High Impact Polystyrene (HIPS) is a versatile thermoplastic known for combining toughness with low cost, making it ideal for packaging, consumer products, and point-of-sale displays. Its unique structure, which blends polystyrene with polybutadiene rubber, gives it superior impact resistance while maintaining excellent processability.
High Impact Polystyrene
High Impact Polystyrene (HIPS) is a low-cost, tough thermoplastic material. It is a co-polymer that combines the stiffness of general-purpose polystyrene with the superior impact resistance of polybutadiene rubber. It’s the “workhorse” of thermoplastics—the reason your point-of-sale displays can take a hit and your yogurt cups can bend without shattering. This combination of low cost and exceptional processability makes it one of the most versatile and widely used plastics available today.
Standard Mechanical & Physical Properties Table (Typical Values for General-Purpose HIPS Grade)
| Property | Standard | Test Condition | Typical Value | Unit |
| Tensile strength @ Yield | ISO 527 | Speed 5 mm/min, Grip 115 mm | 18.33 | MPa |
| Elongation @ Break | ISO 527 | Speed 5 mm/min, Grip 115 mm | 7.28 | % |
| Tensile strength @ Break | ISO 527 | Speed 5 mm/min, Grip 115 mm | 16.33 | MPa |
| Elongation @ Yield | ISO 527 | Speed 5 mm/min, Grip 115 mm | 3.03 | % |
| Flexural Modulus | ASTM D790 | Speed 1.3 mm/min, Deflection 0.5 mm | 2197 | MPa |
| Flexural strength | ASTM D790 | Speed 1.3 mm/min, Deflection 5.0 mm | 37.85 | MPa |
| Melt Flow Index (MFI) | ASTM D1238 | 5.00 kg / 200°C | 8.2 | g/10 min |
| Filler Content | ISO 3451/1 | 600°C / 30 min | 7.21 | % |
| Density | ISO 1183 | 23°C, 50% RH | 1.08 | g/cm³ |
What is High Impact Polystyrene High Impact Polystyrene is an amorphous thermoplastic created by grafting 5-10% polybutadiene rubber into a polystyrene matrix. This addition of an elastomer phase is what gives the material its name; it dramatically increases the material’s toughness and impact strength, solving the primary drawback of General Purpose Polystyrene (GPPS), which is its brittleness. The rubber particles scatter light, which is why HIPS is naturally opaque or translucent (milky white), unlike the crystal-clear GPPS. As a member of the styrenic family, it retains the excellent processing characteristics of polystyrene while offering significantly enhanced durability.
High Impact Polystyrene Key Properties The following properties represent typical values for a general-purpose HIPS grade. Specific values will vary based on the manufacturer, grade, and presence of additives.
- Impact Strength (Izod): Good (Significantly higher than GPPS)
- Tensile Strength: Fair (Lower than GPPS)
- Flexural Modulus (Stiffness): Good
- Heat Deflection Temperature (HDT): Relatively Low (e.g., 68°C – 88°C)
- Flammability Rating: UL 94 HB (Slow burn; not self-extinguishing)
- Food Grade Status: FDA Compliant Grades Available
- Clarity: Opaque / Translucent
Advantages and Disadvantages of HIPS
Advantages
- Excellent Impact Resistance: Its primary feature, offering good toughness at a low cost.
- Low Cost: One of the most economical thermoplastics available.
- Ease of Fabrication: Exceptional for thermoforming and vacuum forming; it forms deep draws easily.
- Good Dimensional Stability: Holds its shape and size well after forming.
- Printable: Ideal for graphics and signage due to its receptive surface.
- Food Grade Available: FDA-compliant grades are common for packaging.
Disadvantages
- Poor UV Resistance: Standard grades will yellow and become brittle with prolonged outdoor exposure.
- Poor Chemical/Solvent Resistance: Susceptible to attack from many solvents, oils, and greases.
- Flammable: Carries a UL 94 HB rating, meaning it will burn slowly and is not for applications requiring self-extinguishing properties (like UL 94 V-0).
- Opaque: Cannot be used for transparent (see-through) applications.
Common HIPS Applications and Uses
HIPS’s combination of low cost, impact strength, and excellent thermoformability makes it a go-to material for high-volume, single-use items and non-structural housings.
Packaging
- Food packaging, such as yogurt cups, dairy containers, and food service trays (using FDA grades).
- Clamshells and blisters for consumer goods.
Point of Sale and Signage
- Retail displays, shelving, and POP (Point-of-Purchase) stands (due to printability and low cost).
- Indoor signage and promotional materials.
Consumer Products
- Appliance housings (e.g., internal refrigerator liners, TV housings, smoke detector casings).
- Toys, plastic models, and prototypes.
