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 PTFE sheet molding and sintering of Contour-parallel spin
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| Fault Name |
Causes and Countermeasures |
| Pre-mold platen surface, and crack patterns |
(1) resin poor thermal stability. Should use a better thermal stability properties of the resin. (2) different batches of resin mix. Should use the same batch of resin. (3) pre-forming pressure is too high. Should be appropriately reduced. (4) improper pressure process control. Pressure should be slowly and evenly, does not allow the impact-type pressure. (5) mold mismatch. Mold with the structure should be improved. In addition, the mold should be placed in the press center of the table, a solid and reliable connection |
| Pre-mold platen surface roughness and the white spots |
(1) pre-forming pressure is too low. Per unit area should increase the pressure to maintain sufficient holding pressure time. (2) resin particle size too large. A smaller particle size of resin should be used to require an average particle size of resin, 25,200 pm |
| Pre-mold platen surface discoloration and depression |
(1) resin components of low impurity content is too high. Impurities should use less resin and to prevent the operation of foreign impurity entrainment. (2) Feeding uneven. Feeding should be uniform, dense line. (3) compression method is incorrect. Both sides should be pressurized. (4) The holding pressure time is insufficient. Should be an appropriate extension of time for holding pressure |
| Pre-Mold platen dimension inaccurate |
(1) resin molecular weight is too small or unevenly distributed. Should use the same batch number, performance, consistent resin. (2) pre-compression molding uneven. Should be evenly slowly pressurized. (3) non-uniform feeding. Mold kit should be uniform feeding, add ingredients Calibrating finished. (4) improper packing. At different pressure, must be given certain amount of holding pressure time, •, to ensure that all parts of the pressure delivered to the resin, the pressure the greater the pressure more slowly, holding pressure time should be longer |
| Sintered plate crack |
(1) heating or cooling too fast. Should be properly controlled rate of temperature rise. Typically, the heating rate of 0.4-1 â"ƒ / shelter no products the greater the heating rate should be slower when the temperature rose to about 330 â"ƒ, the plate outside the first began to melt, and then gradually penetrate inward. The use of a 1.5-3t / and n, heating rate, inward penetration of the melting rate of about 5-6 per mm thickness and no order for the entire A sheet to melt, we must control a certain time of heating rate and temperature. (2) The sintering temperature is too high. Should be appropriately reduced. (3) The holding time is too long. Should be appropriately reduced. (4), when the pre-manufactured Stripping bumps, leading to sintering cracks. Stripping should be careful to avoid collisions. Preform, the pressure slowly after pressure relief to prevent the product burst |
| Peeling thickness and uneven surface of the transverse wave |
(1) installation of non-performing blades. Should be adjusted appropriately. General peeling thickness 0.5-3mm plate, the knife sharp corners and 38 '; spin Cutting thickness o. 5mm, the knife sharp corners 34 ', the latter angle is generally not more than 5'. Tip height should be slightly more suitable than the spindle centerline. (2) Mandrel bad installation. Mandrel shall be adjusted or replaced. (3) clip knife device nut loose. Should be re-commissioning and installation of rotary knife knife block. (4) The cutting edge is not straight. Grinding should be carried out, or ATC |
| Peeled surface vertical scratches or cracks |
(1) parison contain metal impurities. Parking should be removed. (2) there are gaps in the blade. Should be grinding or tool change. (3), when peeling the hard impurities stuck in between the blade and peeling surfaces. Should stop processing, and should always clear the plates and the blade between the impurities |
| Sintered plate deformation |
(1) The holding time is too short. Should be appropriately extended. In order to sintering temperature uniform inside and outside pieces should be 300-330 â"ƒ under the conditions of heat for some time. (2) cooling down too fast. Should be properly slow down. Cooling rate related to the crystallization plates, is affecting the physical properties of the important parameters, cooling too fast, plate easily lead to strain and crack. -50 â"ƒ generally increases the speed of cooling the cooling of several more appropriate. "3) The furnace temperature unevenly distributed. Should increase the accuracy of temperature measurement points and temperature control, so that furnace temperature distributed evenly, it may be appropriate to extend the cooling time |
| Opaque sintered plate |
(1) The sintering temperature is too low. Should be appropriately increased. (2) The holding time is too short. Should be appropriately extended. It is noteworthy that in the resin thermal stability should be a good case can be extended appropriately increasing the sintering temperature and holding time |
| Board or intermediate raised on both sides of unequal length at both ends of Matsube |
(1) The sintering conditions unreasonable. Sintering conditions should be adjusted. Such as sintering temperature, heat and cooling times. (2) the blade is not parallel with the mandrel axis. Should be adjusted to parallel |
