News Time2016.06.04 News Sources Views
Heat shrinkable film, such as polyethylene, polypropylene, polyvinyl chloride (PVC) and polyvinylidene chloride, polyester, nylon, etc. They are general single component structure. After packaging shrinkage can fit tightly on the surface, no fold, with luster. Along with the social economy and the improvement of living standards and the development of production technology, the heat shrinkable packaging puts forward higher and newer demands. People have been able to research and produce all kinds of heat shrinkable film with special functions. Here are some latest researches on development of heat shrinkable special film. Film recycling washing line
A heat shrinkable film, has a concave and convex fold
This kind of film is composed of A, B two film resin, as A composite film, when the heat shrinkage can form the concave and convex fold, when it is used as packing material, has good barrier properties, but also has good shockproof, anti-skid and cushion. The principle of heat shrinkable film formation of concave and convex fold: A layer of thin film or 8 layer have been in the proper temperature tensile, another layer is no stretch, when the composite membrane is heated to A certain temperature, the stretch of A layer of shrink, and another layer of almost no shrinkage, thus formed the fold; Or two layers resin have been stretching, have heat shrinkage, but different shrinkage temperature.
Second, double bubble with buffer heat shrinkable film
This kind of heat shrinkable film characteristics as both has the thermal contraction and well protected against dampness, transparency and buffer, in some ways similar to the wrapping paper, in its side has a tiny mesh structure, it is the other side is smooth. The structure of double-layer composition. One for foam layer, is a polypropylene as the main ingredients; Another layer of the foam layer, heat shrinkable resin layer, using low density polyethylene or ionic polymer.
Production method is: will be formed after the film along the longitudinal and transverse stretching more than 3 times each, the bubble burst in the foam layer to mesh, resulting in heat shrinkable packaging film with buffer action.
The film in the 170 ℃ glycerine bath heating test, the longitudinal and transverse shrinkage rate were 30%. Such as the contraction membrane used for paper box outside packaging, contraction can be good, good transparency, and decorative good packing effect.
Three, automatic sealing heat shrinkable packaging film
The heat shrinkable film is a multilayer composite film, its characteristic is in a composite joined the barrier layer, make the film has a good barrier property to oxygen and water vapor. In addition, when it is heated to a certain temperature, can rely on the membrane of the contraction and inside and outside the bonding effect of the membrane to realize automatic sealing, this makes the film is very suitable for fresh meat, poultry, and general merchandise packaging, has a broad prospect.
The following for matters layer structure automatic sealing compound heat shrinkable film production methods. With EVA (I) (acetic acid ethylene content is 30%, the melt index of a 106 Ml), and EVA (II) (acetic acid ethylene content is 25%, the melt index of Ml a 17) mixture as the lining of the composite film, automatically sealing layer, with EVA (III) (acetic acid ethylene content is 9.0%, the melt index one 3 Ml) as the base, that is, the second floor. The layer 1 and layer 2 components by multiple tube extrusion method, membrane, its diameter is 79 mm, automatic sealing layer thickness is 0.05 mm, base thickness is 0.38 mm. When the film cooling tube, with 65000 gy doses of electron beam irradiation, make its crosslinking, and then on the base are coated with poly (vinylidene chloride coating constitute a barrier layer, or layer 3, the thickness of 0.100 mm. The most outer layer with the basic unit of the same material, thickness of 0.18 mm. Will get the four layers of structure of the composite film of 94 ℃ hot water bath to blow up, until the film 305 mm in diameter, which got the good thermal shrinkage and automatic sealing performance of composite heat shrinkable film.
Four, environment-friendly multi-layer co-extrusion polyolefin (PO) heat shrinkable film
P0 is nearly two years European and American countries the latest successful development and widely use of environmentally friendly packaging materials. Now Europe and the United States in many developed countries for the material of all kinds of packaging materials, formulate the corresponding rules and regulations, and banned the production and use of packaging materials and imports may cause pollution, such as PVC, etc. P0 heat shrinkable film, fully meet the FA and USA standard, in European and American markets
Unimpeded, is the ideal heat shrinkable packaging material in the world.
P0 heat shrinkable film completely by foreign production, such as multinational chemical companies Mr. Montier Montell company and dow chemical company), is in line with international standards of chemical raw materials, the product has a non-toxic, harmless, non-polluting, can be recycled etc, conform to the state food and drug health standard.
P0 heat shrinkable film is three extrusion machine operation at the same time, by the second bubble blowing up, and then after two-way stretch shaped by cooling. Third extrusion machine through co-extrusion layer membrane, the raw material for the different uniform after extrusion, formation, middle and outer layers co-extrusion film of different material structure, its middle layer is LLPE, inner and outer of copolymerized PP, the three layer structure of the film will be combination of the advantages of PE and PP, the quality is better than pure PE film, also is better than that of pure PP film. Its characteristics are the following points. 1) P0 film high transparency, high brightness, better than the ordinary PVC and PE.
(P0 film tensile strength, impact resistance is strong, make the product after packing is quite good, not easily broken, damaged, the performance is better than that of PVC and single polypropylene PP membrane.
(3) P0 membrane resistance to low temperature performance is good, not easy ageing. Product packaging, with no deformation - 50 ~ + 90 ℃, contractive, not broken, hard brittle, performance is better than that of PVC film and PE film.
