Paper or plastic? In the world of industrial packaging, this question isn’t just for grocery bags – it’s about choosing the right heavy-duty sack for the job. Multiwall kraft paper sacks and kraft paper laminated polypropylene (PP) bags represent two pillars of packaging technology, each with unique strengths. VidePak, a key supplier of both these packaging solutions, stands at the forefront of this field. We marry deep technical expertise with state-of-the-art manufacturing to offer our clients the best of both worlds. In this article, we will compare multiwall kraft paper sacks and kraft paper laminated PP bags in detail – from their structural differences and performance characteristics to their ideal applications.
Structural Differences: Traditional Layers vs. Paper-Plastic Composite
At a glance, a multiwall paper sack and a paper-laminated PP bag might look similar – both often have a brown or white kraft paper exterior and robust feel. However, their constructions under the surface are fundamentally different. It’s a classic case of traditional layered engineering versus a modern composite design. Below, we break down how each type of bag is built:
Multiwall Kraft Paper Sack Construction
Multiwall kraft paper sacks (also known as multi-ply paper sacks) are built by layering several sheets of paper to create a single, sturdy bag. The word “multiwall” literally means multiple walls of paper. Key structural features include:
- Multiple Paper Layers: Typically made from two to four plies of high-strength kraft paper, each layer adds strength and puncture resistance. These layers are usually bonded together with glue across the bag’s surface. By using several thinner sheets rather than one thick sheet, the bag gains durability while remaining flexible. For example, a common design might use a 3-ply structure: an outer layer for print and weather resistance, a middle layer for strength, and an inner layer for additional reinforcement or smoothness. Each ply of kraft paper (often 70–100 gsm in weight) contributes to the overall tensile strength.
- Optional Inner Liner: Depending on the application, a plastic liner or coating can be integrated into a multiwall sack. Some multiwall sacks include a thin polyethylene (PE) film on the innermost side or a loose poly liner bag inserted inside. This liner provides a moisture barrier for products like cement, chemicals or food ingredients that absolutely must stay dry. When included, the liner is usually heat-sealed or glued to the paper at a few key points to keep it in place. However, many multiwall sacks used for dry products (like flour or sugar) omit the liner to keep the packaging fully paper-based and breathable.
- Closure Formats (Open Mouth or Valve): Multiwall paper bags can be produced in different formats. Open-top sacks (often called sewn open-mouth, or SOM, bags) are left open on one end for filling, then closed by stitching or adhesive after filling. Valve sacks, on the other hand, are a special design where the bag is pre-closed on both ends with only a small opening (valve) in one corner for filling. The valve allows quick filling using specialized equipment and then self-seals or can be folded shut. Multiwall paper valve bags are famously used for products like cement and flour – they facilitate fast, dust-free filling on high-speed lines. VidePak produces both styles: for example, we offer pasted valve paper sacks for cement, and open-mouth sacks for things like animal feed or chemicals, depending on customer needs.
- Paper Quality and Orientation: The kraft paper itself is usually unbleached (brown) or bleached (white) virgin kraft pulp known for its long fibers and toughness. Each layer’s grain direction might be alternated for better tear resistance. The outer layer is often the highest quality paper for good printing and scuff resistance, while inner layers can be slightly lighter or include recycled content if appropriate. The outer surface may also be treated to be water-repellent (with a sizing agent) or slip-resistant if needed.
- Glued or Stitched Bottoms: In multiwall sacks, bottoms can be pasted (glued) or stitched. Pasted block bottoms are common for valve sacks – the bottom and top are folded and glued into a brick-like square shape, giving a flat base that stands well and stacks efficiently. For open-mouth bags, the bottom is often factory-stitched or pasted, and the top is stitched closed after filling. VidePak’s multiwall sack lines (using Windmöller & Hölscher (W&H) equipment from Germany) can produce both block-bottom bags for optimal stackability and pinch-bottom or sewn sacks for traditional uses. We even offer innovations like paper tape-reinforced stitching for a more eco-friendly closure (using paper tape over the stitches instead of plastic tape).
In short, a multiwall kraft paper sack builds strength through layers of paper. It’s a monolithic paper structure, sometimes enhanced with a bit of plastic internally, but fundamentally it relies on the natural strength of kraft paper arranged in multiple plies.
Kraft Paper Laminated PP Bag Construction
Kraft paper laminated polypropylene bags (often called “paper-poly” bags) take a different approach: they are a hybrid construction, combining a woven plastic fabric with an outer paper layer. Essentially, these bags marry the strength of plastic with the printability and feel of paper. Key structural features of this composite design include:
- Woven PP Core: The backbone of a kraft laminated PP bag is a woven polypropylene fabric. Polypropylene strips (called tapes) are extruded from PP resin, stretched for strength, and woven into a fabric much like weaving textile threads. This woven PP fabric is what gives the bag its exceptional tensile strength and tear resistance. It looks like a mesh or weave of plastic threads if viewed closely. Typically, the weave is tight (for example, 10×10 or 12×12 tapes per square inch) to provide a solid structural net. This woven layer can bear heavy loads and resists punctures far beyond what paper alone can handle. It’s the same material base used in standard woven PP sacks (like those white grain or rice bags common worldwide).
