Fulfilled R&D projects

Finite element modeling and analysis of relief images pressing technological process on paper materials. Relief stamping method

Industry:
Keywords Relief stamping, paper, cardboard, polyurethane, stamp, pressing
Programs in use LS-DYNA, SolidWorks

Description of relief stamping method 
Elements used in relief stamping: a metal stamp with an engraved image, paper material or paperboard, a polyurethane plate. The relief image on the polyurethane is obtained by pressing the paperboard by the stamp into the polyurethane.

Рис. 1 Технологическая схема процесса тиснения
​Fig. 1. Manufacturing scheme of the relief stamping process

 

Рис. 2 Фотография штампа с набором тестовых выгравированных изображений

Fig. 2. Photo of a stamp with a set of engraved test images

The stamping process is followed by a by-effect - tension of paper material (Fig . 3). In addition, as a result of created pressure elastic material "leaks" outside the stamp area and bursts the paperboard by the stamp perimeter (Fig. 4).

. 3. Результат растяжения картона по сторонам в процессе тиснения
Fig. 3. The result of paperboard side tension during the stamping process

 

Рис. 4. Результат растяжения и прорыва по контуру штампа
Fig. 4. The result of tension and breach by the stamp contour 

Modeling of the relief stamping process is done for two different metal stamps (Fig. 5). The large stamp is the one with three columns of type-setting elements: square, rectangular and hemispherical. The small stamp is the one with a single column of type-setting elements (rectangular). 

Рис.5 Профиль штампов

Fig. 5. Stamp profiles
 

Small stamp:

Sheet of paper. Contours of z-axis deformations. Click to view animation Polyurethane mat. Contours of z-axis deformations. Click to view animation
Sheet of paper. Contours of z-axis deformations.  Polyurethane mat. Contours of z-axis deformations.


Large stamp:

Sheet of paper. Contours of z-axis deformations. Click to view animation Polyurethane mat and sheet of paper. Contours of z-axis deformations. Click to view animation
Sheet of paper. Contours of z-axis deformations. Polyurethane mat and sheet of paper.
Contours of z-axis deformations.


During the relief stamping process thinning of a perforated sheet occurs, which can lead to paper rupture. The paper thinning typical for the studied process is represented in Fig. 6. The initial (paper) thickness is equal to 0.1 mm. The most probable rupture zones are located in the areas of connection of the paper with side surfaces.  

Рис.6 Изменение толщины бумаги (мм)

Fig. 6. Variation of paper thickness (mm)

 

Большой штамп. Поле перемещений. Лист бумаги

The large stamp. Displacement field (m). Paper sheet

 

Большой штамп. Поле перемещений. Полиуретановая подложка

The large stamp. Distribution field (m). Polyurethane base plate

Other materials on topic:
Material Study