How It’s Made: Corrugated Memory Straws
***All extrusion equipment utilized by SELA is of the highest quality available to make the very best straws available.***
Corrugated memory straws are made in a continuous extrusion process where pellets of PP plastic are fed into a plastic extruder, which heats the plastic (for this product to approximately 460°F), it then compresses the molten plastic under high pressure to remove any air, and mixes any colorant into a homogeneous molten material extruding (pushing) this material through a pin and bushing into the corrugator. All SELA extruders are made in America.
SELA uses color feeders which are linked to the extruder drive with digital settings to precisely feed the correct amount of color pellets directly into the extruder instead of making batches and feeding the mixed batch into the extruder. This provides for very precise color control and the ability to repeat the same color tint time after time. All SELA color feeders are made in North America.
A corrugator is a machine with metal “blocks” which are rotating continuously around a channel, accepts the molten plastic into the blocks for forming, are inflated with compressed air, and then brought to the exit area of corrugator and goes into the puller/cutter for cutting into final straw length. SELA corrugators are servo driven for accuracy, and utilize blocks which are 2.25” long, which is why our available straw lengths are in multiples of 2.25”, less shrinkage during final cooling. All SELA corrugators are made in Germany.
A chiller cools the corrugator to bring the temperature of the plastic down from 460°F to approximately 85°F , while the straw is being formed and cooled, in a length of 14’-18’ depending on the corrugator. All SELA chillers’ are made in Italy.
SELA chillers are connected to an Italian made recirculating water tower which does not use evaporative cooling, which saves many thousands of gallons per month and eliminates the use of rust and microbial inhibiting chemicals from being discharged into the atmosphere as most water towers do. This water tower also utilizes inverter technology to further save on electrical consumption. This water tower technology is the center piece of our green efforts. SELA’s water tower was made in Italy.
The puller literally pulls the continuous chain of formed straws into the cutter with SELA puller/cutters being servo driven for accuracy and utilizes fiber optic eyes to “see” when the corrugates end and the cuff begins. A computer in the cutter then sends a signal to the servo driven knife to make a cut at an exact point we select long the cuff, normally in the middle, which is why most of our cuffs are 1.125” long. All SELA puller/cutters are made in America.