

Vacuum skin packaging technology has proven itself for many years in the food sector. Now it is being used ever more frequently in the medical products industry as well – particularly in those cases, where there are many product variants or several product components in different batch sizes.
A typical pack for sterile products must ensure, that the delicate and sensitive components do not slide around in the pack, and that the pack is easy to handle. It is absolutely essential during an operation for example, that the pack can be opened easily, that the sterile product is secure in the packaging during and after opening, and that the product can also be removed safely from the pack. In order to ensure the product is adequately protected and securely located in the pack, it follows that the pack has to be designed for the particular product. This means a separate pack shape has to be developed for each individual product. The costs for the different dies therefore have to be reflected in the budget. In addition to this, the time for converting the machine also reduces the availability of the machine. And last but not least, the company’s storage and logistics costs may also increase due to the manufacture and stockholding of individual types of pack.
Vacuum skin packs provide an ideal solution to these many challenges. They can be produced on traysealers as well as on thermoforming packaging machines.
The product to be packed is placed in a tray or in the formed pack cavity. The pack is then sealed with a skin film, which drapes over the product like a second skin and holds it in place in the pack cavity.
The skin film’s high level of transparency enables the pack content to be seen easily, and the soft-peel characteristics of the films allow the product to be removed simply and conveniently from the pack. This technology enables a wide range of products with very different shapes to be securely packed. When selecting suitable pack shapes, the same principle still however applies: the fewer the number of pack shapes, the less frequent are the necessary format changes. This reduces the set-up time and increases the machine availability, thereby increasing the efficiency of the packaging machine – and this also of course has a positive effect on the overall costs and productivity.
In the case of traysealers, pre-formed trays are used, which can be made in a wide range of materials and with many different shapes. They are the ideal packaging solution, if small to medium-sized batch sizes are being produced, or if very delicate products have to be loaded manually into the packs.
In addition to manually operated semi-automatic machines, MULTIVAC also offers automatic traysealers for producing such skin packs. A new die concept has recently been developed for the skin packing of products with high product protrusion, and this concept guarantees a high level of pack quality and output. All the stages that are necessary for the process, such as the heating of the skin film, take place within the die. Only the die and grippers therefore have to be changed to carry out the format change.
In the case of thermoforming packaging, the pack cavities are produced from reel-fed film. The pack cavities are thermoformed and then filled either manually or automatically with product, following which the packs are sealed over their entire surface in the sealing die. Cutting units then give the pack the desired contours and finished pack shape. It is possible for example to produce packs with rounded corners or with individually shaped contours, and ribs or other designs can be formed in the sides and base of the packs to give them a higher degree of rigidity. During the skinning process, the integrated upper web chain guidance on the thermoforming packaging machine holds the film under permanent tension at right angles to the running direction, and this ensures the upper web is firmly guided right into the sealing station.
MULTIVAC’s comprehensive machine range fulfils all the requirements as regards pack size, output and degree of automation, and it offers the right solution for small and medium-sized batches as well as high output.
Vacuum skin packs release their full potential in particular, where the upper and lower web materials are ideally matched to the product. MULTIVAC’s film range comprises skin upper webs in various thicknesses for different product requirements and heights, and it also includes a range of lower webs, which consist of different composite films and cover a wide spectrum of barrier properties, mechanical characteristics and peel systems.