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Mono Material Pouch is the pouch made by mono-material; which also means it is made by single type of material. Normally it is mono-material PP pouch and mono-material PE pouch, these 2 types of pouches are the most often see mono material pouch nowadays.
The biggest advantage of mono material pouch is 100% fully recyclable, without the difficulty of splitting or separating various materials.
Mono material pouch is the hottest laminated flexible packaging in these 2 years. It is 100% recyclable characteristic will make it perfect for packaging sustainability.
But the technology for mono material pouch is not very mature, not all the factories can make it in good quality.
Today we will talk about mono material pouch technology, hope it will help those factories to make qualified pouches.
It’s an in-depth article that takes 15 minutes to read.
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No matter whether it is mono material PE or mono material PP flexible packaging; the printing and lamination are no problems and can adapt to all inks and glues.
However, the tensile strength of single material will be lower and the elongation will be larger.
PE / PE is mainly about tension control. Because PE material is soft and easy to stretch, the biggest problem is that the bag making process is difficult to control.
PP / PP has better barrier property than PE, and water, oxygen, light and oil resistance are better than PE. It is less sensitive to tension and has good flatness.
However, pure PP bags lack softness and have poor drop resistance.
So you will choose the best materials base on your needs.
If the outer layer PE is MDO-PE, it can be considered that there is no printing problem. Because the rigidity and flatness of the stretched PE have been greatly improved, which is close to that of BOPET. At present, the overprinting accuracy can be basically achieved in the actual operation.
If the outer layer PE is HDPE, that is, the main component is HDPE. Special attention shall be paid to the flatness. Generally speaking, HDPE film has good stiffness, so long as the flatness is good, it can meet the overprint requirements. In practice, HDPE film has shown a good performance price ratio.
In printing, we must choose printing equipment with high tension control accuracy. Attention should be paid to overprinting, ink adhesion and drying effect (residual and reverse adhesion). The material shall be flat, the tension shall be controlled, and the drying temperature shall be controlled below 55 ° C. when making plates, the color stacking position shall be slightly increased; Ensure the drying effect and select the appropriate ink. Use fast drying solvent as much as possible, and the drying air volume shall be as large as possible. Do not print or composite immediately.
For offset printing film, EB drying is one of the important ways to solve VOCs and carbon emissions. EB drying plus surface printing is a direction that can be considered for a single material.
High barrier is the most difficult point in mono material pouch packaging. As we know many of the laminating pouches will need barrier function to protect from oxygen, water and light. Especially for food packaging.
Both PP and PE are ok to make mono material pouch. But the barrier is difficult. Normally we have 3 ways to make barrier function:
Co-extrusion: add some addictive when blowing the PE film. Normally it is EVOH. In this case you can reach barrier function in oxygen.
Coating: you coat high barrier adhesive on the outer film, and then laminate to the inner layer.
Lamination: laminated the barrier film, normally it is in the mid layer. Just as the conventional film structure.
With the development of PE mono material technology, one of the major changes in our flexible packaging industry is that flexo printing technology will gradually occupy a certain market share in flexible packaging printing.
As we all know, 95% of the printing process of the flexible packaging industry adopts rotogravure printing technology. Because most of the printing layers of our food packaging laminated films are BOPP, BOPET, BOPA, etc. These films have good tensile strength and are suitable for rotogravure printing.
If PE film is used as the printing layer in a large number of food and daily chemical products in the future, the rotogravure printing process is difficult to adapt to. Because PE film has low tensile strength and high tensile elongation. When it is printed with traditional rotogravure printing machine; if the speed is high, the film is easy to stretch and wrinkle, resulting in inaccurate color registration. Moreover, the tension control requirements of the equipment during printing are extremely strict.
The printing speed of the gravure printing machine can not be fast at all, which will greatly affect the production efficiency.
Flexographic printing technology can solve this series of problems. Flexographic printing uses soft resin plates, which transfer ink through anilox ink transfer rollers. The printing pressure is small, and it is especially suitable for printing substrates such as PE films that can not bear excessive pressure, especially the sleeve type satellite flexographic printing machine. It has the characteristics of high overprinting accuracy, fast printing speed (generally up to 600m / min for foreign equipment), rapid plate change and wide printing range.
PE is in a molten state at high temperature. When making bags, it will be stretched by tension. The heat seal will be stretched and broken If the temperature is lowered; the inner layer PE cannot be melted, resulting in incomplete heat sealing, which is often referred to as the virtual sealing state. However if the heat seal is not firm, the contents will leak or deteriorate, thus leading to food or drug quality accidents.
Therefore, PE / PE mono material laminating bag is a difficult point in the bag making process. How to ensure the heat sealing fastness and flatness of PE composite bag poses a new challenge to the bag making process of our soft bag industry.
Japanese Totani company showed the bag making equipment and process of HDPE / / LDPE laminating bag.
Longdapc demonstrated the bag making technology of PE material. In addition to proving that it has successfully overcome the difficulties of this bag making process and proved its profound technical accumulation to the industry; Longdapc also foresaw the future flexible bag market. There will be more and more mono material bag types. Therefore, it has made full technical preparation and market preheating in advance.
In a word, with the development of mono material recycling technology, it will certainly bring innovation and change to the film production, printing, laminating and bag making processes of flexible packaging enterprises. Enterprises should prepare for the rainy day and make technical reserves in advance, so as to seize the opportunity in this market and obtain new breakthroughs and development!
Longdapac is the leading flexible packaging manufacturer from China. We focus on sustainability packaging as you can see below:
Longdapac is the first high barrier MDO-PE film supplier in China.
Longdapac is the first Chinese factory who can make high barrier mono-material PE pouch.
Longdapac recyclable high barrier mono-material PE pouches can meet the recyclability of
Longdapac is a BRC and ISO certified factory with annual capacity of more than 25,000 tons.
Basically Longdapac can satisfy all your recyclable packaging needs, both standard and high barrie
With our professional packaging team on artwork design, bag production, and recyclable material development, we are the first high barrier mono-material pouch manufacturer in China who can make
Recyclable Coffee Bag
Recyclable Tea Bag
Recyclable Dog Food Bag
Recyclable Cat Food Bag
Recyaclable Laminating Pouches