Abstract:
This invention is related to a manufacturing method of a printing plate by using a free-seal, free-quantity liquid photopolymer sachet and an apparatus thereof. Using this technology, the liquid photopolymer sachet is no longer to be limited by quantity with 3 dimensions—width, length and thickness. It is now very free, easy and convenient to use liquid photopolymer resin in a bag to make a printing plate at any width and length with any thickness you want.

Description:
BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The invention relates to a manufacturing method of a printing plate using a liquid photopolymer sachet and an apparatus using the same, and more particularly to a manufacturing method of a printing plate using a liquid photopolymer sachet, which can be freely sealed and freely quantified, to replace a conventional liquid photopolymer sachet, which has been completely sealed and contained the quantified liquid photopolymer. 
     (2) Description of the Prior Art 
     At present, the plate making methods of manufacturing a printing plate from a negative film includes a precoating method and a non-precoating method. The precoating method is to use a molded polymer plate, which has the fixed length, width and thickness, as a printing plate body, and a pattern the same as that of the negative film is formed on the polymer plate by way of exposing, washing and other procedures so that the printing plate is manufactured. In the non-precoating method, the molded polymer plate is not used, but a liquid photopolymer is used as an original material. In this method, the liquid photopolymer encloses a range having the fixed length, width and thickness, and then the exposure and harden procedures are performed so that the printing plate is formed after the washing procedure. The typical non-precoating method is performed in conjunction with an exposure machine. In addition, before the molding and exposing procedures are performed, the following steps are necessary. As shown in  FIG. 1  in conjunction with the operation guide of the conventional exposure machine, a drawer A 1  for exposure of the exposure machine is opened (pulled out). A clamping plate device composed of two pieces of transparent glass A 2  and A 3  is disposed in the drawer A 1 , wherein suction channels are typically provided in the sandwich layer of the clamping plate so that air can be sucked at a time simultaneously. Then, the upper glass A 2  of the clamping plate is opened, a negative film A 4  is placed on the lower glass A 3 , and supporting columns A 5  are disposed at four corners. Next, a covering film A 6  is placed on the negative film so that the liquid photopolymer is completely isolated from the negative film to protect it. Then, a close frame A 7  is provided around the negative film using a rubber tape as a thickness gauge. Next, a quantified liquid photopolymer is poured into the frame A 7 . The liquid photopolymer is typically contained in a canned container, the poured quantity of the liquid photopolymer has to be properly controlled, and no bubble is allowed to be formed therein. If a bubble is formed, it must be removed. Thus, a uniform liquid photopolymer layer A 8  having the suitable thickness can be formed. Then, a plastic film, such as a polyethelyne polyester, is applied to the surface of the liquid photopolymer layer A 8  to serve as a base film A 9 . The plastic film has to be applied to the liquid photopolymer layer A 8  from the middle portion to the outer edges very carefully in order to prevent the bubble from being generated between the base film A 9  and the liquid photopolymer layer A 8 . Next, the upper glass A 2  covers the lower glass A 3  tightly so that the assembly of  FIG. 1  is formed. Then, the drawer A 1  is pushed into the exposure machine to perform the exposure procedure, in which a light source A 10  illuminates the drawer A 1  from the bottom to the top. After the exposure procedure, the printing plate having the base film A 9  and the partly hardened photosensitive portion of the liquid photopolymer layer A 8  is taken out, and a solvent or water is used to perform the washing procedure so that the printing plate having the base film A 9  is formed, as shown in  FIG. 2 . However, the above-mentioned procedures are very complicated. In particularly, the quantity of the material of the liquid photopolymer layer A 8  poured into the frame A 7  has to be properly controlled, and the operator has to be very familiar with the technique to prevent the bubble from being generated, or otherwise the molding quality of the printing plate cannot be ensured. In addition, the liquid photopolymer in the opaque portion after the exposure procedure cannot be hardened and can be recycled. However, the liquid photopolymer in the above-mentioned procedure is placed in an open manner and thus cannot be easily collected. So, it is disadvantageous to the recycling operation and the environment protection purpose. 
