Kraft paper bags have been a leader in the paper packaging industry since its appearance in the 18th century. Due to their durability and sturdiness, kraft paper packaging covers an extensive range of applications. Therefore, it is necessary to get to know them in depth. This article will be a comprehensive guide for you.
What is Kraft Paper?
The term is named after the German word”Kraft”, meaning “strength”, which should well illustrate the durability and sturdiness of the paper sheet. Besides, kraft paper gets its name because of its yellow-brown color and toughness, which looks a lot like cowhide.
Kraft paper would be considered paper made of cowhide. But that’s not the case. They are made from wood pulp that are taken from wood.
The Production Process of Kraft Paper
Kraft paper is produced under a series of processions. Generally, there are three stages.
- The first stage: wood pulp making
Conifers are the source of wood for the manufacture of kraft pulp. First, the wood needs to be crushed into sawdust. The wood chips are then steamed, a process that adds some chemicals (sulfates) to deal with them. This chemical process destroys the molecular structure of the wood, which turns the wood into pulp. Finally, the cooked wood pulp needs to be put into the beater for pulping, and then some rubber or dyes are added.
- The second stage: papermaking
After chemical treatment, the wood pulp can be made into large-size paper by putting it in a paper machine.
- The third stage: processing
After papermaking, a paper sheet is required to process. For example, a production plant must cut paper to a fixed size according to specified requirements. Some need to be printed by a specific printing method.
Kraft Paper vs Common Paper
The biggest difference between kraft paper and common paper is the difference in the pulp manufacturing process. Kraft pulp(also called sulfate pulp) is obtained by cooking fiber raw materials with sodium hydroxide and sodium sulfide as the main components of liquid medicine at a certain temperature and pressure. The chemical action of this preparation method is relatively mild, so the original strength of the wood fiber is less damaged. In addition, manufacturers choose longer fiber to produce kraft, but not that of common paper.
Because of their different process, they will differ in properties.
What are the Properties of Kraft Paper for Bags?
Bags made from kraft have excellent properties. As follow:
- Toughness: A mild chemical manufacturing process makes kraft bags more durable and resistant than common paper bags. They can carry and load heavy-duty items and prevent puncture and rupture. Therefore, products can be well protected.
- Wet-strength: Kraft paper has a high wet strength that ordinary paper does not have. To a certain extent, kraft paper bags have a certain degree of water and oil resistance.
Eco-friendly: Compared to traditional poly bags, this bag is a more environmentally friendly alternative. They can be recycled and processed, which consumes less resources. - Good processability: The color of the kraft paper itself is beautiful, and if it needs to be printed, a simple design can construct the beauty of the product. Compared with shrink film, kraft paper has good stiffness and cushioning, which is convenient for composite processing.
Types of Kraft Paper Bags
With the development of paper manufacturing processes, a wide variety of kraft paper bags have appeared on the market. A brief introduction is as follows.
- Pure kraft paper bags
Natural virgin kraft paper bags, as the name suggests, are made from pure wood pulp. They have a tightly intertwined fiber structure, so the bag has a very good load-bearing capacity and is not easy to tear. In addition, some paper bags are made from recycled waste pulp. These recycled materials often need to be added with colorants to stabilize the color of the paper. While it’s not as durable as the original kraft paper, recycled kraft paper bags are a more eco-friendly option.
- Kraft paper aluminum foil composite bags
These bags are made of whole wood pulp as the base material, and then a waterproof film is poured with polypropylene on the paper, and aluminum foil is added to the inner layer. They have excellent moisture and shading properties, making them the best choice for storing dry food.
- Kraft paper woven bags
These woven kraft composite bags are compounds of plastic and kraft paper. The plastic layer inside is a woven cloth made of PP or PE. Due to its great resistance and durability, the finished bags are heavy-duty.
The emergence of a variety of composite kraft paper bags may meet the needs of customers to the greatest extent.
Benefits of Using Kraft Paper Bags
The continued existence and widespread use of kraft paper bags is due to the large number of benefits they offer. 4 main benefits make us fall in love with them.
- Environmental friendly: Kraft paper bag is a kind of packaging container made of composite materials or pure kraft paper, which is non-toxic, tasteless, and non-polluting. Moreover, the waste liquid of cooking wood pulp can be recycled, extracted, evaporated, burned, and other processes to obtain the chemical liquid of sodium hydroxide and sodium sulfide, which can be used for cooking wood pulp again.
- Stronger bearing capacity: With excellent toughness and durability, kraft paper pouches have the advantage of stronger bearing capacity. You don’t need to worry about rupture and leakage.
- Versatility: Brown paper bags can be seen in packaging, storage, and shopping. Whether it’s fresh fruits and vegetables, food scraps, table knick-knacks, cosmetics, bread, pastries, and beverages, these paper bags can come in handy.
- Cost-effective: Kraft paper can be made from a variety of woods, such as pine, bamboo, and oak. This means it’s easier to manufacture and therefore in abundant supply – which means lower material costs. In addition, they retain their natural color and texture, so they don’t require any additional bleaching and dyeing steps, which can save costs on production. Almost all chemicals in the production can be recycled, so kraft paper bags are circular and renewable, which is both environmentally friendly and economical. In terms of durability, they are highly durable. Therefore, it is an economic cost-saving for consumers.
Applications
Thanks to their plenty of benefits, brown paper bags are widely used in various fields.
- Food packaging
Flat merchandise bags are the typical packaging used for food. For example, the bakery used these merchandise bags to pack pancakes, burgers, and block pizzas, easy for customers to take out. At home, you can also apply them to hold snacks, like candies, nuts, and cookies.
- Goods storage
Kraft paper storage bags are specially designed to store the contents of the house. If you are annoyed by the clutter of your clothes, socks, cosmetics, and stationery in your bedroom, the storage bags can be your helper.
- Gift bags
Gift bags are essential for occasions such as weddings, birthday parties, daily gatherings, etc. Wrapping the gift in a brown or other printed color paper bag can better protect the product inside and also keep the gift mysterious.
- Shopping bags
When you’re out shopping for everyday items, easy-to-fold kraft paper bags are a good choice. Flat merchandise bags and shopping bags with handles are available. Ditch the traditional plastic shopping bags and bring more eco-friendly kraft paper bags to the shop to reduce carbon emissions and protect the green planet.
Conclusion
Compared with ordinary paper bags, the advantages of kraft paper bags are more significant. They have become a highlight in our daily lives. Choose these eco-friendly bags as your packaging to make efforts to reduce carbon.