Cold Plastic Drinking Bowls vs. Hot Plastic Drinking Bowls

I. Differences in Material Characteristics

1.1 Differences in Plastic Type Selection

• Polystyrene (PS): High transparency, good rigidity, and low cost. Its glass transition temperature is 100℃, and its structure is stable below 0℃, making it an ideal container for low-temperature foods such as ice cream and salads. A certain cold drink brand uses PS containers for delivery, with a breakage rate of only 0.3% at -5℃, and the cost is 40% lower than PP containers. However, PS has poor thermal stability, softening at 75℃ and releasing styrene monomers above 80℃, which may harm the central nervous system with long-term ingestion.
• Polyethylene terephthalate (PET): Excellent transparency and strength, outstanding low-temperature resistance, maintaining physical properties from -20℃ to -40℃. It retains rigidity and transparency even when exposed to condensation and low temperatures, making it suitable for holding cold drinks containing ice or carbonated beverages. PET has a density of 1.35 g/cm³. Although the raw material price is 10%-30% higher than PP, less is needed for the same volume.
• Polypropylene (PP): Primarily used for hot beverage bowls, but can also be used for cold beverage bowls if both hot and cold applications are required. PP has a temperature resistance range of -20℃ to 120℃, good chemical stability, and modified PP can withstand extreme environments from -18℃ to 110℃. Its elongation at break reaches 300%, far exceeding PS's 50%, making it more resistant to drops and compression.

• Polypropylene (PP): The preferred material for a hot, large plastic bowl with lid, with a melting point as high as 167℃. Its typical operating temperature is -6℃ to 120℃, and some products can withstand temperatures up to 130℃. PP5 food containers are the mainstream material in the takeout industry; they are heat-resistant, non-toxic, and microwave-safe. Their chemical inertness ensures that their total migration is far below national standard limits, making them widely recognized for their safety.
• Polystyrene (PS): Limited applications. Due to poor heat resistance, the continuous operating temperature is only 60-70℃. Exceeding these temperatures easily causes softening, deformation, and the development of odors, making it unsuitable for microwave heating. Experiments show that PS food containers begin to soften at 75℃ and release styrene monomers above 80℃. A random inspection in one area found that some PS food containers, when holding 60℃ hot soup, showed styrene migration levels exceeding the standard by three times.

1.2 Differences in Heat and Cold Resistance

• PET: Brittleness increases at low temperatures. Below 0℃, molecular chain mobility decreases. Impact strength decreases by 40%-50% at -20℃. Low-temperature embrittlement temperature is -40℃ to -50℃. Specially modified low-temperature PET can maintain toughness and transparency at -40℃.
• PS: Good low-temperature performance. Structure is stable below 0℃ with no significant embrittlement. Suitable for frozen food packaging. One brand of PS lunch boxes has a breakage rate of only 0.3% at -5℃.
• PP: Wide temperature adaptability, usable from -20℃ to 120℃. Suitable for refrigerated, frozen, and room temperature environments, offering the best versatility.

• PP: Outstanding heat resistance. Standard PP can withstand 120℃, modified PP up to 130℃, and its melting point of 167℃ is far higher than the temperature of everyday hot drinks. It does not soften or deform when filled with 80℃-100℃ hot water or soup.
• PET: Limited heat resistance, glass transition temperature 70-80℃, heat distortion temperature (under 0.45MPa load) approximately 70℃. It can only withstand 70℃ for short periods; long-term use easily deforms, limiting its application in hot beverage packaging.
• PS: Poorest heat resistance, continuous use temperature 60-70℃. Above 65℃, it may release harmful substances. "PS6" material tableware releases long-chain alkanes after contact with 100℃ boiling water for 10 minutes; migration is positively correlated with temperature.

1.3 Differences in Additive Use

1.4 Food Safety Standards and Certification Requirements

1.5 Chemical Stability at Extreme Temperatures

• PET: Fragile at extremely low temperatures (-20℃ to -40℃), impact resistance decreases. Although mainly physical changes, chemical stability may be affected.
• PS: Stable at low temperatures, does not release harmful substances, but brittleness increases, easily broken upon impact.
• PP: Stable performance at -20℃ to -40℃, strong chemical inertness, does not release harmful substances, highest safety.

• PP: No chemical changes below 120℃. Its chemical inertness results in a total migration amount far below the national standard, with the best stability.
• PET: Slight chemical changes may occur above 70℃; long-term high-temperature exposure affects stability.
• PS: Temperatures above 60℃ may release harmful substances; softening at 75℃; release styrene monomers at 80℃; and rapidly release long-chain alkanes in boiling water at 100℃. Migration increases with increasing temperature.

