In the modern food packaging industry, plastic packaging is widely popular due to its lightweight, durability, and cost-effectiveness. For packaging like sushi boxes, which require both aesthetic appeal and functionality, choosing the right manufacturing process and materials is crucial. As a factory specializing in high-quality sushi box production, we utilize thermoforming and PET materials. This article will delve into the differences between thermoforming and injection molding processes, analyze the differences between PET and other common plastic materials, and highlight the unique advantages of our products.
Thermoforming and injection molding are two mainstream processes for plastic molding, and they differ significantly in their principles, applications, and the characteristics of the final products.
Thermoforming
Thermoforming is a process that involves heating a plastic sheet until it softens, then using vacuum suction to mold it onto the surface of a mold, and finally cooling it to solidify the shape.
Process flow: Sheet heating → Vacuum suction → Cooling and shaping → Cutting and trimming.
Features:
Suitable for producing thin-walled, large-surface-area products, such as trays, cup lids, and blister packaging.
Lower mold costs, shorter production cycles, suitable for small to medium-volume production.
High material utilization rate, and scrap materials can be recycled.
Limitations: The uniformity of product wall thickness is relatively poor, the structural strength is usually lower than that of injection-molded products, and it is difficult to produce complex three-dimensional structures.
Injection Molding
Injection molding is a process in which molten plastic is injected into a closed mold, and the product is obtained after cooling and solidification.
Process flow: Plastic granules are heated and melted → High-pressure injection into the mold → Cooling and solidification → Mold opening and part removal.
Features:
It can produce products with complex structures, uniform wall thickness, and precise dimensions, such as bottle caps, containers, and parts.
The products have high strength and good surface gloss, suitable for mass production.
High degree of automation and high production efficiency.
Limitations: High mold costs, long production cycle, not suitable for small-batch production.
The core difference between thermoforming and injection molding
| Thermoforming process | Injection molding process | |
|---|---|---|
| Molding Principle | Vacuum suction is used to attach the heated sheet material to the mold surface | High-pressure injection of molten plastic into a sealed mold |
| Features | Thin-walled, lightweight,and with a large surface area | Thick-walled, high-strength, and complex structure |
| Mold Costs | Lower cost | Expensive |
| Production Lot Size | Suitable for small to medium-sized batches | Suitable for large-scale production |
| Material Utilization Rate | High material utilization rate | Low material utilization rate |
For products like sushi boxes, which require lightweight, transparent materials and don't demand complex structures, thermoforming offers a more economical and efficient option while still meeting the hygiene and display requirements of food packaging.
PET material: Why is it the ideal choice for sushi boxes?
PET (polyethylene terephthalate) is a plastic material widely used in food packaging. Compared to other common plastics, PET has unique advantages.
PET VS other common plastic materials
| Material | Characteristic | Application Products | Compared to PET Material |
|---|---|---|---|
| PET | High transparency, high strength, excellent barrier properties (moisture and gas resistance), low-temperature resistance, recyclable, and good food safety | Beverage bottles, food trays, plastic wrap | Benchmark material: Offers excellent overall performance, and is especially suitable for food packaging requiring transparency and preservation |
| PP | Translucent to opaque, resistant to high temperatures (up to 120℃), soft, and resistant to chemical corrosion | Microwave oven trays, yogurt cups, straws | It has low transparency, making it unsuitable for packaging that requires content display; its high-temperature resistance is better than PET, but its barrier properties are poor |
| PS | High transparency (GPPS), relatively high brittleness, good sound insulation and heat insulation properties | Disposable tableware, CD cases, foam boxes | It is highly brittle and not suitable for packaging that requires impact resistance; its environmental friendliness is poor and the recycling rate is low |
| PVC | Soft to hard texture options available, low cost, resistant to chemical corrosion | Plastic wrap, cards, pipes | Containing chlorine, its combustion may produce harmful substances, leading to significant environmental and health concerns; it is gradually being replaced by materials such as PET |
| PLA | Biodegradable, derived from renewable resources, and highly transparent | Environmentally friendly tableware, fresh food packaging | It has prominent environmental protection advantages, but its heat resistance and barrier properties are poor, and the cost is high. Currently, it is more suitable for markets with specific requirements for environmental protection |
The core advantage of PET
1. Outstanding transparency and display quality: PET has a transparency similar to that of glass, which can perfectly showcase the color and shape of sushi, enhancing the appeal of the product.
2.Excellent preservation properties: PET offers good barrier properties against oxygen and water vapor, which helps maintain the freshness of sushi and extends its shelf life.
3.High strength and durability: The PET material is sturdy and shock-resistant, which can effectively prevent sushi from deforming or getting damaged during transportation.
4.Food safety: PET complies with food contact material standards and does not contain harmful substances, thus not affecting the flavor of food.
5.Environmentally friendly and recyclable: PET is one of the plastics with the highest recycling rate, supporting the circular economy and reducing environmental burden.
6.Excellent low-temperature resistance: Suitable for packaging sushi that needs to be refrigerated or frozen.
Why choose our PET blister sushi boxes?
As a factory specializing in the production of PET blister sushi boxes, we are committed to maximizing the advantages of our processes and materials to provide our customers with superior packaging solutions.
1.Precise process control ensures consistent quality
We utilize advanced CNC thermoforming equipment and precision molds to ensure that each sushi box has uniform wall thickness, precise dimensions, and smooth, burr-free edges. Through strict control of process parameters, we achieve high consistency and reliability in our products.
2.Customized design capabilities to meet diverse needs
Whether it's traditional square sushi boxes, round platters, or uniquely shaped boxes designed for specialty sushi, we can quickly create prototypes and mass-produce them according to customer needs. The flexibility of the thermoforming process allows us to achieve personalized customization at a lower cost, helping brands differentiate themselves.
3.Optimized structural design enhances functionality and user experience
Our sushi boxes not only focus on aesthetics but also strive for perfection in functional details:
Tight-fitting lid design: Ensures a tight seal to prevent leakage and odor transfer.
Stackable & Stable: Saves space for easy storage and transport.
Easy to open: User experience is friendly, no need to strain to tear it apart.
4.Cost-effective advantages, creating value for customers
Compared with the injection molding process, our blow molding production mode offers greater cost advantages in small and medium batch orders. This enables us to provide customers with cost-effective solutions and shorten the delivery time.
5.Full-process quality control to ensure food safety
From the time the raw materials are stored in the warehouse to the time the finished products are shipped out, we implement a strict quality management system. Each batch of PET materials comes with a food safety inspection report, and the production environment complies with GMP standards, ensuring that every sushi box is safe and reliable.
