polymer

LCP is a general term for a polymer, which exhibits liquid crystal properties at molten-state (thermotropic LCP). The above is a typical chemical structure for LCP.  LCP is used for precision and high-cycle injection molding as a result of its negligibly small mold shrinkage and high flowability. Typical applications, which include electric components requiring fine-size and thin wall, or miniaturization, are aligned with the future trends of fining and integration in the chip manufacturing industry.

PEI Polyetherimide

Polyetherimide is an amorphous polymer within the ether group and imide group. It has heat durability, chemical resistance, flame resistance, and hydrolysis resistance properties, and PEI is also relatively easy to mold, compared to other amorphous polymers having their glass-transition temperatures of above 200℃. 

PAI Polyamide-imide

PAI in its previous state solved in an organic solvent, is coated and heated to form a tough PAI film. PAI displays its outstanding mechanical properties at heated temperatures over a long period of time due to its glass-transition temperature of 280℃.