Regrind vs. Repro: Understanding Recycled Plastics

 Unlock the secrets of recycled plastics! Discover the crucial differences between regrind and repro materials, and learn how manufacturers are driving sustainability and efficiency. 

This article clarifies these terms, helping you optimize production and contribute to a circular economy.

What is Regrind Plastic?

Regrind plastic refers to plastic material that has been reprocessed, typically by grinding or shredding, from scrap generated during a manufacturing process. This scrap can include rejected parts, sprues, runners, or other waste materials produced within a factory.

The key characteristic of regrind is its origin: it is a post-industrial material, meaning it has not left the manufacturing facility or entered the consumer waste stream. It is often referred to as Post-Industrial Regrind (PIR) or in-house scrap.  At Wenplastics for example we create our regrind from water and gas pipelines as well as pallets, making sure this way they are totally oil free. 

The process of creating regrind involves taking these plastic waste materials and chopping or grinding them into smaller, more manageable pieces, often resembling flakes or granules. This material can then be directly reintroduced into the manufacturing process, either on its own or, more commonly, mixed with virgin (new, unused) plastic resins. The primary advantage of using regrind is its cost-effectiveness, as it reduces material waste and lowers raw material expenses. Furthermore, because regrind originates from a controlled manufacturing environment, its properties are generally well-understood and consistent, making it easier to integrate into production without significant quality compromises.

Manufacturers often use regrind in injection molding and other plastic forming processes. The percentage of regrind that can be incorporated into a product depends on various factors, including the specific plastic type, the desired quality of the final product, and regulatory requirements. When used appropriately, regrind can help companies achieve sustainability goals by minimizing waste and promoting a more circular approach to plastic production within their own operations.

What is Repro Plastic?

Repro plastic, short for reprocessed plastic, refers to plastic materials that have undergone a more extensive recycling process compared to regrind. Unlike regrind, which is typically generated and reused within a single manufacturing facility, repro plastic often originates from external sources, including post-industrial scrap from various facilities or even post-consumer waste. The key distinction lies in the processing: repro materials are usually extruded, filtered, and pelletized to create a more uniform and consistent raw material.

The reprocessing of plastic involves several steps. First, discarded plastic scrap or byproducts are collected and sorted, often by resin type and color. These materials are then cleaned to remove impurities and contaminants. Following cleaning, the plastic is typically melted down and extruded through a die, forming strands that are then cut into pellets. 

While repro plastics offer significant environmental benefits by diverting waste from landfills and reducing the demand for virgin materials, they often come with certain limitations. The quality of repro plastic can be more variable than regrind due to the diverse origins of the source material and the additional processing steps. This variability can sometimes lead to lower mechanical properties, inconsistent color, or the presence of impurities, which may limit their application in certain high-performance or aesthetic products. 

Key Differences Between Regrind and Repro

While both regrind and repro plastics contribute to the circular economy by utilizing recycled materials, their fundamental differences lie in their origin, processing, and resulting material characteristics. Understanding these distinctions is crucial for manufacturers to make informed decisions about which type of recycled plastic best suits their specific applications.

Processing:

• Regrind: Involves a relatively simple mechanical process of grinding or shredding the plastic waste into smaller, irregular particles or flakes. This process typically occurs on-site and does not involve melting or chemical alteration.
• Repro: Undergoes a more extensive reprocessing chain. After collection and sorting, the material is usually cleaned, melted, filtered to remove impurities, and then extruded into uniform pellets.

Material Form:

• Regrind: Is typically in the form of irregular flakes, granules, or shredded pieces, directly reflecting the shape of the original scrap material after grinding.
• Repro: Is almost always in the form of uniform pellets, similar in appearance to virgin plastic pellets.

Quality and Consistency:

• Regrind: Generally maintains properties very similar to virgin material, especially when mixed with virgin resins. Because it comes from a known, controlled process, its quality and consistency are often high, and contamination is minimal.
• Repro: Tends to be of lower and more variable quality compared to virgin material or regrind. The diverse origins and multiple processing steps can introduce impurities, lead to degradation of polymer chains, and result in inconsistent mechanical properties or color. This variability can pose challenges for applications requiring strict material specifications.

Cost:

• Both regrind and repro are generally more cost-effective than virgin plastic resins, contributing to reduced material costs for manufacturers. 

Wenplastics’ Approach to Recycled Plastics

Wenplastics, a Canadian manufacturer of IBC totes and plastic pails, is deeply committed to sustainability through its innovative plastic reprocessing practices. As a pioneer in British Columbia’s sustainability movement, Wenplastics has led the way in regrinding industrial plastics, particularly HDPE pipes.

Our process focuses on reclaiming and repurposing discarded HDPE and PP materials, such as water pipes, natural gas pipes, and plastic pallets. At the core of our operations is the mechanical regrinding of these industrial plastics—breaking down large, used items into smaller, granular forms. These regrinded materials then become the primary raw material for our manufacturing processes.

By carefully sourcing HDPE pipes and PP pallets, we ensure a consistent material stream that not only supports sustainability but also strengthens the durability and performance of the products we deliver.

Conclusion

In short, regrind and repro serve different roles in plastic recycling. One focused on consistency, the other on broad waste reduction. By understanding these differences, industries can make smarter choices that push sustainability forward and strengthen the circular economy.