Polytex
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While grain bags can offer many benefits for growers, there are also potential risks and challenges associated with their use. It’s important to be aware of these risks in order to mitigate them effectively. Some potential risks in using grain bags include:

  1. Moisture Ingress: Although grain bags are designed to be airtight, there is still a risk of moisture entering the bags, especially if they are not sealed properly or if there are tears or punctures in the material. Moisture ingress can lead to mold growth, spoilage, and a decrease in grain quality.
  2. Pest Infestations: Grain bags, while providing a barrier against pests, may still be vulnerable to pest infestations if not properly sealed or if pests manage to breach the bag’s defenses. Insects and rodents can cause significant damage to stored grain. The best way to minimise this risk is to ensure good hygiene around the bags, i.e no spilt grain or food that would attract pests and rodents.
  3. Temperature Fluctuations: While grain bags can provide some insulation against temperature fluctuations, extreme temperature changes can still affect the internal environment of the bags. Rapid temperature shifts can cause condensation, leading to moisture buildup and potential spoilage.
  4. Bag Strength: The quality of the material and construction of the grain bags is crucial. If the bags are made from inferior materials or are not properly constructed, they may be more prone to tears, punctures, or seam failures, which can compromise the integrity of the storage environment.
  5. Handling and Loading Challenges: Filling grain bags requires proper equipment and techniques to ensure uniform loading and minimal stress on the bag material. Inadequate handling practices can lead to bag ruptures, uneven loading, and inefficiencies.
  6. Long-Term Storage Considerations: While grain bags can be a useful short- to medium-term storage solution, they are not recommended for long-term storage due to the potential degradation of the bag material over time.

To mitigate these risks, it’s important for growers to carefully follow manufacturer guidelines for bag usage, sealing, loading, and unloading. Regular inspection of the bags for signs of damage or compromise is crucial. Additionally, implementing integrated pest management strategies and proper site selection can help minimize the risks associated with moisture, pests, and other environmental factors.

Using grain bags for storage comes with its own set of advantages and disadvantages. Let’s explore the pros and cons:

Pros:

  1. Cost-Effective: Grain bags are often more cost-effective than building permanent storage structures like silos. This can be especially beneficial for growers with limited budgets or temporary storage needs.
  2. Flexible Storage: Grain bags offer flexibility in terms of capacity. They can accommodate varying quantities of grain, making them suitable as a backup storage option for high-yielding harvests.
  3. Quick Setup: Setting up grain bags is relatively quick compared to constructing traditional storage facilities. This can be especially advantageous during peak harvest times when the need for storage space is urgent.
  4. Space Efficiency: Grain bags utilize available space efficiently, as they can be placed in locations where traditional structures might not be feasible. They can also be a handy option for collecting grain direct from the chaser bin and storing it at a central site on the farm.
  5. Reduced Capital Investment: Grain bags eliminate the need for significant upfront investments in permanent storage structures, allowing growers to allocate resources to other areas of their operation.

Cons:

  1. Risk of Damage: Grain bags are susceptible to damage from rodents, birds, pests, and even machinery during loading and unloading. Proper sealing, handling and good site hygiene are essential to prevent these issues.
  2. Limited Long-Term Storage: While grain bags are suitable for short- to medium-term storage, they are not be the best option for long-term storage due to potential degradation of the bag material over time and grain quality risks.
  3. Moisture Management: While grain bags are designed to be airtight, proper moisture management is essential to prevent mold, fungal growth, and spoilage within the bags. Sampling and regular checks are recommended.
  4. Quality Control Challenges: Monitoring and maintaining grain quality within bags can be more challenging compared to traditional storage facilities that offer better ventilation and control.
  5. Labor and Equipment: Loading and unloading grain bags require specific equipment and labor. Improper loading techniques can lead to uneven settling and air pockets within the grain.

Overall, grain bags offer flexibility and cost savings, particularly for short-term storage needs. However, they come with challenges related to potential damage, proper sealing, moisture management, and quality control. Growers should carefully consider their specific storage requirements and weigh the pros and cons before deciding whether grain bags are the right choice for their operation.

A key advantage of grain bags is the flexibility of where to store them. You can store grain bags anywhere on your farm as long as it is clean firm ground, well drained and free of sharp objects. Also avoid placing grain bags near trees. Having this flexibility can be handy during peak harvest to have central locations on farm to reduce the time it takes chaser bins to empty and return.

