Hot Air Stenter Troubleshooting Analysis

• Posted by licheng flatprinter November 10, 2020 - Filed in Business - #Hot Air Stenter  #open rotary screen printer  - 1,164 views

  (1) The deviation of the printing guide belt: The open rotary screen printer must undergo deviation correction operation and trimming of the guide belt during installation and debugging, so that the deviation of the printing guide belt is controlled within the correctable range. However, with the extension of use time, the deviation of the conduction band may become larger and larger and become out of control. There are many factors that affect the deviation of the printing belt. In summary, the main points are as follows: the deformation of the printing belt, the uneven tension control of the belt tension roller, the different supporting force of the supporting roller, and the obstruction or failure of the correction device.

   

  (2) Twisted or broken screen: The twisted or broken screen of the printing machine during the printing process often interrupts the production and affects the normal production. At the same time, it has varying degrees of impact on product quality and production costs. There are many factors that lead to network twisting or disconnection, and the following are analyzed one by one:

  ①The influence of printing belt:

  
  ②The influence of assembly: Carelessness during installation and debugging will often cause network twisting or disconnection.

  
  ③Operational influence: Operational errors can also cause fatal damage to the rotary screen. When loading and unloading the rotary screen, two people must cooperate with each other, and the action should be light. Do not make the rotary screen bump against other hard objects. Any inadvertent bump will bring hidden dangers to the normal use of the rotary screen. In addition, be careful when loading and unloading the scraper. Never bump the wall of the net. Once you leave a scar on the round net, it may become a breach of fracture. In addition, the tension of the cylinder must be appropriate, and the pressurization of the scraper must be gentle and without impact. To achieve this, the one-way throttle valve on the scraper lift air path should be properly adjusted to make the air flow smooth and without obvious impact.

  ④Other influencing factors: In addition to the above-mentioned factors, the factors that affect the twisting of the rotary screen include the selection of the material of the rotary screen, the bonding of the head and the rotary screen, and the maintenance of the rotary screen. No link should be neglected.

  (3) Slurry blocking: The open rotary screen printer may block the slurry during use. The main reasons for plugging are as follows

  several aspects:

  1. The influence of the grey fabric: the grey fabric has not been properly dust-removed before entering the printing belt, which will often make the surface of the grey fabric gray, fluff and impurities to block the circular mesh holes. The operator can achieve the purpose of dust removal by adjusting the pressure of the brush roller on the gray cloth in the dust removal device according to the cleanness of the gray cloth to ensure that the gray cloth entering the printing belt is clean.
  2. The influence of the slurry: If the printing slurry is not well filtered before use, the impurities and insoluble particles in the printing slurry will be beaten into the cylinder along with the slurry through the slurry supply device, which will block the mesh and cause The slurry is difficult to penetrate, and the viscosity of the printing slurry also has a certain effect on the permeability.
  3. The influence of rotary screen: In actual production and application, nickel screens of different meshes should be selected according to different fabric varieties and different patterns. Generally speaking, 31.5~39.4 mesh/m (80~100 mesh) mesh is more suitable for printing general patterns, and 49.2 mesh/cm (125 mesh) or even higher meshes for individual fine lines.的网。 When a patterned round net is unloaded and not in use, the round net should be cleaned immediately, and the slurry attached to the wall and head of the net should be washed off, and then the round net should be carefully placed in a clean and dust-free room. When using pigment printing, the same measures should be taken to prevent the clogging of the mesh and the slurry path.

  (4) Flower escape: When the open rotary screen printer is printing multi-color patterns, the precise positional relationship between the colors during the printing process cannot be maintained in a stable state, which leads to the dislocation of the pattern, and the result of the dislocation makes the color difference The phenomenon of showing whiteness or coloring is called escape from flowers. The phenomenon of flower escape is caused by a combination of many factors, and the main points are as follows:

  ① Transmission error: When designing, the running speed of the cylinder guide belt is 2% faster than the circular running linear speed of the cylinder. ~4%. Left right. Once the speed difference between the two is too large or the conduction belt slips during operation, the pattern between the colors will be misaligned, resulting in flower escape.

  ②Registration error: the adjustment range of the open rotary screen printer's registration is: longitudinal registration ±20mm, realized by differential structure (magnetic bar type open rotary screen printer is not limited); horizontal registration is ±10mm, realized by thread structure ; Oblique alignment ±3mm, realized by eccentric structure. The change of the gap between the parts of the open rotary screen printer adjustment mechanism and the looseness of the cam pair will affect the accuracy of the open rotary screen printer and cause the phenomenon of flower escape. Therefore, the severely worn parts in this mechanism should be removed and replaced in time. In addition, it should be checked whether the "0" ring in the longitudinal damping system is invalid. If it fails, it should be replaced in time to prevent the resulting flower escape. phenomenon.

  ③Scraping error: If the installation of the squeegee blade is not firm, the straightness is not good, or the width of the squeegee blade is inconsistent with the scale marked on the squeegee support, it will cause the pattern to be misaligned and cause flower escape.

  ④Operation error: The phenomenon of flower escape caused by operating error is mainly manifested in the sudden lifting of the printing machine, the abuse of the emergency stop button, and the unevenness of the fabric seam. The most fundamental way to avoid these influencing factors is to do a good job in personnel training and management, and to produce in strict accordance with operating regulations and process regulations.

  ⑤The nature of the fabric itself: the nature of the fabric itself is unstable, there is pre-stress before printing, and it will shrink when it encounters the printing paste or paint during the printing process, which will cause escaped flowers. Therefore, try to choose the pre-treated grey cloth. In addition, prior to printing, thermoplastic or water-soluble patch glue should be selected according to the different types of fabrics, so that the gray fabric will not shrink and shift when it is pasted on the printing belt, so as to avoid the escape caused by the shrinkage of the fabric. Flower phenomenon.

  ⑥Other factors: The deviation of the guide belt during the operation of the Hot Air Stenter, the loosening of the cylinder beam, the failure of the netting cylinder, the congenital manufacturing error of the nickel net and other factors will cause the pattern to be misaligned and cause escape. Therefore, measures should be taken to eliminate them according to different situations.