The core to improving the efficiency of containerized shipping in the United States lies in reducing volume, making use of dead space and standardizing packaging. Through scientific packaging methods, you can effectively reduce the billing volume (CBM), thereby saving shipping costs. 
Ultra-compression: Reduce billing tonnage 
The cost of ocean shipping for containerized goods is usually calculated based on the higher of the volume and weight (W/M). For bulky items (with large volume and light weight), compressing the volume is the key to saving money.
*   Vacuum compression: For fluffy items like down jackets, quilts, and sweaters, vacuum compression bags must be used. This can reduce the volume by 30% to 50%, significantly reducing the billing tonnage.
*   Compact filling: There should be no gaps in the cardboard boxes. Use bubble wrap or fill the corners of the clothes themselves to prevent the boxes from collapsing during transportation, causing the box to expand and even being re-measured for volume. 
2. Regular shape: Maximize the use of space 
The interior of the container is a regular rectangular shape. Irregular packaging will result in unusable "pyramid" gaps.
Uniform specifications: Try to use standard-sized cartons (such as 6040*50cm or American standard boxes), and try to unify the size of the outer box. This makes it easier to stack in a "grid" or "square grid" pattern within the container, eliminating the gaps between the boxes.
* Rectangular packaging: Avoid cylindrical or irregularly bulging packaging. If the goods themselves are irregular, the outer packaging box must be made square, leaving the irregular parts inside the box. 
3. Exploitation of dead angles and combination of heavy and light elements 
• Gap Filling: In the gaps of heavy goods (such as hardware, furniture), insert soft, small items of off-cuts (such as socks, underwear). This makes use of the otherwise wasted "air volume" without adding any additional billing tons. 
Weight and volume separation: If the goods contain both heavy items and loose items, it is recommended to calculate the volume separately. If the heavy items reach the billing weight standard first, the remaining space can be filled with loose items, which is equivalent to "free" space. 
4. Palletization and Pallet Placement Strategy 
Although palletizing will increase a small amount of volume, it can improve efficiency in certain situations:
* Bulk goods palletizing: If the number of cargo boxes is extremely large (such as more than 10 boxes), palletizing is convenient for forklift loading and unloading, which can reduce dock operation time and reduce the risk of cargo damage, and indirectly avoid storage fees caused by delays.
* Volume control: When palletizing, ensure that the cartons are stacked neatly. Any part exceeding the edge of the pallet will be regarded as an irregularity and may cause the measured volume to be larger. 
5. Precise Measurement and Declaration 
• Self-measurement: Before shipment, measure the length, width, and height precisely (to the centimeter) and calculate the total CBM. If the re-measurement data from the freight forwarder's warehouse differs from your data by more than 0.5 CBM, you need to verify the measurement method on-site (whether it includes the pallet, and whether it is measured based on the maximum protrusion point). 
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Expansion of Perspective: Optimization of Packing List
Apart from physical loading, proper handling of documents can also enhance efficiency. When preparing the packing list, try to group similar items together to reduce the number of product names (HS Codes). Having too many product names (more than 5-8) may lead to the US customs demanding more detailed classification declaration, thereby increasing the complexity of customs clearance. If the goods have a low value, making use of the US $800 de minimis exemption limit for separate container declaration is also a cost-cutting strategy, but it should be noted that containerization may increase operational costs.