4 differences between molded fiber and molded pulp

Table of Contents

Molded fiber often includes virgin fibers, enhancing durability and aesthetics, uses 3,000 kWh/ton, and features customizable designs. Molded pulp is made from 100% recycled materials, uses 2,500 kWh/ton, and is cost-effective for bulk packaging.

Composition and Material

Molded pulp and molded fiber are both made from recycled paper products. However, the details of their composition are important to the range of applications and cost of the packaging. Molded pulp employs primarily lower-end recycled paper fibers such as newsprint and cardboard. As such, it is suitable for low-cost and readily biodegradable packaging solutions for everyday products. For instance, egg cartons are such common products, weigh up to 100 grams, and may support 500-600 grams of eggs.

Molded fiber, in turn, may include these and many other paper-based products, potentially up to virgin fibers and coated high-quality paper to enhance its strength and aesthetics. This expanded range of fibers allows for more complex structures to be formed and, therefore, is typically used for more structural and visually appealing packaging solutions. For example, some molded fiber packages for consumer electronics must support several kilograms and provide plenty of cushioning. Additionally, and with the example of a fragile item in mind, molded fiber may be used for smartphone packaging that includes a custom-fit formed tray made from what feels like a smooth and non-porous material. A typical cell phone case weighs around 200 grams of packaging can typically have an on-note mass, but the consumer would notice and value the absence of fibrous texture and any blemishes on the visible surface of the formed tray.

The choice of the material significantly affects the cost and most real-world applications of the packaging. A lower-quality paper and simplification of the molded pulp material lead to lower upfront costs, but, in contrast to plastic, the cost/benefit margin here is shifted significantly towards the favor of the environment. The broader range of added fibers and paper-based products may make a seemingly simple product appear significantly uppriced while, in reality, offering a much broader range of retail value.

Manufacturing Process

Manufacturing processes for molded pulp and molded fiber are fundamentally the same; however, they differ significantly in complexity and the refined technologies they employ. The molded pulp is often a very simple process where a slurry of water and paper fibers is made. Then it is vacuum-formed on screens to shape the required product. This method works perfectly when producing packaging, such as plant pots or egg cartons, where no designs are required, and the production does not need to be precise. Molded fiber, on the other hand, can utilize after-pressing and in-mold drying to improve the toughness, precision, and finish of the products throughout the manufacturing process.

This approach can produce packaging with better design and smoother surfaces required for packaging more sophisticated products such as cosmetics or high-end electronic devices. By using these techniques, it is possible to create perfectly matched trays for smartphone devices where the required tolerance is only 0.5 millimeters. Otherwise, mold pulp production requirements could allow as low as 1-2 millimeters which means that additional space should be added, and the device would have no protection from moving around the packaging during shipping.

Produced molded pulp packaging might require to be dyed, while it is not required when creating molded fiber trays for consumer electronics. The energy consumption of the production differs as well. Mold pulp production per ton of product takes around 3,500 kWh of energy, while a more complex process of production might require up to 5,000 kWh per ton of molded fiber packaging. The reason for this is the necessity of an energy-consuming process to dry and press the product better. This increase in the refinement of the manufacturing process might ultimately result in the higher unit cost of the product.



The actual applications of molded pulp and molded fiber show the existing differences in their materials. This, in its turn, suggests the type of category appropriate for each material. Both products might be applied for certain types of packaging as molded pulp is widely used in cheap and deliberately functional scenarios when the structure is to be preserved and costs are to be decreased. In such situations, nothing is of greater importance than just a need to pack a particular item into a natural material forming a kind of bulk. The product is a visually unappealing carton for eggs made out of molded pulp every piece of which costs about $0.05.

As a rule, an egg carton includes 12 cavities or an additional part to tie 12 eggs. Poultry farms take advantage of this type of product across the world due to the ease of use and minimum costs. Concerning the molded fiber, its use is based on the necessity to present the products in a more beautiful fashion. This is the case when the goods are super fragile and require an additional level of protection, or an item is highly designed to be glossy and highly marketable. The typical molded fiber carton for a cell-phone costs about $0.30-0.50 per one. For instance, sometimes, molded fiber is used for food products as well, but usually, their cost is higher in such a case as the customers are from a more demanding category than, in this particular case, for eggs.

The molded fiber category is distinguishable by the mentioned characteristics as it might easily be dyed, embossed, or have extra lamination. This provides the packaging with a chance to carry the logos and colors of the brands. The outward visual representation is of a great value and allows fitting it into the overall branding strategies. The market has a complex nature, and any additional selling point contributes to the success of the object it encloses.

One of the factors of the choice is the complexity of designs, which could be easily added, and this is one of the reasons why molded fiber form is such a category. The total appearance is one of the core factors, which have a particular importance in the customer segment as it is capable of differing one brand from another. Overall, the choice is up to the customer. When the expenditure force is limited and the item is not fragile or of a highly attractive appearance, molded pulp is the best choice. As for fragile items with designs, molded fiber should be an alternative in such a case.

Environmental Impact

Molded pulp and molded fiber both offer significant environmental benefits as they are biodegradable and recyclable; however, they differ in the carbon and water footprint and the required manufacturing process. At the same time, molded pulp products constitute recycled paper waste and require less energy to produce an average of 2,500 kWh per ton of produced material. For instance, egg crates, shoe supports, and packaging inserts are all perfect examples of low-cost, environmentally friendly, and highly robust products that can be mass-produced. At the same time, the molded fiber also has recycled contents; however, it includes both post-consumer waste and the virgin fiber to achieve sufficient strength and aesthetics, which result in slightly higher energy consumption, around 3000 kWh per ton. Nevertheless, both provide marked environmental benefits as the majority of the products used in commerce are not biodegradable.

The smaller average life cycle water requirement of molded fiber attests to the water efficient production processes; molded pulp production is also water-intensive as large volumes of this resource are essential to creating the slurry of recycled paper. However, the recovery and utilization of water in the molded fiber manufacturing process have been shown to reduce overall water consumption and waste water production. Both molded pulp and molded fiber are fully compostable and break down to particles in a compost environment in 90 days. Moreover, the degradation time of molded fiber is similar to that of molded pulp assuming the former does not include any synthetic additives. However, if the molded fiber contains coatings or treatments, for instance for increased moisture resistance and durability, it may take longer to degrade. Therefore, molded pulp and molded fiber are different in their carbon, energy, and water footprints, degradation time, and manufacturing processes.

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