High-end facial mask has become a trend. In addition to showing excellent performance, texture and shelf life on facial mask packaging bags. Most masks have a shelf life of more than 12 months, some even 36 months.For such a long shelf life, the most basic requirements for the packaging bag are: high sealing property, high barrier property and stability.
The consumption characteristics and shelf life requirements of the mask determine the material structure and requirements of the mask packaging bag.
At present, the main structures of most facial masks are: PET/AL/PE, PET/AL/PET/PE, pet/vmpe/pe, BOPP/VMPET/PE pe, BOPP/AL/PE, mat-opp/vmpe/pe, MAT-OPP/AL/PE, etc.From the point of view of the main material structure, aluminum plating film and aluminum foil are basically used.
Compared with aluminum plating, aluminum foil has good metal texture, silvery white and anti-gloss properties.Aluminum metal has soft characteristics, and can be customized with products of different composite materials and thicknesses according to requirements, which conforms to the pursuit of high-end products for thick texture, and enables high-end facial masks to be more intuitively reflected from packaging.
Because of this, from the initial basic functional requirements of the mask packaging bag to the high-end requirements of simultaneous rise in performance and texture, the mask packaging bag has changed from aluminum-plated bag to aluminum-foil bag.
From the analysis of the raw materials themselves, the general facial mask packaging bags are mainly divided into two types: aluminum-plated bags and aluminum-foil bags.Aluminized bags are made by uniformly coating high-purity metal aluminum on plastic films under high temperature and vacuum conditions.The aluminum foil bag is formed by stretching pure metal aluminum sheets and compounding with plastic film, which can improve the blocking, sealing, fragrance preservation, shielding and other functions of plastic.In other words, aluminum foil mask bags are more suitable for the market requirements of mask bags.
Key Control Points of Compound Link of Mask Packaging Bag
The composite mainly controls three major aspects: composite wrinkling, composite solvent residue, composite pitting and bubble anomalies.In this process, these three aspects are the key factors that affect the finished product rate of mask packaging bags.
1. Compound Wrinkling
As can be seen from the above structure, the facial mask packaging bag mainly involves the compounding of aluminum foil.Aluminum foil is a very thin film sheet rolled from pure metal, commonly known as "aluminum film" in the industry. The basic thickness used is between 6.5 and 7 μ m. Of course, there are also thicker aluminum films.
Pure aluminum film is very easy to produce wrinkling or breaking materials, or tunnel and other anomalies during the compounding process.Especially for the compound machine with automatic material receiving, due to the irregularity in the automatic bonding of paper cores, it is easy to be uneven, and it is very easy to directly wrinkle or even dead wrinkle after aluminum film is compounded.
For wrinkle materials, on the one hand, we can reduce the losses caused by wrinkle materials through follow-up remedy. When the composite glue is stable to a certain state, rewinding is one way, but this is only the way to reduce it.On the other hand, it can be reduced from the root, such as using a larger paper core to make the winding effect more ideal.
2. Residual compound solvent
As the mask package basically contains aluminum plating or pure aluminum, the presence of aluminum plating or pure aluminum is unfavorable to solvent volatilization for compounding, because the barrier property of the two is stronger than that of other common materials, thus being unfavorable to solvent volatilization.Although it is clearly stated in GB/T10004-2008 "Plastic Composite Film and Bag Dry Composite Extrusion Composite for Packaging" standard: this standard is not applicable to plastic films and bags made by compounding plastic materials with paper or aluminum foil.However, at present, mask packaging enterprises and most enterprises are also subject to the national standard. For aluminum foil bags, the standard is also required, thus causing some misleading.
Although there is no clear requirement in the national standard, we still need to control solvent residue in production, because this is a very critical control point.As far as personal experience is concerned, it is feasible to make effective improvement from the aspects of glue selection, production machine speed, oven temperature and equipment exhaust air volume.
3. composite pitting, bubbles
This problem is also mainly related to pure aluminum, especially when composite PET/AL structure is used.Many "crystal spots" or "bubble" spots will accumulate on the composite surface, mainly due to several reasons:
On the base material: the surface treatment of the base material is not good, which is easy to produce pitting and bubbles;Too many and too large crystal spots on the base PE are also a major cause of the problem.On the other hand is the ink particles, is also one of the factors.Also, the leveling property of glue and the coarser particles of ink will cause similar problems when combining.
Furthermore, when the solvent volatilizes insufficiently and the compound pressure is not large enough in the operation of the machine, similar phenomena will also occur, either the gluing wire roller is blocked or foreign matters are involved.