Not a drop wasted – ReWork at milk processor Emmi

With a turnover of around 3.7 billion Swiss francs, the tradition-rich company Emmi is the largest dairy processor in Switzerland. Emmi has always been aware of the accompanying responsibility for employees, society and the environment – and acts accordingly in a sustainable manner. One success story is the ReWork process at its Suhr location. Using a WEIMA PUEHLER G.300 ReWork draining press, overfilled or underfilled milk cartons are automatically opened and emptied in order to return the recovered milk to the production process. The result: an efficient resource cycle.


More than a third of all food produced worldwide is wasted. That's reason enough for Emmi from now on to campaign even more strongly against food waste as an official Waste Warrior Brand. As part of this association initiated by Too Good To Go Schweiz, Emmi is fighting for greater awareness among consumers and against waste. The measures in its own companies prove that Emmi is leading by example.

Pressed milk carton discs from a PUEHLER ReWork press

Emptied and compressed milk cartons at Emmi

PUEHLER press discharge pipe with emptied milk cartons

Material discharge with compressed milk carton discs


ReWork solves the waste dilemma


Modern dairy processing equipment must be designed to be as efficient as possible for profitable operation. However, as with any type of manufacturing, defective goods may be produced. In the case of minimally processed basic products such as milk or cream, this mainly relates to things such as over- or underfilled containers or leaky packaging.


This is where the so-called ReWork process comes into play. The focus is on preventing and using high-quality waste. To ensure this, the contents and packaging must be separated mechanically and be guaranteed to be free of contamination. This is the only way that the recovered milk can be refilled and the beverage cartons recycled.


Emmi has relied on PUEHLER technology for two decades

At the largest Emmi location in Switzerland, in Ostermundigen, they have been familiar with PUEHLER draining and compressing technology for over 20 years. Thanks to the successful collaboration, Emmi is relying on WEIMA as a partner for its new ReWork system with a PUEHLER press as a key component at another large location, namely in Suhr, where milk, cream and butter are primarily produced.

Key facts at a glance

3k l
Emptied milk per hour
Milk cartons per week
Packaging recycling

Deputy Site Manager Hans-Peter Steuri explains: "We process around 190 million liters of milk and about 60 million liters of cream. Before using the PUEHLER press, we had to manually open every full piece of waste packaging. That was hardly productive. With WEIMA, we have finally found the right partner for our task."

Lift tilt device for machine feeding with milk cartons

Lifting and tilting device to feed the PUEHLER machine

Drained milk from Emmi milk cartons transported to tanks

Transportation of emptied milk for rework

Stainless stell designed PUEHLER press from WEIMA

WEIMA PUEHLER G.300 ReWork press made of stainless steel


PUEHLER advantages: high throughputs, hygienic design, compact footprint

Steuri aptly described the stringent demands that the new PUEHLER ReWork press meets: "As a food manufacturer, hygiene is the be-all and end-all. WEIMA machines are user-friendly to maintain, have CIP cleaning and comply with strict hygienic design specifications. In addition to the high throughput, the WEIMA system requires significantly less space than those of other providers – a clear advantage for us."

Draining and compressing of production waste milk cartons at Emmi in Suhr, Switzerland

Visual inspection of draining and compressing process

WEIMA drainage press for milk cartons at Emmi in Suhr, Switzerland

PUEHLER G.300 ReWork draining press from WEIMA

Lifting and tipping device with PUEHLER ReWOrk press

WEIMA ReWork press with lifting and tilting device

Steuri aptly described the stringent demands that the new PUEHLER ReWork press meets: "As a food manufacturer, hygiene is the be-all and end-all. WEIMA machines are user-friendly to maintain, have CIP cleaning and comply with strict hygienic design specifications. In addition to the high throughput, the WEIMA system requires significantly less space than those of other providers – a clear advantage for us."


Automated drainage operation

Up to 20 different employees operate the ReWork system during the week. In order to further automate the processes, the machine loading takes place via a compact lifting and tilting device. Like the entire machine body and the discharge conveyor, it is made of stainless steel. The milk cartons collected in plastic boxes are then transported into the large hopper of the WEIMA PUEHLER G.300 ReWork. At regular stroke intervals, the milk cartons are then pressed horizontally in the pressing channel by a pressing cylinder moving against a press plate lowered for the process. This drains the packaging and simultaneously compresses it. A major advantage: the machine can be used flexibly. No conversion for different packaging sizes or types is necessary.