     Also, the inventor has disclosed a liquid photopolymer sachet dedicated for the printing and plate making in a non-precoating method in Taiwan Patent Number M259927 in order to solve the drawback of the manufacturing method of the printing plate in the typical non-precoating method. In the M259927 patent, the technical report of the utility patent with the comparison result coded “6” is obtained, wherein a flat transparent sachet body B 10  is used, as shown in  FIG. 3 , and a suitable quantity of liquid photopolymer B 20  is contained in the thin sachet body according to the inner size of the thin sachet body. Thus, a closed liquid photopolymer sachet B 1  is formed and can be directly placed into the clamping plate and flattened to form a liquid photopolymer structure layer as a printing plate body during the plating making procedure of the non-precoating method. However, the liquid photopolymer sachet B 1  is a closed sachet body having the outer sachet body B 10  being completely sealed, and the liquid photopolymer B 20  contained therein has been completely quantified. That is, the liquid photopolymer sachet B 1  is a completely sealed and quantified liquid photopolymer sachet. When the printing plate is to be manufactured, the liquid photopolymer sachet B 1  having accurate quantity corresponding to the specifications (i.e., length, width and thickness) has to be selected or provided according to the printing plate so that the plate making procedure can be performed. However, the specification of the printing plate size and the thickness are in variations. Therefore, it is not so easy to prepare an accurate liquid photopolymer sachet B 1  having the completely corresponding specifications, or many sachets have to be prepared in stock so that the plate maker may select a proper liquid photopolymer sachet B 1 . But if a bigger liquid photopolymer sachet B 1  is selected, the liquid photopolymer is wasted. This invention is made based on the drawbacks of the conventional liquid photopolymer sachet B 1 . 
     SUMMARY OF THE INVENTION 
     The main object of the invention is to provide a manufacturing method of a printing plate using a liquid photopolymer sachet, which can be freely sealed and freely quantified, and an apparatus using the same. The liquid photopolymer sachet, which may be freely sealed and freely quantified, is provided according to the specifications (length, width and thickness) and in accordance with the quantity to a to-be-manufactured printing plate. The transparent sachet may have the non-restrictive shape and has at least one side, which is not sealed. The transparent sachet can be freely quantified so that the liquid photopolymer can be poured therein. The input quantity of the liquid photopolymer can be greater than the estimated quantity of the printing plate. Then, the transparent sachet is evenly placed on a lower transparent clamping plate, and a negative film to form printing image may be interposed between the transparent sachet and the lower transparent clamping plate. That is, the negative film is placed below the transparent sachet or above the transparent sachet. Thickness gauges are disposed around the transparent sachet body. The thickness of the gauge is equal to a sum of a predetermined thickness of the printing plate, a thickness of two layers of the transparent sachet and a thickness of the negative film. At least one thrust rod, which can roll or slide freely and has a diameter or height smaller than the thickness of the gauge, is provided to press against the liquid photopolymer transparent sachet in parallel to the side, which is not sealed, at a position distant from the side, which is not sealed, by a distance such that a stop end, which is movable relative to the liquid photopolymer contained in the liquid photopolymer transparent sachet, is formed to temporarily stop the liquid photopolymer. Thus, the liquid photopolymer contained in the liquid photopolymer transparent sachet is higher than the thickness gauge to prevent the liquid photopolymer from flowing to the side of the liquid photopolymer transparent sachet, which is not sealed. Then, an upper transparent clamping plate is provided to press against the lower transparent clamping plate evenly and thus to flatten the liquid photopolymer transparent sachet to a thickness the same as the thickness of the gauge. The liquid photopolymer, which is contained in the liquid photopolymer transparent sachet and higher than the thickness gauge, can freely flow to the side that is not sealed during the flattening, and push the thrust rod outwards until the thrust rod is stopped naturally so that the liquid photopolymer contained in the liquid photopolymer transparent sachet is formed into a uniform liquid photopolymer layer, which has a predetermined thickness and serves as a printing plate body. Then, subsequent exposure and hardening procedures are performed. Next, an exposed printing plate body is taken out of the transparent sachet after the exposure and hardening procedures are finished. Then, a washing procedure is performed to finish the printing plate. Thus, it is possible to avoid the drawbacks that the conventional method of manufacturing the printing plate using the liquid photopolymer sachet, which is completely sealed and quantified, and to simplify the manufacturing processes of the printing plate and the plate making apparatus so that the manufacturing cost and the apparatus cost of the printing plate can be reduced and the working efficiency of the plate making can be enhanced. 
