Patent Publication Number: US-2006008610-A1

Title: Device for fabricating plastic plates

Description:
BACKGROUND OF THE INVENTION  
      I. Field of the Invention  
      The present invention is related to device for fabricating plastic plates and particularly to device for fabricating plastic plates with multi-layer gas barrier.  
      2. Brief Description of Related Art:  
      The extruder is usually used for making plastic products and the melting plastic material is squeezed with the extruder to form various plastic products. The plastic products can be provided with various cross sections such as rod, pipe, film or plate as continuous products. Taking the plate shaped continuous products as an example, the manufacturing process with regard to squeezing forming has four steps:  
      (1) Pour the powder or particle thermoplastic material into a hopper;  
      (2) The plastic material in the hopper falls into a heating cylinder with revolving screw and a driving motor actuates the revolving screw to rotate about an axis so that the plastic material is liquefied due to heat generated from the revolving screw and device of heating unit. The temperature of the heating cylinder is between 180˜485° F.  
      (3) The plastic material passes through the heating cylinder and is pushed outward under a pressure between 100˜2,500 psi to be formed a shape after moving over a forming die of the heating cylinder. The cross section of the forming die has decided the shape and size of the finished product. This part is called mold hole.  
      (4) The finished product is pulled out with pull-off device and cooling section and becomes harden gradually. Finally, the finished product is cut into proper length.  
      Referring to  FIG. 1 , the plastic plate A has two plate members A 1 , A 2  and a plurality of line shaped reinforced ribs A 3 , which are arranged between the plate members A 1 , A 2 . The plate members A 1 , A 2  are capable of standing pressure due to aid of the reinforce rib A 3  so that the plastic plate A is largely used as indoor building material such as window and door guard or for making various box products.  
      The plastic plate A basically can resist ordinary foreign forces but are subjected to different pressure resistances at different directions. When a foreign force is exerted along a direction perpendicular to the reinforce ribs A 3  to bend the plastic plate A, the plastic plate A is capable of keeping unchanged from being deformed due to the foreign force is evenly supported by the reinforce ribs A 3 .  
      Further, when the foreign force is exerted along a direction parallel to the reinforce ribs A 3  to bend the plastic plate A, the plate members A 1 , A 2  at locations between any two adjacent reinforce ribs is bent and deformed and even becomes fracture. This is the serious deficiency of the plastic plate A.  
      Referring to  FIGS. 2 and 3  in company with  FIG. 1  again, Taiwanese Patent Gazette No. 545377 (application No. 90215603) is illustrated. The plastic material is placed in a heating cylinder B 3  to be heated up to a state of melting and the molten plastic material is agitated with a revolving screw B 4  till even consistency is reached. Then, the molten plastic material is squeezed into a forming mold tool B 5  and the mold tool B 5  is provided with a flow opening B 50  to press the plastic material into a plastic plate B 2 . Next, a shape device B 6  is used to move back and forth a distance with a controlled speed so that the plastic plate B 2  can be formed as a shape of sine curve after leaving the soled mold tool. Finally, a conveyer B 9  pulls the plastic plate B 2  outward gradually and the conveyer B 9  has a detecting circuit B 12 . The plastic plate B 2  provides two plate members B 20 , B 21  and a plurality of reinforce ribs B 22 , which are disposed between the plate members B 20 , B 21 . The reinforce ribs B 22  also constitutes a sine curve shape. Under this circumference, the plastic plate B 2  is incapable of being bent and deformed due to the reinforce ribs dispersing the foreign force when the plastic plate is subjected to bending forces from any directions.  
      The preceding device for fabricating the plastic plate has the following shortcomings:  
      (1) The Finished Plastic Plate is Hard to Keep Flat:  
      While the molten plastic material is squeezed to form a plastic plate, the plastic plate has not hardened yet. A shaper moves back and forth a distance with a proper speed to treat the plastic plate so that the plastic plate has a shape of sine wave after leaving the mold tool. However, it is hard to keep the produced plastic plate in flatness while the conventional device is utilized to fabricate the plastic plate.  
      (2) The Plastic Plate is Made of Single Material Only and it is Unable to Meet Required Economic Effect:  
      The conventional device merely fabricates the plastic plate with single material so that, for instance, a plastic partition needed by a building is require to provide property of anti-inflammation and plastic material with property of anti-inflammation is specially required before the plastic partition is made. However, making a plastic plate for specific purpose with the conventional device costs high production expense. That is, the conventional device is unable to fabricate a plastic plate satisfying different needs such as preventions of abrupt piercing, air leak and providing properties such as anti-elongation, anti-shock, corrosion resistance, acid resistance, alkali resistance and insulation resistance.  
     SUMMARY OF THE INVENTION  
      The crux of the present invention is to provide a device for fabricating plastic plates with which each of the fabricated plastic plates has multi-layers in different materials and offers a function of gas barrier with gases such as O2, N2, CO, CO2 and etc.  