ReWork draining press from WEIMA for milk carton compressing

WEIMA PUEHLER G.300 ReWork press with hydraulic unit and control cabinet


The milk first flows through a round-hole screen into the collection tray under the press channel before it is pumped out into large stainless-steel tanks. With the next press stroke, the emptied packages, now formed into manageable compressed disks with a diameter of 300 mm, are transported away via a discharge tube. The residual moisture of the milk cartons is minimal due to the compaction. The contents have been cleanly separated from the packaging. Both material flows can be flawlessly processed. In the case of the packaging, this means: 100 percent recycling at Emmi.

Discharge pipe with drained rework milk cartons

Emptied milk cartons

Pumping out rework milk from PUEHLER draining press

Collection tray with hose for pumping of ReWork milk

Pressed milk carton discs falling into recycling bin

Drained and compressed discs in recycling container

Automated ReWork process at Emmi with Emmi employee watching

An Emmi employee monitors the ReWork process


Partnership on equal terms


As soon as the production waste from the last shift has been processed, fully automatic cleaning, or CIP (Cleaning in Place), follows. Hans-Peter Steuri is very positive about maintenance: "The WEIMA PUEHLER G.300 ReWork is very accessible and clearly designed. This makes maintenance and cleaning easier for us. As a partner, we feel very well supported and are provided expert advice by WEIMA. Their adherence to deadlines is exemplary. We can really always rely on that."


Emmi’s ReWork facility pays off in many ways. It is not only particularly economical and efficient but above all sustainable in dealing with resources. WEIMA PUEHLER G.300 ReWork thus actively supports the Swiss dairy processor in its ambitious environmental goals – away from a linear economy and towards a recycling-based circular economy. According to Emmi, the volume of waste has already been reduced by ten percent compared to 2017.


WEIMA Maschinenbau GmbH

Bustadt 6-10

74360 Ilsfeld


Additional Information

About Emmi

Emmi is the leading milk processor in Switzerland. Its roots date back to 1907, when it was founded by 62 dairy cooperatives in the region around Lucerne. Over the last 20 years, Emmi has developed into an international group of companies that is listed on the stock exchange (ticker symbol EMMN). Emmi is pursuing a long-term, successful strategy based on three pillars: strengthening the Swiss domestic market, growth abroad and cost management. An important credo that has accompanied Emmi throughout the company’s history is a strong sense of responsibility towards people, animals and the environment.
In Switzerland, Emmi manufactures a complete range of dairy products for its own brands as well as customers’ brands, including export hits such as Emmi Caffè Latte and Kaltbach. Depending on the country, there are also locally manufactured products – usually in a specialty area. In addition to cow’s milk, goat milk and sheep milk are also processed.
The Emmi Group has 25 production facilities in Switzerland. The company is present abroad with subsidiaries in 14 countries, eight of which have production facilities. Emmi exports products from Switzerland to around 60 countries. In addition to the domestic market of Switzerland, its business activities focus on Western Europe and the Americas. The turnover of CHF 3.7 billion – around 10% of which comes from organic products – is spread about equally between Switzerland and abroad. Of the almost 8,700 employees, more than two thirds are now employed at locations outside Switzerland.


More than 40,000 machines sold worldwide! For over four decades, WEIMA has been manufacturing rugged shredders and briquetting presses for the disposal and processing of all types of waste. Our machines include single shaft shredders, four shaft shredders, cutting mills, briquetting presses and draining presses. The popular blood orange machines are used in the wood, plastics, paper, metal and waste-to-energy industries.

Made in Germany. Built for the world.

Shredders, briquetting presses and draining presses from WEIMA are exclusively made in Germany and come from production plants in Saxony-Anhalt and Baden-Wuerttemberg. Every year, more than 300 employees work on around 1,200 customer solutions for use around the globe. Long-standing sales and service locations exist in the USA, Poland, India and China. More than 80 representatives supplement this global presence.

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