TIPPLEN PP Homopolymer H 388 F is a polypropylene homopolymer film resin supplied by MOL Petrochemicals/Tisza Chemical Group under the TIPPLEN trademark. The grade is positioned for high-output cast film, extrusion coating, and selected thin-gauge oriented film processes in which a medium melt flow rate and controlled molecular weight distribution reduce draw resonance and edge neck-in. The producer technical documentation identifies H 388 F as an F-series film formulation supplied without significant slip or antiblock packages; therefore, the resin is used as a base layer or monolayer component rather than as a formulated heat-seal resin. Published data for this specific configuration is limited to the manufacturer’s technical bulletin and lot-specific certificate of analysis. The typical values in the table below are method-specific and should be confirmed against the current datasheet for the production campaign.

Film-grade verification is usually performed on a 50 µm cast film. Homopolymer H 388 F typically shows haze below 2.5% under ASTM D1003-21 and clarity above 98% when chill-roll temperatures are held below 25 °C. Gloss at 45° is typically above 85 GU under ASTM D2457-21. Without slip additives, the kinetic coefficient of friction is normally above 0.60 under ISO 8295:2023, which makes automatic packaging line use dependent on a separately dosed slip masterbatch. Dart impact for the 50 µm homopolymer film is usually below 150 g under ISO 7765-1:2021, reflecting the brittle behavior of an unreinforced homopolymer matrix.

What Limits H 388 F in Low-Temperature Impact and Hot-Fill Service?

Because the matrix is a homopolymer, low-temperature crack propagation is not arrested by an ethylene-propylene rubber phase. Under ISO 179-1:2010 at 0 °C, the notched Charpy impact strength typically falls below 1.5 kJ/m², and at −20 °C brittle failure occurs without stable ductile tearing. The resin is therefore unsuitable for freezer-grade packaging unless an impact modifier is added by the converter, which usually reduces stiffness and shifts the flexural modulus toward 1200 MPa or lower. In hot-fill or retort exposure above 100 °C, the absence of ethylene comonomer reduces long-term creep resistance: under ISO 899-1:2017, prolonged stress at 120 °C can degrade tensile strength by more than 50% after 1000 h in air. Dimensional stability under load is constrained by the heat deflection temperature of 95 °C at 0.45 MPa. Continuous load-bearing use should therefore remain below 90 °C, and hot-fill applications should be limited to short residence times at 85 °C unless additional long-term thermal stabilizers are formulated.

Melt rheology influences both film clarity and edge stability. At a melt temperature of 230 °C and an apparent shear rate of 1000 s⁻¹, the apparent viscosity for this MFR class is approximately 90 Pa·s to 120 Pa·s. On a 90 mm single-screw extruder with a 30:1 L/D ratio and a barrier screw, specific energy consumption for cast film is typically 0.18 kWh/kg to 0.22 kWh/kg at a throughput of 350 kg/h. The resin is also processable on a 75 mm grooved-feed extruder, but melt pressure before the screen changer should be kept below 250 bar to limit shear heating and molecular weight breakdown. Pre-drying is unnecessary when bags are stored below RH 60%. When the resin is transferred from a conditioned warehouse at 5 °C to a conversion hall at 25 °C and RH 70%, condensation on the pellet surface can create surface splay in the cast web. In this case, a desiccant dryer set to 80 °C with a dew point of −30 °C for 2 h to 4 h is recommended before extrusion.

Chill-Roll Conditions, Die Gap, and Plate-Out Control in Cast Film Production

In cast film processing, the die gap is typically set at 0.5 mm to 0.8 mm, with a die temperature between 240 °C and 250 °C. The chill-roll temperature is maintained at 18 °C to 25 °C for high gloss and reduced blocking; raising the chill-roll temperature to 30 °C to 35 °C can improve clarity but may increase blocking and roll-winding defects. Draw resonance is less severe than with lower-MFR PP because the medium flow rate reduces melt elasticity, but edge neck-in on thin webs remains a practical constraint. Reducing die gap and increasing melt temperature can lower neck-in, yet excessive melt temperature above 280 °C accelerates thermo-oxidative chain scission, forming volatile low-molecular-weight species that cause plate-out on the die lip. Processors balance these variables by monitoring gel count and die-lip deposit formation at the production line rather than relying solely on resin melt flow rate.

Barrel temperature profiles should be set at 190 °C in the feed throat, 210 °C to 220 °C in the compression zone, and 230 °C to 250 °C in the metering zone. The adapter and die should be maintained at 240 °C to 250 °C. Melt temperature measured at the die exit should not exceed 260 °C for extended runs; excursions to 280 °C are acceptable only for short periods during purging. Back pressure should be maintained at 10 bar to 30 bar for stable metering. A screen pack with 100/80/100/60 mesh layers is often used to increase melt pressure and improve dispersive mixing.