- Paper Outer Layer (Lamination): The woven PP core is laminated with a layer of kraft paper on one side (usually the outside of the bag). Lamination is achieved by bonding the paper to the plastic fabric using a thin layer of molten polymer. In manufacturing, this is often done by extrusion coating: a thin film of polyethylene (PE) or polypropylene is extruded and acts like a glue between the kraft paper and the PP weave. Once cooled and pressed, the result is a single composite material: paper on the outside, plastic woven on the inside. The kraft paper used for lamination is often in the range of 60–80 gsm – sturdy enough to add some stiffness and take print well, but not too thick as to make the bag unwieldy. The paper can be brown or white, depending on printing needs and aesthetic. After lamination, the paper and fabric move as one unit, so converting (cutting, folding) can be done similarly to other sack materials.
- Hybrid Wall Structure: Effectively, a kraft laminated PP bag can be thought of as a two-layer structure (not counting the bonding resin): one layer of paper, one of woven PP. In some designs there may also be a very thin internal coating on the inner surface of the woven PP to improve moisture barrier or to make the inside smoother (important for certain products so they flow out easily). But generally, the structure isn’t “multiwall” in the traditional sense – it’s a single-wall composite. However, because the inner layer is woven plastic, it behaves differently than a simple single-layer paper bag; it’s far stronger and less prone to tearing.
- Bag Conversion (Cutting & Sewing): Once you have the laminated roll (paper+PP fabric), the bag is formed similarly to other woven sacks. Usually, these bags are made as open-mouth sacks: the laminated material is cut to size, a tube is formed (with the paper side out), and then one end is folded and stitched shut. The stitching often goes through the laminated material; a strip of protective fabric or paper may be applied over the stitches for reinforcement. The top is left open for filling and will be sewn or otherwise sealed after filling. It’s also possible to create block-bottom paper-poly bags – newer machinery (including some Starlinger lines) can fold and glue the bottoms of woven bags to make a square-end sack much like a paper valve bag. In such cases, even valve openings can be added, giving a valve sack made of woven PP/paper composite. This is a more advanced configuration used for things like cement in some markets, where the bag has the brick shape of a paper cement bag but is actually a laminated woven sack. VidePak’s equipment includes Starlinger conversion lines which can produce these modern block-bottom PP bags with paper lamination, providing options for clients who need valve filling or self-standing sacks.
- Reinforcements and Features: Paper-laminated PP bags can also incorporate additional features. For example, micro-perforations can be added through the paper and fabric if the product inside needs to “breathe” (to let air escape during filling, which is common for fine powders). Handles can be die-cut into the paper and fabric for smaller consumer-oriented sacks. The lamination process itself seals the outer surface, but if needed, an inner PE liner can still be inserted for extreme moisture-sensitive products (though often not necessary as the woven fabric plus lamination already provide substantial water resistance). The outer paper gives a somewhat rigid structure, so these bags hold their shape well when filled, similar to paper sacks, which aids stacking stability.
In summary, a kraft paper laminated PP bag is built by fusing paper onto a plastic skeleton. It’s a composite wall – paper for printability and surface, polypropylene fabric for the muscle. This design results in a bag that looks and feels like a paper sack at first touch but has hidden reserves of strength and weather resistance courtesy of its PP core.
Side-by-Side Structural Highlights
To clarify the differences between the two constructions, here’s a quick comparison:
- Materials: Multiwall sack = all paper (with optional inner plastic liner); Paper-PP bag = combination of paper + woven plastic throughout.
- Layers Count: Multiwall = 2–5 separate paper layers (multi-layered structure); Paper-PP = effectively 1 paper layer + 1 woven layer bonded (a dual-layer composite).
- Joining Method: Multiwall = layers glued together (and possibly stitched at ends); Paper-PP = paper and PP bonded by lamination, with sewn or glued ends.
- Typical Formats: Multiwall = often available as valve sacks or open-mouth sewn sacks; Paper-PP = most often open-mouth sewn sacks (though valve/block-bottom styles are possible with advanced manufacturing).
- Filling Considerations: Multiwall paper valves allow very fast filling for powders; paper-PP bags in open-mouth format might fill slightly slower and need sewing. However, both can be adapted to modern filling lines.
- Feel and Appearance: Both have a paper outside that can be printed and provide a quality look. Multiwall sacks might feel entirely paper (because they are), whereas a laminated PP bag’s exterior is paper but the bag may feel slightly more pliable or fabric-like when handled empty, due to the woven inner layer.
Understanding these structural differences is crucial because structure drives performance, which we will explore next. A bag’s makeup determines how it behaves under stress, exposure, and in real-world use.
Performance Characteristics: Strength, Durability, and Protection
How do multiwall paper sacks compare to kraft laminated PP bags in terms of performance? This section examines the key performance characteristics that matter in industrial packaging: from tensile strength and tear resistance to moisture protection, printability, and handling. Each bag type has its own profile of advantages. Sometimes the differences are stark (e.g. wet strength), while in other aspects both perform admirably. Let’s break down the performance factors one by one:
Strength and Durability
When it comes to sheer strength, woven polypropylene is a powerhouse. As a result, kraft paper laminated PP bags have a higher overall strength threshold than multiwall paper sacks of comparable size:
- Tensile Strength: The woven plastic mesh inside the laminated PP bag provides extremely high tensile strength (the force required to pull the material apart). Woven tapes of PP can support significant loads without snapping. In practical terms, a woven PP bag can withstand rough handling – drops, throws, and pulls – better than an all-paper sack. Multiwall paper sacks, thanks to multiple layers, are certainly strong for paper, but paper fiber will tear or burst under lower forces compared to plastic tape. In quantitative terms, a multiwall paper sack might have tensile strength on the order of, say, 12–18 kN/m in the paper’s grain direction, whereas a comparable woven PP laminated bag might reach 25–35 kN/m. This roughly 2× higher tensile strength of the PP bag means it holds together under heavier weight and impact.
