Let’s talk about something different: Bunnies, Cars, and Mannequins

Evan Silo, Senior Technical Representative, McLube® Release Coatings and Lubricants

The rotational molding industry encompasses a diverse group of processes and materials, but we in the industry only ever seem to talk about plastic.

It has been my pleasure to sell mold release agents all over the world and I have been fortunate enough to witness some extraordinary rotomolding operations along the way.  The giant machines that create highway barriers, kayaks, and dumpsters are fascinating to watch but what about the lesser-known rotational molding processes?  Did you know that dashboards are rotationally molded PVC?  Ever caught a mannequin staring at you and wondered how it was made?  Marvel at the rotomolding technology that brought you chocolate bunnies this Easter. Check out the videos below to see the different process which utilize rotational molding.

Slush Molding:

Slush molding is a method of producing hollow objects like traditional rotational process.  Slush molding typically involves heating the mold before the material (plastisol or vinyl powder) is introduced which allows the material to gel during processing before being cooled and demolded.  A traditional spider rotational machine processes in almost identical fashion.  This video goes over the basics of slush molding machines used to create dashboards, glove boxes and even door panels:


Hand Casting:

Products in the faux design and prop industry tend to be molded by hand in low-volume batches.  The materials they use are very unique and outside of traditional polymers, from two-part thermoset resins like polyester, urethane and epoxy to simple concrete and plasters.  The users in this industry are not overly interested in process specific materials and tend to focus more on the finished product.  Due to the low volume, they can spend more time working with any given material.

The hand rotation shown in this video is not overly exciting but just as important for the end user to have a fully functional part.


This simple desktop rotational molding machine often used for prototype and low volume parts is a step up from hand casting and reduces variations.


Hollow Chocolates:

The chocolate industry is perhaps the best example of fully automated production with little operator intervention.  If we can put aside cost and look at how confectionery manufacturers approach this sleek and high volume production, then we might be able to create the next level of throughput in our industry.


I hope you enjoyed learning about a few lesser-known rotational molding operations! What other rotomolding operations are there?  Can they be applied to larger parts or help other facets of the industry automate?  Are there any new, revolutionary materials out there just waiting to be rotomolded?  Share and post your thoughts and ideas below!

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