Chicago — New research is showing that foaming agents can be successful when used in closures to reduce both product weight and production cycle times, according to a presentation at the Plastics Caps & Closures 2017 conference.
Testing conducted by iD Additives Inc. and injection molding machinery maker Sumitomo (SHI) Demag indicates the introduction of a foaming agent, which creates tiny bubbles within a manufactured plastic product, also does not impact the surface quality of the product tested.
"What's really changed things is it's opened up the market of caps and closures," Nick Sotos, president of iD Additives, told the conference crowd in Chicago. "We're able to set ourselves in parts that we could not have done years before."
The two companies used a borrowed mold from NyproMold Inc. to test the effectiveness of an iD Additives foaming agent on a hinged closure used on a shampoo bottle.
"We wanted to show people you can do these things and still maintain your functionality. So for brand owners, this is a great story for them to tell," he said.
Adding a foaming agent cuts down the amount of resin needed to create a part, lowering both the cost and the carbon footprint, Sotos said. "This is a great way to do it without having to thin wall."
One concern, said Michael Uhrain, technical sales manager for packaging at Sumitomo Demag, was the potential impact the foaming agent could have on the durability of the closure's hinge.
But the foaming agent, he said, transferred across the hinged portion to the top of the closure without impact on performance.
"We did not expect for the foaming agent to sacrifice any of the physical properties of the part," Uhrain said. "So now you can have the same mold thickness, and instead of thinning the wall and losing some of those mechanical properties, you can maintain those," he said.
The two companies were able to reduce the cycle time of this particular flip-top cap from 12.3 to 10.5 seconds through the introduction of the foaming agent and the reduction in resin usage.
Using the foaming agent at rate of 1 percent ultimately decreased overall resin consumption by 8 percent in the finished parts. Factoring in the cost of the agent and the cost of the resin, the change resulted in a 4-percent material cost reduction, the companies said.
The conference was organized by Plastics News.