Appropriate site selection is the first and most fundamental step in successful grain bag management.

■ Placing bags in different paddocks makes filling direct from the harvester or chaser bin easier but increases maintenance and monitoring time. This can compromise grain quality.
■ Bags located in individual paddocks can be challenging in wet weather.
■ A central, common storage site for bags is ideal for easier site preparation, monitoring, bag maintenance, vermin control and out-loading.
■ Select a hard, smooth, elevated site with a gentle slope where water can drain away.
■ Allow plenty of room around the grain bags for machinery access and trucks to turn around.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

■ Grade and roll the site, removing sticks, rocks or sharp objects.
■ Clear, firm ground makes operating the filling and emptying machines easier with less chance of brakes skidding.
■ A firmly-rolled site helps drainage and prevents water pooling where the grain bag has sunken into soft ground.
■ Anything that can puncture the bag is a threat and must be removed. Set up the site away from rocks, sticks, trees (they drop branches and harbour birds) and away from sand hills or long grass where rabbits, mice and foxes shelter.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

The most common filling machines are power take-off (PTO) driven, forcing grain into the bag, stretching it by about 10 per cent as it’s laid. A more recent development is the gravity filling design, which requires no power or tractor to operate and relies purely on gravity to fill and stretch the bag.

Make sure the machine is clean before filling the bags.

Grain pests, such as weevils and other insects, can survive in small amounts of grain left in equipment from the previous season. If the machine is not clean, these pests can infest the new season’s grain and will multiply and spread through the entire grain bag.

Fitting the bag onto the machine with two people saves time and reduces the chance of injury. When setting up the bag on the filling machine, ensure the stretch markers are on a side where they can be seen and measured when the bag is filling.

Once filled, any holes in the bag will allow grain to absorb moisture from the ground.

Options include:
■ sealing the ends of the grain bag with a heat sealer, or
■ clamping the ends between two lengths of timber or steel, rolling each end around the timber then tucking the bag under itself with about a metre overlap. The squarer the starting end of the bag, the easier it is to empty with less shovelling — a cable tie around the end is NOT a good idea.

Before filling the bag, use a string line to mark a straight path along the full length of the bag. A straight bag is a lot easier to empty than a curved bag.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

Patience and accuracy during filling will make emptying the bag much easier, reduce maintenance on the bag during the storage period and result in less spills and fewer stops to realign machinery.

■ Keep the bag filling evenly and straight to avoid creases — mice tend to attack creases.
■ Adjust the brakes and direction often and in small increments.
■ Avoid over-filling (over-stretching) the bag as extra strain makes it more prone to holes, splits and tears.
■ Remember, the polyethylene bags will stretch more easily when filled with warm grain on hot days.
■ Bags can be filled straight from the harvester, but operators may be tempted to rush, which leads to a poor job and increases the risk of an accident. (ie damage to machinery or operators).
■ Stop filling the bag while there is still plenty of bag to seal and re-attach to the emptying machine — about four metres is a good rule of thumb.
■ As with the starting end, heat seal or clamp the bag end to keep moisture out, then tuck the excess bag under itself and cover with soil to stop it flapping in the wind.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

Site security starts with hygiene. Cleaning the site after filling will not only remove harbours for grain insects, it will remove feed that attracts mice and wildlife.

After cleaning up around the site, establish mice baiting stations along the length of each bag and put up signs to warn people of the poison.

Keep the site free of grass by spraying it regularly to remove cover for mice and wildlife.

A sturdy fence, even an electric fence, around the bags can help prevent animals accessing the bags and chewing or walking on them. Even if there are no livestock in the paddock, remember there is always the potential for stray livestock or wild animals to cause a lot of damage in a short time.

Checking as often as twice daily may be required if vermin are plentiful during wet weather. During normal conditions check at least weekly. Patch any tears or punctures with quality tape or silicone to prevent moisture entering the grain bulk.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

When making the initial cut in the bag for out-loading, place a piece of tape horizontally across the bag below where it is stretched tight at the top. make the first cut perpendicular to the bag just below the tape. Do not make the cut parallel to the bag as there is potential for it to split up the entire length of the bag, exposing the grain and making it difficult to pick up.

