Hot Seats
Design Goal // Design and manufacture replicable hot sauce bottle tags to affix notes about flavor profiles
Duration // January 2019 - March 2019
Materials // Parts: Polyethylene, Form2 Elastic resin; Mold bases: Aluminum
Processes // CNC milling, injection molding, 3D printing
Main Skills // Sketching, Concept ideation, Prototyping (laser cutting), CAD (Solidworks), Design for manufacturing (DFM), Manufacturing
My primary design motivation for this project was to create something I could give to my housemates — an eclectic group of friends who love spice. We’ve made a habit of buying hot sauces from our travels as souvenirs for each other. I wanted to create an attachment for hot sauce bottles that would allow for some sort of personalization. Early iterations involved voting plugs and name tags.
SolidWorks Modelling
Based off prototype dimensions, I designed a 3D model on Solidworks. In this iteration, a tab extends from the hoop section to accommodate a living hinge. The other end of the hinge (the “fin”) has a 1/8” diameter hole to allow for a plug and note to be attached. The underside of the fin is curved to fit around larger bottle bodies.
I simulated different injection locations for the part: at either end, at the hinge, and on the side. I checked for spots of lowest pressure and temperature at end-of-fill, which informed where difficult to reach places and knit lines would likely occur. Additionally, I ran a draft analysis and added a 1° draft to ensure my part would not get damaged upon mold opening.
I modeled the gate and runner as solid bodies to create mold cavities in a Solidworks assembly. My final mold uses one ⅛” ejector pin near the important fine features of the part (living hinge and plug hole).
Manufacturing
I used a 3” shell mill and 1/8” flat end mill for my facing and roughing operations, and a 1/16” and 1/32” ball nose end mill for finishing passes. The hole for the ejector pin was 1/8” in diameter. Separately, I manually milled an ejector plate to hold my ejector pin.
Molding
Final Molded Parts
In the end, I molded about two dozen parts in various shades of red and orange. In future iterations, I would increase the length of the living hinge to make it less susceptible to fatigue. Additionally, I would reduce the thickness of the part to reduce sink.
