New worlds: 1977 – 1990.

From 1977 onwards, RETHMANN KG ventured into new business sectors. The takeover of the Schaap rendering plant in Marl meant that the company entered the business field of processing animal by-products.

The company took a huge step in 1982. RETHMANN went down-under and took over the city cleaning activities in Penrith (Australia) under the name of "RESCH". The second Australian branch was established soon after in 1985.

In Germany, RETHMANN continued to purchase firms including Falk in Münster which was later renamed RETHMANN Recycling GmbH.

With its purchase of the PLANO company in Nordwalde in 1983, RETHMANN entered the field of plastics processing. It then began to play a role in the area of file and data destruction when it bought up Data-Lösch in Nottuln in 1986. In 1987, RETHMANN invested, together with Edelhoff, in the business of clinical waste disposal via the INFA (Institute for Refuse, Wastewater and Infrastructure). And, in the same year, shares in the Constance composting plant were bought from FAUN and the patent was also purchased for the "brikollare" composting process. In 1989, the family holding company, "RETHMANN AG & Co.", was founded with the shareholders being Norbert Rethmann and his four sons.