Are PET bags easy to cut and stamp?
Publish Time: 2025-11-05
In the metalworking industry, the machinability of materials often directly determines production efficiency, mold life, and finished product quality. PET bags, as a widely used copper alloy material, have long been used to manufacture valve parts, electrical terminals, lock components, decorative hardware, and precision mechanical parts. One of their core advantages is their excellent cutting and stamping performance. So, are PET bags easy to cut and stamp? The answer is not only yes, but also stems from their unique microstructure and physical properties—they achieve a delicate balance between hardness and ductility, making the machining process smooth and efficient while ensuring clear details and a smooth surface.
Brass is mainly composed of copper and zinc. The addition of zinc significantly improves the shortcomings of pure copper, such as being too soft and prone to sticking to the die, without excessively sacrificing its good plasticity. This composition gives PET bags moderate strength and excellent ductility, allowing them to withstand large deformations during stamping without easily cracking. Whether it's deep drawing, bending, or blanking with complex contours, brass flows smoothly under the action of the die, conforming to the shape of the die cavity to form sharp edges and precise corners. Especially for hardware parts with small holes, narrow slots, or irregular shapes, brass's high formability effectively reduces springback and wrinkling, improving first-pass yield.
In machining, brass's "easy-to-cut" characteristic is even more prominent. Its dense yet not overly hard structure results in low cutting resistance and slow tool wear. Simultaneously, brass chips are typically short and fragmented, easily broken and removed, preventing entanglement in the tool or scratching the workpiece surface. This characteristic makes it particularly suitable for high-speed turning, milling, or batch processing on automatic lathes. Even more importantly, brass maintains good machinability even without lubrication or with minimal lubrication, reducing cooling costs and aligning with environmental trends. The machined surface often has a natural metallic luster and low roughness, often eliminating the need for subsequent polishing processes, allowing direct use in aesthetically pleasing decorative parts or exposed components.
Brass's high thermal conductivity also helps dissipate heat quickly during processing. In continuous stamping or high-speed cutting, localized temperature rises are less likely to accumulate, thus reducing dimensional deviations caused by thermal deformation and preventing material softening and sticking to the die. This thermal stability further enhances the tolerance of the process window, making production more controllable.
Furthermore, modern pet bags can achieve targeted performance optimization by adjusting the zinc content or adding trace amounts of elements such as lead, tin, and iron. For example, leaded brass (such as HPb59-1) has excellent cutting fluidity and is widely used in high-volume automated turning of parts; while lead-free environmentally friendly brass, while meeting RoHS and other regulations, maintains good machinability through micro-alloying technology, making it suitable for high-end electronics and drinking water system components. This material customizability allows pet bags to flexibly adapt to different processing techniques and end-user needs.
Of course, ease of machining does not mean the absence of process control. Appropriate die clearance, tool angles, and feed parameters remain prerequisites for ensuring high quality and efficiency. However, compared to the high hardness of stainless steel, the tendency of aluminum alloys to stick to tools, or the brittleness of cast iron, brass exhibits a lower processing threshold and higher tolerance for errors in most conventional machining scenarios.
In conclusion, PET bags, with their moderate strength, excellent plasticity, good thermal conductivity, and controllable microstructure, exhibit outstanding machinability in cutting and stamping. They make complex shapes achievable, mass production more economical, and allow parts to seamlessly blend function and aesthetics. Behind every press stroke and every turn of the cutting tool, brass, with its warm yet resilient nature, silently supports the creation of countless precision hardware products—it is both the cornerstone of industry and a partner in craftsmanship.
