The growing demand for trays of menu require specific and differentiating termomoldeo methods

The multiple possibilities that provides the packaging not only confined to wrap and protect; transport information, have a design to increase sales and a respectful attitude to the environment are equally important factors. Increasing emphasis more on the presentation of the packaging; a better visual effect is achieved through attractive designs. Illig is ILLIG Maschine GmbH & Co., represented by Helmut Roegele, S.A., specializes in the thermoforming and packaging market.

After the vacuum with soft plastic packaging, the current trend of food packaging are trays or plates of deep drawing. Homes, increasingly smaller, and the professional obligations make that you are cooking less.

The increasing demand of recent years menu trays begins to show signs of differentiation. It must apply different methods of termomoldeo according to the applications specific to pop, filling, sealing, and according to the properties that you want to have the closed container, such as transparency, properties of barrier, load capacity and duration. Finally, batches also determine the different solutions to choose the most economical method Variant.

Menu trays satisfy several requirements. They can be sterilized and freeze, although it is also possible to heat the contents of the package, for example in the case of the "convenience food", fresh prepared meals for the microwave and oven (sausage with curry). Consumer is also interested to return to close the container. Why are used lids for sausages and cheese, although packaging with hinge and lock buttons are also used. Food closures meet the requirements of protecting the product and be comfortable for the consumer, being also visually very attractive. The reduced weight of the packaging, the great shock absorption, the great variety of shapes and materials multilayered with barrier properties make the termomoldeo of trays is very attractive. They must be stable and resistant to the cold. The trend to move away from the soft packaging is due to the demand for a greater carrying capacity of the container, as the apilabilidad and stability play an important role for the transport and storage.

Taking advantage of the growing ecological awareness of the food industry and consumers, they also offer packaging made from biodegradable materials (corn starch). Containers have a good barrier to aroma and are suitable for a range of temperatures from 0 - 40 ° C.

The different applications of the containers and goods of consumption also require different plastics which can dye according to the requirements of the customers. Termomoldeadas trays can be offered in almost all colors. For applications of termomoldeo that require a high degree of transparency is often used materials such as A-PET, OPS or similar. The customer wants a high degree of transparency for example in respect of the vessels for drinking or the packaging of food, such as salad or vegetables.

Lately trays of fruit and vegetables are also available in black in order to provide a background contrasted with respect to the packaged food. A new trend is the marking by color, for example the black for the beef and pork; the yellow birds, etc.

The market calls for that tray has increasingly more functionalities, such as several compartments for different types of meat, or bridges (e.g. for shashlik). The termomoldeo also meets the quality requirements of the tray of meat in regards to resistance and crushing.

The condition for the preservation of the contents are completely accurate and flat closing edges in the entire perimeter of sealing, which is achieved with a padded cooled in the mould. He is achieved by extending the conservation through modified atmospheres of gas, which guarantee an appetizing aspect.

To manufacture containers should take into account not only the desired material properties, but also the costs of disposal. A-PLA can reduce the cost of elimination in the places where there is the selective collection of garbage. Other raw materials are ground online and can be recycled cleanly.

Fig. 2 Side of RDKP download 72d, working shaping and troquelando separately.

Menu trays and current trays can be manufactured in various types of facilities from termomoldeo. It systems that process the plastic from coils. Methods of moulding may therefore be used by vacuum, air compressed/vacuum or only by compressed air.

For decades ILLIG is offering several concepts of machines to provide all the conventional solutions of packaging, molding and stamping separate, both for the functioning of the molding/stamping.

Machines for moulding and die separate cutting always work in the same way. After unwinding the plastic, it is guided through the station of heating cycles. The process of molding and stamping occurs in separate stations; the die cutting process can be made by court with steel strapping or a die and press desbarbadora. Then the molded parts are stacked and are transported out of the machine, already rare. Stacking a-B provides a good chance of pop pieces molded for further processing. It is available for moulding mold or stacking station. The high degree of automation, in combination with the matured technology of mould, allows maximum availability.

With the technology of vacuum molding is possible economic output, especially for small batch sizes. The economic effect improves even further by combining molding vacuum with compressed air, which leads to better results of molding in the majority of cases. Both machines have a technology of simple mold that provides an economic alternative to the conventional termomoldeo by compressed air. The wide range of application includes pieces of packaging, menu trays or inserts and trays. The molds used are economic thanks to its simple construction and provide higher earnings in the case of small batches. Special features (such as floating arrays with focused prior) give rise to greater accuracy in court during the molding and stamping on separate stations.

