Nowadays, many industries need to use cartons, but if the hardness is not good, the articles packed in cartons will be easily deformed or seriously damaged. So how to enhance the hardness of cartons?

1、添加劑

1. Additive

這種方法就是在造紙前和造紙后向中添加各種化學晶，用于提高的粘結力，從而提高瓦楞紙箱的抗壓強度。這些添加劑包括如玉米、淀粉、膠、粘合劑和重金屬，及塑料和脲（甲）醛樹脂。有時，也采用化學品噴涂紙箱外層的方法來加強紙板。

This method is to add various chemical crystals before and after papermaking to improve the adhesion of corrugated boxes, so as to improve the compressive strength of corrugated boxes. These additives include corn, starch, gum, adhesives and heavy metals, as well as plastics and urea formaldehyde resins. Sometimes, chemicals are also used to spray the outer layer of the carton to strengthen the cardboard.

2、高壓

2. High pressure

高壓紙板成形法也是一種在造紙過程中增強紙板強度的方法。采用擴大紙上的受壓點來緊密地壓縮紙板。而紙板結構越緊密，強度就越大。高壓紙板成形也有助于從紙漿中擠出更多的水分，但是關鍵是要制成更緊密的紙板，提高其抗壓強度。

High pressure paperboard forming is also a method to enhance the strength of paperboard in the papermaking process. Expand the compression point on the paper to compress the paperboard tightly. The tighter the paperboard structure, the greater the strength. High pressure paperboard forming also helps to squeeze more water from the pulp, but the key is to make a tighter paperboard and improve its compressive strength.

3、交聯

3. Crosslinking

交聯是一種在造紙過程中改變方向的加工方法。通常紙是縱向平行走向的，這種箱子成型后水平方向圍繞在箱子周圍，而這是造成紙箱抵抗壓力的的壞方向。交聯則使許多與機器方向呈90度走向，加工結果是許多與箱邊上下垂直走向，這樣就能不增加而增加了紙箱堆碼強度。

Crosslinking is a processing method that changes direction in the papermaking process. Usually, the paper runs parallel in the longitudinal direction. After the box is formed, the horizontal direction surrounds the box, which is the bad direction that causes the carton to resist pressure. The cross-linking makes many 90 degrees to the direction of the machine, and the processing result is that many are perpendicular to the top and bottom of the box edge, so that the stacking strength of cartons can be increased without increasing.

4、層合

4. Lamination

這種增強瓦楞紙箱強度的方法是建立在兩層或更多層；芯紙層合的基礎上的。粘合劑可以是一種簡單的玉米淀粉粘合劑，產生一種強度的芯紙以夾在交聯的、加壓成形的或常規強度的紙中間。

This method of enhancing the strength of corrugated boxes is based on two or more layers; Based on core paper lamination. The adhesive can be a simple corn starch adhesive that produces a strong core paper to be sandwiched between cross-linked, pressure formed or conventional strength paper.