     Still another object of the invention is to provide a manufacturing method of a printing plate using a liquid photopolymer sachet, which can be freely sealed and freely quantified, and an apparatus using the same. When the transparent sachet is evenly disposed on a lower transparent clamping plate and a negative film is interposed between the transparent sachet and the lower transparent clamping plate (i.e., disposed below the transparent sachet), suction channels can be provided to perform a vacuuming procedure so that the transparent sachet, the negative film and the lower transparent clamping plate can tightly contact with each other to prevent gaps from being formed therebetween. Thus, the image precision in the subsequent negative film exposure procedure may be enhanced. 
     Yet still another object of the invention is to provide a manufacturing method of a printing plate using a liquid photopolymer sachet, which can be freely sealed and freely quantified, and an apparatus using the same. When an upper transparent clamping plate is provided to evenly press against a lower transparent clamping plate, suction channels may be utilized to perform a vacuuming procedure again so that the upper transparent clamping plate can tightly contact with the transparent sachet to prevent gaps from being formed therebetween and from influencing the plate evenness of thickness. Then, an upper light source for the plate bottom exposure procedure is disposed above the upper transparent clamping plate to perform the plate bottom exposure procedure so that the exposure procedure of the liquid photopolymer is finished. 
     Yet still another object of the invention is to provide a manufacturing method of a printing plate using a liquid photopolymer sachet, which can be freely sealed and freely quantified, and an apparatus using the same. A transparent plastic film may be further provided to cover an upper surface of the transparent sachet so that the plastic film is interposed between upper and lower transparent clamping plates and has the function of air isolation. Thus, airtight upper and lower airtight spaces may be respectively formed between the plastic film and both the lower transparent clamping plate and the upper transparent clamping plate. When vacuuming procedures are performed in the upper and lower airtight spaces using suction channels, the upper and lower transparent clamping plates may tightly contact with the transparent sachet and the negative film to prevent gaps from been formed therebetween so that the working efficiency of the vacuuming procedure can be enhanced. 
     Yet still another object of the invention is to provide a manufacturing method of a printing plate using a liquid photopolymer sachet, which can be freely sealed and freely quantified, and an apparatus using the same. When a plastic film is provided to cover an upper surface of the transparent sachet so that airtight upper and lower airtight spaces are respectively formed between the plastic film and both the upper and lower transparent clamping plates, the vacuuming procedures of the upper and lower airtight spaces may be performed when the upper and lower transparent clamping plates are to be pressed against each other so that the manufacturing processes can be simplified and the working efficiency can be enhanced. Also, because the plastic film is a transparent film, it cannot influence the transmission of the light source for the exposure procedure. Thus, it is unnecessary to remove the plastic film when the exposure procedure is being performed. 
     Yet still another object of the invention is to provide a manufacturing method of a printing plate using a liquid photopolymer sachet, which can be freely sealed and freely quantified, and an apparatus using the same. Upper and lower transparent clamping plates may be disposed on the same machine base, an upper light source for a plate bottom exposure procedure may be disposed above the upper transparent clamping plate, and a lower light source for a negative film exposure procedure may be disposed below the lower transparent clamping plate so that the light rays of the upper and lower light sources for exposure may respectively or simultaneously perform the plate bottom exposure procedure and the negative film exposure procedure to the liquid photopolymer layer in the transparent sachet through the upper and lower transparent clamping plates. Thus, the manufacturing processes can be simplified and the working efficiency can be enhanced. 
     Yet still another object of the invention is to provide a manufacturing method of a printing plate using a liquid photopolymer sachet, which can be freely sealed and freely quantified, and an apparatus using the same. Various apparatuses to be used in conjunction with the manufacturing method include upper and lower transparent clamping plates, suction channels, an upper light source disposed above the upper transparent clamping plate and used for a plate bottom exposure procedure, a lower light source for a negative film exposure procedure disposed below the lower transparent clamping plate, and a transparent plastic film for air isolation. The structures may be disposed on the same machine base so that various operation flows, such as the vacuuming procedure, the pressing operation of the upper and lower transparent clamping plates, and the negative film or plate bottom exposure procedure, can be conveniently operated and performed, and the best plate making effect that the upper and lower parts are respectively or simultaneously vacuumed and exposed can be achieved. 
