If you are storing silage in round bales, you need to wrap them as tight as possible to prevent moisture, air, and pests from entering the silage. However, not all films can meet the requirements for silage storage. What factors determine an excellent silage film?
There are several factors to consider when choosing the proper film for your silage wrapping needs, including clarity, strength, chemical resistance, and texture. However, the most crucial factor you should keep in mind is permeability; if the film you choose allows oxygen and moisture through its barrier, your silage could spoil, and your investment will go down the drain.
Here are other factors that determine the quality of a silage film.
1. The Materials of The Silage Film
Silage film is typically made from Metallocene Polyethylene or LLDPE.
MPE, or metallocene polyethylene, is a special type of thermoplastic made using metallocene catalysts and copolymers. This product is characterized by uniform co-monomer content, narrow molecular weight distribution, high resistance to puncture and damage, high toughness, tensile strength, and stiffness. Through the use of metallocene catalysts, the manufacturer is able to introduce desirable properties in the product based on its application. A variety of products can be manufactured using mPE, such as films, sheets, injection moulding, extrusion coating, etc.
LLDPE is a substantially linear polyethylene, with a large number of short branches, generally obtained by copolymerizing ethylene with long-chain olefins. It differs structurally from conventional low-density polyethylene (LDPE) in that it is free of long-chain branching and impurities. Since LDPE is recycled into LLDPE, the linearity of LLDPE is almost the same as that of LDPE. In addition to having a narrower molecular weight distribution than conventional LDPE, LLDPE has significantly different rheological properties because of its linear structure.
As a result of the use of these materials, the silage film is extremely ductile and highly resistant to punctures and tears.
2. Function of Oxygen Barrier
An important function of good quality silage film is the barrier to oxygen. This is because the silage film needs to provide an oxygen-free environment for the silage to react without oxygen and thus ensure that the internal nutrients are not damaged. This is what distinguishes silage from hay. The materials used in the manufacture of silage packaging film, metallocene polyethylene or LLDPE, provide such a barrier to oxygen. At the same time, studies have shown that a multi-layer structure (e.g. five or more layers) is also effective in ensuring an oxygen-free environment inside the bales, preventing adverse factors such as mold from occurring. This is because many studies have shown that bales with less than four layers of structure produce more mold.
3. Strength Per Unit Weight
One of the essential qualities of a good silage film is its strength per unit weight. This determines how much the film can support without breaking or tearing. The stronger the film, the better it will protect your feed from oxygen and moisture. There are a few factors that affect the strength of a Silage film.
These include the type of plastic used and whether it has been extruded or cast. The thickness of the film also plays a role, with thinner films being weaker than thicker ones.
4. Tensile Strength and Tear Resistance
Tensile strength is the amount of load or stress that a material can withstand before stretching and breaking. As the title suggests, tensile strength is a material’s resistance to strain caused by mechanical loads.
Qualified silage stretch film must have a certain amount of tensile strength to ensure a firm and tight fixing when used. And tear resistance ensures that the film does not break or crack during machine operation.
The high tensile strength and tear resistance of the silage film ensures the integrity of the silage film during use, allowing silage to be stored safely so that our livestock can eat a safe and healthy diet.
5. UV Stabilizer
Silage Bale Warp of good quality must be able to be stored outdoors for a long period of time. Ideally, this period should last at least one year. In this period, the silage film must be able to withstand the weather. Ordinary plastic can be seriously damaged by long periods of direct sunlight, resulting in deterioration and eventual breakdown, affecting the storage of silage. To combat the effects of aging, UV stabilizer should be added to the film. The use of these ingredients prevents the plastic from being damaged by direct sunlight and allows it to last for a sufficient amount of time.
A good silage film should be impermeable to oxygen and water vapor, strong enough to withstand the weight of the material it covers, yet flexible enough to allow for expansion and contraction. It should also be durable so that it does not degrade over time. UV resistance is another essential quality, as sunlight can cause the breakdown of the film.
Understanding the qualities of a good silage film will help you choose one appropriate for your needs.