II. Differences in Appearance Design

2.1 Considerations for Wall Thickness Design

• Hot Beverage Bowls: Primarily feature a thickened design, with a wall thickness 30% greater than ordinary products. The standard thickened version has a wall thickness of 0.8-1.2mm (ordinary bowls are only 0.5mm), improving both structural strength and heat insulation. Actual tests show that the thickened version can withstand an 800g platter of braised food without deformation and can withstand 100℃ high-temperature steam sterilization. The bowl bottom is often thickened by 3.2mm to enhance load-bearing capacity and heat insulation; the thickened bowl wall improves pressure resistance. One "double-layer leak-proof" design combines raised textures on the inner wall with reinforcing ribs on the outer wall, increasing pressure resistance by 40%. 
• Cold Plastic Christmas Bowls: The walls are relatively thin, with a standard design of about 0.5mm, meeting basic strength requirements while controlling costs. Strength is ensured through structural optimization, such as differentiated designs for the inner and outer walls (thin inner walls for easy eating, thicker outer walls for enhanced durability). Special types, such as thickened dessert bowls, employ uniform wall thickness and reinforced bottom designs to prevent low-temperature condensation, leakage, and deformation. Thickened edges enhance pressure resistance, making them less prone to collapse during stacking and transportation.

2.2 Differences in Shape Design

• Conical Design: The rim flares slightly outward, conforming to ergonomics for easy handling and drinking, while also facilitating heat dissipation to prevent burns.
• Straight Cylindrical + Conical Ridge: The bowl body is vertical or slightly conical, with an outward-flaring rim, balancing stacking convenience and comfortable grip.
• Anti-slip Texture: Commonly used textures such as mesh, raised texture, and wave texture, with a thickness ≤2mm, providing both anti-slip and heat insulation. For example, mesh bowls can be used for hot pot and barbecue without slipping or deforming.
• Ergonomics: Smooth edges and a comfortable grip design. The bottom has an anti-slip pad or texture to increase friction on the table and prevent tipping.

• Conical Design: Mostly used for ice cream and desserts, with a pointed or round bottom. Some are flower-shaped or spiral-shaped, aesthetically pleasing, and material-saving.
• Straight Cylindrical Design: The mainstream choice, with vertical or slightly conical walls, facilitating stacking and storage, suitable for supermarkets, convenience stores, and similar settings. Special Design: The curved bowl body and lotus-shaped smooth transition design combine aesthetics and structural performance.
• Stackability: The matching bottom concave and top convex design reduces stacking height by 25%, saving storage and transportation space; the lids are mostly flat-topped or slightly domed, with a stacking groove design (the lid convex matches the bottom of the box), ensuring stable parallel stacking.

2.3 Bowl Bottom and Edge Treatment Design

• Bottom: Wavy design with wavy stepped lines to prevent collapse and increase contact area, improving stability; thickened (3.2mm) with anti-slip texture or silicone pads enhances stability and heat insulation.
• Edges: The bowl rim is turned outwards or has an insulated structure to prevent burns; the rim is smooth and comfortable, with a flat, burr-free edge; the thickened bottom prevents burns and is pressure-resistant and not easily broken.

• Bottom: Flat or slightly concave bottom, simple, practical, and low-cost, ensuring stable placement; for dessert bowls and other products requiring display, a reinforced bottom design prevents low-temperature leakage and deformation.
• Edges: The rims are mostly transparent or semi-transparent, facilitating the display of contents; the rims are soft and smooth, enhancing the user experience; some have small handles with a non-slip surface for easy opening.

2.4 Printing and Surface Treatment Processes

• Printing Process: Heat transfer printing (PET film as the medium, 175℃-200℃, 1-2 minutes), the ink is high-temperature resistant, water-resistant, and meets food safety standards; UV printing (UV curing technology), the ink is environmentally friendly and solvent-free, with fast curing speed, suitable for PP materials.
• Surface Treatment: Corona treatment (high-voltage discharge activates the surface, improving ink adhesion), plasma treatment (increases surface tension, enhances adhesion), ensuring the stability of the printed layer at high temperatures.

