"Kelp" is generally a sheet or floc that is suspended in a liquid resin or attached to a model or support surface. The 

formation of "kelp" is usually  due to some  newly  generated layers that are not attached to the previously generated 

layers,  which is different  from the bottoming  ( about  bottoming:  how to solve the  problem of model bottoming in 

pull-up  light curing  printing ? ) ,  These  newly  generated  layers  are not adhered to the release film, but fall into the 

liquid resin. As the molding platform moves up and down, the liquid surface shakes, and may still be suspended in the 

liquid resin, or stuck on the model or Support surface.

             Knowing the causes of "kelp", it is easy to find out which factors caused the formation of "kelp".
                                                                             Exposure time

       Insufficient  exposure  time  may  cause  the  layer  to fail to  fully  cure,  so  that  some semi-cured flocs continue

 to accumulate  in  the  liquid resin,  or part of the layer  directly falls into the liquid resin due to  adhesion  problems, 

and the accumulation becomes more flakes or Floc.

                                                                                  support

       Support  is  not  added  in  place,  especially  for  suspended and bridge positions.  If there is no support  in these

 positions,  or the  support cannot  play its due role,  these positions will fall due to lack of support during the printing 

process.  If the bottom is not attached to the release film,  it will accumulate into more flakes or flocs with the printing 

process.

                                                                                light source

       Attenuation  of  the  light  source  will  also  cause  problems  with  insufficient  curing  energy,  and  the  above-

mentioned semi-curing and adhesion problems will occur, forming flakes or floccules in the liquid resin, or sticking to 

the model or supporting surface.

                                                                              Screen contrast
 
       The  contrast  of the screen is low,  resulting in some areas of the screen where no image is output may also have 

light passing through. Although the intensity is not high, it will gradually accumulate to form flakes or flocs.