Process compounds, extrudes, and calenders PVC flooring in one step.

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KraussMaffei Berstorff (U.S. office in Florence, Ky.) has developed a new process to make multi-layer PVC floor coverings, also referred to as luxury vinyl tiles (LVT). Whereas conventional LVT processes are multistage, this new method combines compounding and tile production in one step.

LVT flooring is composed of a highly filled core layer—usually with an integrated glass mat—plus decorative film and a wear-protection layer. While the glass mat gives strength and dimensional stability, the core layer is designed to keep the floor covering flat while providing impact sound insulation. The decorative film is laminated to the thick sheeting to produce the desired design and the product is rounded off by wear-protection layers of different thickness, depending on the application.

Similar to roofing sheets, the three-layer floor covering core is produced on two twin-screw extruders and two smoothing calenders. The first extruder is used for plasticating and homogenizing the PVC compound. It’s equipped with a side feeder that doses minerals and other additives. The sheet is applied to the glass mat on the first downstream calender. The structure is then guided through the second calender, where sheet from the second extruder is applied to the other side of the glass mat.

Further downstream, decorated film and the wear-protection layer are applied to three-layer core material. The five-layer composite then passes through an embossing station as well as a temperature-control section to ensure dimensional stability before being cut to size.