When we talk about the materials for spout pouch packages, we will have to identify the products to be packed, and the processing conditions when the product is sterized. Single polymer film should not be able to meet the requirements for the spout pouch packages, so we are going to analyze the foil materrial structures available for spout pouch package when it is intended for specific products.
Based on the middle support layer and barrier layer applied, we can divide the foil materials structures into plastic film foil structures, metallized film structures, aluminum foil structures, kraft paper structures, with many varities under each category, and here we are going to get closer to each item.
Plastic film foil structures
PET/LDPE foil material structure
This foil structure is considered as the lowest cost to realize the a standing spout pouch, as BOPP/LDPE foil is too soft to present a standing pouch with enough stiffness. However, without a barrier layer in the pouch materials, this foil spout pouch can only be intended for food & beverage products with short shelf life, and also other chemical liquid products, with details as below.
- soybean milk for 1-3 days (exact time will be depending on the storage temperature)
- Sauce products (sauce productw will higher salt will result in a longer shelf life)
- Juice (intended for 1-3 months shelf life)
- Household cleaning chemicals (Maximium 500ml, as PET/LDPE foil structure is not strong enough to withstand unexpected drop fro the shelf when the package volume is larger.)
- Cheese products (short shelf life)
- Colorants products (Very good package with very good cost.)
PA/LDPE foil material structure
PA/LDPE foil material structure is able to realize the pouch in better mechanical strength than PET/LDPE pouch, however, as the stiffness for PA film is worse than PET film, so the final standing effect realized by PA/LDPE foil structure is not good as PET/LDPE foil pouch. It can be well intended for the packages as below.
- liquid food products. (such as mayonesa, cheese products, with shelf life 1-6 months based on different products)
- Juice (longer shelf life than PET/LDPE foil bag)
- Milk product
- Yoghourt product
- Household cleaning chemicals (usually limited to volume less than 250ml, as the standing effect is not good.)
PET/PET/LDPE foil material structure
This foil structure is developed to achieve better standing effect than PET/LDPE foil pouch and PA/LDPE foil bag for some products, and at the same time,try to keep a lower cost. Of couse, the pouch strength will be improved a lot as of the double PET film layer, and this foil package can be well intended for the products as below.
- Liquid food products, such as mayonnaise, maiz, cheese
- Household cleaning chemicals (up to 1litre)
- Cat litter
- Juice products
PET/PA/LDPE foil material structure
PET/PA/LDPE foil material structure is developed to achieve a spout pouch with both good standing effect and excellent mechanicals strength, that will be needed to present large volumes of products in 1litre, 2lier, 3litre, 1 gallon or even 5 liters, with details as below.
- Liquid laundry detergents (1liter to 5litres will be ok for this structure, however, package with more than 3litres are so heavy fo the consumers, so usually you are not advised to choose 5 liter package)
- Windshield washer fluids (1-3liters are all ok for our produce, which are widely welcome in the consumer market)
- Liquid fertilizer (1-5 liter are all ok for the market)
- Tomato ketchup (not the consumer size, but the 3-5liter sizes intended for restaurant purpose)
- Mineral water
- Beer product
- Cat litter products (up to 10litre)
There are also some variance for this PET/PA/LDPE foil structure, as the most common used thickness for biaxially oriented PA film is 15 microns. However in some cases, to achive better pouch strength, PA film 25 microns will be adapted, such as PET12/PA25/LLDPE190 foil structure can be applied in some packages.
PA/PA/LDPE foil material structure
This PA/PA/LDPE foil material structure is delveloped for some large volume package like 5 liter or even 10liter, when the products will need the package to have top level mechanical strength, especially the liquid products, with details as below.
- Water (package of more than 5liter)
- Adblue (package of more than 5liter)
- Liquid fertilizer (package of more than 5liter)
PET/GL-PET/LDPE foil material structure
PET/GL-PET/LDPE foil material structure is developed to achieve excellent barrier property for the package and also keep the clear bag effect, so the consumers can see the products inside. With the high barrier property for GL-PET film, the spout pouch will be able to provide a longer shelf life than previous plastic film pouches.
- Soybean milk (Some may need retort treatment for the package)
- Vegetable mixs (Some may need retort treatment for the package)
- Baby food (Some may need retort treatment for the package)
Metallized Foil Materials Structures
Metallized foil materials structures refers to the multilayer foil laminate with a layer of metallized film trapped inside, with VMPET film the mostly common used. VMPET film is able to provide the barrier property that is enough for most products, like candy, biscuit, food, dog food, tea, dry nuts, etc. When it comes to spout pouches, some juice, sauce products may be packed in metallized foil structure pouches.
For the sterization of juice or sauce products, it may need to be water boiled in hot water for 10~20 minutes, that will be a sufficient method to evacuate the bacteria inside the package, and make the shelf life even longer. In this case, the VMPET film will have to be reinforced to withstand water boiling treatment, and we are going to get deeper into each item.
BOPP/VMPET/LDPE foil material structure
BOPP film or matte BOPP film works as the outside print substrate, that is also able to present a soft hand feeling for the package than clear PET film.
- Juice (100-500ml, 3-6 months shelf life)
- Sauce (100-500grams, 9-12 montsh shelf life)
- Conditments powder.
PET/VMPET/LDPE foil material structure
PET/VMPET/LDPE foil material structure is able to present more stiffness to the package, which will be able to realize a better standing effect for the package.
- Conditment or seasoning powder (that may need sunlight resistance, and high barrier)
- Lemon tea
- Honey products
- Liquid laundry detergent (Some formula of the detergent may need be protected against the sunlight carefully, however it still need the package to stand up straight.)
PA/VMPET/LDPE foil material structure
With PA film working as the outside film layer, PA/VMPET/LDPE foil materials is able to provide better mechanical strength and anti-puncture resistance to the package. Package volume with 400~500ml may be reinforced with this foil structure, just as the above flat bottom pouch for 450grams garlic sauce.
Aluminum foil laminate
Aluminum foil lamiante refers to the foil structure with a layer of thin aluminum foil sheet inside, as the barrier performance for aluminum foil is considered as the best barrier property against moisture and oxygen among all the substrate films.
PET/AL/LDPE foil material structure
The strength for this structure is not very good, as there is not reinforced layer between Aluminum foil and LDPE film. Further more, without this buffer layer, the Aluminum foil may have subtle crack if the package is crumpled or unexpected shock, which will be further explained in future posts.
- Juice (50-200ml)
- LIquid food (50g-200g)
- Fruit jam (50-200grams)
PET/AL/PET/LDPE foil material structure
PET/AL/PET/LDPE foil material structure is going to be a reinfoced foil than PET/AL/LDPE with the extra clear PET film, with property not good as the typical PET/AL/PA/LDPE foil, however, the property for this foil can be enough for many products, with details as below.
- Baby food
- Fruit jam
PET/AL/PA/LDPE foil material structure
PET/AL/PA/LDPE foil material structure is considered the most successful foil for the products that need excellent barrier property and mechanical strength. It should be considered to pack nearly all of the products available for spout pouch package as long as the customer approve the cost.
As the foil strength is largely improved the by optimization of the foil structures, the volume of the package can reach up to 5litres
- Baby food
- Tomato ketchup
- Fruit jam
- Mineral water
PA/AL/PA/LDPE foil material structure
if some customer believe PET/AL/PA/LDPE foil material more rigid than his requirements, then he may choose PA/AL/PA/LDPE foil material structure, as PA film is less stiff than PET film.
Of course, each of the package for a specific product should be carefully considered before it moves to application, and we are going to give further explaination on each item in future posts. Just reach us if you have any questions.