How to improve material selection using ASTM material standards
How do you specify materials for your plastic injection-molded parts? Do you have favorite resins you like to use? If so, you may be paying too much for them or you may be over-engineering the parts for their applications.
A more cost-effective approach is to specify an ASTM material standard for the material that you believe meets all your performance requirements.
“We see this happen often,” explains New Berlin Plastics Vice President of Sales Joseph Mechery. “A young designer specifies a brand-name resin for a part. It ends up being a very successful project. He then continues to specify that material for other projects. It becomes a ‘safe’ choice for him.”
Mechery compares it to the way that people build up loyalty to a specific brand of pickup truck. “It has served me well, so I’ll buy it again. It’s human instinct,” he adds.
But that approach to material selection isn’t advantageous to the designer or his employer. “By specifying a brand name of resin, you’re limiting the number of suppliers we can work with,” Mechery points out. “As a result, we’re not always able to negotiate the best material price for the project.”
The other problem is that each part has slightly different performance requirements. A resin that may be perfect for one part may be over-engineered for another. As a result, the OEM’s material costs may be higher than they need to be.
A more economical approach to resin selection
A more cost-effective approach to material selection is to specify an ASTM standard for the type of material you’ve selected, instead of a brand-name resin.
ASTM is an independent lab that tests and assesses the physical, mechanical and chemical properties of plastic resins. It publishes them in detailed standards that engineers and molders can download and use when they need to select resins for a project.
Why is this a better approach?
Mechery explains: “With an ASTM material standard in hand, we can recommend a material that fits our customer’s application’s needs rather than relying on sourcing a specific brand of resin. That, in turn, means we can usually negotiate a better price for them. Overall, it helps us do a better job of aligning cost and performance for our customers,” he adds.
The benefits of this approach extend to both the designer and the purchasing person who is responsible for sourcing the parts.
“Most designers and engineers aren’t material experts. Giving us an ASTM material standard lets them focus on what they do best – designing a part that elegantly solves a problem and has certain characteristics,” Mechery points out. “We can then focus on what we do best – finding the right material that meets those performance needs.”
For the purchasing manager, the ability to source resin at a lower cost per part is very attractive.
Finally, this approach gives the molder and OEM a common ground to discuss material options. “These standards are publicly available on the ASTM website. That means we can have a detailed discussion about the characteristics of the resins we’re considering and agree upon the best solution. Ultimately, that results in better outcomes for everyone,” Mechery concludes.
Contact New Berlin Plastics today to discuss your next plastic injection molding project.