What is Impact resistance?

Impact resistance is a fundamental mechanical property that defines a plastic material’s ability to absorb energy and resist fracture when subjected to a sudden force or impact. This property is particularly important in applications where parts are exposed to drops, vibrations, shocks, or demanding conditions, making it essential to ensure the durability and safety of the final product.

In plastics, impact resistance depends on several factors, including the type of polymer, service temperature, impact speed, presence of fillers or reinforcements, and the part’s geometric design. Amorphous plastics like polycarbonate (PC) typically offer excellent impact resistance, while some semi-crystalline materials may require modification or reinforcement to achieve similar performance.

Standardized tests such as the Izod and Charpy methods are commonly used to measure impact resistance. These involve applying a controlled blow to a test specimen (notched or unnotched) to evaluate the energy absorbed before breaking. Results are usually expressed in kJ/m² or J/cm, allowing for comparison between materials under consistent conditions.

Impact resistance is a critical parameter in sectors such as:

• Automotive: body parts, bumpers, brackets, and interior components must withstand collisions and vibrations without cracking.

• Appliances and electronics: housings and frames that protect delicate components from falls or impacts during use or transport.

• Packaging industry: reusable containers, drums, or crates that must endure stacking and mechanical handling.

• Construction and urban furniture: plastic elements exposed to vandalism or severe weather conditions.

In many cases, impact resistance can be enhanced by using impact modifiers like thermoplastic elastomers (TPE) or reinforcing with fibers (such as glass fiber), although this may affect other properties like stiffness or cost.

It’s also important to consider that impact resistance typically decreases at very low temperatures, especially in brittle polymers. For this reason, materials are tested at different temperatures to evaluate their behavior under varying environmental conditions.

At Plásticos Lezo, we carefully assess the impact resistance required for each project and select the most suitable materials based on the intended application of the part. We work closely with our clients to balance this property with other technical, aesthetic, and economic requirements to provide the most effective solution.

We also work with modified compounds and specialty grades for demanding applications and carry out internal impact validation tests when design or usage conditions call for it. Our experience in part design allows us to optimize geometries to better distribute stresses and avoid concentration points that could cause failures.

In summary, impact resistance is a key property in designing and manufacturing durable, safe plastic components. At Plásticos Lezo, we treat it as an essential technical criterion in material selection, product design, and quality validation, ensuring reliable solutions even in the most demanding environments.