Chemical-resistant materials: A beginner's guide

Chemical-resistant materials are vital for many 3D printing applications. Corrosive chemicals can’t permeate their surface or cause degradation, making them ideal for industrial or end-use parts. There are several different chemical-resistant materials to choose from, each with specific benefits.

Why is chemical resistance important?

“Chemical resistance” means that materials can fulfil their function, even in harsh working environments. Chemical-resistant materials don’t require surface treatment; they are able to withstand exposure to chemicals such as bases, solvents, and acids.

Without chemical-resistance, a material may erode, soften, or become misshapen. This is due to the chemical’s molecules diffusing within the material and pushing the polymer chains apart. When this happens, it reduces functionality, and may damage other surrounding parts.

Common uses of chemical-resistant materials

Chemical-resistant materials play an important role in packaging applications, particularly in the packaging of cleaning agents, reagents, and other chemicals. They’re also useful for manufacturing tooling. During use, jigs and fixtures are often exposed to chemicals (liquid, gas or solid). Chemical resistance ensures they don’t degrade over time.

Many industries require end-use parts to be chemically resistant. Automotive parts, for example, are often exposed to oil or chemicals used for cleaning or maintenance. When created with chemical-resistant material, exposure to even harsh chemicals isn’t a problem.

What else should you know? The main factors that influence a polymer’s chemical resistance

A material’s chemical resistance is impacted by several different factors. These include:

the molecular structure of the polymer

the time of exposure to a chemical

the temperature at the time of exposure

the nature of the chemical

the stress applied to the material

Chemical resistance depends on the application

Materials are usually only resistant to certain types of chemical. For example, Nylon isn’t adversely affected by acetone, but can be damaged by water. Conversely, PETG isn’t affected by water, but acetone will degrade it. Every material has different properties, and it’s vital to choose the right one for the job.

Materials with good chemical resistance

Several materials have excellent chemical resistance, such as PP, PVDF, and Nylon. PETG is unaffected by water-based chemicals, and (like CPE and CPE+) has good resistance against common chemicals such as alcohol and weak acids.

The above table refers to general characteristics of the listed material. Chemical resistance strongly depends on the design and formulation of a 3D printed part A fragile part, for example, will not last long against chemical liquids as a massive print.

Things to note when using chemical-resistant materials

It’s vital to consider temperature, as most diffusion processes are temperature dependent

Amorphous thermoplastic polymers, when exposed to chemicals, may crack. This can lead to part failure

When choosing a material, think about the concentration of the chemicals, and the mechanical load

Our chemical-resistant material partners Arkema

Arkema FluorX™ is a tough, semi-crystalline fluoropolymer made from Arkema’s Kynar® PVDF. It is formulated for printability, and is a great option for parts subjected to demanding conditions, such as solvents, acids, fire, and UV radiation.

“Kynar® PVDF is the material of choice for many harsh chemical environments,” Steven Serpe,  Market Manager, Specialty Powders and 3D Printing at Arkema, said. “Fluoropolymers are well known for chemical resistance, but ability of Kynar® PVDF to be easily processed via many methods

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