As previously stated for filling the bag, frequent, small adjustments to align the machine and roller speeds are better than large adjustments.

When the bag is almost empty and there’s not much weight left in it, the unloading machine may drag the bag towards itself. This can cause tears from the ground or from over stretching. To prevent this, drive the tractor slowly backwards as the last bit of the bag is emptied.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

Clean grain residues from machinery used for grain handling to prevent reinfestation with insect pests next season. Structural treatments are a wise addition to a thorough clean down. An inert dust such as diatomaceous earth (DE), can be blown into the machinery to prevent insects harbouring during the off season.

Site clean-up is vital for success. Spilt piles of grain and leftover small bags of grain provide an ideal harbour for insects to live and breed.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

Grain Bags

Short-term protection for your grain on-farm.

Grain bags, also known as silo bags, can be a cost-effective option for growers storing grain short-term to support harvest logistics, allowing growers access to higher-value marketing opportunities post harvest.

Construction: Polytex’s grain bags are made to a high standard from polyethylene through a three-layer co-extrusion process, to a thickness of 250 microns. The layers are melted, creating a uniform film, inseparable and with great resistance. The outer white layer contains heat resistant resins and UV stabilisers to protect against harsh UV and heat conditions. The inner layer has a high concentration of carbon black and is designed to keep out the sunlight. This process provides important properties required in grain bags such as perforation resistance, thermal resistance, good stretching, internal temperature stability, reflection of solar rays and flexibility.

Quality: Polytex’s grain bags are imported from Argentina, from a well-known and recognised company who produce premium grain bags and export to more than 40 countries.
These bags have a proven track record in the Australian climate for over 7 years, therefore you can be assured of premium quality where it matters the most; protecting your investment.

While grain bags are a cost-effective and quick option, they do come with significant risks especially if you haven’t had previous experience. Site planning and preparation is the first and most important step for successful storage. We have outlined the basic risks in the accordions below however if you are new to grain bags we recommend talking to an expert or grower with previous experience.

Grain bunkers are an alternative option for storing grain with less risks and ability to store longer-term. They are slightly higher cost per tonne and take more preparation but can be used over multiple seasons.

Grain bags are ideal for a quick backup storage solution and with good preparation, sampling and regular checks, can be an effective option.

Capacity: Polytex’s grain bags are available in a number of sizes from 60 meters to 150 meters long, providing storage for 200T – 550T of grain.

  • 60m x 2.75m grain bag holds 200 tonnes
  • 75m x 2.75m grain bag holds 260 tonnes
  • 100m x 2.75m gran bag holds 330 tonnes
  • 75m x 3.05m grain bag holds 345 tonnes
  • 100m x 3.05m grain bag holds 460 tonnes
  • 120m x 3.05m grain bag holds 550 tonnes

While grain bags can offer many benefits for growers, there are also potential risks and challenges associated with their use. It’s important to be aware of these risks in order to mitigate them effectively. Some potential risks in using grain bags include:

  1. Moisture Ingress: Although grain bags are designed to be airtight, there is still a risk of moisture entering the bags, especially if they are not sealed properly or if there are tears or punctures in the material. Moisture ingress can lead to mold growth, spoilage, and a decrease in grain quality.
  2. Pest Infestations: Grain bags, while providing a barrier against pests, may still be vulnerable to pest infestations if not properly sealed or if pests manage to breach the bag’s defenses. Insects and rodents can cause significant damage to stored grain. The best way to minimise this risk is to ensure good hygiene around the bags, i.e no spilt grain or food that would attract pests and rodents.
  3. Temperature Fluctuations: While grain bags can provide some insulation against temperature fluctuations, extreme temperature changes can still affect the internal environment of the bags. Rapid temperature shifts can cause condensation, leading to moisture buildup and potential spoilage.
  4. Bag Strength: The quality of the material and construction of the grain bags is crucial. If the bags are made from inferior materials or are not properly constructed, they may be more prone to tears, punctures, or seam failures, which can compromise the integrity of the storage environment.
  5. Handling and Loading Challenges: Filling grain bags requires proper equipment and techniques to ensure uniform loading and minimal stress on the bag material. Inadequate handling practices can lead to bag ruptures, uneven loading, and inefficiencies.
  6. Long-Term Storage Considerations: While grain bags can be a useful short- to medium-term storage solution, they are not recommended for long-term storage due to the potential degradation of the bag material over time.

