KraussMaffei
KraussMaffei Berstorff has launched a new foam extrusion line specialised for the production of cap seals.
The extrusion line, named Schaumex ISO-PAC, reportedly offers eco-friendly and cost-effective production of the seals, which are made of PE low-expansion foam.
The Schaumex single-screw extruder series produces sheets, film, pipes and profiles. The machines combine all process steps in a single machine - from compounding, blowing agent injection and incorporation up to the final cooling stage.
The extruder has a processing section of 40 L/D length with electrical heating and air-heating systems in the compounding and mixing section to melt the plastic material at about 200 °C and to mix in the required additives. The CO2 blowing agent is injected through a special injection system in the central section of the extruder barrel. The processing zone downstream from the injection point is equipped with a fluid temperature control to cool down the melt with the blowing agent to about 130°C.
“We are faced with an increasing demand for Schaumex lines at international level. Recently, we have sold two Schaumex 120 lines with an output rate of 210 kg/h and two Schaumex 150 extruders with a low-expansion film production capacity of up to 320 kg per hour to customers in Asia and Eastern Europe,” said Matthias Reimker, project manager for foam extrusion lines at KraussMaffei Berstorff.
All four lines sold feature round-section dies and Teflon-coated die lips and are equipped with an efficient outside air-cooling. The cut flat sheet is cooled down on a take-off unit with two water-cooled cooling rolls of 600 mm length and subsequently wound up.
In addition to the single-stage Schaumex process, KraussMaffei Berstorff offers Schaumtandex solutions composed of a primary extruder for plasticizing and homogenizing and a secondary extruder used for melt cooling.
As this particular market is faced with an increasing demand for eco-friendly solutions, about 75% of low-expansion foam products are produced on the basis of non-polluting physical foaming processes, and only 25% using chemical foaming.
Aside from environmental aspects, this is also due to the fact that reaction products of chemical foaming processes may affect odour and taste, which must be avoided in the food sector.