- Tear and Puncture Resistance: Woven PP bags are highly resistant to punctures. If something sharp presses into a paper-poly bag, the plastic weave tends to localize the damage (it’s like trying to poke through a net made of tough fibers). Multiwall paper sacks have decent puncture resistance because of layered paper – the object has to work through several plies – but once a tear starts in paper, it can propagate more easily. Paper tears can elongate, whereas plastic weave might stop a tear from spreading far by the fibers catching on each other. Bottom line: for sharp or irregularly shaped contents (think of jagged crystals, metal parts, or rough gravel), laminated PP bags are less likely to rip open. Multiwall bags can be fortified with more layers or stronger paper grades, but that adds bulk and cost, and still may not equal the rugged tear resistance of PP fabric.
- Burst Strength: Burst strength is the pressure at which the bag’s wall will rupture when pressure is applied from inside (imagine the force of dense powder or grain pressing outward). Multiwall sacks have a good burst resistance due to the multiple layers sharing the load, often around 15–25 psi in standardized tests for heavy paper bags. Kraft laminated PP bags, however, can achieve burst strengths in the range of 30–45 psi or more, thanks to that woven layer holding the material together. This means when a paper-poly bag is dropped from height, the sudden impact (which causes internal pressure spike) is less likely to burst the bag compared to a paper sack. In practice, a pallet of product in PP bags can often be stacked higher or dropped from a greater height without failure.
- Load Capacity and Weight of Contents: Both types of sacks are used for 20–50 kg (approximately 50–110 lb) packaging routinely. Multiwall paper sacks commonly handle 25 kg or 50 kg of product (for example, a 50 kg cement sack in some countries is still paper). Kraft laminated PP bags easily handle 50 kg and can even go beyond (some fertilizers are packed 50–70 kg in such bags, especially in regions where manual handling is less of a concern). If someone asked which bag to choose for extremely heavy contents (say, 75 kg of material), the safer bet would be the PP woven variety simply because of its higher safety factor. But up to standard weights like 50 kg, both can be engineered to suffice – it’s the other conditions (environment, handling) that often become deciding factors.
- Longevity and Reusability: Multiwall paper sacks are generally intended as single-use packaging – fill it, ship it, deliver the product, then the bag is discarded or recycled. They don’t usually survive reuse because paper will crease, tear or wear out after one cycle. Kraft paper laminated PP bags, on the other hand, have the potential for reuse. The plastic inner layer doesn’t degrade from folding the way paper might. In some cases, end-users emptying a product (like animal feed or seeds) might repurpose the empty laminated bags for secondary storage or tasks, since the bag remains quite sturdy. The woven plastic can last a long time; it’s similar to tarpaulin or sturdy fabric. So if reusability or secondary use matters, the paper-poly bag has an edge.
In summary for strength: Multiwall kraft sacks are very strong for a paper product and have served industries well for decades. However, kraft laminated PP bags take durability to the next level, outperforming paper in tensile, tear, and drop tests especially under harsh conditions. As we’ll see though, raw strength isn’t the only performance metric – environment and other factors play a big role too.
Moisture and Weather Resistance
One of the most critical differences between multiwall paper sacks and laminated PP sacks is how they handle moisture, humidity, and general weather exposure:
- Moisture Absorption: Kraft paper, being a wood-based fiber product, will absorb moisture from the environment. In a humid warehouse, a paper sack can slowly pick up moisture and become softer or weaker. Multiwall sacks often have specifications for moisture content – for example, a paper sack might reach equilibrium at around 8% moisture content by weight in 85% relative humidity air. This absorbed moisture slightly diminishes the paper’s strength and can cause the sack to lose its crisp shape. In contrast, polypropylene is hydrophobic – the woven PP core in a laminated bag does not absorb moisture at all. The outer kraft paper on a laminated bag is a thinner layer and also somewhat protected by the lamination – the plastic layer between the paper and fabric can act as a moisture barrier that prevents moisture from directly wicking through. As a result, a kraft laminated PP bag remains practically dry (nearly 0% moisture uptake in the PP layer, and the paper layer is shielded) even in high humidity. The paper outside might get slightly damp if directly exposed to moisture in air, but it’s far less than an all-paper sack would.
- Humidity and Product Sensitivity: Some products actually require a package that breathes. For example, certain seeds or agricultural commodities might be a bit damp when packed and need to release moisture, or they risk mold. Multiwall paper sacks excel here because paper is naturally breathable – it allows slow exchange of air and moisture. Think of a sack of raw peanuts or cocoa beans; the paper allows the commodity to “sweat” out moisture or breathe. Kraft laminated PP bags are much less breathable due to the lamination; they are nearly airtight except maybe at the sewing seams or micro-perforations if added. So if the product is moisture-sensitive in the sense that it releases moisture or gas (like freshly processed seeds, or certain chemical powders that release gas), a paper sack might be preferable to avoid accumulation of moisture inside. Conversely, if the product needs to be protected from external moisture (like cement, which must stay dry, or powdered milk, or certain chemicals that clump with water), the sealed nature of a laminated PP bag is a huge advantage.
