How will the heat shrinkable film performance of PVC be affected?

So what factors can affect the performance of PVC heat shrinkable film? After analysis by our technicians, there are three factors:

1, pressure control:

In order to determine its good strength, the correct pressure is also very necessary. Generally speaking, the correct and uniform pressure helps to reduce the generation rate of bubbles, thus improving the overall yield and reducing the unnecessary losses of enterprises. Therefore, the correct pressure is also an important factor affecting the heat shrinkable film strength of PVC.

2. Heating temperature:

Affected by PVC material, the heating temperature will affect the strength of heat shrinkable film, thus affecting its quality. Generally speaking, the temperature should be controlled at about 160 degrees Celsius in the actual heating process; If it is too high or too low, it will have different degrees of influence.

3. Heating time:

On the premise of determining the temperature and pressure, the longer the time, the more the combination between seals, so the better its performance; However, if the length of time is not accurate, then there will be problems such as wrinkles and poor flatness; Thereby affecting the overall aesthetics.

Different container shapes have different requirements for shrinkage of materials. For example, OPP or PVC materials can be considered for approximate cylindrical containers with low shrinkage requirements, while OPS films with high shrinkage and strength can be considered for containers with multi-curve or streamlined design. OPS film can be closely attached to containers with different shapes, which can not only print exquisite patterns, but also achieve the use of novel packaging containers with different shapes. OPS is nontoxic and tasteless, and it is not afraid of grease, which conforms to the food hygiene standards. It allows designers to adopt eye-catching colors, realize 360 label design, and give full play to creativity and imagination, thus making the label pattern more vivid, highlighting the image on the shelf and producing unexpected container effects. For example, the curve glass bottle newly promoted by Blue Ribbon Beer in China adopts high shrinkage OPS substrate and uses solvent-based adhesive for labeling.

Heat shrinkable film's packaging materials are updated from time to time. In addition to the traditional paper, plastic, glass and metal packaging, people have begun to explore the use of new raw materials to make packaging, and plant raw materials have begun to enter the market. Consumers are fickle creatures. Its purchasing habits are constantly difficult to figure out. Even if it looks like a big trend in the future, it will be ignored for a few weeks. This characteristic hobby makes the specified long-term product planning become a guessing game; Consumers' likes and dislikes are too hard to predict.

At present, there are still three major injustices in domestic packaging property:

1. The product structure is simple, and there are a lot of original products, and the slower the product is updated, the unfair structure of plastic packaging products will be caused, and it is impossible to fully adapt to the change of market demand.

2. The overall planning of packaging enterprises is small and the industrial concentration is low.

3. The development of each region is not balanced, and the packaging property in the western region lags behind.

Generally, PVC heat shrinkable film is disposable, and a large number of PVC packaging filmswill produce more environmentally unfriendly wastes, which will bring many problems to the disposal of wastes. For example, plasticizers and stabilizers in PVC additives will pollute groundwater and soil when treated by landfill; However, when incineration is needed, carcinogens have adverse effects on the environment and human body. Relevant domestic industries should formulate relevant laws and regulations to restrict the use of PVC packaging film, and at the same time make great efforts to create new environmental protection and substitutes as substitutes for PVC film, and OPS film will be increasingly widely used.

PVC heat shrinkable film is made of vinyl PVC resin mixed with more than a dozen auxiliary materials and then inflated twice. Its characteristics are good transparency, easy shrinkage, good strength, and the shrinkage rate can be adjusted freely according to users' needs. PVC heat shrinkable film has the characteristics of high transparency, good gloss and good shrinkage.

PVC heat shrinkable film can be divided into printing grade and ordinary packaging grade. Printing grade PVC heat shrinkable film, as its name implies, is used for printing and can be processed into printed labels. Most drinks on the market use PVC labels, for example, labels used outside black tea, green tea and mineral water bottles. Ordinary packaging grade PVC heat shrinkable film can be made into tubular film and L-shaped folded film as required, and can be processed into tube bags and flat pocket. Although ordinary packaging grade PVC heat shrinkable film can also be used for printing, the printing effect is not good, and there are few printable colors, and most of them are printed in one or two colors.

Heat shrinkable film is mainly used for labels, heat-shrinkable packaging or winding films. Polymer resins suitable for preparing heat shrinkable film mainly include PVC, PE, PS, PET, etc. Heat shrinkable film can be obtained by stretching and cooling the film after preheating (as long as it is not heat-set).

At the Tf close to the resin, the resin casting was stretched horizontally and vertically, and then quenched, so that the resin molecular chain was frozen in the oriented state, and heat shrinkable film was formed. The process from raw materials to heat shrinkable film is a process of entropy reduction, and the thermodynamic state of heat shrinkable film is unstable. When the shrink film is subjected to heat treatment, the oriented molecular chain will slowly return to random coil (curled state), and the film will shrink. Using this characteristic of heat shrinkable film, the label of special-shaped bottle can be prepared.