When selecting a face shield, it’s important to consider the type of polycarbonate used in the visor, as this can affect its impact resistance. Polycarbonate is a popular material for face shields due to its durability and optical clarity. However, there are two different manufacturing processes used to produce polycarbonate visors for face shields: extrusion and injection molding.

　　Extrusion-grade polycarbonate is manufactured using an extrusion process that results in a more uniform sheet of material. This process allows for greater consistency in the thickness and properties of the material, resulting in a polycarbonate sheet that is highly transparent, durable, and resistant to impact and scratches. Additionally, extrusion sheets are made of high molecular weight plastic pellets, which contribute to their high level of impact resistance. The uniformity of the material also makes it less likely to warp or distort over time. These properties make face shields made with extrusion-grade polycarbonate visors an excellent choice for a variety of applications, including healthcare, construction, and manufacturing.

　　In contrast, injection-grade polycarbonate is manufactured using an injection molding process that can result in some variability in the thickness and properties of the material. While this process requires less initial investment to start producing visors, it may not provide the same level of impact resistance as extrusion-grade polycarbonate. Injection molding requires lower molecular weight plastic pellets, which provide better melt flowing properties needed for the molding process. However, this can result in variability in the thickness and properties of the material, which may reduce the impact resistance of the polycarbonate sheet.

　　The difference in the manufacturing process can also impact the impact resistance of the polycarbonate sheets used in face shield visors. Therefore, it’s crucial to consider not only the type of polycarbonate but also the manufacturing process used when selecting a face shield for high-impact environments. Face shields made with extrusion-grade polycarbonate visors are known to provide superior impact resistance and optical clarity, making them the best choice for most applications.

　　Another advantage of face shields made with extrusion-grade polycarbonate visors is their superior optical clarity. The uniformity of the material results in a polycarbonate sheet that is highly transparent, with minimal distortion or haze. This is important for applications where clear vision is critical, such as in check station in production line, healthcare, or laboratory settings.

In short, we can conclude extrusion-grade polycarbonate has advantage as follows:

• 　Superior impact resistance due to the use of high molecular weight plastic pellets in the extrusion process
• 　Greater consistency in thickness and properties of the material, resulting in a highly transparent and durable polycarbonate sheet
• 　Resistance to warping and distortion over time, ensuring long-lasting protection and visibility
• 　Minimal risk of stress fractures and cracking when subjected to impact, providing reliable protection for high-impact environments
• 　Ideal for applications that require clear vision, such as healthcare and laboratory settings

In summary, face shields made with extrusion-grade polycarbonate visors offer superior impact resistance and optical clarity compared to those made with injection-grade polycarbonate. The uniformity of the material and absence of defects make extrusion-grade polycarbonate a highly reliable and durable material for face shield visors.