So far, there are different kinds of one way degassing valve in the market. Personally, we think that the most convenient degassing valve is pasted degassing valve. Pasted degassing valve, also called the patch valve which is used for coffee bag to save time and labor and for fermented feed bag to reduce the cost of the packaging bag (usually used ordinary PE bag), is easy to be pasted. Recently, this kind of pasted valve is not only used for coffee bag and fermented feed bag, but also suitable for iron tank, paper can, plastic can, pickle jars and other containers like composite packaging bag.
Wojin WJ01p is pasted valve, which is different from WJ1901 and WJ1902. The one way degassing valve with filter and one way degassing valve without filter are round in appearance and of the same size, each with a diameter with 20mm and a certain thickness. However, WJ01p pasted valve is not round but is a rounded square disc with size of 20mm in length, 20mm in width and 0.55 mm in thickness.
The other two types of plastic degassing valve are large in volume and after installation behind the packaging bag, it is occupied the inside space of the packaging bag. WJ01p is small in volume and attached on the outside packaging bag. It is transparent and beautiful, which has no influence on the display of packaging bag design and it is upmarket and bighearted. Plastic one way degassing valve is thicker than pasted degassing valve. Therefore, transportation cost of plastic one way degassing valve is usually more expensive than WJ01p.
The patch valve doesn’t need to be heat-sealed. It can be labeled or pasted by hand to improve the efficiency and shorten the date of delivery. It is pasted firmly and the adhesive force can reach 22N/25MM, so it will not fall off even if the bag is rubbed repeatedly. What is more, it can be long-term heat resistance of 100℃, short-term heat resistance of 120℃.The air valve is thin, which can reduce the cost of packaging and transportation. In the process of pasting, the inside of the bag will not be touched by hand so the food will not be polluted. To some extent, people don’t need to buy a valve pressing machine additionally, so it is more cost-effective. The application scope of pasted degassing valve: it is fit for coffee bag, coffee can, rice bag, fermented feed bag, biofermentation bag, biosaprost packaging bag and so on.
Pasted degassing valve is a functional component. Roasted coffee beans sealed in a bag will release carbon dioxide, inflating the bag and the gas will seriously affect the quality of coffee. The valve plate of the one way degassing valve may be pushed open from the inside to outside to discharge the excess gas. When the inside pressure has been not enough to push off the valve block, the valve will close automatically. Only when the pressure inside the bag is higher than the outside pressure, the valve can open automatically, vice versa. The outside air and vapor can’t enter into the packaging bag.
The usage of pasted degassing valve is simple: drilling a small hold on the container and covering the hold in the center of the disc. The reason why the pasted degassing valve is more expensive than the common one way degassing valve is that it can widely use in iron tank, plastic can, pickle jars and so on.
In function, the two plastic one way degassing valves are the same as the WJ01p pasted degassing valve. As long as the one way degassing valve is quipped on the packaging bag, it can discharge the carbon dioxide released by the baked coffee out of the bag, avoiding the breakage of the bag. At the same time, it can prevent the outside air from entering into the packaging bag, causing the coffee bean oxidation and guaranteed that the flavor of the coffee doesn’t change. As for fermented feed bag, the processed feed will release a lot of gas in a week. If a plastic one way degassing valve or a pasted degassing valve is equipped, the gas will be discharged from the bag. At the same time, the valve can prevent the outside air from entering the fermentation system, leading to the growth of miscellaneous bacteria. The bag is equipped with a one way degassing valve, which greatly guarantees the success of feed fermentation.
Originally published 27 May 2018, updated 27 May 2018.
By reviewing the harmfulness that conventional plastic brings to our planet, Wojin has taken actions and developed degradable coffee exhaust valves.