Plastic continues to play an integral role in the global economy, with manufacturers generating more than 400 million tons of it each year for use in new parts and products1. However, the increasing prioritization of sustainability goals coupled with gaps in the plastic and resin supply chain has automakers and molders looking more closely at how to make existing scrap plastic resources a viable supply source for their production lines.
One of their biggest challenges is how to incorporate more of their own scrap regrind, as well as other post-consumer resins (PCR) with their varying viscosities into existing injection molding processes. It’s this challenge that iMFLUX seeks to address with one of the first major innovations in plastic injection molding in decades.
Managing Resin Variations
Conventional methods for injection molding automotive parts cannot adequately process materials with resin variations like those inherent in PCR because of differences in weight, viscosity, and melt temperatures. Without a technology to accommodate these anomalies within each shot, parts molded with PCR have typically contained gaps, flashes, and other errors that erode output quality and cause significant waste of time and material. Consequently, plastic injection molding manufacturers and contractors have traditionally relied on a steady supply of virgin resin to create their goods, despite its cost and environmental impact.
However, recent global events have interfered with resin supply chains, reducing or eliminating supply sources altogether. Worse, because the Original Equipment Manufacturer (OEM) typically specifies the product material, parts suppliers with no access to or without a reliable supply of the specified material were unable to complete their contracts, or at least not complete them on time.
iMFLUX addresses these two concerns with its low-constant-pressure injection molding platform, opening supply options to a broader range of material streams and enabling the use of alternative resin sources, including PCR, without eroding the quality of the product. The innovative technology uses a melt pressure sensor to detect variations in viscosity within the flow and adjusts the pressure to accommodate those specifications. The low-constant-pressure process ensures that the quality of the fill and pack are optimal, regardless of the material’s content. The resulting part has few, if any, defects.
As a result, there is a great opportunity for OEMs and plastic parts producers who install the iMFLUX injection molding technology onto their existing machines, as they can now efficiently and economically incorporate varying types of plastics and resins into their injection molded products while gaining quality and efficiency in the process.
More Materials = More Options
The opportunity to use a broader range of materials without losing quality is a game-changer. Many other resins and plastics2 are available that, if managed correctly in the injection molding process, could produce the same or higher-quality products as are made from virgin resin.
Researchers are investigating these alternate materials3 to discover how their properties compare to those of conventional injection molding material streams. Like metals, different plastic resins have distinct properties that vary their capacity for specific applications.
- Acrylonitrile Butadiene Styrene (ABS) is found throughout the automotive body. Its capacity to absorb and redistribute energy caused by impacts makes it ideal for interior surfaces.
- Polypropylene (PP) is used most often because of its heat, chemical, and impact resistance. It’s routinely found in scuff plates, bumpers, and electrical housings.
- Polyvinyl Chloride (PVC) is a flame retardant plastic with both rigid and flexible properties. It’s used throughout the vehicle body.
- Polycarbonate (PC) plastic usage is rising as electric vehicles (EVs) gain prominence. Lightweight, durable, and malleable, PC replaces conventional metal auto parts without marring the car’s visual appeal or brand aesthetic. For example, EVs have no combustion engine, so they don’t need a front-end grill for air circulation, but removing the grill altogether may spoil the car’s look for the consumer. OEMs now install PC ‘grills’ that mimic the look of conventional vehicles while adding almost no additional weight. Notably, PC has difficult flow properties but the iMFLUX technology processes PC very easily, making it an excellent option for injection molded parts.
All these plastics provide the essential durability required, and their malleability facilitates several additional benefits:
- They all reduce vehicle weight, which improves overall engine performance.
- They cost less to source and produce than conventional metal parts.
- They can be molded into unique and innovative designs that meet the specifications of the OEMs, industry regulators, and vehicle consumers.
Testing Perfects the Process
Testing each of these resins against a variety of objectives will determine which individual or combination of resins will work best for automotive parts. iMFLUX’s Auto-Viscosity Adjust™ (AVA) feature facilitates testing as easily as it enables production.
The iMFLUX injection molding system can help your automotive parts production plant operate more efficiently while addressing your — and your customers — sustainability objectives. In the next article, you’ll discover how it can also save you time and money by reducing challenges posed by sequential valve gates. Contact us today for more information.