- UV and Sunlight Exposure: Prolonged sunlight can degrade both paper and plastic, but plastic is typically more vulnerable to UV unless additives are used. Unprotected polypropylene will become brittle after long sun exposure (hundreds of hours). However, in laminated bags, the outer paper layer actually acts as a UV shield for the plastic beneath. Paper will yellow and weaken under sun over time as well, but paper doesn’t photodegrade as rapidly as untreated plastic. Still, neither bag is truly meant for multi-month sun exposure. In field tests, a multiwall paper sack left in direct sun and weather might fall apart within a few months (and is easily attacked by rain or dew as mentioned). A woven PP bag with UV stabilizers can last several months in the sun without losing too much strength, and with the paper lamination, it’s partially protected. VidePak addresses UV concerns by using UV-stabilized PP resins (from top suppliers like Sinopec and BASF) for the woven component, extending the life of our PP bags under sunlight. For paper sacks, we can incorporate special additives in the paper or coatings to improve moisture resistance a bit, but those measures are modest compared to the inherent water-shedding ability of plastic.
- Temperature and Chemical Resistance: Polypropylene woven bags can handle a wide range of temperatures – they remain stable in freezing cold and up to moderately high temperatures (the plastic softens around 130°C, which is far above any condition a filled bag would face normally). Kraft paper sacks can char or burn at high heat and can weaken in very high humidity heat (like steam). For chemicals: if packing something with slight chemical volatility or oils, note that paper can absorb oils and get stained or weakened, whereas PP is chemically inert to most substances (except strong oxidizers). For example, some fertilizer formulations or minerals might be fine in either, but if there are any oily additives, a plastic layer ensures no seepage through the bag.
To sum up moisture/weather performance: Multiwall paper sacks offer breathability and are fine in dry, controlled conditions, but they are vulnerable to water and high humidity. Kraft paper laminated PP bags provide far superior moisture barrier and weather resistance, making them ideal for harsher supply chains or outdoor exposure. The choice often boils down to the environment the bag will encounter and whether you need the bag to “keep moisture out” or “let moisture out.”
Handling, Stackability, and Logistics
Both types of sacks are designed for practical handling, but there are some differences in how they perform in filling lines, stacking on pallets, and general logistics:
- Filling Speed and Dust Control: Multiwall paper valve bags have a notable advantage for high-speed filling of powders (like cement, flour, etc.). The valve design allows a packer to just push the bag onto a filling spout and the product flows in quickly, then the valve closes. This makes filling extremely efficient and relatively dust-free. Woven PP bags historically were mostly open-mouth, requiring a bit slower filling and manual or machine stitching – a process that can release more dust if not carefully managed (because the top is open while filling). However, modern advancements mean paper laminated PP bags can also be made with valve spouts (using block-bottom technology). VidePak’s capabilities include producing valve style woven bags, so we can supply bags that run on clients’ existing valve bag filling machines but deliver the benefits of PP strength. For open-mouth formats, both paper and PP bags can be used on automatic fillers; multiwall paper bags might need careful handling to avoid ripping on high-speed equipment (paper can tear on a misfeed, whereas PP fabric can handle rougher treatment by the filler’s bag graspers). Overall, each type can be optimized for efficient filling, but if a customer already has an infrastructure for valve paper bags, we can provide an equivalent in PP woven to drop-in, or supply high-quality multiwall valves if they prefer to stick with paper.
- Stacking and Shape: Once filled, a multiwall paper sack tends to have a more rigid, brick-like shape, especially if it’s a pasted block-bottom style. Paper’s stiffness means the bag holds its rectangular form, which stacks very neatly on pallets. That’s one reason paper sacks have been popular – they create stable pallet loads with clean edges. Kraft laminated PP bags, with a woven inner, are a bit more flexible; they might bulge or deform slightly more when filled because the plastic fabric can stretch a little. However, the outer paper lamination imparts some stiffness and shape retention, so these composite bags actually stack quite well too – much better than a plain woven poly bag without any lamination (which can be very slouchy). If the laminated PP bag is made in a block-bottom format, it will mimic the square shape of a paper sack and stack just as nicely. VidePak’s paper-poly bags can include features like gussets and block bottoms to ensure they palletize efficiently. Additionally, we can apply anti-slip coatings or textures to the bag surface (common on PP bags) so that they don’t slide on each other during stacking. Paper has a naturally high friction surface, which is good for stack stability; smooth plastic can be slippery, but since our PP bags have a paper outer or optional anti-slip treatment, both types remain secure in a pile.
- Ease of Handling & Ergonomics: Filled multiwall paper sacks have a somewhat rigid, square form that can be easier to grab from the sides. However, if they are very stiff, they might not “nestle” against a carrier’s body – think of a very boxy 25kg paper sack of flour, it’s secure but not very conforming when carried. A woven PP sack (especially if not block-bottom) tends to be a bit more conforming to the contents, which can make it slightly easier for individuals to shoulder-carry or grab from underneath. In many cases though, both types are similar, and handling aids (like sewn-on handles or hand holes) can be provided on either type if needed for smaller bag sizes. For instance, VidePak can add die-cut handles in the paper lamination of a 10kg or 20kg paper-poly bag to make it easier to lift, something less commonly done with multiwall paper bags (which would tear if holes were cut without reinforcement).