     Further aspects, objects, and desirable features of the invention will be better understood from the detailed description and drawings that follow in which various embodiments of the disclosed invention are illustrated by way of examples. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic illustration showing an enlarged cross-sectional view of a structure, in which a liquid photopolymer is placed before an exposure procedure in a conventional non-precoating method for making a plate. 
         FIG. 2  is a schematically cross-sectional view showing a side surface of a printing plate finished in  FIG. 1 . 
         FIG. 3  is a schematic illustration showing an enlarged cross-sectional view of a structure, in which a liquid photopolymer sachet dedicated for printing and plate making is used in the conventional non-precoating method. 
         FIG. 4  is a pictorial view showing a manufacturing process and the associated apparatuses of the invention, in which a negative film is placed below a transparent sachet, according to an embodiment of the invention. 
         FIG. 5  is a side surface cross-sectional view showing an embodiment of the invention, in which the negative film is placed below the transparent sachet, and an upper transparent clamping plate and a lower transparent clamping plate are not pressed against each other. 
         FIG. 6  is a side surface cross-sectional view showing an embodiment of the invention, in which the negative film is placed below the transparent sachet, and the upper clamping plate and the lower transparent clamping plate have been pressed against each other. 
         FIG. 6A  is a schematically cross-sectional view showing positions of the upper and lower transparent clamping plates, upper and lower light source devices for the exposure procedure, the plastic film, the liquid photopolymer transparent sachet and the negative film according to the embodiment of  FIG. 6 , in which the negative film is placed below the transparent sachet. 
         FIG. 7  is a side surface cross-sectional view showing another embodiment of the invention, in which the negative film is placed above the transparent sachet, and the upper clamping plate and the lower transparent clamping plate have been pressed against each other. 
         FIG. 7A  is a schematically cross-sectional view showing positions of the upper and lower transparent clamping plates, upper and lower light source devices for the exposure procedure, the plastic film, the liquid photopolymer transparent sachet and the negative film according to the embodiment of  FIG. 7 , in which the negative film is placed above the transparent sachet. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The above-mentioned and other features and advantages of the invention will be described in detail with reference to the accompanying drawings. 
     As shown in  FIGS. 4 to 7 , the invention provides a manufacturing method of a printing plate using a liquid photopolymer sachet, which may be freely sealed and freely quantified, and an apparatus using the same. The embodiment includes the following steps and associated apparatuses. 
     First, a liquid photopolymer transparent sachet  20  is provided according to molding specifications of a to-be-manufactured printing plate, such as the length, width and thickness of the printing plate, or according to the dimensional size of a negative film  10  and an estimated thickness. The liquid photopolymer transparent sachet  20  includes a transparent sachet  21  and a liquid photopolymer  22  accommodated therein. The shape of the transparent sachet  21  is not particularly restricted. The user can prepare the transparent sachet  21  using a sealing machine or tape to freely seal two plastic film sheets  21   a  according to the requirements in the length, width and height of the printing plate. In addition, at least one side of four peripheral sides of the transparent sachet  21  is not sealed so that an opening end  23  is formed. Herein, the so-called “free-seal” is due to that the conventional liquid photopolymer sachet (B 1 ) is a liquid photopolymer sachet having four peripheral sides completely sealed. So, its dimensional sizes have been restricted, and the user only can choose a suitable sachet having the fixed sizes and cannot choose the sizes of the transparent sachet  21  according to the requirements, such as the molding specifications of the printing plate or the dimensional sizes of the negative film  10 . Thus, the transparent sachet  21  cannot be freely sealed to form any shape so that the opening end  23  cannot be formed. Also, the user can freely quantify the liquid photopolymer  22  to be put into the transparent sachet  21  from the opening end  23  of the transparent sachet  21  so as to form the liquid photopolymer transparent sachet  20 . Herein, the so-called “free-quantity” is due to that the conventional liquid photopolymer sachet (B 1 ) is a liquid photopolymer sachet having four peripheral sides completely sealed. Thus, the liquid photopolymer has been packaged in a quantified manner and the quantity of the liquid photopolymer cannot be freely determined. Therefore, the user only can choose a suitable sachet, and cannot freely decide the total quantity of the liquid photopolymer  22  to be put into the transparent sachet  21  according to the molding specifications (the length, the width and especially the thickness) of the printing plate. Consequently, the invention is entitled “Manufacturing Method Of Printing Plate Using Free-Seal And Free-Quantity Liquid Photopolymer Sachet And Apparatus Using The Same”, wherein the liquid photopolymer sachet, which can be freely sealed and freely quantified, is directed to the liquid photopolymer transparent sachet  20 . Also, the input quantity of the liquid photopolymer  22  in the transparent sachet  21  may be greater than the estimated quantity of the printing plate. 
