What's the general applications of heat-sealable BOPP film

Heat sealable BOPP film is a biaxially oriented polypropylene film with a modified sealing layer on one or both sides, allowing it to bond to itself under heat and pressure - no glue or cold-seal adhesive required. It is mainly used for snack and bakery flow wrap, form-fill-seal (FFS) bags, box overwrap, and as the sealant web in printed laminates.

That short answer covers the "what." This guide goes deeper into the "which and why": how the seal layer actually works, seven application areas where BOPP heat sealable film is the standard choice, the specifications buyers should check, and how it compares with plain BOPP and CPP - so you can match the right film to your packaging line.

What Is Heat Sealable BOPP Film?

Standard BOPP film has a high crystalline melting point (around 160-170 °C) and does not form a reliable seal on packaging machines - by the time the surface softens, the oriented film shrinks and distorts. Heat sealable BOPP film solves this by adding a lower-melting skin layer that fuses at jaw temperatures the base film can tolerate.

There are two main ways this seal layer is built:

• Coextruded heat sealable BOPP - a copolymer or terpolymer (ethylene-propylene-butene) skin is extruded together with the homopolymer core. This is the workhorse grade for flow wrap, FFS bags, and overwrap, typically sealing from about 105 °C upward.

• Coated heat sealable BOPP - an acrylic, PVDC, or low-temperature sealable coating is applied to the base film. Coated grades offer lower seal initiation temperatures, better hot slip on high-speed wrappers, and (with PVDC) added barrier. See our BOPP coated films for these options.

Films are supplied as one-side sealable (the outer side stays printable and heat-resistant, ideal for laminating or printing) or both-sides sealable (needed for fin seals and overlap seals on flow-wrap and overwrap machines).

Three Properties That Define Sealing Performance

When packaging engineers evaluate a BOPP heat sealing film, three numbers matter most:

1. Seal initiation temperature (SIT) - the lowest jaw temperature at which a usable seal forms. Lower SIT means faster line speeds and a wider operating window.

2. Seal strength - the force needed to peel the finished seal apart, usually reported in g/25 mm or N/15 mm. Snack packaging typically requires 250 g/25 mm or higher.

3. Hot tack - the strength of the seal while still hot, before it cools. Critical on vertical FFS machines where the product drops onto a just-formed seal.

What Is Heat Sealable BOPP Film Used For? 7 Key Applications

1. Snack and Bakery Flow Wrap

Horizontal flow wrap (HFFS) for biscuits, chocolate bars, wafers, instant noodles, and baked goods is the single largest use of heat sealable BOPP film. The film's stiffness feeds cleanly through formers at high speed, its clarity and gloss show the product well on shelf, and the sealed pack keeps moisture out to protect crispness. Both-sides sealable grades handle the fin seal on the back and the crimp seals at each end in one web.

2. Vertical Form-Fill-Seal (VFFS) Bags

Pillow bags for candies, dried fruit, nuts, frozen foods, and powders are formed, filled, and sealed in one continuous vertical process. Here hot tack is decisive: the seal must carry the falling product's weight seconds after the jaws open. BOPP heat sealable film with low SIT and strong hot tack lets converters run these lines fast without leakers or burn-through.

3. Overwrap and Multipack Wrapping

Cigarette packs, cosmetics boxes, tea cartons, playing cards, and promotional multipacks are overwrapped with thin (18-25 µm) both-sides sealable BOPP. The film's high stiffness produces tight, crisp folds and a glossy "cellophane look," while the seal layer closes the envelope folds cleanly on automatic overwrappers. Anti-static and easy-tear-tape versions are common in this segment.

4. Sealant Web in Printed Laminates

In two- and three-layer laminates - for example PET/print/adhesive/heat sealable BOPP, or plain BOPP film reverse-printed and laminated to a sealable BOPP inner web - the heat sealable film is the inside layer that actually forms the pack's seals. It contributes seal strength, puncture resistance, and low density (which lowers cost per square meter versus heavier sealants) in pouches and pillow bags for snacks, confectionery, and dry foods.

5. Metallized and Pearlized Barrier Packaging

Heat sealable base film is the standard substrate for metallized BOPP: the aluminum layer adds light, oxygen, and moisture barrier for chips, biscuits, and chocolate, while the reverse side still seals. Pearlized BOPP film (cavitated, heat sealable) adds opacity, a soft matte-white look, and lower density - widely used for ice cream wrappers, soap wrap, and candy twist alternatives.

6. Bags for Textiles, Stationery, and E-Commerce Accessories

Side-weld and back-seam bags made from heat sealable BOPP give garments, socks, greeting cards, and small hardware a glass-clear, rigid presentation that hangs and stacks well at retail. The film seals on simple bag-making equipment and resists scuffing better than PE bags of similar gauge.