Printability and Aesthetics
Packaging isn’t just about function – it’s also a brand billboard. Both multiwall paper sacks and kraft laminated PP bags offer good surfaces for printing logos, product information, and marketing graphics, but there are some differences in print quality and options:
- Printing on Multiwall Paper: Paper is an excellent print medium. Multiwall sacks often use flexographic printing directly on the outer paper layer (before or after the bag is formed). The print can be quite detailed – multiwall sacks commonly achieve up to 6 or 8 colors in a design, with decent resolution. The paper surface can accept fine linework and smaller text clearly. For premium applications, some manufacturers even use offset printing on paper (printing on flat sheets with very high resolution, then converting those into bags). This is rare for mass production but shows that paper can achieve near magazine-quality imagery if needed. The natural matte finish of kraft paper also gives a quality, rustic look that some brands prefer (for example, organic product companies often like the brown paper look). VidePak’s paper sack production includes high-quality printing capabilities – we use water-based inks that are eco-friendly and still vibrant on paper. So, multiwall sacks shine in delivering sharp, colorful, and large branding on all faces of the bag.
- Printing on Kraft Laminated PP: When you laminate kraft paper onto PP, the outermost surface is still kraft paper, so in terms of printing, it’s actually quite similar to printing on a regular paper sack. We can use flexographic printing on the paper lamination with multi-color designs. The difference might come in the texture: the laminated paper is supported by the woven structure, so it might not be as perfectly smooth as a standalone paper sheet – the very faint impression of the weave can sometimes impart a slight texture. However, generally the lamination film smooths that out, and print results are comparable. It’s possible to achieve up to 4–6 colors with crisp logos and text on paper-poly bags. If extremely high-resolution imagery or gloss is desired, an alternative would be BOPP film laminated woven bags (which use a printed plastic film on the outside instead of paper). But since we’re focusing on kraft paper laminated bags, we’ll note that these usually have a more matte, natural look (coming from the paper) rather than the high-gloss photographic look of BOPP film bags. Many clients choose the paper lamination specifically because they want a premium, traditional appearance but with modern strength. For instance, a pet food brand might prefer the rustic paper feel to appeal to consumers, even though underneath it’s a strong plastic bag – in such cases, the printing quality on the paper lam will meet their branding needs, just as it would on an all-paper bag.
- Graphic Durability: One thing to consider is scuff and abrasion. Paper graphics can scuff if bags rub against each other in transit. Multiwall bags might lose some ink on edges if roughly handled; we mitigate this by using high-quality inks and coatings. Laminated PP bags have an advantage that the ink is actually on the paper which is bonded to plastic – it doesn’t necessarily make the ink more durable by itself, but the bag’s higher tear resistance means less fraying or tearing at printed surfaces. Also, if desired, we can apply a thin transparent coating over the printed paper during lamination for added rub resistance (like a protective layer). In many cases, though, both bag types hold print well enough through typical logistics without significant issue.
- Aesthetic Options: Multiwall paper sacks usually have a natural brown or white look. The entire bag can be one base color (brown kraft is common) and then printing adds design. Kraft laminated PP bags can similarly use brown or white paper as the outer – giving either a rustic look or a clean white canvas. Because the paper is laminated, you also have the option to use bleached white kraft with full-color printing to make very vibrant designs. One could argue that laminated bags present the product as a bit more “premium” because the material feels high-tech, but visually to an end customer, they might not even realize it’s a composite – it often just looks like a sturdy paper bag with printing. Both types can incorporate design features like glossy highlights (by spot UV or varnish on paper) or window patches (a plastic window in a paper sack, though that breaks the full paper recyclability) or unique textures. However, complex decorative effects are more commonly done on consumer retail bags; for industrial sacks, function tends to trump fancy finishes. Still, VidePak works with clients to ensure their branding is showcased effectively on whichever bag type they choose – we routinely print batch numbers, barcodes, and vibrant logos on both multiwall and paper-PP bags as required.
Environmental Considerations
In today’s world, no performance review is complete without considering sustainability and environmental impact, as this can be a “performance” factor in the eyes of many customers and regulators:
- Recyclability: Multiwall kraft paper sacks are made primarily of paper, which is easily recyclable in paper recycling streams (as long as they aren’t contaminated with product residue or heavily laminated with plastic). If they have a plastic liner, that liner is usually easily separable by the recycler or during the pulping process the plastic can be skimmed off. So multiwall sacks are often seen as environmentally friendly packaging. They also can biodegrade over time if accidentally released into the environment (though adhesives and any liner will not biodegrade as easily). Kraft paper is a renewable resource from trees, and many paper sacks incorporate some percentage of recycled fiber as well.
Kraft paper laminated PP bags are a mixed material, which poses a bit of a challenge for recycling. The paper is bonded to plastic, so traditional recycling would require separating the two. In some recycling processes, it’s possible: one can shred the bags and use water to float off fibers and recover plastic, but it’s not as straightforward as recycling pure paper or pure plastic. That said, the woven PP part is recyclable as polypropylene plastic, and the paper is recyclable as fiber – it’s just the separation step. Some end-users may strip the paper off and recycle components separately, but most likely these bags end up in either plastic recycling (if that’s available) or general waste if no suitable route exists. The advantage is that the PP woven bag can be reused multiple times, potentially giving it a longer life before disposal. And if incinerated for energy recovery, it has a high calorific value (like other plastics) while paper has lower.