     Then, the liquid photopolymer transparent sachet  20  is evenly placed on a lower transparent clamping plate  30 . In this embodiment, as shown in  FIGS. 4 ,  5 ,  6  and  6 A, the negative film  10  for plate making is interposed between the liquid photopolymer transparent sachet  20  and the lower transparent clamping plate  30 . That is, the negative film  10  is disposed below the liquid photopolymer transparent sachet  20 . However, the negative film  10  may also be disposed above the liquid photopolymer transparent sachet  20 , as shown in  FIGS. 7 and 7A . 
     Next, four thickness gauges  40  are disposed around the liquid photopolymer transparent sachet  20 . As shown in  FIG. 4 , the four thickness gauges  40  are respectively disposed on the four peripheral sides of the liquid photopolymer sachet  20 . The thickness of the thickness gauge  40  is equal to a sum of a predetermined thickness of the molded printing plate, the thickness of two layers of the sachet sheets of the transparent sachet  21  (i.e., two plastic film sheets  21   a ), and the thickness of the negative film. 
     Then, at least one thrust rod  50  capable of freely rolling or sliding is provided. The thrust rod  50  may be a circular rod or have any other shape, and the diameter or height of the thrust rod  50  is smaller than the thickness of the thickness gauge  40 . When the upper and lower transparent clamping plates are pressed against each other, the thrust rod  50  is placed in parallel to the side and placed at a position distant from the opening end  23  of the liquid photopolymer sachet  20 , which is not sealed, by a distance. Thus, a stop end, which is movable relative to the liquid photopolymer  22  contained in the liquid photopolymer transparent sachet  20 , is formed. That is, the liquid photopolymer  22  contained in the liquid photopolymer sachet  20  is pushed away from the opening end  23  toward the sealed side of the sachet and is temporarily stopped to prevent it from flowing to the side of the opening end  23  that is not sealed. Thus, the liquid photopolymer transparent sachet  20  containing the liquid photopolymer  22  therein is correspondingly formed with a bump  20   a , wherein the height of the bump  20   a  may be higher than the thickness gage  40 , as shown in  FIGS. 4 and 5 . 
     Next, an upper transparent clamping plate  60  is used to press against the lower transparent clamping plate  30  and thus to flatten the liquid photopolymer transparent sachet  20  so that the sachet  20  has the thickness the same as the thickness of the thickness gage  40  around the sachet  20 . During the flattening procedure, the liquid photopolymer  22  contained in the sachet and higher than the bump  20   a  of the thickness gauge  40  is forced to flow to the opening end  23  on the side that is not sealed, and the flow of the liquid photopolymer  22  can simultaneously push the thrust rod  50  outward until it naturally stops, as shown in  FIGS. 4 and 6 . At this time, the liquid photopolymer  22  contained in the liquid photopolymer transparent sachet  20  can face the negative film and thus form a uniform liquid photopolymer layer ( 22 ), which has the predetermined thickness, to serve as the body of the printing plate. As shown in  FIGS. 6 and 6A , the liquid photopolymer  22  is disposed above the negative film  10 . As shown in  FIGS. 7 and 7A , the liquid photopolymer  22  is disposed below the negative film  10 . 
