How plastics are replacing metals in high-tech industries

Polymeric materials are increasingly being used to replace metals in multiple applications, including in markets characterized by high technology content such as aerospace, the renewable energy sector, automotive, oil and gas, the chemical industry, the medical and pharmaceutical sector, the food processing and packaging industry, and the electronics and semiconductor sector.

 

Plastic materials can improve the performance of components and systems through

• Reduction of weights and inertia
• Absence of corrosion, high resistance to chemical attack
• Low friction and low wear coefficient even in the absence of lubrication
• Quiet operation
• Thermal and electrical insulation

The market provides us with many dozens of different semi-finished plastic products (bars, sheets and tubes) suitable for tooling that can replace metals bringing advantages in various applications.

The following table compares schematically the mechanical properties of some polymers and metals*.

 

Properties	U.M.	UHMW PE	PA6 G	PEEK	Bronze	Steel	Aluminum
Density	g/cm³	0.96	1.15	1.31	8.8	7.8	2.7
Tensile yield stress	MPa	23	80	100	150	300	200
Relative strength to weight	Acciaio = 1	0.62	1.85	1.98	0.44	1.00	1.93
Elastic modulus	MPa	1100	3200	4200	110000	220000	70000
Coefficient of linear thermal expansion	10⁻⁵ K⁻¹	18	12	5	1.8	1.7	2.4