(4) density of just 0.92 P0 membrane, and the density of PVC nearly l. 4, therefore P0 34% smaller than PVC membrane density, thickness and weight of the product, P0 membrane area is bigger than PVC area of 34%. At the same time, P0 membrane resistance to tensile strength than PVC, P0 film thickness in 30% ~ 30% lower than the thickness of PVC film, due to the high tensile strength P0 membrane, its packaging does not decline. Therefore when using P0 film packaging products, the unit cost will not increase, and the effect will be better, such as thickness of 15 ~ 19 FFM alternative P0 membrane thickness is 25 ~ 40 PVC membrane.
5. P0 membrane avirulent insipidity, use and processing process does not produce toxic or harmful gases, in line with international food and medical health standards, will not change the taste and quality of packing materials. And PVC products in Europe and America and many developed countries have banned the use of the medical profession that PVC vinyl chloride monomer of harmful to human body, and produce carcinogens. In the developed countries of food grade PVC vinyl chloride monomer content in the standard 0.01 x 10 a, vinyl chloride monomer content in PVC in our country are now a 5 x 10-6, 500 times more than foreign standards. Also in the process of machining operations, PVC will release hydrogen chloride gas, the gas not only stimulate the respiratory system, and is harmful to human body. PVC during incineration process of flue gas will be serious damage to the ozone layer, causing secondary pollution. In addition, PVC itself has a bad smell, such as food packaging, will destroy the package itself, affect the product quality and effect.
6 P0 film good toughness, high tensile strength, shrinkage rate can reach 50% ~ 60%. And PVC shrinkage rate is only 30%, and low tensile strength, easy to aging, easy to damage, low temperature brittle, easy to crack, temperature contraction deformation easily and alter the packaging shape, packing effect is poor. P0 membrane due to its advantages, can improve the packaging of goods value and class, increase the display effect of goods. All landowners P0 membrane after dealing with the static electricity and static electricity is not easy to absorb dust, and due to its high transparency, can keep the product in the process of put, clean and bright. PVC membrane in the process of production and processing, static electricity itself with static electricity, easy to absorb dust, low transparency and because of itself, make the product fuzzy uncleanness, and affect the vision and display effect.
Today P0 membrane broad scope and can be used for packaging convenience foods, pharmaceutical products, beverage, frozen food, etc.
Pet-name ruby P0 membrane itself can be recycling use, is internationally recognized environmental protection products, is the European and American countries and the developed countries in the world to allow the use of and imported products. PVC membrane has been banned in many countries in the world. So in the packaging of export products, P0 membrane is the ideal heat shrinkable packaging material.
Five, the PF - C3 heat shrinkable packaging film
PF - C3 heat shrinkable packaging film is PE and PP as the main raw material by a multi-layer co-extrusion blow molding processing technology production environmental protection non-toxic type heat shrinkable packaging material. That originated in Italy in the early 1990 s, the main characteristics of the product are as follows.
(1) high gloss, good transparency can clearly show the product appearance, improve the grade of exhibition effect and commodity.
(2) good flexibility, easy to use. Because of this flexibility can be packaged goods from external shocks make get buffer, also prevent the packing for brittle container vessel flying.
(3) reduction. Shrinkage rate up to 75%, the use of the contraction force produced by its high shrinkage can be a group of items to packaging, wrapping, have very good binding effect, very suitable for more than a collection of items packaging, especially for different items of packaging effect
Well. And after special craft processing of PF - Ca membrane can control contraction force, to meet the requirements of the different articles on the contraction force. (4) welding sealing performance is good, high strength, suitable for manual, semiautomatic and fully automatic packaging at a high speed.
(5) good cold resistance, can be in - 50 ℃ maintain flexibility without brittle, suitable packing materials storage and transportation in a cold environment. 6. Environmental non-toxic. PF - the main raw materials including LLPE C3 heat shrinkable packaging film, the TPP, PPC and necessary functional additives, such as smooth agent, anti adhesion agent, antistatic agent and so on are non-toxic materials, accord with American FA standard, can be packaged foods. All landowners moistureproof and dustproof.
Today packaging costs low, is better than that of paper boxes and other packaging materials.
PF - C. Series heat shrinkable packaging film application is very extensive, completely accords with the world of today's environmental protection non-toxic consumption trend. This material can not only reduce the user's packaging production costs, transportation costs, and reduce the packaging volume to save space, greatly improve the productivity. Also because of its better transparency, can improve the visibility of the product, in the fierce competition, goods full of beautiful things in the supermarket shelves quickly seize the consumer attention, and cater to the psychological characteristics of the consumers like convenient, save to set bundle packaging of goods, particularly suitable for supermarket goods packaging and put, therefore developed countries in Europe and has been widely attention and application. Convenient in beverage, food and other products are very popular in the field of packaging applications, has been basically replace PVC heat shrinkable packaging film become mainstream products in the heat shrinkable packaging material. PF - Cs heat shrinkable film and PVC heat shrinkable film performance comparison are shown in table 2 to 5. Table 2-2 - C PF, heat shrinkable film and PVC heat shrinkable film performance comparison