- Resource Footprint: The production of multiwall paper involves forestry and paper mills, which consume water and energy but are based on renewable wood (when sourced responsibly). PP plastic comes from petroleum or natural gas feedstock (unless bio-based PP is used), which is non-renewable, but the manufacturing of plastic bags is very efficient with little waste. In terms of weight, as mentioned, PP bags use less material weight for the same strength, so one could argue fewer resources per bag in that sense. An environmental life-cycle assessment might show trade-offs: paper sacks often have a higher carbon footprint in production per bag due to heavier weight and water use, but plastic sacks have issues at end-of-life and are fossil-based. It really depends on what aspect of environment one prioritizes (emissions, biodegradability, etc.). Many companies now seek sustainable packaging, and interestingly, some view the composite paper-poly bag as a compromise: it uses less plastic than a full plastic sack and still gives better performance, potentially reducing product waste (spillage) which is an environmental benefit too.
- Compliance and Regulations: In some regions, there’s a push for reducing plastic usage. While this mostly targets single-use shopping bags and not industrial sacks, a company might prefer paper packaging to meet a marketing goal of “plastic-free packaging.” Multiwall paper sacks obviously meet that (if no liner), making them attractive for certain eco-conscious brands or customers. On the other hand, the durability of plastic sacks can reduce product loss and food waste (for food products, a burst bag spilling food that gets wasted is also an environmental loss). So both have their narratives in sustainability. VidePak is committed to sustainable practices whichever bag type a client chooses – we source paper from responsibly managed forests and use recyclable plastics, and we’re also exploring innovations like biodegradable plastics and recycled content in our PP fabrics to reduce environmental impact.
In summary of performance: Multiwall kraft paper sacks excel in providing a sustainable image, breathability, and stable stacking for many dry products under benign conditions. Kraft paper laminated PP bags offer superior strength, tear resistance, and moisture protection for demanding conditions, while still providing a paper-like appearance. There is no outright “winner” – the best choice depends on the priorities: Is maximum durability the goal? Is moisture a factor? Is sustainability or tradition a key concern? These questions lead us to consider the specific applications each type is best suited for.
Application Suitability: Choosing the Right Bag for Your Product
Different industries and products have unique packaging requirements. One type of bag may be more suitable than the other depending on what is being packed, how it’s shipped, and the conditions it faces. In this section, we’ll explore where multiwall paper sacks shine and where kraft paper laminated PP bags are the preferred solution. By understanding application-specific needs, you can determine which bag type is the optimal choice for your business.
Food and Agriculture
- Flour, Sugar, and Food Ingredients: Multiwall kraft paper sacks have a long history in food packaging. Dry foods like flour, sugar, starches, and baking mixes are often packed in multiwall paper bags (typically 2-4 layers, sometimes with a thin inner layer for grease resistance if needed). These products benefit from paper’s breathability – for instance, flour can expel residual air as the sacks are palletized, reducing the risk of bursting. Paper is also generally approved and accepted for food contact, and it doesn’t have static issues (fine powders and plastic can create static cling, whereas paper dissipates static, making filling less messy). Many flour mills and sugar processors in North America and Europe still use paper sacks for 25kg and 50kg bags. Kraft laminated PP bags are used in food as well, especially when higher strength is needed. For example, large rice sacks (25–50 kg) in Asia are often woven PP with either a simple coating or paper lamination for branding. If a sugar exporter needs the bags to survive long sea transport in humid conditions, they might opt for laminated PP bags to avoid any breakage or caking from moisture ingress. VidePak supplies both types to the food industry, and we ensure all materials are food-grade (our inks and adhesives comply with food packaging regulations). We often advise: for powdery foods processed in clean, dry facilities going to market relatively quickly, multiwall paper sacks are usually sufficient and are attractive for marketing (e.g., a high-end flour with a rustic paper package). But for bulk agricultural commodities that face harsher logistics – say a 50kg bag of rice or grain shipped overseas – the laminated PP bag offers extra insurance against tears and moisture.
- Animal Feed and Pet Food: Animal nutrition products can range from dry, powdery feed supplements to oily pet foods (kibble) or birdseed. Multiwall paper sacks are commonly used for animal feed – they allow the feed to breathe (important if feed pellets or seeds have any residual moisture that could cause condensation). Also, feed mills often have sewing lines for paper bags that are time-tested. However, heavy feed bags are prone to rough handling (farmers throwing them around, stacking in barns where it might be damp). So we see a strong trend toward paper-poly woven bags in pet food and livestock feed. The laminated PP bags can handle 20–25kg dog food or horse feed without tearing, even if dropped. The outer paper gives a nice canvas for branding (pet food often has full-color graphics to appeal to consumers), and the inner PP means a burst-proof bag even if mishandled. For moisture-sensitive feed, one can include an inner PE liner in a paper sack, but then you’ve essentially got a hybrid anyway. One particular example: premium dog food brands often switched from pure paper bags (which sometimes would tear or fail if the product was oily or heavy) to woven bags with either paper or BOPP film lamination, drastically reducing complaints of bag breakage in stores. VidePak has the capability to provide pet food bags with valve-style filling as well, which some producers use to minimize oxygen exposure (though that’s more common with BOPP laminated bags with valve). In summary, for feed and pet food: if your distribution is local and controlled, paper sacks can work and send a message of natural packaging; but if you need absolute strength or your product has high oil content (which weakens paper), laminated PP is a safer bet.