For extrusion coating of paper or board, the resin is usually applied at coating weights from 15 g/m² to 40 g/m². Adhesion is promoted by ozone treatment of the melt surface and by oxidizing the substrate surface with corona discharge. Line speeds of 200 m/min to 400 m/min are achievable on modern coaters, but the high shear rates in the coating die can cause local melt-temperature rise. Because H 388 F is a homopolymer with a narrow molecular weight distribution, it exhibits lower melt strength than high-melt-strength PP grades. This limits performance in low-coating-weight applications below 10 g/m², where web edge tearing and draw instability dominate. Converters requiring low neck-in at extreme line speeds may select a controlled-rheology PP with a broader molecular weight distribution or a high-melt-strength resin.

When Biaxially Oriented Film Lines Require Lower Melt Strength and Rapid Relaxation

In biaxially oriented film production, the cast sheet is quenched and then oriented at machine-direction draw ratios of 4.5:1 to 6.0:1 and transverse-direction draw ratios of 8:1 to 10:1. The preheat sections are typically operated at 130 °C to 150 °C in the machine direction and 160 °C to 175 °C in the transverse direction. H 388 F is selected when rapid molecular relaxation is needed to reduce orientation-induced stress and film curl. The medium melt flow rate permits lower extruder melt temperatures than lower-MFR BOPP grades, but heat-set stability can be slightly reduced because the homopolymer crystalline network develops faster during quenching. This trade-off is acceptable in coextruded BOPP structures where H 388 F forms the core layer and sealable copolymers form the skin layers.

Compared with random copolymer PP film grades, H 388 F provides higher flexural modulus and Vicat softening point, but lower transparency in thick sections and a higher seal-initiation temperature. Random copolymers are preferred when heat sealing must occur below 130 °C; the homopolymer seal-initiation temperature is typically above 150 °C, making it suitable for base films where sealant layers are coextruded. Compared with heterophasic impact copolymers, H 388 F exhibits improved stiffness and surface gloss but severely reduced low-temperature impact strength. The grade also differs from high-crystallinity PP homopolymers in that its flexural modulus is lower and its crystallinity is less developed, which supports better film drawability at moderate line speeds. Within the TIPPLEN homopolymer film series, the numeric suffix 388 denotes a higher melt flow rate than grades intended for BOPP or heavy-gauge sheet, thereby orienting H 388 F toward cast film, extrusion coating, and thin-gauge oriented applications requiring good flow and rapid melt relaxation.

Incoming resin inspection typically includes melt mass-flow rate verification under ISO 1133-1:2022, bulk density under ISO 60:1977, and pellet size distribution by sieve analysis. Xylene cold-soluble fraction is measured under ISO 16152:2005 and is normally below 4% for this homopolymer class, indicating a highly crystalline matrix. Catalyst residue, measured as ash content under ISO 3451-1:2019, is typically below 0.05% for modern Ziegler-Natta grades. These lot-to-lot controls reduce the risk of film gels and die lip deposits, but converters should maintain incoming inspection records because additive levels and molecular weight distribution can shift between catalyst batches within the manufacturer’s specification band. The absence of slip and antiblock means that film-to-film coefficient of friction is typically high; any requirement for low COF must be met by externally dosed masterbatch rather than by relying on the base resin.

Regulatory Compliance and Food-Contact Status Under EU and FDA Frameworks

The homopolymer base resin is typically covered by the manufacturer’s compliance declaration for food contact under EU Regulation (EC) No 1935/2004, EU Regulation (EU) No 10/2011, and 21 CFR 177.1520 for olefin polymers. Specific migration limits for total non-volatile residue are generally below the 10 mg/dm² overall migration limit of EU 10/2011, but final compliance depends on the converter’s additive package, printing inks, and lamination adhesives. The grade is not certified for medical implant or parenteral use unless separately validated. Under REACH, the polymer is exempt from registration as a polymer, but monomers and additives are subject to registration and restriction under Annex XVII. Under RoHS Directive 2011/65/EU, the resin contains no intentionally added lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE above the maximum concentration values. Lot-specific certificates of analysis should be requested for pharmaceutical packaging or high-purity film applications.

Outside food packaging, the grade can be used for adhesive tape backings, stationery films, and textile packaging. In adhesive tape backings, corona treatment is necessary to raise surface energy above 38 mN/m for water-based acrylic adhesives. For solvent-based adhesives, higher surface energy above 42 mN/m may be required. The treated surface decays with time because low-molecular-weight species migrate to the film surface; inline corona treatment is therefore preferred over off-line treatment. Shelf life of treated film is influenced by storage temperature and slip additives; without slip additives, the surface is less prone to migration-induced treatment decay but more difficult to unwind at high speed.

The operational boundaries for H 388 F are defined by the homopolymer matrix, not by the extrusion equipment. Sustained exposure to oxidizing acids, chlorinated solvents, or strong UV without stabilization will degrade the polymer and cause embrittlement. Outdoor film applications require at least 0.2% hindered amine light stabilizer and 0.2% UV absorber by weight, unless the film is coextruded with a stabilized skin. Contact with copper or copper alloys at melt temperatures above 250 °C accelerates oxidative degradation; therefore, bronze screen packs should be avoided. These limitations are not unique to H 388 F but are stricter than for heterophasic copolymers because the homopolymer lacks rubber-phase toughening.