With the development of technologies in the chemical industry, the products are being improved. A considerable segment of the industry is represented by packaging materials, with the help of which manufacturers of non-food products and food products retain their properties and performance. Shrink film for packaging, a photo of which is presented below, received great popularity.
Features of shrink film
The main difference between the shrink film is the ability to shrink to the size corresponding to the target. Its compression occurs under the influence of high temperatures. After cooling, the material takes the form of a packaged product. Thus, the shrink film for packaging allows you to maintain the technical and physical qualities of various products, including construction and food.
Depending on the area of use, manufacturers provide some features in the film. For example, perforated film is produced for bakery products. The basis for the raw material is polyvinyl chloride or polyolefin granules. If PVC is traditionally in demand due to its strength, then POF is advantageous in that it has no harmful impurities. As a rule, shrink film for packaging bottles or food packaging is produced from polyolefin raw materials.
Film application
Depending on the shrinkage and thickness, the film can be used for different purposes. So, if we are talking about a small degree of clamping, the material can be used to work with soft fabric products, printed products or food products. Conversely, severe shrinkage allows you to serve heavy building materials, as well as products with non-standard shapes. These include heat-shrink film for packaging lumber, which covers group batches, reliably fixing them during transportation. By the way, polyvinyl chloride is used to make such a film. It is important to note that in addition to the protective and packaging functions, the film can be used for visual design of products. Shrink wrapping is often wrapped in wallpapers, toys, magazines, giving the product an extra gloss and shine.
Material characteristics
The film comes in different formats, the choice of which depends on the packaging machine. As for the choice for a specific product, you should pay attention to two characteristics - the percentage of shrinkage and thickness. As a rule, the percentage of shrinkage in the longitudinal line is about 60-70%, and in the cross section from 10 to 50%. The strength of the package is affected by the thickness. The thinnest shrink film for packaging, made according to the standards of the process, has a thickness of 10 microns. High strength variations can have up to 200 microns. In addition, it is worth considering the temperature regime at which the material can be used. On average, the permissible temperature range is from -40 to +50 ° C, although, depending on the scope of application, technologists can add additives that expand this range.
Operational properties
There is a basic set of qualities that almost all modifications of shrink films possess. First of all, this is high mechanical strength, which determines the protective qualities of the package. Also, this type of material is distinguished by a combination of elasticity and transparency. Resistance to the formation of water condensate and moisture resistance also expand the possibilities for using this film.
Of course, almost the unique property that the shrink film has for packaging is the ability to change linear parameters and take the shape of the target product. Another thing is that this requires special equipment that implements the packaging. But then in the future a tight and compact fit will give two significant advantages. Firstly, protection against tampering will be provided, and secondly, during transportation, consignments with goods will occupy a minimum of space. If we talk about individual properties, then among them environmental safety and attractiveness of appearance can be noted. These qualities are applicable to special modifications of the film product.
Varieties
Although outwardly the majority of heat-shrinkable film materials look the same, they have many differences. Technologists classify the packaging by type of structure, stiffness, the presence of certain modifiers in the composition, size, form of release, etc. One of the most significant signs of separation is the type of structure. The most convenient for use is cross-crossed film fabric. It does not set records in terms of strength, but in its structure the optimal balance of web thickness and tensile strength is observed. This property is significant if, for example, a heat-shrink film is used to pack the lining in large volumes. In this case, the service workers are faced with the task of maximizing the preservation of free space and at the same time ensuring the integrity of the film itself. As for the differences in composition, materials that contain rubber hydrochloride, polystyrene, polyamide, etc. are distinguished. Classification by the number of film layers deserves special attention.
Multilayer and single layer film
To begin with, it should be noted that the basic differences are determined by the manufacturing method. A single-layer web is produced by extrusion, that is, by extrusion of a plastic mass. The advantages of products thus obtained include increased viscosity, elasticity and transparency. But if you choose a shrink film for packing bricks or other building materials, then it is better to turn to multilayer analogues. Such material is produced by coextrusion technique. The main difference between the manufacturing process is that special extruder heads are used. The multilayer web includes a copolymer layer and a modifying acid, as well as an ethylene copolymer. The film structure may include several additional layers.
Packaging configurations
There are various options for packaging goods in shrink film, the choice of which is determined by the characteristics of the product. In particular, single, group and stack packaging are used. The first option is used to work with piece goods - this is the so-called individual packaging. The group method is used for a single set of several products with the same dimensional characteristics. For example, this configuration allows you to implement a shrink film for packaging pallets that are previously laid on a special substrate. In addition to storage, this method of packaging makes it possible to carefully and safely transport products. A stackable configuration also provides for the use of a pallet, but with improved stiffness. This option is suitable for serving a wide range of products: from cans and books to bricks and bags. After stacking, the product is covered with a film cover.
Release form and labeling
The made film is wound on special sleeves and delivered in the form of rolls. On top of each winding is also covered with a protective shell made of paper or the same polyethylene. As a rule, shrink film for packaging in a roll is up to 500 mm wide and weighs 35 kg. But in industry and the production of building materials, other formats are also used, for example, with a width of more than 1000 mm and a weight of up to 50 kg. Each roll is necessarily marked with a label containing information about the manufacturer, product parameters, release date, etc. When choosing a film product, you should also receive information about the tests - knowledge of operational properties and capabilities will help to obtain the most suitable packaging for specific needs.
Conclusion
The market for packaging products is quite wide, which is due to the huge demand for goods of this group. High-quality packaging today is required in various fields: from the food industry to retail outlets. As the practice of using shrink material shows, about 90% of these products are used in servicing non-food items. However, increasing environmental safety expands the possibilities of using packaging for vegetables, bakery products, semi-finished products, etc.
Shrink film is being improved for packaging goods and in terms of strength. Rigidity, tensile strength and tightness - these qualities are of great importance in the maintenance of building materials, including wallpaper, furniture, tiles, panel cladding, etc. There is also a tendency to increase demand for special modifications of the film, provided with additional operational properties.