To mitigate these risks, it’s important for growers to carefully follow manufacturer guidelines for bag usage, sealing, loading, and unloading. Regular inspection of the bags for signs of damage or compromise is crucial. Additionally, implementing integrated pest management strategies and proper site selection can help minimize the risks associated with moisture, pests, and other environmental factors.

Using grain bags for storage comes with its own set of advantages and disadvantages. Let’s explore the pros and cons:

Pros:

  1. Cost-Effective: Grain bags are often more cost-effective than building permanent storage structures like silos. This can be especially beneficial for growers with limited budgets or temporary storage needs.
  2. Flexible Storage: Grain bags offer flexibility in terms of capacity. They can accommodate varying quantities of grain, making them suitable as a backup storage option for high-yielding harvests.
  3. Quick Setup: Setting up grain bags is relatively quick compared to constructing traditional storage facilities. This can be especially advantageous during peak harvest times when the need for storage space is urgent.
  4. Space Efficiency: Grain bags utilize available space efficiently, as they can be placed in locations where traditional structures might not be feasible. They can also be a handy option for collecting grain direct from the chaser bin and storing it at a central site on the farm.
  5. Reduced Capital Investment: Grain bags eliminate the need for significant upfront investments in permanent storage structures, allowing growers to allocate resources to other areas of their operation.

Cons:

  1. Risk of Damage: Grain bags are susceptible to damage from rodents, birds, pests, and even machinery during loading and unloading. Proper sealing, handling and good site hygiene are essential to prevent these issues.
  2. Limited Long-Term Storage: While grain bags are suitable for short- to medium-term storage, they are not be the best option for long-term storage due to potential degradation of the bag material over time and grain quality risks.
  3. Moisture Management: While grain bags are designed to be airtight, proper moisture management is essential to prevent mold, fungal growth, and spoilage within the bags. Sampling and regular checks are recommended.
  4. Quality Control Challenges: Monitoring and maintaining grain quality within bags can be more challenging compared to traditional storage facilities that offer better ventilation and control.
  5. Labor and Equipment: Loading and unloading grain bags require specific equipment and labor. Improper loading techniques can lead to uneven settling and air pockets within the grain.

Overall, grain bags offer flexibility and cost savings, particularly for short-term storage needs. However, they come with challenges related to potential damage, proper sealing, moisture management, and quality control. Growers should carefully consider their specific storage requirements and weigh the pros and cons before deciding whether grain bags are the right choice for their operation.

A key advantage of grain bags is the flexibility of where to store them. You can store grain bags anywhere on your farm as long as it is clean firm ground, well drained and free of sharp objects. Also avoid placing grain bags near trees. Having this flexibility can be handy during peak harvest to have central locations on farm to reduce the time it takes chaser bins to empty and return.

Appropriate site selection is the first and most fundamental step in successful grain bag management.

■ Placing bags in different paddocks makes filling direct from the harvester or chaser bin easier but increases maintenance and monitoring time. This can compromise grain quality.
■ Bags located in individual paddocks can be challenging in wet weather.
■ A central, common storage site for bags is ideal for easier site preparation, monitoring, bag maintenance, vermin control and out-loading.
■ Select a hard, smooth, elevated site with a gentle slope where water can drain away.
■ Allow plenty of room around the grain bags for machinery access and trucks to turn around.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

■ Grade and roll the site, removing sticks, rocks or sharp objects.
■ Clear, firm ground makes operating the filling and emptying machines easier with less chance of brakes skidding.
■ A firmly-rolled site helps drainage and prevents water pooling where the grain bag has sunken into soft ground.
■ Anything that can puncture the bag is a threat and must be removed. Set up the site away from rocks, sticks, trees (they drop branches and harbour birds) and away from sand hills or long grass where rabbits, mice and foxes shelter.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

The most common filling machines are power take-off (PTO) driven, forcing grain into the bag, stretching it by about 10 per cent as it’s laid. A more recent development is the gravity filling design, which requires no power or tractor to operate and relies purely on gravity to fill and stretch the bag.

Make sure the machine is clean before filling the bags.

