Sturdy spindle linear system for pulling off paper envelopes

• What was needed:  drylin® -linear axis with spindle drive
• Requirements: The plant is characterised by humidity, exhaust fumes, high temperatures, a high volume of wafer dust as well as abrasive salts and sugar. At the same time, trouble-free operation must be guaranteed in three-shift operation seven days a week.
• Sector: Food industry
• Success for the customer: The drylin® spindle linear technology is both a simple and reliable solution. The linear bearings are maintenance-free, cost-effective, versatile and FDA-compliant, depending on the material selected. As they are completely lubrication-free, product contamination is ruled out. And friction and wear have been optimised thanks to their tribological specification, which has a positive effect on machine running times.

The capacities of Walterwerk Kiel GmbH & Co. KG's wafer baking systems are constantly increasing and, depending on the size of the machine, range from 3,000 to 19,000 standard wafers per hour.
The baking process of a standard wafer for industrial ice cream production is always the same: it is baked flat in the oven, fed to a wrapping station and rolled up while still warm. It is then transported to the cooling tower via a conveyor belt before the cone is wrapped in a paper cone in the packaging area. Only then is it filled with ice cream. Only one cone is guaranteed to be fed in, otherwise there will be problems with filling. With different paper cone sizes, the system has to be adjusted again and again.
And it is precisely in this section, the packing area for separating and feeding paper ice-cream bags, that linear bearings are used. They guarantee the format adjustment in the stripping station and have to fulfil high requirements: For example, operation in the system is sometimes characterised by high levels of humidity and exhaust fumes. In addition, there are sometimes temperatures of around 50°C in combination with the omnipresent, sticky wafer dust. Sugar and some of the salt used are extremely abrasive. And a sugar solution used in gluing equipment, which also sticks the cone and wafer together, must not affect the separation process despite the possibility of splashing. Under these conditions, all machine components must function smoothly in three-shift operation, seven days a week, in order to guarantee smooth downtimes and minimised service intervals for national and international customers.
Due to the high requirements of the trade show, a fully customised complete solution from a single source was a priority for Walterwerk Kiel.

Walterwerk Kiel GmbH & Co KG has pursued various solutions for format adjustment and ultimately opted for a simple and reliable system solution that can be adjusted manually by the user. More specifically, the special machine manufacturer has been using lubrication-free plain bearing technology in its modular baking systems for format adjustment for many years. The drylin® spindle linear unit used is maintenance-free, cost-effective and versatile. Plain bearings made from high-performance plastics for the food and packaging environment are FDA-compliant, depending on the material selected. Product contamination due to additional active lubrication is therefore ruled out. Friction and wear have been optimised due to their tribological specification, which has a positive effect on machine running times. Even regular cleaning with aggressive media poses no problems.
The special machine manufacturer purchased the complete spindle linear unit as a customised system. This means that not only the technical parameters, which are designed 100 per cent to meet the requirements on site, are right, but also the economic ones.
In a wafer baking system to be delivered to Korea, for example, it had to be possible to adjust two parallel systems simultaneously over a length of almost one metre. The two spindles are coupled via a helical bevel gear on one side. Due to the low loads, it was possible to dispense with a shaft construction for support. The aluminium guide tube guides the internal stainless steel spindle. The combination of materials defies the adverse environmental conditions. There is also a position indicator and a hand wheel. The entire system is maintenance-free. And due to the lack of lubrication, contact with food is harmless.