6 Reasons Moulded Pulp Packaging Can Mold

Table of Contents

Moulded pulp packaging can mold due to its absorption of moisture, especially in environments with high humidity or inadequate storage conditions. Preventive treatments like antimicrobial coatings can reduce mold risks by up to 50%.

Material Composition

Molded pulp packaging is often made of recycled paper or natural fibers, such as sugarcane or bamboo. These fibers are designed to be porous, which means that the pulp naturally absorbs moisture. However, the characteristic of molded pulp also increases the risk of mold formation if the delivery boxes are exposed to humid environments. For instance, in a study, the molded pulp has been shown to absorb 20 percent more moisture than plastic under similar conditions. The typology indicates that the packaging absorbs moisture by increasing the risk of mold growth when the moisture is not completely evaporated due to low ventilation.

Molded pulp packaging is promoted for its environmental benefits. Considering that mold pulp packaging is biodegradable, it can be recycled or composted without causing waste generation and harming natural resources. Composting molded pulp packaging is an appealing solution for the cement because the product decomposes completely in less than 90 days when exposed to optimum composting conditions. In other words, the mold pulp product does not leave any harmful residue in the soil and generates nutrient-rich soil.

However, the industry often makes molded pulp without the possibility of mold formation or by degreasing the final molds to improve the finished product. Molded manipulations often discourage mold growth because many companies use antimicrobial agents during the pulping process or during the product’s construction. Practically, antifungal weapons work. Advantages in Quality: A molded pulp berry container that inhibits mold improves the berry’s appearance and, therefore, extends its shelf life. However, the consumer can reduce the risk of mold by storing them in a dry and well-ventilated state. A more acceptable solution for the customer that ensures the characteristics and longevity of the package is different produced preparations.


Moisture Exposure

Moulded pulp packaging is highly hygroscopic as organic fibers predominantly represent it. Thus, it tends to absorb moisture more rapidly than many other packaging materials, and it is evident that in moist environments or when it comes into the direct contact with moisture, it can develop mold. According to the results of a comparative analysis, moulded pulp can remain as much as 65% of its weight in moist if it is exposed to such conditions for two days.

On the contrary, a similarly measured polyethylene can absorb only about 2% of its weight. The manifestations of these occurrences in supermarkets where fruits are stored in moulded pulp packaging are fairly common. With each new refrigeration cycle, the humidity levels in the air around the products change, inevitably triggering the condensation buildup on the equipment and the products. Naturally, such events urge swift action is there are more or less humid conditions in certain areas – including such places as supermarkets – where the use of moulded pulp is to take control over excessive moisture and provide the means of ventilation.

The solvent of the dilemma listed above are generally logically apparent. First of all, there is a need to control the levels of moisture tightly with the help of dehumidifiers. The other viable option includes the control of atmosphere in the package where silica gel packets are to absorb moisture. Another solution with lesser effectiveness refers to altering moulded pulp’s properties slightly. This can be achieved through the introduction of a water-resistant coating while the main attributes and environmentally friendly virtues of the material remain intact. Such coatings are generally made from waxes or polymers that naturally repel water. All in all, the problem with mold in moulded pulp packaging to a certain extent persists, and it is conditional to keep the products initially in the proper conditions before packaging them.

Storage Conditions

The most effective factor affecting the growth of mold in moulded pulp packaging is proper storage condition. The susceptibility of the material to humidity makes environments where the packaging is stored an important aspect. Since mold spores require at least 50% relative humidity for growth, the storage area must either have 50% or less relative humidity or the packaging should be stored in a way to prevent the moisture from penetrating.

In retail, such as grocery stores or warehouses, regular maintenance of the environment helps the longevity of both the packaging and the contents. Implementing a system that controls the climate can decrease the risk associated with moisture to a significant extent. For example, keeping a warehouse at or below 50% relative humidity consistently can prevent the molding of the stored packages by at least 30% when compared to environments where relative humidity was not controlled.

Home storage produces different challenges, particularly in humid regions. While moulded pulp packaging can be stored with portable dehumidifiers to be used in storage areas or with silica gel packages that can further reduce the moisture, these methods are successful enough to be used both. For instance, when silica gel packages, which can absorb up to 40% of its weight in water and effectively create a nearly dry microenvironment in which moisture in the cases is prevented significantly, are placed with moulded pulp storage, mold growth can be prevented. Proper ventilation also prevents water contained in air from remaining in a specific location and helps mold growth to be prevented. This fact indicates that basements or closets with limited or no fresh air input requires the storage of packages with silica gel or dehumidifiers to limit or remove mold growth.


