Liner Inserted BOPP Bags
Liner Inserted BOPP Bags are high-strength woven polypropylene sacks laminated with reverse-printed BOPP film and fitted with an internal polyethylene (PE) or polypropylene (PP) liner. The inner liner provides an additional layer of protection against moisture, oxygen, dust, and contamination, making these bags ideal for hygroscopic, fine-powder, or sensitive products such as sugar, salt, flour, chemicals, and pharmaceutical ingredients where product purity and extended shelf life are critical.
Liner Inserted BOPP Bags — also known as BOPP bags with inner liner, laminated woven bags with liner, or duplex/triplex BOPP bags — represent the highest level of product protection in woven polypropylene packaging. These bags combine the structural strength of woven PP fabric, the high-definition branding of BOPP lamination, and the barrier performance of an internal plastic liner.
Why Use a Liner?
Standard BOPP bags, while offering good moisture resistance from the lamination, are not completely hermetic. Woven fabric, by its nature, has microscopic gaps between the polypropylene tapes. For products that are:
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Hygroscopic (absorb moisture from air — sugar, salt, flour, chemicals)
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Fine powders (can leak through woven gaps — cement, detergent, spice powders)
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Sensitive to contamination (food ingredients, pharmaceuticals)
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Requiring extended shelf life (premium rice, pulses, seeds)
...a liner is essential. The inner liner creates a complete, continuous barrier that seals the product away from external elements.
How Liner Inserted BOPP Bags Are Constructed:
The manufacturing process involves several precision stages:
| Stage | Process | Details |
|---|---|---|
| 1. Woven Fabric Production | Circular or flat weaving | Polypropylene tapes woven into high-density fabric (65–120 GSM based on load: 5kg–50kg) |
| 2. BOPP Lamination | Adhesive lamination | Reverse-printed BOPP film (up to 10 colors) bonded to woven fabric |
| 3. Liner Extrusion/Insertion | Co-extrusion or pre-made insertion | PE/PP liner is either co-extruded directly onto the inner surface or inserted as a separate pre-made bag |
| 4. Liner Fixing | Heat sealing or loose insertion | Liner can be spot-sealed to the outer bag at the top or bottom, or left loose |
| 5. Bag Formation | Cutting, folding, stitching | Bags cut to size, bottom stitched or heat-sealed (liner sealed simultaneously) |
| 6. Quality Inspection | 100% testing | Liner integrity, seal strength, moisture barrier testing |
Liner Types and Configurations:
| Liner Type | Description | Best For |
|---|---|---|
| Loose Liner (Detachable) | Separate liner bag placed inside the woven BOPP bag. Not attached to outer bag. Can be removed after opening. | Products where the outer bag may be reused separately (e.g., pet food, rice). Most economical liner option. |
| Spot-Sealed Liner | Liner heat-sealed to the outer BOPP bag at 2-4 points (usually top or bottom). Prevents liner from slipping or bunching during filling. | Automated filling lines, fine powders, consistent filling operations. |
| Fully Sealed Liner | Liner completely heat-sealed to the outer bag along the entire top and bottom circumference. Creates a unified bag-liner structure. | High-barrier requirements, liquid/semi-liquid products, hazardous materials. |
| Co-Extruded Liner (Triplex) | Liner is extruded directly onto the inner surface of the woven fabric during lamination. Integral, non-removable liner. | Premium products, maximum protection, export-grade packaging. |
| Aluminum Foil Liner | Metalized or foil laminate liner (instead of clear PE/PP). Offers ultra-high oxygen and moisture barrier (OTR <0.05). | Oxygen-sensitive products: coffee, nuts, spices, pharmaceuticals. |
Types of Liner Inserted BOPP Bags
| Type | Short Form Content |
|---|---|
| Loose Liner BOPP Bag | Separate PE/PP liner bag inside woven BOPP bag. Not attached. Removable by end user. Most economical. Best for sugar, salt, rice, cement (5kg–50kg). Outer bag can be reused. |
| Spot-Sealed Liner BOPP Bag | Liner heat-sealed to outer bag at 2-4 points. Prevents liner bunching during filling. Ideal for flour, detergent powder, pet food (5kg–25kg). Compatible with high-speed filling lines. |
| Fully Sealed Liner BOPP Bag | Liner completely heat-sealed to outer bag along full top and bottom. Creates unified structure. Best for fine powders, semi-liquids, pastes (1kg–25kg). Maximum leak protection. |
| Co-Extruded (Triplex) Liner BOPP Bag | Liner extruded directly onto inner fabric surface. Integral, non-removable. Premium option for coffee, spices, pharmaceuticals (500g–10kg). Highest barrier performance. |
| Metalized Liner BOPP Bag | Features metalized PE or aluminum foil laminate liner. Ultra-high oxygen & moisture barrier (OTR <0.05). Essential for coffee, nuts, spices, premium pet food (500g–5kg). Extends shelf life. |
| Valve Liner BOPP Bag | Side gusseted BOPP bag with filling valve plus internal liner. Designed for automatic high-speed filling of powders (cement, flour, chemicals). Valve self-seals (25kg–50kg). |
| Printed Liner BOPP Bag | Inner liner features custom printing. Visible when outer bag is opened. Used for premium products where unboxing experience matters. Coordinated branding on outer bag and liner. |
| Anti-Static Liner BOPP Bag | Liner made from anti-static PE/PP. Prevents static charge buildup. Used for electronic components, explosive powders, fine chemicals (10kg–25kg). |
Giriraj Flexipack is always known for its specialties in the industry. In terms of Liner Inserted BOPP Bags also, we are way ahead of others. With 5 automatic pouch making machines and dedicated liner insertion lines, we deliver unmatched product protection, moisture barrier performance, and customization from our Delhi, India facility.
Our Specialties in Liner Inserted BOPP Bags:
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Complete Liner Solution Under One Roof: We manufacture all liner types — loose, spot-sealed, fully sealed, co-extruded, metalized/foil, and anti-static liners. No need to outsource.
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Multiple Liner Materials & Thicknesses:
| Material | Thickness Range | Our Specialty Application |
|---|---|---|
| LDPE | 30–80 microns | Sugar, salt, cement (cost-effective) |
| LLDPE | 40–100 microns | Fine powders, sharp granules (puncture resistant) |
| HDPE | 25–60 microns | High-humidity environments (export) |
| Metalized PE | 40–80 microns | Coffee, spices, nuts (aroma retention) |
| Aluminum Foil | 60–120 microns | Pharmaceuticals, oxygen-sensitive chemicals |
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100% Liner Integrity Testing: Every liner-inserted bag undergoes air inflation leak testing (submerged in water, pressurized) to ensure zero pinholes or seam failures.
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Custom Liner Attachment Matched to Your Filling Line:
| Attachment | Best For | Filling Speed |
|---|---|---|
| Loose | Manual filling, reusable outer bag | Slow |
| Top Spot-Sealed | Semi-automatic filling | Moderate |
| Top & Bottom Spot-Sealed | High-speed automated filling | Fast (20–40 bags/min) |
| Full Perimeter Seal | Liquids, pastes, vacuum packaging | Moderate |
