FAQ

Here you will find answers to frequently asked questions about paper sacks from Feldmann Verpackungen.

Can I reduce plastic usage by using your sacks?

Yes, in many cases. By using modern, high-strength papers, we can eliminate the need for additional plastic layers for many products or reduce the grammage of the paper without the sack tearing. We would be pleased to review your current packaging concept for potential savings.

Do you also produce small batches and custom sizes?

Custom-made products are our core business. The minimum quantity depends on the specification; our orders start at around 3,000 units per variant.

How does Feldmann secure our supply during fluctuating demand?

Nothing is more expensive than a production line that stands still because packaging is missing. We work extensively with framework agreements and call-off orders. This means: We produce based on your annual planning, store inventory for you, and deliver exactly when you need the sacks – reliably and on time.

Do your sacks protect hygroscopic powders from clumping?

Yes. To achieve this, we use moisture barriers. Depending on requirements, we integrate PE-coated papers or a free-standing PE film (Free-Film) between the paper layers. Your product remains dry and free-flowing.

Are the sacks approved for direct contact with food?

We use papers, adhesives, and printing inks that are strictly approved according to current EU regulations for food contact. You will receive the corresponding declarations of conformity for your audits (e.g., IFS, BRC) proactively from us.

Will your sacks run smoothly on our existing filling systems?

Yes. Before we produce, we clarify your technical parameters: What is the filling process? How must the valve be constructed? Then we design the sack construction, valve size, and paper porosity precisely so that you can run your machines at maximum speed.

What filling weights can be accommodated by your cross-bottom bags?

The ideal dimensions depend on the volume and bulk density of your product. As standard, our bags are designed to meet common industry standards. The most popular format on the market is the 25kg cross-bottom bag. However, for heavier goods or industries with different standards, we also produce the bags in even more robust versions.

How exactly is the Pinch Top sack sealed after filling?

A reactivatable hot-melt adhesive is applied to the stepped layers at the open sack end during production. After filling in your system, this adhesive is activated by hot air, the layers are folded over and pressed together. The result is an immediately load-bearing, tight seal.

How long does it take to produce my sacks?

The lead time depends on specification, printing, and quantity. After clarifying the details, we will provide you with a binding delivery date and adhere to industry-standard delivery times.

Do your valve bags fit with our existing filling equipment?

Yes. Regardless of whether you use turbine, air, or screw packers: We precisely adapt the valve type (e.g., external valve, internal valve, thermal valve) and valve dimensions to the filling spouts of your machines.

How do you ensure moisture protection for hygroscopic products?

For moisture-sensitive goods, we equip the paper sacks with a moisture barrier. This can be a coated paper layer (PE coating), a PE film interlayer (free film), or a glued-in liner.

Are Feldmann paper sacks recyclable?

Yes. Our pure paper block-bottom and Pinch Top sacks can be easily disposed of via waste paper recycling. We also offer recyclable designs for paper-plastic combinations, where the film and paper can be easily separated from each other after emptying.

What is the technical difference between the Pinch Top sack and the block-bottom sack?

The main difference lies in the closure technology. While the block-bottom sack is sealed with a tear-open strip or capping strip, the Pinch Top sack uses offset-cut and flat-glued plies. This makes the Pinch Top sack significantly more resistant to the leakage of fine dusts and better suited for extremely fine-powdered goods.

Can I accompany the manufacturing process for an initial order?

Yes. Especially with new designs, we closely coordinate samples and approvals with you before series production begins.

When is a paper cross-bottom sack sufficient, and when is a plastic combination required?

A pure cross-bottom sack (paper) is ideal for non-sensitive goods that need to breathe, as is the case with certain construction materials or animal feed. However, as soon as your product is hygroscopic, requires aroma protection, or strict hygiene requirements must be met, we integrate plastic films. These serve as an effective moisture, grease, or gas barrier.

Which barrier materials can be integrated into the sack?

In addition to robust kraft sack paper as the carrier material, we integrate various plastics (e.g., PE) as interlayers or inner bags (liners), depending on your requirements. This allows grease, moisture, or gas barriers to be precisely matched to the product being filled.

What lead times and minimum order quantities should we expect?

The minimum order quantity (MOQ) depends on the specification (format, printing, material) and generally starts at 3,000 units per order/per type. Thanks to our efficient production planning and logistics, we achieve reliable and industry-standard lead times. We would be pleased to discuss specific dates within the scope of your particular project.

Are your Feldmann cross-bottom bags suitable for fully automated filling lines?

Yes. For high filling performance in your operations, the dimensional accuracy of the empty packaging is crucial. During production, we place the highest value on clean cuts and precise gluing of the cross-bottom. This ensures that the bags are flawlessly separated and attached by the machine’s vacuum grippers. This minimizes setup times and machine downtime.

Can this bag type be processed on our fully automated pinch filling systems?

Yes. The bags are specially designed for machine processing. During production, we ensure precise cuts, correct adhesive bonding, and high dimensional accuracy of the empty packaging. This ensures trouble-free separation and error-free sealing on automated systems.

Can the valve be sealed dust-tight for particularly fine powders?

Yes. For products that generate significant dust or are very fine, we recommend ultrasonic-weldable valves (thermal valves). These are hermetically sealed after the filling process, which prevents 100% of product leakage as well as dust accumulation on the pallet.

How does the special construction of the cross-bottom affect logistics?

The block-like structure of the base causes the sack to assume a rectangular shape under filling pressure. This geometry ensures excellent stability and enables compact, flush stacking on the pallet. The result: optimal utilization of cargo space, reduced logistics costs, and high load security.

Is the sack suitable for hygroscopic materials?

This is one of the main areas of application. The combination of dense film layers and the hermetic hot-melt closure reliably blocks the ingress of moisture. Materials that absorb water and clump remain free-flowing and retain their specific product properties.

What surface treatment options are available?

In addition to multicolour printing (up to eight colours) for your corporate design or for legally required warning notices, we can adapt the raw material to logistical requirements. Especially with stacked pallets, an anti-slip coating on the paper makes sense to prevent the sacks from slipping during transport.

Mockup Cross Bottom Sack FAQ