• Printing Process: Primarily offset and letterpress printing, low cost and suitable for mass production; offset printing supports multi-color overprinting; automated processes (automatic bowl loading, pre-printing corona treatment, high-speed printing, UV curing, finished product stacking) ensure clear patterns.
• Surface Treatment: Decorative processes such as hot stamping (gold or silver) require precise temperature control (too high a temperature leads to coating oxidation, too low a temperature results in poor adhesion); some use special coatings to improve surface hardness and wear resistance, or wax coatings or PE coatings to enhance water resistance, but these may affect recyclability.

 

III. Performance Differences

3.1 Leak-proof Performance Differences

• Structural Innovation: Double-layer leak-proof design (inner wall raised texture + outer wall reinforcing ribs), increasing pressure resistance by 40%; inner groove seal + thickened snap-on lid, 360° leak-proof sealing + triple-thickened cup wall, no leakage even after 3 minutes of inverted shaking.
• Sealing Technology: Ultrasonic hot-pressing technology (20kHz-40kHz high-frequency vibration sealing), leak-proof duration of 300 hours, far exceeding the traditional 8 hours of heat sealing, precisely controlling energy output to ensure a tight seal after the sealing ring melts and cools.
• Actual Test Results: After a chain restaurant used thickened bowls, the leakage rate of takeout soup dropped from 15% to below 2%, and the complaint rate decreased significantly.

• Basic Design: Relying on material properties (such as the good barrier properties of PET) and a simple structure, they meet general leak-proof requirements.
• Special Requirements: Products requiring long-term refrigeration/freezing must show no leakage after standing at -18℃ for 24 hours, with a 99.8% pass rate in the sealing test; PS is stable at low temperatures and does not easily deform, while improved low-temperature PET maintains its toughness and sealing properties even at -40℃.

3.2 Differences in Abrasion Resistance

• Material Advantages: PP material has good toughness (300% elongation at break) and better abrasion resistance than PS (50% elongation at break), making it less prone to breakage from friction.
• Performance Indicators: Shore hardness ≥70 (Shore D), scratch resistance ≥5N, scratch width ≤0.1mm; in Taber abrasion tests (load 125g-1000g), the coefficient of friction change rate ≤10%, ensuring a consistent user experience.

• Material Limitations: PS has high hardness but is brittle and easily scratched; PET becomes more brittle at low temperatures, which may also affect its abrasion resistance.
• Surface Dependence: Greater emphasis is placed on transparency and appearance, requiring special coatings to improve surface hardness and reduce scratches; the abrasion resistance requirement is lower for milder environments than for hot plastic drinking bowls, but long-term storage or frequent handling requires careful consideration.

3.3 Differences in Deformation Resistance

• Material Heat Resistance: PP can withstand high temperatures of 120℃-130℃ without deformation when holding hot drinks; modified PP has even better performance.
• Structural Reinforcement: Thickened design (30% increase in wall thickness), with a 3.2mm thicker bottom, enhancing resistance to deformation; remains stable during 100℃ hot water and steam sterilization, and is microwave-safe.
• Impact Resistance: A 1.2mm thick bowl with 500ml of soup survives a 1.5-meter drop with a 97% survival rate, ensuring high safety during transportation and use.

• Low Temperature Effects: PET becomes more brittle below 0℃, with impact strength decreasing by 40%-50% at -20℃, and may crack at extremely low temperatures; PS is stable at low temperatures but has poor heat resistance, easily softening and deforming above 60℃.
• Structural Optimization: Although the wall thickness is thin (0.5mm), the differentiated design of the inner and outer walls ensures basic resistance to deformation; PP material cold plastic drinking bowls have good flexibility, instantly rebounding after compression, offering optimal resistance to deformation and impact.

3.4 Comparison of Other Key Performance Aspects

• Temperature Cycling Performance: The hot beverage bowl can withstand temperature changes from -20℃ to 120℃ without performance degradation, suitable for refrigeration, room temperature, and heating scenarios; while high-quality cold beverage bowls can also cover this temperature range, their usage time and upper limit at high temperatures are limited.
• Physical Strength Indicators: According to GB/T 18006.1-2025, tensile strength requires a breaking strength ≥15MPa and elongation ≥100% (PP easily meets the standard, PS may have insufficient elongation); compressive strength requires a compression deformation rate ≤5% and an elastic modulus ≥500MPa (the thickened design of the hot beverage bowl is superior); temperature resistance testing requires no deformation or peeling from -20℃ to 100℃ (the hot beverage bowl has better high-temperature stability); compressive strength requires a vertical load ≥50kg (the robust structure of the hot beverage bowl results in a higher value).
• Hygiene and Safety Performance: Hot beverage bowls, due to their contact with high temperatures, have a higher risk of harmful substance migration, requiring stricter requirements for raw materials, additives, and processes. While cold beverage bowls are used at low temperatures, long-term storage or contact with acidic/oily foods still pose a risk of migration. Both types have consistent microbiological indicators (coliforms/pathogenic bacteria not detected, mold ≤50 CFU/g).