Comparison Table: HIPS vs GPPS vs ABS (Typical Values)
| Property | GPPS (General Purpose) | HIPS (High Impact) | ABS |
| Impact Strength | Very Poor (Brittle) | Good (Tough) | Very High |
| Clarity | Transparent (Clear) | Opaque / Translucent | Opaque |
| Tensile Strength (MPa) | 40–60 | 18–35 | 37–110 |
| Flexural Modulus (GPa) | 2.5–3.5 | 1.6–2.4 | 2.0–2.6 |
| Heat Deflection Temp (°C) | 70–90 | 68–95 | 82–100 |
| Cost | Lowest | Low (Slightly > GPPS) | Higher |
| Chemical Resistance | Poor | Poor | Good |
| UV Resistance | Poor | Poor (unless stabilized) | Better (with additives) |
| Best For | Transparent items | Impact-resistant packaging | Demanding durable parts |
HIPS vs GPPS
This is the most fundamental comparison. General Purpose Polystyrene (GPPS) and Polystyrene granule iran are the base material, which is crystal-clear, rigid, and brittle. High Impact Polystyrene (HIPS) is simply GPPS with polybutadiene rubber added, which makes it tough and opaque. Think of GPPS as a clear, brittle CD jewel case and HIPS as a tough, opaque yogurt cup.
HIPS vs ABS
ABS (Acrylonitrile Butadiene Styrene) is often considered the “next step up” from HIPS in terms of performance. While both are tough, ABS offers superior impact strength, higher heat resistance, and better chemical resistance. However, HIPS is generally lower in cost and easier to thermoform than ABS, making it a more economical choice for less demanding applications.
- Choose HIPS if: Cost, FDA compliance, and ease of thermoforming are your primary drivers.
- Choose ABS if: You need higher temperature resistance (HDT), superior toughness, or better performance in the presence of chemicals or UV (with proper grades).
HIPS Manufacturing and Fabrication
- Manufacturing
HIPS is produced through the polymerization of styrene monomer in the presence of dissolved polybutadiene rubber. This process, typically bulk or emulsion polymerization, creates a “grafted” co-polymer where the rubber phase is dispersed throughout the stiff polystyrene matrix.
- Fabrication
HIPS is prized for its excellent processability and can be fabricated using a wide range of methods:
- Thermoforming & Vacuum Forming: This is the most common use. The material’s low melt strength and good stability allow for deep, detailed draws, making it ideal for packaging and trays.
- Injection Molding: Used to create solid, 3D parts like appliance housings and toys.
- Machining: HIPS is easily machined. It can be drilled, sawn, and routed using standard metalworking or woodworking tools without chipping or cracking.
- Printing & Bonding: The material’s surface is receptive to screen printing, offset lithography, and digital printing. It can also be easily joined using solvent-based adhesives.
High Impact Polystyrene Recycling
As a thermoplastic, High Impact Polystyrene is 100% recyclable. It is identified by the resin identification code #6 (PS). While technically recyclable, the practical recycling rates for HIPS remain low. This is often because it is used for food packaging (e.g., yogurt cups) and can be difficult to decontaminate. Furthermore, sorting and separating #6 plastics is often less economically viable for municipal facilities compared to PET (#1) and HDPE (#2). Recycled HIPS (rHIPS) is increasingly available from post-industrial sources, helping reduce carbon footprint, conserve resources, and support circular economy practices in packaging and consumer goods.
Yasin Polymer – Your Trusted Supplier of High Impact Polystyrene (HIPS) in Iran
At Yasin Polymer, we supply various high-quality HIPS grades from globally renowned manufacturers. Perfect for food packaging production, retail displays, household appliance components, and consumer goods. We also offer GPPS Polystyrene granule, Recycled GPPS Granule, Recycled EPS Granule, and other Polystyrene granule Iran options for sustainable and cost-effective solutions. Enjoy free technical consultation, fast delivery, and competitive pricing – the ideal choice for Iranian manufacturers and international buyers.
High Impact Polystyrene FAQ
Is High Impact Polystyrene waterproof?
Yes. HIPS has very low moisture absorption and acts as an effective moisture barrier, which is why it is widely used for food and medical packaging.
Is HIPS safe for food?
Yes, specific grades of HIPS are FDA-compliant and approved for direct food contact. These grades are commonly used for dairy containers, disposable cutlery, and food service trays.
Can you 3D print with HIPS?
Yes, HIPS is a popular 3D printing filament. It is often used as a dissolvable support material for ABS prints. HIPS dissolves in limonene (a citrus-based solvent), while ABS remains unaffected, allowing for the creation of complex parts with large overhangs.
Does HIPS work outdoors?
Standard HIPS is not recommended for long-term outdoor applications. It has poor UV resistance, which causes it to become brittle and yellow. For outdoor use, UV-stabilized grades or HIPS co-extruded with a protective acrylic “cap” layer must be used.