- Seeds and Agricultural Inputs: Seeds (for planting) are an interesting case. They often need to breathe to avoid mold, and they are high value, so packaging quality is paramount. Many seed companies use multiwall paper bags with special liners that allow some air exchange but keep moisture moderate. Paper sacks are traditional for seeds and even for fertilizers in some regions (particularly lawn and garden products sold retail in paper for nicer appearance). However, large bulk seeds (like soybeans, corn seed in 25kg sacks) in international trade sometimes use woven bags due to strength needed during export. Fertilizer is a product that absolutely cannot get wet (or it clumps) – for large agricultural or industrial fertilizer (like 50kg bags of urea, ammonium nitrate, etc.), the industry standard has shifted heavily toward woven PP bags (often with just a lamination or coating, not always kraft paper laminated, sometimes just plastic). Fertilizer bags need to survive stacking high and sometimes outdoor storage at ports. A kraft paper bag wouldn’t hold up in those conditions unless fully protected, so the laminated PP bag is the typical choice for heavy fertilizers. There are exceptions for specialty fertilizers or garden products where appearance matters – those might still come in paper sacks because they’ll be kept in a store or shed (e.g., a 10kg garden fertilizer sold at retail might use a laminated paper bag with bright printing to look consumer-friendly). VidePak caters to both: we can provide moisture-barrier multiwall bags for certain fertilizer products (including a PE coating on the paper or an inner liner), but for maximum durability in bulk fertilizers, our kraft laminated PP sacks are recommended, potentially with an inner lining for 100% waterproofing.
Building Materials and Industrial Powders
- Cement, Mortar, Concrete Mix: This category really illustrates the paper vs. plastic debate. For decades, cement was packed in multiwall paper sacks (usually 3-4 plies with a valve). Paper had the advantage of being cheap, stackable, and the sacks would disintegrate when thrown into the concrete mixer (some construction crews liked that you could toss a paper bag into a mix and it would break up). However, paper cement bags had high wastage – they could burst in handling, and if they got wet at all, the cement could be ruined. In recent years, many cement manufacturers worldwide have shifted to woven polypropylene bags (some with paper lamination, many with just coated PP or BOPP film). These PP bags virtually eliminate breakage losses – a woven PP cement bag can survive being dropped from a truck or manhandled on site much better. The cost can be comparable or even lower in bulk. The trade-off: plastic bags don’t tear apart in mixers as readily (some specially designed ones do, like very thin film bags). Also, disposal of plastic bags at construction sites became an issue in some regions. There’s still a split: some markets, like parts of Europe, still use a lot of paper cement sacks (partly for tradition and recycling ease), while others, like many Asian countries, use PP sacks for cement (for durability and cost). VidePak actually produces both types, but for clients aiming to reduce product loss and improve shelf life (cement can absorb moisture from the air through paper over time), we often recommend our laminated PP cement bags. These can be done in valve form – using our Starlinger equipment, we produce block-bottom PP bags (often known by the trade name ADStar type in the industry) which behave like paper valve sacks on filling machines. They give the best of both worlds: quick filling, stackable brick shape, and water/tear resistance. Meanwhile, we continue to supply multiwall paper cement sacks for clients who require them, ensuring they are produced to high burst strength standards. In building materials* like dry mortar, gypsum, stucco mix, etc., the considerations are similar to cement. If the usage environment is mostly indoor and turnover is quick, paper sacks work. If the product might be stored or exported, PP sacks prevent damage.
- Chemicals and Minerals: A wide range of industrial chemicals (e.g., plastic resin pellets, minerals like carbon black, titanium dioxide, salt, etc.) and pharmaceutical raw materials are shipped in 25kg or 50kg sacks. Multiwall paper sacks are commonly used for many chemicals, especially if they are fine powders and require a very clean packaging (paper doesn’t shed fibers significantly and can be made with food-grade paper for pharma). Also, for oxidizing chemicals (like certain nitrates), paper is safer because plastic can build static that could ignite some sensitive contents – though that’s a rare scenario. Kraft laminated PP bags are used for chemicals that are heavy or need extra protection. For example, a client shipping 50kg of a dense mineral powder internationally might choose laminated woven bags to avoid any breaks (even if historically they used paper and had say 1% bag breakage, switching to PP could nearly eliminate that). Another example: plastic raw material pellets (like PP or PE pellets) are often packaged in laminated PP bags or even fully plastic bags (since it’s their own product, they trust plastic). Paper sacks could also carry pellets, but pellets are heavy and smooth – they can exert pressure and slip, so many resin producers prefer woven bags that won’t tear and can be made anti-slip. Fertilizers and chemicals that are hygroscopic (absorb moisture readily) absolutely need plastic barrier – we’ve seen cases where a multiwall paper bag, even with a liner, let slight moisture in over a long transit and the product caked; switching to a laminated woven bag solved the issue. So for chemicals, the rule of thumb: if the product is stable and not sensitive, and if packaging disposal or regulatory acceptance of paper is easier, paper sacks are fine. If the product is heavy, abrasive, or moisture-sensitive, or if shipping losses have been an issue, consider the PP laminated sacks. VidePak’s technical team often consults with chemical customers to determine the right sack – for instance, we might run a trial where we pack a chemical powder in both bag types and stack them in a humid warehouse for a month, observing any clumping or bag integrity issues. This kind of thorough approach ensures the chosen packaging is truly fit for purpose.
- Other Industrial Uses: There are miscellaneous uses like charcoal or wood pellets for fuel (often packed in paper bags for retail 5-10kg, but for larger 20kg wholesale, PP bags are common because charcoal can poke through paper). Metal parts or hardware (sometimes nails or bolts are packed in 25kg bags): paper can tear from sharp edges, so woven bags are safer. Textiles or recycled materials: sometimes rags or fibers are shipped in sacks – usually woven PP because it’s cheaper and strong. Essentially, for any application where bag breakage costs are high (either financially or safety-wise), the trend is toward the more robust woven PP solution. Where marketing, cleanliness or tradition matter more (like food or specialty products), paper retains a strong position.
