Plastic packaging is a common part of everyday life: bottles; containers for foods, beverages, medicines and more fill our pantry shelves and recycling bins. Thin-walled and hollow plastic bottles (later filled with the customer’s product) are made on a large scale with a process called blow molding, where hot air is blasted into a precisely calibrated metal mold, and the waiting thermoplastic assumes the shape of the mold. Because of the heat and pressure inherent in the blow molding process, large-scale production requires traditionally machined metal molds. However, for short turns, the molds can actually be 3D printed using PolyJet-based 3D printing technology from Stratasys.
Plasel Precision Plastics, a worldwide provider of these types of packages, designs and engineers each type for a variety of industries and customer applications. Recently, a Plasel customer needed to prototype a new package design to make sure it would fit with an automated conveying system. Plasel used Stratasys 3D printing technology to create a blow mold for a run of 100 package prototypes. Choosing 3D printing over traditional machining for these prototypes offered savings of time (90% faster) and money (94% less expensive) compared with traditional machining methods for blow molded prototypes. The 3D printed blow molds allowed this small-scale production run to happen in just two days. “Stratasys 3D printed blow molds were ideal for producing the prototypes our customer urgently needed to get their new product to market,” explained Nir Hadar, a research and development manager at Plasel.
To recap, 3D printed blow molds provide a quick process for design validation before metal molds are machined for big runs. Modifications to designs – including caps, snaps and hinges – can be easily and inexpensively made, and these prototypes can be used to check form, fit and function.
Plasel Comparison of Stratasys PolyJet 3D Printed Molds with Conventional Metal Molds
|CNC Machining*||Up to 20 days||$5,000|
|Aluminum Mold||Up to 20 days||$5,000|
|PolyJet Mold||2 days||$280|
* For 100 finished parts
This blog post is part of our series Tools Without Tooling, where we are exploring the benefits of 3D printing in the manufacturing industry. To read more posts from this series, click here.