The type listed first in the designation\u2014featuring a flute height of 4.5 to 5 mm and approximately 33 to 38 flutes per 30 cm\u2014is characterized by relatively large flutes. Its key features include spacious flute cavities, excellent cushioning, and strong vertical compression resistance, making it ideal for fragile items, glassware, and ceramics that require shock absorption. The trade-offs are increased board thickness and bulk; boxes of the same dimensions take up more space, fewer units fit into a given volume during stacking, and higher consumption of corrugating medium (inner paper) leads to higher costs. Additionally, the surface is not perfectly smooth, resulting in average print quality; it is best suited for box designs with simple graphics.<\/p>\n
Combining a tall-flute type with a short, dense-flute type creates five-layer board\u2014commonly known as “AB flute.” With a thickness of 7 to 8 mm and superior compression and cushioning capabilities, this robust structure is widely used for shipping appliances, machinery parts, heavy tools, and goods destined for long-distance ocean freight. However, the weight and volume of double-wall board are significant; the box’s own weight adds to shipping costs\u2014a factor that must be considered when rates are calculated by volume. Another configuration involves combining two medium-sized flute types; this results in a board that is thinner than standard five-layer double-wall board yet retains strong compression resistance, making it suitable for stacking scenarios that do not require extreme load-bearing capacity.<\/p>\n
Low, dense flutes provide a smooth surface and excellent printability.<\/p>\n
Corrugated board consists of outer liners and an inner corrugated medium; the medium is pressed into a wave-like shape, known as the “flute profile.” Flute profiles are categorized by flute height and the number of flutes per unit length. The industry assigns letter codes to these categories, with common types corresponding to specific ranges of thickness and strength. Flute profiles primarily influence three factors: board thickness, compression and cushioning performance, and surface smoothness (which determines printability). Taller flutes with fewer waves result in thicker board and superior cushioning but create a rougher surface, making it difficult to reproduce fine graphic details. Conversely, shorter flutes with more waves yield thinner, smoother board with better print quality, though cushioning performance is somewhat reduced. This trade-off is the starting point for selecting a flute type.<\/p>\n
The type with a flute height of 2.5 to 3 mm and approximately 47 to 52 flutes per 30 cm is commonly known in the industry as “B-flute.” With low, dense flutes, the resulting board is thin and has a smooth surface, allowing for clear printing of text and simple graphics; it is a common substrate for color-printed cartons and inner boxes. It offers good flat-surface compression and puncture resistance, making it suitable for products of moderate weight that do not require heavy cushioning, such as canned goods, bottled beverages, and small appliances. Its cushioning performance is inferior to that of high-flute types, so internal inserts are often used to provide additional protection for fragile items.<\/p>\n
Thin, smooth specifications are suitable for small-item packaging and color-printed cartons.<\/p>\n
Double-wall corrugated board is used for heavy goods and long-distance transport.<\/p>\n
Specifications that balance performance and cost are frequently used for export cartons.<\/p>\n
E-flute has a flute height of approximately 1.1 to 1.8 mm and 90 to 100 flutes per 30 cm, with a thickness comparable to heavy cardstock. It offers a smooth surface and excellent print fidelity, making it ideal for small packaging, color-printed cartons, inner boxes, and display stands; it is widely used for products like cosmetics, electronics, and toys that require both aesthetic appeal and a degree of protection. Its cushioning and compression resistance are relatively weak, so products that are heavy or subject to long-distance transit with multiple transfers usually require an additional outer shipping carton. The next thinner grade is typically called F-flute (or “micro-flute”) and is often used for small electronics and premium inner boxes.<\/p>\n
High-flute types offer good cushioning but require greater thickness and material usage.<\/p>\n
The category with a flute height of 3.5 to 4 mm\u2014commonly known as “C-flute”\u2014falls between the two types mentioned above, balancing compression resistance and thickness. While its cushioning performance is not as high as that of taller flute types, the board is thinner and takes up less space during stacking; offering a good balance of overall performance and cost, it is a highly versatile specification for international shipping. It accounts for a significant share of transport packaging in North America and Europe, and many clients specify it by default in their carton design drawings. If an order has no special requirements, starting with this grade is usually a safe bet. There is also a “D-flute” designation; while used in the past, it is now rarely seen among mainstream specifications.<\/p>\n
A client once sent an inquiry for a shipment of bottled sauces\u2014packed in cartons\u2014to be shipped by sea from the Port of Ningbo to Rotterdam. He had initially quoted based on the carton specifications commonly used for domestic courier services. I pointed out that for the same weight, simply changing the flute type could significantly alter the carton’s stacking strength; the bottom layer in a shipping container is often where failures occur first. He subsequently switched to a five-layer double-wall carton; although the cost per unit increased, the entire shipment arrived without any breakage. While the flute type might appear to be merely a matter of cardboard thickness, it actually determines whether the carton can withstand the journey to its destination.<\/p>\n
The flute type determines a carton’s load-bearing capacity, cushioning performance, and print quality.<\/p>","protected":false},"excerpt":{"rendered":"
The type listed first in the designation\u2014featuring a flute height of 4.5 to 5 mm and approximately 33 to 38 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24],"tags":[],"class_list":["post-1074","post","type-post","status-publish","format-standard","hentry","category-industry-updates"],"_links":{"self":[{"href":"https:\/\/www.chengtop1.com\/fr\/wp-json\/wp\/v2\/posts\/1074","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.chengtop1.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.chengtop1.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.chengtop1.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.chengtop1.com\/fr\/wp-json\/wp\/v2\/comments?post=1074"}],"version-history":[{"count":1,"href":"https:\/\/www.chengtop1.com\/fr\/wp-json\/wp\/v2\/posts\/1074\/revisions"}],"predecessor-version":[{"id":1075,"href":"https:\/\/www.chengtop1.com\/fr\/wp-json\/wp\/v2\/posts\/1074\/revisions\/1075"}],"wp:attachment":[{"href":"https:\/\/www.chengtop1.com\/fr\/wp-json\/wp\/v2\/media?parent=1074"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.chengtop1.com\/fr\/wp-json\/wp\/v2\/categories?post=1074"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.chengtop1.com\/fr\/wp-json\/wp\/v2\/tags?post=1074"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}