Tel:86-0750-6228802
Fax:86-0750-6228277
Mobile Phone:+8617718861990
Email:yingtong@yingtongpack.com
Address:Xinsha Industry, Muzhou Town, Xinhui District, Jiangmen, Guangdong Country Region China
In industrial and agricultural packaging, the choice of bag material is critical. Multi-ply kraft bags with PE liner merge the strength of kraft paper with the moisture resistance of a polyethylene inner layer. These bags are widely used in sectors like cement, chemicals, food ingredients, minerals, feed, and more. In this article, we will explore their structure, advantages, applications, design considerations, and tips for selecting a supplier.
A multi-ply kraft bag with PE liner is a composite packaging bag made by combining layers (plies) of kraft paper, with an inner polyethylene (PE) film or liner adhered between or inside the plies. The basic components are:
Kraft paper plies: Kraft paper (often brown) provides mechanical strength, rigidity, and puncture resistance. A bag may be 2-ply, 3-ply, or even more.
PE liner: A thin polyethylene sheet or film layer inserted inside to act as a moisture, water vapor, or chemical barrier.
Adhesive or lamination: Between layers, adhesives or lamination techniques bond the PE liner to the paper plies for structural integrity.
Thus, the final bag is a hybrid: the kraft layers give tensile strength, while the PE liner protects contents from moisture, humidity, or leakage.
The PE liner offers an inner shield against moisture ingress and leakage, which is essential when packaging hygroscopic or moisture-sensitive materials. It helps keep contents dry even in humid or rainy environments.
Multiple kraft paper plies provide high burst strength, puncture resistance, and stacking capability. The bag can sustain mechanical stress during filling, transport, handling, and storage.
Compared to full plastic (film) bags, kraft + PE hybrid bags can be more economical while still offering sufficient barrier. They also reduce plastic usage compared to fully plastic laminated bags.
By adjusting the number of plies, paper basis weight, liner gauge (thickness) of PE film, and internal coatings, manufacturers can tailor the bag to specific products — such as cement, powders, granular chemicals, food ingredients, or animal feed.
The outer kraft layers accept printing, logos, product names, barcodes, and handling instructions, making them well suited for branding and information display.
Here are some common construction styles:
2-ply with PE liner: Two kraft paper layers with a single PE liner either between them or on the inner face. Sufficient for lighter, less demanding materials.
3-ply with PE liner: Three kraft layers with one or more liners—this is a common choice for medium to heavy duty packaging.
4-ply or more: For high strength and large bag sizes, multiple layers plus liner ensure extra durability.
Valve style / bottom gusset style: Some bags are valve-filled (filled through a valve) while others are open mouth, flat bottom, or square bottom depending on application.
Liner up to two layers: In some designs, dual liner films (two PE layers) are inserted for extra protection against leak, chemical fumes, or volatile content.
On YINGTONG’s product pages, you can see examples such as 3-Ply Bags with PE liner and 4-ply kraft bags with PE liner offered for various industrial usages.
Multi-ply kraft bags with PE liner find wide use in industries where both strength and moisture protection are critical. Common applications include:
Cement and construction materials: Cement, mortar blends, gypsum, and related powders benefit from moisture barrier and stacking strength.
Chemicals and minerals: Dry chemicals, pigments, carbon black, minerals, metal powders.
Feed, grain, and food ingredients: Some foodstuffs (e.g. flour, milk powder, starch) or feed materials when strict barrier and protection are required.
Fertilizers: Dry fertilizers or blends, often needing protection from humidity.
Additives, catalysts, and industrial powders: Fine powders prone to moisture absorption.
These bags help maintain product quality, reduce spoilage, and ensure safe transport through supply chains.
When selecting or designing multi-ply kraft bags with PE liner, consider the following:
| Parameter | Impact / Concern |
|---|---|
| Ply count & paper basis weight | Higher ply or stronger paper gives more mechanical strength and stacking support. |
| PE liner thickness (microns or gauge) | Thicker liner gives better barrier, lower risk of pinholes or leaks. |
| Adhesion / bonding method | Ensures liner and paper layers stay intact during stress (vibration, bending). |
| Bag style | Valve, open mouth, flat bottom, gusseted, side seam, square bottom, etc. |
| Sealing method | Heat sealing, adhesive sealing, ultrasonic, or sewing plus flap. |
| Printing / coatings | Water-based inks, barrier coatings, anti-slip coatings on exterior. |
| Moisture / puncture / tear resistance | Choose materials to resist tearing or puncture in rugged handling. |
| Regulatory / food contact compliance (if applicable) | For food / feed use, liner films must comply with food safety rules. |
Balance of strength, barrier, and cost is key. Overdesigning may raise cost; underdesigning leads to product damage or failure.
When sourcing multi-ply kraft bags with PE liner, evaluate suppliers on several fronts:
Production capacity & experience Look for companies with professional manufacturing lines, experience in industrial packaging, and stable output.
Quality control & testing Supplier should test burst strength, tensile strength, moisture barrier, liner integrity, seam strength, etc.
Customization ability They should support custom sizes, ply counts, printing, liners, bag styles as per your product needs.
Certifications & compliance For food or feed packaging, check whether liner materials are food-grade and whether necessary certifications are met.
Logistics & delivery reliability Good suppliers have efficient logistics, timely delivery, and packaging for export/shipping.
Cost transparency Understand cost breakdown: raw materials, liner, lamination, printing, finishing, freight.
One such experienced packaging enterprise is YINGTONG (Guangdong Yingtong Paper Co., Ltd.). YINGTONG focuses on cement paper bags, PE-lined kraft paper bags, and related packaging. Their product catalog includes 2-ply, 3-ply, 4-ply kraft bags with PE liner, and they promote integrity, quality and green development in packaging solutions. You might explore their offerings if you need an experienced producer for multi-ply kraft bags.
Delamination: Poor bonding of liner to kraft paper may cause layer separation under stress. Solution: choose adhesives and lamination techniques suitable for your materials and ensure quality control.
Pinhole or leakage: Thin liners or flawed liners can develop holes. Use sufficiently thick PE film and inspect before assembly.
Dusting / Powder migration: For fine powders, micropores or seams might allow fine dust escape. Use tighter sealing, proper liner overlap, and quality seam design.
Moisture condensation inside: Rapid temperature or humidity change may cause condensation. Venting designs or desiccant inside may help.
Printing issues: Printing on kraft surfaces can smear or flake. Use suitable inks and surface treatments.
Multi-ply kraft bags with PE liner combine the mechanical strength of kraft paper with the moisture barrier of polyethylene, making them ideal for cement, chemicals, feed, minerals, and other sensitive materials. Their flexibility in design (ply count, liner thickness, bag type) allows tailoring to a broad variety of products. When choosing a supplier, emphasize quality controls, customization ability, compliance, and reliable delivery. YINGTONG is one such supplier that offers multi-ply kraft paper bags with PE liners, with experience in the cement and industrial packaging space.
WhatsApp:
Phone:
Contact Now