what is About kraft paper bags and their valves | Global Fortune Package

November 03, 2022

Kraft paper bags

Kraft paper bags are more and more used in the packaging industry as one of eco-friendly packaging . In daily life, the packaging of kraft paper materials can be seen everywhere, such as  one-way exhaust valve coffee bags, coffee powder bags, and seed bags in supermarkets etc.

Today, with the trend of green environmental protection, kraft paper bags are favored by more and more industries and enterprises. They have begun to replace plastic packaging bags, common shopping bags, etc. , because kraft paper bags have the unique advantage while flexible plastic packaging doesn’t.





Quality kraft Paper Breakfast Bread Bags Toast Bags With Open Clear Window And Wire SealingFood Bags   

Eco-friendly Kraft Paper Dried Fruit Nut Biscuit Candy Bag Zipper Stand Up Bag With Window Snack Food Bag












The friendly-environmental performance of kraft paper bags is why this kind of bags is widely used in the market. In the packaging industry, people pay more and more attention to green environmental protection.Although there are many flexible plastic packaging materials which are non-toxic and tasteless, kraft paper also has the advantages ,such as non-pollution and recycle.

In addition to the environmental protection performance of kraft paper bags, its printing performance and processing performance are also excellent. The kraft paper bag is divided into two kinds, white kraft paper bags and yellow kraft paper bags.

Customized biodegradable coffee bags wholesale manufacturers From China 

It does not need full-page printing.

Simple lines can be used to outline the beauty of the product pattern during printing, and the packaging effect of kraft paper bags is better than that of ordinary plastic packaging bags. Good printing performance greatly reduces the printing cost of kraft paper bags, as well as the cycle of packaging production.

The value on the kraft paper bag


Kraft paper bags are also widely used for coffee beans. Kraft paper bags used for coffee beans are different from ordinary kraft paper bags. Most of them are with an valve, but do you know what is the valve is and what the function of the valve is?


   Customized Eight-side Sealing Bag With Zipper Coffee Bag 

"Coffee Exhaust Valve", it is called a one-way venting valve. The one-way exhaust valve plays a vital role in helping your fresh coffee beans stay fresh longer.

The one-way venting valve is the bag accessory that prevents back-flow of air.

A brief overview of the one-way exhaust valve :it has two functions,one is to discharge the gas in the bag, and the other is to isolate the air outside the packaging bag from entering.



Coffee beans contain acids, proteins, esters, carbohydrates, water and caffeine. After coffee beans are roasted at high temperature, carbon dioxide is produced through a series of chemical reactions such as the Maillard reaction.

Because coffee beans emit carbon dioxide by themselves, we will see roasted coffee beans in a sealed bag that will bulge over time. This is the so-called "inflated bag". With the one-way exhaust valve, it will help to remove these inert gases from the bag in time, so that these gases will not oxidize the coffee beans and maintain a good fresh state for the coffee beans.


II.Isolating the air

How to isolate the air while exhausting it? The one-way valve is different from the ordinary air valve. If a common air valve is used, while the gas in the packaging bag is discharged, it will also allow the air outside the packaging belt to flow into the bag, which will destroy the sealing performance of the packaging bag and cause the coffee to continue to oxidize. Oxidation of coffee beans will cause aroma volatilization and composition deterioration. The one-way exhaust valve does not. It exhausts the carbon dioxide in the bag in time, and does not allow the outside air to enter the bag.

When the air pressure in the bag reaches a certain threshold, the valve of the one-way exhaust valve is opened to release the gas in the bag; until the air pressure drops below the threshold of the one-way valve. The valve of the one-way valve is closed, and the packaging bag returns to a sealed state.

Basic Information
  • Year Established
  • Business Type
  • Country / Region
  • Main Industry
  • Main Products
  • Enterprise Legal Person
  • Total Employees
  • Annual Output Value
  • Export Market
  • Cooperated Customers
Contact Us
Take advantage of our unrivaled knowledge and experience, we offer you the best customization service.

Send your inquiry

Choose a different language
Current language:English