Material selection is one of the most consequential decisions in product development. The right material affects how your product looks, how it performs, how much it costs to manufacture, and what markets it can be sold into. Here is a practical comparison of three of the most commonly confused material groups.
Plastic
Plastic is the broadest category and covers hundreds of different materials with very different properties. For product development, the most relevant distinction is between rigid and flexible plastics.
Rigid plastics like ABS, polycarbonate, and polypropylene are used for housings, structural components, and anything where dimensional stability matters. They are typically injection moulded and offer good strength, reasonable cost at volume, and a wide range of surface finishes.
Flexible plastics like TPE (thermoplastic elastomer) and TPU are used where you need a plastic that flexes or has a soft-touch feel. They can be processed using similar equipment to rigid plastics, which makes them cost-effective for parts that need flexibility without the complexity of silicone or rubber.
Silicone
Silicone is a synthetic rubber-like material with exceptional temperature resistance, biocompatibility, and durability. It is used in medical devices, food-contact products, baby products, and anywhere where chemical resistance and temperature performance are critical.
Liquid silicone rubber (LSR) is processed by injection moulding in a similar way to plastic, though with different tooling and equipment requirements. Solid silicone can be compression moulded.
Silicone is more expensive than most plastics, both in material cost and processing cost. But for applications where its unique properties are needed, there is often no viable alternative.
Natural and Synthetic Rubber
Rubber offers flexibility and resilience similar to silicone but at lower cost. It has lower temperature resistance than silicone and is generally not biocompatible. It is used in seals, gaskets, vibration damping, and grips.
Natural rubber is derived from rubber trees. Synthetic rubbers like EPDM and neoprene are produced from petroleum derivatives and offer tailored properties for specific applications.
How to Choose
The right material depends on your product requirements, not on cost alone. Consider: what temperature range will the product encounter? Does it need to be biocompatible or food-safe? What regulatory standards apply? What is the target unit cost and volume? What manufacturing process is most appropriate?
These are questions we work through with clients during the design phase. Getting material selection right early prevents expensive redesigns later.