 

IV. Cost, Recycling, and Market Brand Analysis

4.1 Cost Difference Analysis

• PP: 8000-10000 RMB per ton; the cost of a single 250ml, 12g bowl is approximately 0.101 RMB, allowing for the production of approximately 100,000 sets/ton.
• PS: Cost similar to PP, with a single production cost of 0.15-0.25 RMB.
• PET: Raw material price is 10%-30% higher than PP, but its density (1.35g/cm³) is higher than PP (0.9g/cm³), requiring less material for the same volume, giving it a cost advantage in some applications.
• Overall cost structure: Raw materials account for 40%-60% (highly affected by international oil prices), manufacturing costs (equipment depreciation, labor, utilities) account for 30%-40%, and transportation costs are a small percentage. Traditional plastic bowls have a raw material component of 65% and labor 18%; biodegradable bowls have a raw material component of 78% (PLA granules account for 60%), resulting in higher costs.

• Wholesale price: PET beverage bowls: $0.0192-$0.06/piece (approximately RMB 0.14-0.43), 16oz PET bowls: $0.038-$0.042/piece; PP products: $0.01-$0.06/piece (approximately RMB 0.07-0.43); PS products: RMB 0.15-$0.25/piece.
• Retail Price: 250ml bowls: 4.40-84.00 RMB/100 pieces (approximately 0.04-0.84 RMB/piece), with differences stemming from brand, quality, and distribution channels.
• Price Influencing Factors: Significant fluctuations in international oil prices (the 2022 Russia-Ukraine conflict caused PP prices to rise from 8500 RMB/ton to 12500 RMB/ton, increasing costs by 18%-22%); economies of scale (large enterprises have a daily production capacity of 1 million pieces, compared to the 300,000 pieces of production capacity of leading biodegradable bowl manufacturers, resulting in 18%-25% lower unit costs); technological innovation (thin-wall construction reduces raw material consumption by 6%, and modified formulas help 15% of leading companies achieve raw material substitution).

4.2 Comparison of Recycling Potential

• PET: 100% recyclable, reusable multiple times, global recycling rate 50-60%, can be mechanically recycled or chemically depolymerized. Recycling 1 ton of PET saves 3 tons of crude oil and reduces carbon emissions by over 1 ton.
• PP: Recycling rate is approximately 20%. Technically, it can be recycled to make new bowls, but the process is complex, costly, and requires specialized equipment. Recycling can reduce dependence on petroleum and carbon emissions.
• PS: Recycling rate is extremely low, a major contributor to "white pollution." Most recycling programs do not accept it. Traditional PS cannot be decomposed according to standards, and expanded polystyrene (EPS) is typically only recyclable once.
• Recycling Marking System: Number 1 (PET) is heat-resistant up to 70℃ and must be placed in a recycling bin; Number 5 (PP) is microwaveable and can be reused after cleaning; Number 6 (PS) has poor heat resistance and is not suitable for recycling; Number 7 represents other types (PC, ABS, PLA). The markings only indicate the material type; recyclability depends on the local recycling system.
• Actual Recycling Situation: Pact Group in Australia recycles 12,800 tons of PET, 18,500 tons of PE, and 4,900 tons of PP annually. Only 1,800 tons of PS and ABS mixed plastics are recycled, reflecting the significant recycling advantage of PET, limited PP recycling, and almost no effective recycling pathways for PS.

4.3 Characteristics of Mainstream Brands

V. Recommendations

5.1 Core Differences

5.2 Targeted Recommendations

• Catering Businesses: Choose materials according to need; choose PP hot plastic drinking bowls for hot food/hot drinks (ensuring safety), and choose PET/PS cold plastic drinking bowls for cold drinks/display (controlling costs); prioritize recyclable/biodegradable materials to comply with environmental protection requirements.
• Consumers: Distinguish between bowls for hot and cold drinks, and do not use cold plastic drinking bowls for hot food (avoiding deformation or release of harmful substances); dispose of waste according to waste sorting to improve recycling rates.
• Policymakers: Improve high-temperature migration limits and strengthen the recycling system (focusing on increasing PP recycling rates and solving PS recycling challenges); promote the research and application of environmentally friendly materials, and guide the industry towards safety and circularity.