     Then, a light source device  70  is provided to perform the subsequent exposure and hardening operations, as shown in  FIG. 6 . The exposure procedure includes a negative film exposure procedure and a plate bottom exposure procedure. When the negative film  10  for plate making is interposed between the liquid photopolymer transparent sachet  20  and the lower transparent clamping plate  30  (i.e., disposed below the liquid photopolymer transparent sachet  20 ), as shown in  FIGS. 6 and 6A , the light source device  70 ( 70   a ) for the negative film exposure procedure is disposed below the lower transparent clamping plate  30  so that the negative film exposure procedure can be performed. The light source device  70 ( 70   b ) for the plate bottom exposure procedure is disposed above the upper transparent clamping plate  60  so that the plate bottom exposure procedure can be performed. When the negative film  10  for plate making is placed above the liquid photopolymer transparent sachet  20 , as shown in  FIGS. 7 and 7A , the light source device  70  disposed below the lower transparent clamping plate  30  is changed to the light source device for the plate bottom exposure procedure, and the light source device  70  disposed above the upper transparent clamping plate  60  is changed to the light source device for the negative film exposure procedure so that the negative film exposure procedure can be performed. Thus, the light rays of the light source for the lower exposure and the upper exposure can respectively or simultaneously perform the negative film exposure procedure and the plate bottom exposure procedure on the liquid photopolymer layer ( 22 ) in the liquid photopolymer transparent sachet  20  through the lower and upper transparent clamping plates  30  and  60 . 
     Then, after the exposure and hardening procedures are completed, the exposed printing plate body ( 22 ) is taken out of the liquid photopolymer transparent sachet  20  and then the printing plate is formed through the washing procedure. 
     As mentioned hereinabove, the manufacturing method of the printing plate and the apparatus using the same according to the invention can avoid the drawbacks caused when the printing plate is manufactured using the completely sealed and quantified liquid photopolymer sachet. In addition, the manufacturing processes of the printing plate and the plate making machine apparatus can be simplified. Thus, the apparatus cost and the manufacturing cost of the printing plate can be reduced, and it is advantageous to the enhancement of the working efficiency of the plate making. 
     In the manufacturing processes of the invention, when the liquid photopolymer transparent sachet  20  is evenly placed above the negative film  10 , which is placed on the lower transparent clamping plate  30  in advance, that is, the negative film  10  is interposed between the liquid photopolymer transparent sachet  20  and the lower transparent clamping plate  30  (i.e., the negative film  10  is disposed below the liquid photopolymer transparent sachet  20 ), a suction channel can be provided to perform a vacuuming procedure through a lower vacuuming port  80   a  so that the liquid photopolymer sachet  20 , the negative film  10  and the lower transparent clamping plate  30  may tightly contact with each other to prevent gaps from being formed therebetween and thus to enhance the image precision in the subsequent negative film exposure procedure. Because the suction channel and the lower vacuuming port  80   a  may be easily arranged by one of ordinary skill in the art, the detailed structures will be omitted. 
     Also, in the manufacturing processes of the invention, when the upper transparent clamping plate  60  and the lower transparent clamping plate  30  are evenly pressed against each other, another suction channel may be provided to perform another vacuuming procedure through an upper vacuuming port  80   b . Thus, the upper transparent clamping plate  60  and the liquid photopolymer transparent sachet  20  may tightly contact with each other to prevent gaps from being formed therebetween and thus influencing the even effect of the plate being made. Also, a light source device  70   b , which is disposed above the upper transparent clamping plate  60  and used for the plate bottom exposure procedure, is provided to perform the plate bottom exposure procedure so that the exposure and hardening procedures of the liquid photopolymer are completed. Because the suction channel  80  and the lower vacuuming port  80   a  may be easily arranged by one of ordinary skill in the art, the detailed structures will be omitted. 
     The manufacturing processes of the invention may further utilize a transparent plastic film  90  to cover over the liquid photopolymer transparent sachet  20  and thus to enhance the operation convenience. When the negative film  10  for plate making is interposed between the liquid photopolymer transparent sachet  20  and the lower transparent clamping plate  30  (i.e., disposed below the liquid photopolymer transparent sachet  20 ), the transparent plastic film  90  covers over the liquid photopolymer transparent sachet  20 , as shown in  FIGS. 6 and 6A . When the negative film  10  for plate making lies on the upper surface of the liquid photopolymer transparent sachet  20 , the transparent plastic film  90  covers over the negative film  10  of the liquid photopolymer transparent sachet  20 , as shown in  FIGS. 7 and 7A . Thus, the plastic film  90  is interposed between the upper transparent clamping plate  60  and the lower transparent clamping plate  30  and has the function of air isolation so that lower and upper airtight spaces  90   a  and  90   b  are respectively formed between the plastic film  90  and both the lower transparent clamping plate  30  and the upper transparent clamping plate  60 , as shown in  FIGS. 6 and 7 . When the lower and upper airtight spaces  90   a  and  90   b  are being respectively vacuumed using the suction channels through the lower and upper vacuuming ports  80   a  and  80   b , the upper and lower transparent clamping plates  60  and  30  can be tightly contact with the liquid photopolymer transparent sachet  20  and the negative film  10  interposed therebetween to prevent the gaps from being formed so that the working efficiency of the vacuuming procedure can be enhanced. As shown in  FIGS. 6 and 7 , a leakage protection ring  91  may be disposed at the periphery of the plastic film  90  so that the airtight effect of the upper and lower airtight spaces formed by the plastic film  90  may be enhanced. 
