The warping of corrugated cardboard is a very headache, which seriously affects the quality of the next printing and slitting process. Due to the warping of the cardboard, it cannot be accurately positioned when entering the printing slotting machine, resulting in inaccurate overprinting, inconsistency in the position of the slotting and cutting corners and inability to fine-tune, and sometimes creases appear on the surface of the cardboard. The reason for the warping of single-sided corrugated cardboard is very simple, that is, the moisture content of the inner and (core) corrugated base paper is inconsistent or the thickness is inconsistent. Of course, there must be a definition of "warping" to prevent cardboard from warping. The author's understanding of the meaning of "warping" is that the single-sided (see pit) cardboard is determined to be corrugated as the upper side, and the arc is bent downward (bending in the direction of the inner paper). On the contrary, it is regarded as a downward warping.
Yog tias ib sab -ib sab (saib qhov pit) cardboard yog upturned, yog vim li cas yog cov dej cov ntsiab lus ntawm cov corrugated puag ntawv yog ntau dua li ntawm cov ntaub ntawv tseem ceeb. Yog hais tias nws warps down, yog vim li cas yog: cov dej cov ntsiab lus ntawm cov corrugated puag ntawv yog tsawg tshaj li ntawm cov core daim ntawv los yog cov gram ntawm lub puab core ntawv yog siab tshaj ntawm cov corrugated puag ntawv. Tom qab txiav txim siab qhov ua rau ntawm cardboard warping, nws yuav tsum tau daws nyias raws li cov kev taw qhia ntawm cardboard warping. Thaum ib zaug -ib sab (saib qhov pit) cardboard ntawm ib zaug -sab corrugating tshuab yog warped upward, lub tshav kub qhov chaw ntawm corrugated ntawv preheating rau cov menyuam rau ntawm ib tug - sided corrugating tshuab tuaj yeem muab tso rau, thiab ib los yog ob lub hnab ntawv preheating rau cov menyuam kub qhov chaw tuaj yeem muab tua tib lub sijhawm, thiab lub tsheb ceev yuav tsum raug txo kom raug. Nws yog ib qho tsim nyog yuav tsum tau ua kom cov cua sov ntawm cov nplais ntawv preheating rau cov menyuam (ua kom lub tshuab hluav taws xob ua kom sov, ua kom cov cua siab, thiab lwm yam) los yog nce lub kaum sab xis ntawm cov ntawv pobzeb ntawm cov menyuam preheating. Thaum warping, daim ntawv hauv ob sab phlu yuav tsum tau txau thiab humidified. Ua kom cov dej noo ntawm cov ntawv sab hauv thiab cov ntawv corrugated puag yuav luag tib yam.
Thaum ib zaug -ib sab (saib qhov pit) cardboard ntawm ib zaug -sab corrugating tshuab yog tilted downward, lub tshav kub qhov chaw ntawm corrugated ntawv preheating rau cov menyuam rau ntawm ib tug -sab corrugating tshuab yuav tsum muab tua, thiab ib los yog ob daim ntawv sab hauv preheating rau cov menyuam cov cua sov yuav tsum tau muab rau tib lub sijhawm. ceev. Thaum tseem muaj warpage, nws yog ib qho tsim nyog yuav tsum tau ua kom cov cua sov ntawm cov ntaub ntawv preheating rau cov menyuam los yog ua kom lub kaum sab xis ntawm cov ntaub ntawv preheating rau cov menyuam. Cov dej noo ntawm daim ntawv yog ze li qub. S- hom warpage ntawm ib zaug -ib daim duab los qhia feem ntau yog tshwm sim los ntawm qhov tsis sib xws ntawm cov dej noo hauv cov ntawv hauv paus. Raws li warpage, tus nqi ntawm cov kua nplaum tuaj yeem hloov kho raws li cov saum toj no -hais ua rau warpage, los yog cov ntawv hauv paus uas tsis tshua muaj ya raws tuaj yeem txau thiab ntub hauv zos. Nws yog qhov zoo dua los siv cov ntsuas dej noo los ntsuas cov dej noo ntawm sab hauv (core) thiab corrugated ntawv raws li ua ntej pib lub tshuab, thiab tom qab ntawd tswj qhov kub ntawm txhua tus menyuam raws li qhov sib txawv ntawm cov dej noo. Feem ntau hais lus, thaum cov duab los qhia tawm ntawm lub tshuab, khaws nws me ntsis upward (corrugated ntawv) warping, thiab txais yuav txoj kev rau pem hauv ntej thiab rov qab stacking. Tom qab li ib teev, cov duab los qhia yuav rov qab los rau hauv lub xeev tiaj tus.