Parts molded with carvings, molded hinges or close buttons can shape even better by combining with compressed air. A pressure of 2 bar casting is available directly in the mold.

The fed from coil automatic termomoldeo machines operating with compressed air are designed for increased production and allow speeds of more than 40 cycles/min cycle If required closer tolerances, parts are molded through the RDK technology (molding and stamping in a single season) and are separated from the tape of moulding lines of steel strip cutting, integrated in the mold of moulding.

The advantage is economic technology of mould and the wide range of formats. The cutting quality is somewhat limited by the buttons of subject which are needed in this method of transporting parts molded through the machine.

Fig. 3 Manufacture of trays of menu in a vacuum RV molding machine 53b, design of cast moulding to simultaneously produce trays and lids

Moulding and cutting in a single operation, RDM technology, equivalent to the termomoldeo of performance with the highest quality of the piece moulded with respect to the distribution of the thickness of the walls and the precision of the cutting contour. With this method the subject buttons are not necessary. The machines are interconnected with appropriate stacking systems to manually remove the pieces and/or ensure a fully-automatic sequence of the manufacturing process, from the manufacture of plastic packaging end. Stacking systems are synchronized with the great production capacity of machines. Because all the steps of manufacturing - like molding and stamping, stacking and packaging final - are integrated into the packaging line, the safety of the process is greater.

Fig. 4 ILLIG RDK54 molding mold / die for the manufacture of pre-printed lids

The considerable thermal expansion that occurs when processing PP require using preheating stations in all termomoldeo machines fed from coil. Heating cylinders placed in a closed cupboard uniformly heat the material up to a temperature of approx. 90 ° C. Thus, the material placed on the cylinders of heating can expand without restrictions, thus reducing the camber of the plastic in the machine while it is heated to the temperature of molding.

An additional machine, equipment essential for processing PP, is the device of expansion for the transport of the plastic. This device compensates for the camber of the plastic and prevents wrinkles to form during the moulding process. The application of technology of molding/stamping RDM (RDK) is advantageous because avoids additional transport steps and therefore obtained optimal results in what about accuracy of stamping.

All concepts of the machine ensures a process of continuous production with the parameters that can be stored in memory and retrieve at any time. In case of repeated product recovered the conditions of manufacture, guaranteeing product quality standard. During the turn of the moulds are avoided the expensive downtime as a result of entering data into the system of command. The use of drives by servo motor increases the useful capacity of the machines of termomoldeo, decisively improving the dynamics and smoothness of gear.

Molding station is ancillary to the heating station. Here is embuten the trays. During this process, the material was mechanically preestira. Gets an optimal distribution of the thickness of the walls thanks to the cardan, which allows an exact synchronisation of the molding table and the movements of the piston of preestirado. A better distribution of the material allows to obtain the same stability of the product using thinner material, which gives rise to a higher quality of products.

Measures have been taken to achieve an air pressure of moulding uniform and controllable allowing higher filling speeds, a phase of molding faster and that the cooling phase begins before, leading directly to major production capacities.

Fig. 5 ILLIG RDK 54 with moulding mold / die out of the machine to change the bases.

Fig. 6 - ILLIG RDM 75 K with moulding mold / die to make menu trays

Of course, manufacturing containers for the food industry must comply with the rules of hygiene. The hygienic properties of the machine are improved through structures smooth, easy to clean, and the use of air not lubricated for cylinders and gaskets.

According to the production and material, should adjust the temperature of resistance to the different temperatures of processing. Computer aided basic adjustment is useful for this. In addition to the adjustment of the machine data, it also presents an optimal heating. Thanks to the regulation of temperature by pilot resistance are not necessary additional control systems.

ILLIG offers more and more embedded systems for the automation of machines and installations in the sector of the termomoldeo.

The modular construction allows applying different techniques of processes for moulding, cutting and stacking products, and can add a shredder of grids of die to have a complete installation. An empty post where to place these devices is used for inserting pieces of aspiration, decorate the container or print barcodes.

The use of mostly electronic systems allow, through mechanical desacoplamientos, less complicated constructions of machines and new concepts of facilities. This is the basis for carrying out continuous and flexible manufacturing processes with high cycle speeds, ensuring at the same time an easy manipulation using standard parts.

Coming from a single source solutions are very advantageous to taking into account the large number of machines and processes applicable techniques. As a leading manufacturer, ILLIG offers leading-edge technology in its integrated systems.