Commercial and Retail Considerations
- Brand Image and Customer Expectations: If your product will be seen by end consumers (even in a wholesale environment like a feed store or home improvement store), the packaging contributes to perceived quality. Paper sacks give a natural, eco-friendly impression. Some customers intuitively feel that if a product is in a paper bag, it’s more traditional or “organic” (consider animal feed or organic fertilizer marketed with green messaging – often in paper). On the other hand, a paper-laminated PP bag can look just like a paper bag to the customer, so you don’t necessarily lose that image. In fact, because it generally stays intact better, the customer sees a clean, undamaged package on the shelf. With increasing focus on sustainability, VidePak also emphasizes that we source kraft paper from sustainably managed forests and we can offer recyclable or even compostable paper options for clients who want the most environmentally friendly sack. For the PP bags, we are exploring using recycled plastic where possible, and even biodegradable additives, but those are evolving areas. The key is, if a brand identity is tied to 100% paper packaging, then multiwall sacks are non-negotiable. If the brand is okay with a composite (especially since it’s hidden, consumers might not know), then it can get the durability benefits without altering brand perception.
- Regulatory or Contractual Requirements: Certain procurement contracts or regulations might specify packaging type. For example, a government tender for grain supply might require packaging in jute or paper sacks (in some countries, to support domestic jute industry or for easier recycling). Or an organic certification might prefer no plastic in contact (though if plastic liners are allowed for function, that gets complicated). Conversely, some contracts might demand a packaging with a certain minimum strength or reuse capability, pushing towards PP. VidePak is familiar with international standards (such as ASTM, ISO, and others) that sometimes come into play in these requirements. For instance, an ASTM standard might specify the drop test a bag must survive. We ensure both our paper and paper-PP bags are tested to those standards. If a paper bag can’t meet a spec, we’ll know and might recommend the PP bag. We keep up with things like ASTM D6400 (compostability) or ISO 21898 (sacks for transport of foodstuffs) etc., depending on client concerns.
- Cost Considerations: While not exactly a performance trait, cost often drives application choices. Generally, woven polypropylene bags are very cost-effective in high volumes. Plastic materials (especially when sourced from giants like Sinopec or BASF in bulk) tend to be cheaper per unit strength than high-grade kraft paper. Multiwall paper sacks have more raw material mass per bag and involve multiple steps (multiple plies to assemble). So at large scale, a shift to woven bags can save money. However, if a company already has an optimized setup for paper sacks (and a supply chain for them), and if losses are low, the difference might be marginal. Sometimes it’s the hidden costs – a few extra bag breakages, or slower filling speed – that make paper actually more expensive overall in an application where plastic would eliminate those inefficiencies. Each case is unique, but VidePak’s position as a supplier of both types puts us in a neutral stance to advise on cost-performance trade-offs. We have clients using both in parallel for different product lines because one product just “works” better in paper and another needs the PP. Cost should be weighed alongside all the performance factors above.
Conclusion: VidePak – Your Partner in Packaging Excellence
Tradition meets innovation in the realm of industrial packaging, and VidePak stands proudly at that intersection. On one hand, we offer time-tested multiwall kraft paper sacks – born from nature’s fibers, exuding a sustainable appeal, and perfected through decades of use. On the other, we provide cutting-edge kraft paper laminated PP bags – a fusion of paper’s print-friendly charm with polypropylene’s unyielding strength, symbolizing modern solution engineering. This comprehensive comparison has shown that each type of bag has its unique strengths and ideal uses. But no matter which you choose, one thing is constant: VidePak’s commitment to quality and customer success.
We emphasize that VidePak is not just a manufacturer, but a key supplier and partner for businesses across construction, agriculture, food, chemicals, and more. Our ability to supply both packaging types means we deliver unbiased expertise – we help you select the right packaging for your product rather than pushing a one-size-fits-all solution. Whether it’s the eco-friendly recyclability of a paper sack or the rugged durability of a paper-poly bag, VidePak has mastered them all. We source materials from the world’s best, operate the finest machinery from Starlinger and W&H, adhere to global standards like ASTM and ISO for each bag we produce, and maintain a rigorous quality assurance process that ensures every bag leaving our facility is ready to perform.
In the end, the choice between multiwall kraft paper sacks and kraft paper laminated PP bags comes down to your specific needs – and we hope this article has equipped you with the technical and practical insights to make that decision with confidence. Why not have the best of both worlds? With VidePak, you have access to the full spectrum of heavy-duty packaging solutions, all under one roof. Our fully equipped production facility (600 million pieces annual capacity) is at your service to deliver on both large-scale volume and specialized requirements. And our team stands behind the products with end-to-end support, from initial consultation and custom design to on-time delivery and after-sales service.
In a world of challenging supply chains and high customer expectations, having a reliable packaging partner is invaluable. VidePak delivers reliability – in the bags we make and the promises we keep. We look forward to supporting your business with packaging that protects your products, builds your brand, and contributes to your success. When it comes to multiwall paper sacks and paper laminated PP bags, you can trust VidePak’s deep technical know-how and unwavering quality focus to provide solutions that truly are “best in class.”