wenglor Sensors at the Family Owned Tea Production Facilities of Häußler & Sauter
On the average, Germans drink 25½ liters of tea each year – meeting this demand is the task of Häußler & Sauter (H&S), the tradition-rich manufacturer of well known H&S medicinal teas, as well as Goldmännchen brand teas. The tea packing facility produces packaging and teabag machines.
The H&S organization is distributed over three locations in Germany: Kressbronn on Lake Constance, St. Gangloff in Thuringia, and Soltau in the Lüneburg Heath. Company headquarters is located in Kressbronn on Lake Constance, along with a manufacturing facility for the production of pharmaceutical teas which are marketed exclusively by pharmacies as medicinal teas under the H&S brand name. Not least of all, Kressbronn is the home of world famous HST teabag and packaging machines, which the company has been producing since 1950 under the HST brand name for its own manufacturing facility, as well as for worldwide marketing.
Lots of little “electronic eyes” are built into these machines, which monitor the individual process steps – sensors from wenglor sensoric. The internationally active sensor manufacturer maintains production and R&D facilities in the electronics city of Tettnang, Germany, just a few kilometers from the H&S tea production plant. And thus sales engineer Klemens Prinz is able to provide his customer with close-by, active support. He’s familiar with the tea production process and can provide his customer with good advice.
Photoelectric Sensors
For the most part, H&S uses Reflex Sensors . Reflex Sensors are one of several types of photoelectric sensor. wenglor’s broad range of Photoelectric Sensors provides users with ideal solutions for a great variety of applications. They’re capable of simply scanning and counting objects, as well as performing high precision distance measurements and recognizing color, gloss and luminescence. Where all types of contactless detection tasks are concerned, wenglor is an experienced and innovative partner for its international customers. Suitable mounting systems for various housings and additional options for connecting sensors to glass or plastic fiber-optic cable allow for flexible and easy installation, as well as use under extreme ambient conditions.
In the case of Reflex Sensors, the emitter and the receiver are enclosed in a single housing. They evaluate light reflected from the object. When the object reaches the selected detection range, the sensor’s output is switched. Bright objects reflect more light than dark objects, and can thus be recognized from greater distances. Reflex Sensors are used where checking for the presence of objects is required, or where objects have to be detected or counted. PNP and NPN switching outputs, a contamination output and an RS-232 interface are included. Sensor functions can be activated, and scanning results can be acquired via the RS-232 interface. Adjustments are performed with a potentiometer. With Teach-In variants, adjustments are made with the appropriate keys, externally or via the RS-232 interface.
Thanks to their fine focusing optics, these sensors are especially well suited for detecting objects at short distances and in front of backgrounds, for example in front of machine components and on conveyor belts. They’re preset at the factory to the customer specified detection range.
The Tea Production Process
Tea production, which is started on the second floor of the production department at H&S, is monitored by Photoelectric Sensors. It smells of mint and a great variety of fruits. An unskilled nose can hardly differentiate the nuances. Large sacks, know as big bags, contain 800 kilograms of any given type of finished tea blend. “The sacks are placed into quarantine and aren’t released to production until they’ve cleared receiving inspection”, explains Professor Dr. Wolf Dammertz, director of manufacturing and legally qualified medicinal representative at H&S.
The tea blend passes through a funnel on its way to the floor below, and into the packaging machines. This is where the sensors are first made use of. For example, they determine whether or not there’s enough tea in the machine hoppers. An HN22 Reflex Sensor with Background Suppression checks to makes sure that there’s still enough paper on the roll in order to package the tea. The paper is fed into the system and the tea falls directly onto it from the hopper. The paper is then folded, after which the label , the string and a staple are attached. A sensor is also involved in determining when the staple is affixed. The Reflex Sensor generates a signal as soon as a teabag is located at the specified position. This signal gives green light for further production steps. “The fact that we use knots instead of staples in the packaging for certain products is something new”, says Edmund Keller, department head for machinery manufacturing, who’s been working at H&S for 27 years.
Foil is used to package the tea in the hot sealing system. Due to the fact that the areas above and below the foil are not suitable for mounting sensors, a wenglor DX22 Reflex Sensor which can be fitted with fiber-optic cables is located about ten centimeters from the foil strip. The hand made fiber optic cable replaces the sensor’s eyes. It transmits light from the Reflex Sensor, and guides it back again as well via bundled optic fibers, after which the sensor generates an appropriate signal. In order to assure that the right type of foil is used, a wenglor Print Mark Sensor has also been installed to the system. Stefan Bonsen, plant electrician at H&S, explains: “Teabags packaged in plastic foil retain their aroma better than they do in paper bags. 160 teabags are packaged per minute in the hot sealing system.”
The sealed teabags are pushed into a cup. As soon as a enough teabags are in a magazine, the magazine is rotated in order to accept further teabags. As slide takes the bags out of the magazine. A suction cup pulls a box into the system from above, which is then folded. The box is then filled and weighed. It can’t be weighed until a sensor generates the appropriate signal.
The teabags are placed into the packages at the end of the system. The packages are transported to the hot-gluing and wrapping machines on a conveyor belt. Numerous Reflex Sensors monitor this process. Up to six wenglor sensors over a length of 20 centimeters assure smooth operations in the spot gluing system.
“After they’ve been packaged and inspected, the teabags are shipped primarily to European countries”, says Professor Dr. Wolf Dammertz. In contrast to this, the machines are shipped as far away as Russia and Sri Lanka according to Edmund Keller, department head for machinery manufacturing.
Quality
Product development and tea inspection by means of sensors is headed up by Stephanie Klar. She develops the individual types of tea and inspects all received raw goods together with her team, in order to makes sure that they taste, smell and look exactly like they’re supposed to. “With quality, imagination and a distinctive love for tea which is lived anew each day, we convince singles, families, men, women and children of all ages of the excellence of our highly diverse products”, says Stephanie Klar.
Alignment to high quality standards goes without saying for H&S, and it’s decisive for the success of the company.
At wenglor too, quality management has enjoyed top priority ever since the company was first founded. The quality management system was certified already in 1997. The goal and purpose of the system is to assure that customer requirements are fulfilled. According to the company’s quality policy, “for wenglor, quality not only means that the product complies with applicable standards and specifications, but rather quality is the basis of all of our action”.
Family Companies
High quality standards aren’t all that H&S and wenglor have in common. Both are family companies as well.
Today, the fate of H&S as a mid-sized company is guided by the Klar family. The designation “family company” not only describes an arbitrary legal form, at the same time it’s the principle and the basis of an independent corporate culture which is distinguished by personal entrepreneurial commitment, a great deal of experience and, in particular, a love for tea. More than 300 employees maintain this corporate culture. Over a period of three generations and 50 years of company history, H&S has succeeded in establishing a good reputation and developing outstanding market competence in the areas of consumer as well as medicinal teas with end customers, bulk consumers and pharmacies, as well as with buyers of teabag machines and service providers.
wenglor started small as well with sensor production in an attic 25 years ago. Today more than 50,000 customer around the world benefit from the know-how of 500 international employees. The wenglor group includes 28 members and 15 commercial representatives, and is thus active in 43 countries. Annual sales amounting to €50 million confirms the high quality of wenglor’s products. The company’s product range encompasses Photoelectric Sensors, Inductive Proximity Switches, Safety Technology and ID Products. Innovation, precision, rapidity and flexibility are essential ingredients in wenglor’s recipe for success. A unique working atmosphere, motivated employees and a strong desire for steady improvement are the strengths of the family company. However, wenglor can only be successful by cooperating closely with customers like H&S in good faith. In doing so, fair play and good sportsmanship are always important goals.