     Also, in the manufacturing processes when the transparent plastic film  90  is provided to cover over the liquid photopolymer transparent sachet  20  so that the lower and upper airtight spaces  90   a  and  90   b  are formed between the plastic film  90  and both the upper and lower transparent clamping plates  60  and  30 , the vacuuming procedures of the lower and upper airtight spaces  90   a  and  90   b  may be separately or simultaneously performed. That is, the vacuuming procedures may be formed while the upper and lower transparent clamping plates  60  and  30  are to be pressed against each other simultaneously so that the manufacturing processes can be simplified and the working efficiency can be enhanced. Also, because the plastic film  90  is a transparent film, it cannot influence the transmission of the light source of the exposure procedure. Therefore, it is unnecessary to remove the plastic film  90  when the exposure procedure is being performed. 
     Among various apparatuses to be used in conjunction with the manufacturing method of the invention, the upper and lower transparent clamping plates  60  and  30  may be disposed on the same machine base  1 , as shown in  FIGS. 6 and 7 . In addition, the upper light source device  70   b  for the plate bottom exposure procedure is disposed above the upper transparent clamping plate  60 , and the lower light source device  70   a  for the film exposure procedure is disposed below the lower transparent clamping plate  30 . Thus, the light rays of the upper and lower light sources for the upper exposure and the lower exposure can respectively or simultaneously perform the plate bottom exposure procedure and the negative film exposure procedure on the liquid photopolymer layer, which is flattened and has the uniform thickness and accommodated within the liquid photopolymer transparent sachet  20  respectively through the upper and lower transparent clamping plates  60  and  30  so that the manufacturing processes can be simplified and the working efficiency can be enhanced. 
     Also, various apparatuses, which are used in conjunction with the manufacturing method of the invention and include the upper and lower transparent clamping plates  60  and  30 , the suction channels, the lower light source device  70   a  for the negative film exposure procedure below the lower transparent clamping plate  30 , the upper light source device  70   b  for the plate bottom exposure procedure above the upper transparent clamping plate  60 , and the air-isolating transparent plastic film  90 , can be disposed on the same machine base, as shown in  FIGS. 6 and 7 . That is, the lower transparent clamping plate  30  is disposed on the machine base and is used as the working surface, and the light source device  70   a  for the negative film exposure procedure is disposed below the lower transparent clamping plate  30  (i.e., below the machine base). Thus, the light rays of the light source device  70   a  can perform the negative film exposure procedure on the liquid photopolymer  22  in the liquid photopolymer transparent sachet  20  through the lower transparent clamping plate  30 . Furthermore, the upper transparent clamping plate  60 , the upper light source device  70   b , the upper suction channel, the lower transparent clamping plate  30 , the lower light source device  70   a  and the lower suction channel are disposed on the same machine base so that the convenience in use can be enhanced and the upper and lower exposure procedures of the plate bottom and the negative film can be performed without turning over. Thus, various operation flows, such as the vacuuming procedure, the procedure of pressing the upper and lower transparent clamping plates against each other, and the negative film or plate bottom exposure procedure can be conveniently performed so that the upper and lower portions can be respectively or simultaneously vacuumed or exposed and the plate making effect can be optimized. 
     New characteristics and advantages of the invention covered by this document have been set forth in the foregoing description. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention. Changes in methods, shapes, structures or devices may be made in details without exceeding the scope of the invention by those who are skilled in the art. The scope of the invention is, of course, defined in the language in which the appended claims are expressed.