Food packaging manufacturer: aluminum plating film dry compound intensity difference and aluminized transfer

Packing: aluminum plating film dry compound strength and aluminized transfer reason for aluminum plating film shading sex and blocking performance close to the performance of the aluminum foil in food, pharmaceuticals, health care products, electronic products, clothing, packaging, and other fields, especially in food puffed food, aluminum plating film to use much more special. Relative to the structure of the aluminum foil packing, the aluminum plating film is a kind of low cost, high performance packaging structure, therefore in the flexible packaging structure, plating aluminium structure is a common, general structure packaging supplies. But after composite plating aluminum film, often there is a problem: aluminum plating film composite strength is poor, aluminum plating, fog, more easy to transfer or white dot. Now more commonly used aluminum plating structure composite films such as BOPP/VMPET/PE, BOPP/VMCPP, PET/VMCPP, such as structure, this paper discusses the aluminum plating film composite anomaly solutions. A poor, composite aluminum plating film peel strength in the production of composite VMPET or VMCPP material, after curing, we test in the laboratory, will find that the majority of products containing such a structure, with aluminized layer composite face, very easy to peel, stripping phenomenon mainly has two kinds: one kind is aluminized transfer of large area, the other is a printing layer easy to peel. And the two phenomena of stripping force is very small, basic boundary at 0. 8 n / 15 mm or so. And the other is a kind of a weird phenomenon in the same volume of composite parts is very difficult to stripping aluminum plating film, or even to spin off, while some are very easy to peel, it is very easy to open, into a block and produce aluminized transfer phenomenon. Solutions: 1, the raw materials from metal or aluminium experienced manufacturer to purchase aluminum plating film, to ensure that the homogeneous degree of the aluminum plating raw material aluminized layer and good adhesion. According to BB/T0030 - 2004 'packing aluminum plating film - — Plastic packaging film deposited with aluminium related standards, aluminum plating film adhesion is less than or equal to 20% ( With aluminized layer falls off area) , but it has been proved that this standard in the production practice, it is difficult to meet the production license and customer requirement. In addition, the mass of aluminum plating film is more stable. For the aluminium base material of choice is a very key factor, the stability of the base material, is the foundation of the aluminized layer quality. On the other hand, the thickness of the aluminum plating problem, is also a factor. VMCPP, for example, the aluminized layer thickness is about 300 ~ 600 el, and a lot of suppliers, tend to cut corners, the aluminized layer is very thin plating. And by the naked eye is difficult for us to distinguish. Currently common practice is: will film at 40 w bulb, with film will look at the surface and lighting, rough test. If the aluminized layer is thin, there will be a slight mist dot, similar to a mirror is not smooth. Another is from completely the judgement, aluminized layer is thin, light transmittance is higher, on the other hand, aluminum plating thickness enough, through the aluminum plating film, only through the faint light, even can't see the light. 2, through the production process control, reduce the transfer rate in a composite aluminized layer, is almost normal temperature composite, hot hot roller temperature closed. Such practice is as much as possible to ensure aluminized layer was not damaged, will be better able to penetrate the mask of glue and aluminum plating film, to form a better mechanical balance. Curing aspects generally adopts low temperature or room temperature conditions, to extend the time of curing, the process is a kind of covert means of increasing peel strength. We through the test, a set of high temperature and curing time of 12 h around 50 ℃, another group is 35 ℃ curing 30 h, use the same structure of the same fabric samples curing. Stripping, after the completion of high temperature 50 ℃ curing group samples, large area of aluminized layer were transferred; And low temperature group samples of aluminized transfer area is greatly reduced. Normal temperature place after a month, and then test the group of low temperature and area of more than half of aluminized transfer, again place two months later, the aluminized layer transfer than the original place, compared to a month when transfer of aluminized layer area increased a lot. Low temperature or room temperature curing is used to reduce the practice of aluminized transfer, akin to that of rated lower ratio of curing agent, its essence is the same. When curing at a certain period, namely the glue crosslinking reaction completely, the aluminized layer of base material and aluminized layer increases to a stable state, a strength to the high-end, the aluminized layer of the aluminum layer adhesive, than the original aluminum plating layer was plated with aluminum substrate bonding strength is higher. 3 improvement, improvement of auxiliary materials, auxiliary formula, there are mainly two ways to change: one is the change into special aluminum plating film glue, aluminum plating film special glue can make the aluminum plating layer and base material of good mechanical allocation proportion between, as far as possible on both sides to base material for aluminium coated interlayer between the mechanical balance, but its essence is with lower curing dose proportion is the same. Another is to use water-based acrylic glue for production. When using water-based acrylic glue, easy to transfer the ink layer to aluminized layer, need to select the corresponding ink. To fundamentally solve the problem of aluminized layer transfer, most of the foreign enterprises including some domestic soft package, for the improvement of raw material, using aluminum plating film or silica aluminum plating film. But this will increase the cost, all aspects for the current labor costs and expenses are on the rise of flexible packaging enterprise, this approach can not accept.