Grain pests, such as weevils and other insects, can survive in small amounts of grain left in equipment from the previous season. If the machine is not clean, these pests can infest the new season’s grain and will multiply and spread through the entire grain bag.

Fitting the bag onto the machine with two people saves time and reduces the chance of injury. When setting up the bag on the filling machine, ensure the stretch markers are on a side where they can be seen and measured when the bag is filling.

Once filled, any holes in the bag will allow grain to absorb moisture from the ground.

Options include:
■ sealing the ends of the grain bag with a heat sealer, or
■ clamping the ends between two lengths of timber or steel, rolling each end around the timber then tucking the bag under itself with about a metre overlap. The squarer the starting end of the bag, the easier it is to empty with less shovelling — a cable tie around the end is NOT a good idea.

Before filling the bag, use a string line to mark a straight path along the full length of the bag. A straight bag is a lot easier to empty than a curved bag.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

Patience and accuracy during filling will make emptying the bag much easier, reduce maintenance on the bag during the storage period and result in less spills and fewer stops to realign machinery.

■ Keep the bag filling evenly and straight to avoid creases — mice tend to attack creases.
■ Adjust the brakes and direction often and in small increments.
■ Avoid over-filling (over-stretching) the bag as extra strain makes it more prone to holes, splits and tears.
■ Remember, the polyethylene bags will stretch more easily when filled with warm grain on hot days.
■ Bags can be filled straight from the harvester, but operators may be tempted to rush, which leads to a poor job and increases the risk of an accident. (ie damage to machinery or operators).
■ Stop filling the bag while there is still plenty of bag to seal and re-attach to the emptying machine — about four metres is a good rule of thumb.
■ As with the starting end, heat seal or clamp the bag end to keep moisture out, then tuck the excess bag under itself and cover with soil to stop it flapping in the wind.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

Site security starts with hygiene. Cleaning the site after filling will not only remove harbours for grain insects, it will remove feed that attracts mice and wildlife.

After cleaning up around the site, establish mice baiting stations along the length of each bag and put up signs to warn people of the poison.

Keep the site free of grass by spraying it regularly to remove cover for mice and wildlife.

A sturdy fence, even an electric fence, around the bags can help prevent animals accessing the bags and chewing or walking on them. Even if there are no livestock in the paddock, remember there is always the potential for stray livestock or wild animals to cause a lot of damage in a short time.

Checking as often as twice daily may be required if vermin are plentiful during wet weather. During normal conditions check at least weekly. Patch any tears or punctures with quality tape or silicone to prevent moisture entering the grain bulk.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

When making the initial cut in the bag for out-loading, place a piece of tape horizontally across the bag below where it is stretched tight at the top. make the first cut perpendicular to the bag just below the tape. Do not make the cut parallel to the bag as there is potential for it to split up the entire length of the bag, exposing the grain and making it difficult to pick up.

As previously stated for filling the bag, frequent, small adjustments to align the machine and roller speeds are better than large adjustments.

When the bag is almost empty and there’s not much weight left in it, the unloading machine may drag the bag towards itself. This can cause tears from the ground or from over stretching. To prevent this, drive the tractor slowly backwards as the last bit of the bag is emptied.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

Clean grain residues from machinery used for grain handling to prevent reinfestation with insect pests next season. Structural treatments are a wise addition to a thorough clean down. An inert dust such as diatomaceous earth (DE), can be blown into the machinery to prevent insects harbouring during the off season.

Site clean-up is vital for success. Spilt piles of grain and leftover small bags of grain provide an ideal harbour for insects to live and breed.

(Sourced from GRDC Grain Storage Fact Sheet www.storedgrain.com.au)

Key Benefits

Polytex Bunker Tarps

Tarp Stenciling

Polytex Bunker Covers or Bunker Tarps can include tarp stenciling to your specifications

Polytex

Tarp Stenciling

Polytex has a vast network of recommended & competent carriers Australia wide.

Polytex Ground Sheets

Tarp Stenciling

Polytex uses only first quality industrial fabrics for the manufacture of all products; well-known brands including Canvacon, Tarpee & Landmark variations

Grain Bunker Calculator

Grain Bunker Calculator

Access our calculator to get a comprehensive guide to planning and designing your grain storage.