So the skinny on old heads - Page 1

Gary and members. I am a manufacturing engineer and spent 20 years in the plastics processing industry so let me explain it a little further for everyone. Some detail but not enough to go into the techno-geek realm.

The plastic that drum heads are made from are done in a process that is called sheet extrusion. The plastic pellets and other filler materials (chemicals that give it strength, elasticity, etc) are melted in the extruder ( basically it is similar to a screw in a tube that is heated to melt and mix the plastic and move it along) and the melted plastic exits the extruder through a sheet head that can be adjusted to varying thicknesses. Depending upon the process, the plastic is moved through heated rollers or calendars that help to keep the sheet pressed to the desired thickness and helps to produce the gloss finish while it is cooled. This is how the "stretch" or dimensional thickness is determined or imparted into the plastic sheet. Plastic has a "thermal memory" and will want to revert back to a different shape, typically like a swirly piece of spaghetti so that is the reason for the calendaring process. The continuous sheet, once cooled, is taken up on a roll so it can be used later.

In the drum head process it is typically then taken to a thermo forming machine where the sheet is heated, the plastic "sags" and stretched or pressed onto the rim form (similar to an upside down pie tin) and the aluminum rim itself to make the varying size heads. To ensure adhesion, a bead of epoxy is run around the rim so the plastic adheres tightly. If the head is coated, it will go into a spray booth process where they spin while the paint is applied (to ensure uniformity of paint application) and then run through a heated process for adhesion and drying.

So, that's Drum head production 101.

Yes the Geek-engineer in me comes out every so often

Michael

So the skinny on old heads Last viewed: 1 day ago