How to select and apply shrink sleeve labels

The shrinkable label has strong adaptability and can be decorated on plastic, wood, paper, metal, glass, ceramic and other packaging containers. It is widely used in beer and beverage, medicine and health, daily chemical, leisure food, stationery and other fields.  

In order to achieve the best overall labeling effect, not only must adjust the heat shrinkage temperature of labeling machine, the choice of label materials and design pattern is also very important.  The following instructions on how to correctly select and use shrink film casing.  

Design essentials and selection principles.

1. Label design  

The pattern design on the film sleeve is determined according to the thickness of the film.  Design mode, the first need to determine the film horizontal and vertical shrinkage, and allowable shrinkage packaging and back in all directions to allow deformation error contraction after the decoration mode, to ensure that the contract mode and text can be accurately restored.  

2. Film thickness and shrinkage  

The materials used for shrink film sleeve labels are mainly concerned with three factors: environmental requirements, film thickness and shrinkage performance.  

The determination of film thickness is based on the field of application and cost factors of the label.  Of course, price is not the deciding factor, as each film is unique in its own way.  Before signing a contract, the user and the printer must specify the film to be used and the most suitable material.  In addition, processing equipment and other technological factors required by the index also directly affect the choice of thickness.  The thickness of the shrink-film sleeve label is 30-70 μm. The thin films of 40 μm and 50 μm are frequently used.  In addition, the shrinkage rate of the film has certain requirements, the lateral (TD) shrinkage rate is higher than the longitudinal (MD) shrinkage rate.  The transverse shrinkage of common materials is 50% ~ 52% and 60% ~ 62%, and can reach 90% in special cases.  Longitudinal shrinkage is required to be 6% ~ 8%.  When making shrinkable film sleeve labels, materials with small longitudinal shrinkage should be selected.  

Thin film materials  

The materials used for making shrink film sleeve labels are PVC(polyvinyl chloride) film, PET(polyester) film, PETG(modified polyester) film, OPS(directional polystyrene) film and so on. Its properties are as follows:  

1. PVC film  

PVC film is the most widely used film material at present.  Its price is very low, the temperature contraction range is large, the requirement of heat source is not high.  The main processing heat source is hot air, infrared or a combination of both.  However, PVC is difficult to recycle and produces toxic gases when burned.  This is not good for the environment.  It has been banned in Europe and Japan.  

2. Ops film 

As a substitute of PVC film, OPS film is more and more widely used.  It has good shrinkage performance and is also conducive to environmental protection.  At present, the product is in short supply in the domestic market.  At present, high-quality OPS membrane is also mainly dependent on imports, which has become an important factor restricting its development.  

3. Pet Film

PET film is internationally recognized environmental protection heat shrinkable film material.  Its technical specifications, physical properties, application range and use method are close to PVC thermal shrinkage film.  It is currently the most advanced unidirectional contraction film.  Its horizontal shrinkage rate reaches 70%, longitudinal shrinkage rate is less than 3%, non-toxic and pollution-free.  It is the ideal material to replace PVC film.  

In addition, the heat shrinkable film tube is also the material for making the shrinkable film sleeve label, which can be formed without sewing once in production.  Using a heat-shrinkable film jacket is less costly and more difficult to print than using a horizontally flattened film.  At the same time, the label of the heat-shrinkable film tube can only be printed on the surface of the film, which is easy to wear during transportation and storage, affecting the whole packaging effect.