Durable and economical bearings for format adjustment in tray inserter

Plastic trays are the most widely used solution in supermarkets for keeping meat, fish, fruit and vegetables cost-effective and fresh. Around 50% of plastic trays contain so-called absorbent inserts that protect the product from pressure and absorb and bind any fruit juice (see image 1 below).
In 2005, LAD GmbH developed an absorbent pad machine that is sold worldwide to ensure that the pad is cut to size and does not slip in the packaging. The system is fast and efficient; one machine can produce 100,000 trays in eight hours.
The suction insert machine is designed for one worker and is built in a U, so that the working distances are short. But how does a tray get a suction insert in the shortest possible time?
Firstly, the employee has to fill a tray with the trays. From here, the trays run into the automated system, where they are "de-nested", i.e. separated, the fleece is cut to size, inserted and welded or glued using two-point ultrasonic technology. The quality check is then carried out using camera technology. If the tray passes the check, it is "nested" again, stacked inside each other and dispensed. The employee can now remove and pack the stacked trays. This means that 200 trays can be packaged in just one minute.
However, as there are many different packaging sizes on the market, the machines must be able to be changed over easily at least once a day. A format adjustment is required for each tray, both for de-nesting and cutting the fleece as well as for nesting. For this, the machine manufacturer needs reliable, durable and cost-effective automation solutions.

LAD GmbH can choose freely from a wide variety of different spindle, materials and glides in the drylin® SHT-linear modular system. They can be customised online in the free drylin® SHTdesigner. The linear SHTmodules enable completely lubrication- and maintenance-free adjustment with high precision.

Customisation of the tray support
At the start of the process, classic slide bearing technology is used in the system.drylin® R-bearing made of iglidur® J are used to adapt the tray support. They ensure a lubrication-free bearing on the stainless steel shaft. Denesting the

suction inserts A
drylin® SHT-linear system made of hard-anodised aluminium with a reverse spindle is used for the format adjustment of the denester(Fig. 2). This can be easily adjusted using a hand wheel. The slides of the linear table move over sliding foils made of iglidur® J tribopolymers, which are lubrication-free and highly wear-resistant.

Format adjustment of the suction pads
We also offer favourable solutions for smaller loads such as adjusting the width of the suction pad. A durable and attractively priced linear bearing is used: The drylin® SHT module as a low-cost variant made of plastic(Fig. 3).

Nesting and dispensing the plastic trays
A special solution had to be found for the vertical nesting and automatic dispensing of the stacked trays: two SHTlinear modules made of aluminium are now used here, which are connected via a toothed belt. The output pushers are driven by drylin® NEMA stepper motors(Fig. 4), while the D1 dryve enables simple and cost-effective control(Fig. 5). The control system is suitable for all stepper, DC and EC/BLDC motors and can be operated without software and without an internet connection via the web browser from a PC, smartphone or tablet without an internet connection.