7. Pharmaceutical and Personal Care Secondary Packaging

Blister-card overwrap, sachet outer webs, wet-wipe lidding laminates, and cosmetic carton wrapping all rely on BOPP heat sealable film for tamper evidence and moisture protection. Food-contact and pharma-relevant compliance (FDA / EU 10/2011) makes the same grades usable across these regulated categories.

Typical Specifications of Heat Sealable BOPP Film

Exact values vary by grade and supplier, but the table below shows the ranges most commercial heat sealable BOPP films fall into. Use it as a checklist when comparing datasheets.

When you request datasheets, confirm the test methods behind the numbers (ASTM F88 for seal strength, ASTM F1921 for hot tack) so grades can be compared like-for-like.

Heat Sealable BOPP vs Plain BOPP vs CPP: Which Do You Need?

The practical rule: if the film itself must form the seal on a wrapper or FFS machine and the product is a dry good, heat sealable BOPP is usually the most economical choice. If you need very high seal strength, deep-freeze toughness, or retort resistance, a CPP sealant laminated to a BOPP or PET print web is the better structure. For a broader technical overview of oriented polypropylene film types, see this industry reference on biaxially oriented polypropylene.

How to Choose the Right BOPP Heat Sealing Film

Before ordering samples, define these six points - they determine the grade far more than price does:

1. Machine type and speed - HFFS, VFFS, overwrapper, or bag-maker; higher speeds favor lower SIT and controlled COF.

2. One-side or both-sides sealable - fin/overlap seals need both sides; laminates usually need one sealable and one treated side.

3. Seal strength target - hermetic snack packs vs easy-open confectionery wraps need different seal ranges.

4. Barrier requirement - clear, PVDC-coated, or metallized, depending on shelf-life targets.

5. Print or lamination process - confirm corona-treated side, dyne level, and ink system compatibility.

6. Compliance - food-contact certificates (FDA, EU) and, increasingly, recyclability documentation for mono-PP structures.

FAQ About Heat Sealable BOPP Film

What is the difference between heat sealable BOPP and plain BOPP film?

Plain BOPP is a single-polymer oriented film that cannot form seals on packaging machinery - it is used for printing, lamination, and tape. Heat sealable BOPP adds a lower-melting copolymer skin or coating on one or both sides, so the film bonds to itself under heated jaws and can run directly on flow-wrap, FFS, and overwrap machines.

What temperature does BOPP heat sealing film seal at?

Most coextruded grades seal from roughly 105-120 °C upward, with the practical jaw-setting window around 110-150 °C depending on dwell time and pressure. Low-temperature coated grades can initiate seals near 90 °C, which supports faster line speeds and heat-sensitive products.

Is heat sealable BOPP film food safe?

Yes. Commercial heat sealable BOPP grades are produced to food-contact regulations such as FDA 21 CFR 177.1520 and EU 10/2011, and BOPP contains no plasticizers. Always request the supplier's current food-contact declaration for the specific grade and market.

Do I need one-side or both-sides sealable film?

Both-sides sealable film is required when the film seals to itself in different orientations - fin seals and end crimps on flow wrap, or envelope folds on overwrap. One-side sealable film suits laminates and reverse-printed structures, where the outer side must stay heat-resistant and printable.

Is heat sealable BOPP film recyclable?

BOPP is polypropylene (plastic code 5), and clear heat sealable BOPP supports mono-material PP packaging designed for recycling. Real-world recyclability depends on the full structure (coatings, metallization, laminate partners) and on local collection systems, so confirm against the recycling guidelines of your target market.

When should I use CPP instead of heat sealable BOPP?

Choose CPP as the sealant when you need very high seal strength, deep-freeze impact resistance, or retort processing. For dry snacks, bakery, overwrap, and general FFS bags, heat sealable BOPP offers better stiffness, higher yield per kilogram, and lower cost.

Conclusion: Match the Film to the Seal, Not Just the Spec Sheet

From snack flow wrap and VFFS bags to overwrap, laminates, and metallized barrier packs, heat sealable BOPP film earns its place by doing two jobs at once - presenting the product with high clarity and gloss while forming fast, reliable seals on automated lines. The right grade depends on your machine, seal-strength target, and barrier needs, not on thickness alone.

SAILLAGE manufactures one-side and both-sides heat sealable BOPP film in thicknesses from 18 to 50 µm, with corona-treated, pearlized, and matte options. Tell us your packaging machine and product, and we'll recommend a grade and ship sample rolls for a line trial - explore our heat-sealable film series or contact us for a quote.