The impact resistance design of plastic blister trays during transportation must balance structural strength, material properties, and cushioning protection, ensuring cargo safety through multi-dimensional technical approaches. Key design areas include material selection and modification, structural optimization, cushioning system integration, and process innovation. The following analyzes key technical aspects.
Material selection is the foundation of impact resistance design. Plastic blister trays are commonly made of materials such as PVC, PET, and PP. PVC is widely used in industrial pallets due to its high toughness and impact resistance, but it produces chlorine gas when burned, requiring environmentally friendly modification. PET, known for its high transparency, recyclability, and chemical resistance, is suitable for demanding applications such as food and pharmaceuticals. However, due to its high melting point, it requires PETG composite film for improved packaging efficiency. PP, due to its non-toxicity and low-temperature resistance, is commonly used in frozen food packaging. However, its dimensional accuracy is limited, requiring the use of toughening agents to improve rigidity. In terms of material modification, adding toughening agents, brightening agents, or nanofillers can significantly improve impact resistance. For example, by adjusting the skin thickness and structural foaming process, HDPE (high-density polyethylene) pallets can achieve increased flexural strength, enabling them to withstand dynamic loads and meet the heavy-duty cargo requirements of e-commerce express delivery.
Structural design is crucial for impact resistance. Blister trays require enhanced stability through bottom ribs, interlocking structures, and cell cavity design. For example, a honeycomb rib structure improves flexural strength. Combined with a flat bottom design, it ensures that the upper pallet fits tightly into the lower grid when stacked in multiple layers, creating a large interlocking area and preventing collapse even when stacked five layers high. Cell cavity design requires precise calculation of retaining wall gaps and support locations based on product dimensions. Boss structures are used to evenly support the product, while avoiding protruding areas such as rear locating posts to prevent product displacement or damage during transportation due to vibration. Furthermore, the design of strong pressure and bearing surfaces ensures that the pallet remains structurally stable even after a 180° rotation, preventing deformation caused by external impact.
Integrated cushioning systems are a key complement to impact resistance design. By embedding removable cold storage boxes or cushioning materials inside pallets, impact energy can be absorbed during transportation. For example, in cold chain transportation, cold storage boxes utilize the latent heat properties of phase change materials to achieve long-term temperature control. Forced ventilation accelerates heat exchange, shortening cooling time and improving temperature uniformity. Furthermore, pallet edges can be designed with anti-slip patterns or chemically treated surfaces to enhance friction, preventing ice buildup and slippage in low-temperature environments, ensuring safe loading and unloading.
Process innovation is a key approach to improving impact resistance. The blister molding process uses vacuum suction to create specific grooves in plastic sheets, ensuring a tight fit between the pallet and the product and reducing vibration during transportation. Regarding mold production, aluminum molds are used for high-volume production due to their high precision and resistance to mold deformation, while copper molds are widely used for proofing and early stages of mass production due to their low cost and excellent transparency. Furthermore, flocking blister technology, by attaching a flocking material to the plastic surface, enhances the packaging's quality while also enhancing anti-slip properties. It is suitable for high-end electronics or gift packaging.
Environmental adaptability is an extension of impact resistance design. For high-temperature environments, materials with improved heat resistance or surface coatings should be selected to reduce the risk of thermal deformation. For humid environments, rust-resistant aluminum alloys or corrosion-resistant plastics should be used to prevent moisture absorption and reduced strength. Furthermore, pallet design must comply with international transportation standards to avoid increased export costs due to inconsistent specifications.
The impact resistance of plastic blister trays requires coordinated optimization of materials, structure, cushioning, and process. In the future, with the development of the Internet of Things (IoT), the integration of smart sensors and RFID technology will enable real-time monitoring of pallets, further improving transportation safety and efficiency.