Environmental Factors

The two environmental factors that affecting moulded pulp packaging are climate and weather. Climate and weather have the highest influence on the moisture levels of environments and thus, affecting the moulding of pulp materials. Mould is mostly common in areas in high humidity. Proximity to a coast or being in the tropics makes the moisture level in the air of such regions very high. For example, in a typical coastal city where the average humidity may be about 80%, it is evident that the moulded pulp packaging materials will always absorb a lot of water content from the air as opposed to areas where the humidity does not rise above30%.

The difference between the moisture levels in the two areas is too significant hence, raising the risk of mould to a greater extent. Retailers in regions affected by high humidity have since reported an approximate 50% decrease in the spoilage rates of products stored in moulded pulp compared to storage in dry areas. A process that mainly requires moulding pulp to withstand certain humidity levels prompts for the use of storage facilities which are mostly climate controlled.

The use of climate-controlled facilities helps greatly in reducing the risk of moulding of pulp materials. The environment in the facility is highly conducive as humidity and temperatures are regulated. Companies upon the investment of climate-controlled storage report a direct 15% increase in the cost of storage. However, in the long run, the cost of product spoilage is significantly reduced by about 40% of the goods that go to waste. For moulded pulp packaging materials used by individual consumers in their homes, the use of air conditioners or dehumidifiers helps curtail the formation of mould in the products. For more information on how climate can affect moulded pulp products, visit the climate influence page.

Product Lifespan and Usage

The lifespan and usage conditions significantly affect the susceptibility of moulded pulp packaging to mold. If the products are designed for short-term or one-time use, the risk is generally low. For instance, if products are moulded pulp that has been made into an egg carton to hold eggs or a soft drink carrier for a few days to a few weeks, the product handlers can dry the mouldings after each application and store them in dry conditions, which should help mitigate mold infestation. Molded pulp used for longer-term or reusable applications, does show some evidence of mold, especially if the product and its other contents remain wet.

As an example, in agriculture, farmers use moulded pulp trays to hold apples or potatoes. If the damp, washed trays are allowed to sit in a damp or warm environment or not dried out appropriately before another load of apples is set in the tray, intercorporal mold will typically grow within 2-4 weeks. The mold rate can reach 25% if containers are reused under similar conditions. The appropriate means of protecting and preventing even these packages’ long-term use would be to store them dry and ensure that their contents are dry as well.

You may also add moisture-absorbing packets or powder coatings when necessary. Depending on the lifespan and user routines for the moulded pulp, the best option may be to provide specific instructions on how to use and dispose of the product. Retailers and producers may raise lifetime values by helping consumers about use over time. For molded pulp, this will mean instructing users to keep trays, for instance, in cool, dry areas and not to let the trays sit in the light, where a molded pulp occurs much more quickly.

Preventive Treatments

The basic idea behind preventive treatments is that the molded pulp packaging becomes resistant to mold. Ideally, manufacturers should use fungicidal or antimicrobial agents added to the pulp during production to prevent mold from developing. This method is particularly important for packaging used in moist environments as well as products that may contain moisture as an attribute of their nature, such as fruits and vegetables.

Perhaps the most popular right now is the use of boric acid for treating the pulp. The research conducted under the comparative humid conditions showed that commercial and industrial use of boric acid for this purpose can cut mold formation on the packaging by approximately 50 percent as compared to the plain molded pulp without these chemicals.

The method was proven effective as boric acid works by disturbing the ability of mold spores to complete their growth cycle. Therefore, spores do not replicate and grow mold on the surface of the product.

Natural essential oils such as thyme and clove also work well as antifungals and antimicrobials. The tests conducted in the field demonstrated that packaging sprayed in the finishing process with these oils or with their active components is highly effective as it can delay the development of mold over more than a dozen days in comparison with untreated-or-sprayed packaging in the case of medium and large size oranges.

Manufacturers can also apply barrier coatings made from polymers like polyethylene and polyvinyl-alcohol on the molded pulp. These coatings provide a moisture-resistant film on the pulp, preventing the water uptake and hence molding. Tests showed that the molding issue occurs due to the principal factor, which is the ability of mold spores to germinate, and is directly related to the water uptake, which was minimized by these films. As a result, treated packages showed a several-fold reduction in water absorption and, hence, in the growth of mold on the packaging.

Therefore, for the end-customer, it is critical to choose molded pulp packaging treated in such a preventive way, particularly, when sensitive items like healthcare products and organic foods are at stake. Each of these methods has its adoption hazards and appeals to different manufacturers based on the existing infrastructure. Being aware of the tools presented in this essay, consumers can make more educated decisions regarding what packaging to choose and hence ensure that the particular product will safely be transferred from the point of packaging to the point of consumption.

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