What is the difference between wet and dry molded fiber

Table of Contents

Wet molded fiber uses 5,000 liters of water per ton and provides smooth finishes, ideal for food packaging. Dry molded fiber uses 500 liters per ton, offering durability for industrial uses.

Manufacturing Process

Wet molded fiber and dry molded fiber are made from cellulose materials, but the processes they go through are different, which has implications for their practical applications. With the development of technologies, the abundance of cellulose materials as a source for both types of paper, the variety of products, and the demands for sustainability and environmentally friendly materials, wet and dry molded fibers today are widely used in a variety of everyday products from food packaging to industrial components. What is this technology about and what kind of products it can be used for?

Wet molded fiber technology includes submerging cellulose fibers in a great deal of water. The resultant fiber slurry is dropped rigorously onto molds that determine the shape of the product. Molder manufacturers claim that wet molded fiber can provide them with high definition and perfectly smooth surfaces of products which is essential for consumer products. For example, a typical machine from HGHY molding machines can be handling one thousand liters of water every minute manufacturing a type of products that surround us daily, such as egg carton and cup carrier, and are found in supermarkets, cappuccino, and coffee shops.

In dry molded fiber products, the fiber mixture goes through a minuscule amount of water. The moisture here serves as a binder to stick fibers together before they are packed inside heat molders and pressed to create new products. The dry molded fiber is a much denser and rougher material. For this reason, it is used in the automotive industry, for car parts that are expected to be more resistant to the environment and wear and tear. Most dry molded processes use less than 10% of the water required for wet molding and subsequently, dry molded fiber products are more economically viable because they are substantially cheaper to produce, or up to 20% less expensive.


Environmental Impact

The wet molded fiber and the dry molded fiber are two different approaches to effectively create an appropriate container for a product. Wet molded fiber consumes a lot of water. While the recycling system returns it to the production process with minimal losses and high levels of retention, the fact that 5,000 liters of water are required for 1 ton of a product remains a significant concern from the water protection standpoint. For the number of water-dependent customers such as manufacturers of electronic components willing to demonstrate their concern for the environment on the corporate scale the dry molded fiber with its insignificant dependence on water, slightly more than 500 liters for a ton of the product, may appear like an independent solution.

Such relatively low demands for water translate into lower costs for its treatment and lower burden caused by the production process on environmentally stressed territories. At the same time, in both solutions, the materials used in the production are biodegradable and are frequently considered environmentally friendly, decrease the overall environmental burden and improve waste processing.

The paper used in dry molded fiber may include the traces of recycled product while the one for wet changes is produced as a result of processing agricultural waste for pressed parts. It means that the usefulness of the product and the waste it eventually turns into is significantly higher than the plastic packaging, which can take several hundred years to disappear. Nevertheless, the need for a significant portion of electrical power in the dry molded fiber to keep the water liquid and plastic in order to form appropriate shapes may limit the ways this alternative can be considered as more ecological.

End Use

Wet-molded and dry-molded fiber products have drastically different end uses due to the different qualities each process imparts. Wet-molded fiber is often used for products that need a smooth finish and fine detail. Many consumer packaging and disposable items are made with wet-molded fiber. Egg cartons, cup carriers, and disposable plates are commonly made with wet-molded fiber, which works well for such items due to its ability to mold intricate shapes and produce a smooth finish.

A wet-molded fiber egg carton, for example, will keep a dozen eggs securely in place while providing a clean and visually appealing package for them. Consumers will appreciate the attractive, easy to handle, and smooth texture of a wet-molded fiber egg carton. Dry-molded fiber’s more sturdy and rough texture, on the other hand, suits products that need to be strong and durable. The automobile industry uses dry-molded fiber in various car parts to take advantage of its durability.

Door panels and trunk liners,  benefit from the strength of dry-molded fiber. Durability is essential to protect the interior of a car and the structure of the car itself. Dry-molded fiber products can also withstand rougher handling and prolonged use, making them suitable for industrial and protective packaging as well.

Even when they are used for similar products, the costs and environmental benefits of the different molding processes can vary. Dry-molded fiber products generally have a lower production cost due to reduced water and energy use compared to wet-molded fiber. Dry-molded fiber items may cost up to 20 % less than the wet-molded counterparts\. This cost-benefit could make the products attractive for relatively low-value applications.

Wet-molded fiber products, on the other hand, are slightly more expensive to produce due to their higher water and energy consumption. They are best used in industries where the precise shape and finish is most critical. The food industry, for example, could take advantage of the superior finish of wet-molded fiber for fruit trays, take-out containers, and other containers where a smooth finish and precise shape is important.

News Post
Scroll to Top