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How Marbles Are Made Modern machine made glass marble making has not changed drastically since it was first introduced over 100 years ago. The fundamental change centers around how glass enters the machine. In the beginning, this was done by hand. Around the late 1920's, hand work was replaced with a gravity feeding device called a gob feeder. The glass furnace itself was placed over top of the marble forming machine. The molten glass only needed to be delivered via gravity to the forming rolls.
Click on the photo to see a video of this happening. Here we can see a stream of molten glass flowing in the middle of the photo. The stream of glass enters a reciprocating shear device that runs at the same speed or rpm that the forming rolls do. Every other gob of glass goes to a different set of rollers. The sheared gobs of glass now slide down a short chute onto the forming rolls. This arrangement is called a duplex machine.
Click on the photo to see a video of this happening. This photo shows the ends of the chutes and hot gobs of glass being rolled and formed into marbles. The gobs are glowing brighter at the top of the photo because they are hotter.
Click on the photo to see a video of this happening. Here is a general view of the complete forming machine. Glass enters at the top, the marbles are formed on the screws, and the finished marbles are ejected out of the machine.
Here is a photo showing the inside of the furnace. The entrance to the furnace is opposite the end that is over the marble machine.
All of the above images and videos were taken in the fall of 2003 at the Jabo Marble Company in Reno, Ohio. |