      The device for fabricating plastic plates according to the present invention includes a divider and the divider connects with a plurality of extruder. The plastic material is placed in a heating cylinder for being heated to a state of melting. Then, the molten plastic material is evenly agitated to an extent of consistency before being pushed to the extruders. Afterwards, the molten plastic material is forced to enter the divider. A driving mechanism is attached to the divider to be controlled with a cam motor or step motor, which is can be reset with a specific cycle by way of computer program, so that the divider can be pushed back and forth in a controlled speed during making the plastic plate. The plastic plate has different curves after being worked with a die and a cooling vacuum forming mold and is pulled with a roller/conveyor cooling section.  
      Furthermore, it is capable of performing extrusion for single or multiple layers as required such that plastic plates in different curves and properties can be formed as needed. The plastic material can be combined with a tie layer in different proportions such that the finished product can prevent from abrupt piercing and air leak and provide properties such as anti-elongation, anti-shock, corrosion resistance, acid resistance, alkali resistance, insulation resistance, inflammation resistance, anti-chemical agent and color change resistance with rigid flexible material.  
      The plastic plate made by way of the device according to the present invention can provide better flat crush strength and prolong time duration for air ventilation and water penetration. Hence, an effect of gas barrier can be obtained effectively. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The detail structure, the applied principle, the function and the effectiveness of the present invention can be more fully understood with reference to the following description and accompanying drawings, in which:  
       FIG. 1  is a perspective view of a plastic plate made with a conventional fabricating device;  
       FIG. 2  is a perspective view of a plastic plate with curve shape;  
       FIG. 3  is a partly block diagram illustrating the conventional device for making the plastic plate;  
       FIG. 4  is a plan view of a device for fabricating a plastic plate according to the present invention;  
       FIG. 5  is a graph of a sine curve applied by the device for fabricating a plastic plate according to the present invention; and  
       FIG. 6  is a cross section of the divider in the device according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring to  FIG. 6 , the device for fabricating a plastic plate provides a divider  10 , which allows extruded layers complying with single axis, double axes, three axes, five axes, seven axes, nine axes or eleven axes to enhance performance of the gas barrier and strength between layers so as to prevent the plastic plate from being broken and leaking.  
      A driving mechanism  12 , which is under the divider  10  and the die  20  respectively, can be reset to perform different cycles with control of a cam motor or step motor by way of computer program so as to make bent plastic plates in different curves. The driving mechanism  12  provides continuous arc surfaces at the front section thereof for moving and bending the plastic plate so as to allow the plastic plate obtaining a smooth surface.  
      Different kinds of plastic materials can be fed to the divider  10  based on need. After being formed with the die  20  and the refrigerated vacuum mold  40 , proper layers in the plastic plate can be formed and the plastic materials can be joined to the tie layers in different proportions to enhance the effects such as anti abrupt piercing, anti air leak, anti elongation, anti-shock, corrosion resistance, acid resistance, alkali resistance, insulation resistance, anti-chemical agent and color change resistance.  
      The Method for Extrusion and Layer Division:  
      Different sizes of extruders are designed to control temperature and thickness of each layer via the divider or each extruding model so as to obtain a proportion, which is can reach best economic effect.  
      An example: a sectional view of the divider  10  is illustrated in  FIG. 6 . The divider  10  provides the innermost layer  10 A being HDPE, the second layer  10 B being a tie layer, the third layer  10 C being nylon, the fourth layer  10 D being another tie layer, the fifth layer  10 E being ABS. Further, a proper color can be chosen to enhance the sense of beauty. Each of the plastic layers can be acrylic, cellulosics, fluorocarbons, polyethylene, vinyls, PC, PP. MDPE, LDPE, LLDPE, C6, C8, POF, PVC, EPDM and the like. Different proportions of tie can be arranged with the plastic materials or a single layer of tie can be used for mixing with the plastic materials before being extruded.  
      The Implement of Making the Bend Plate:  
      By using speed rate control with left and right movements in company with the divider and the leading speed applying the curve principle of Y=X SIN θ and Y2=AX2+BX+CY, the program processor of the step motor forms the material as a regular bending shape before the material enters the vacuum mold. Once the bending shape is formed, anti-shock capability of the lateral sides of the formed material increases 20˜30%. Further, the front side of the formed material also can enhance the anti-shock capability due to density of jut spots being increased.  
      The plastic plate of the present invention can be worked as non-recyclable container and is suitable for being made as a hollow stuff and filling with special gas so as to constitute base material of a special heat guider for being heat up. For example:  
      It is suitable for being filled with and packing super conductor. Hence, it is a revolutionary change from using copper, which is conventionally used as the conductive material, to speed up effect of simple material and low cost.  
      Steps: 1.PA, EVOH, PVDC and PET are belonged to high air blocked plastic material and it is possible to be joined with various fluidic materials, which provide M 1  between 0.025 and 15. The tie layer can be combined with low cost and high strength materials such as PP, HDPE/LDPE, LLDEP, C4, C6, C8, MLLDPE and the like. The proportion is between 0˜99% and fusion via extruding base with temperature range of 120˜380° C. The process is from divider or single axis feeder to T-Die.  
      T-Die is provided with multi-layer structure ( 1 ,  3 ,  7 ,  9 ,  11  and etc.) and the combined materials can be formed as a desired shape via the program stir wheel and left and right moving speed of the control mold after being extruded. The extruded thickness is between 0.5˜30 mm after the materials are treated with air cooling at the first time and ice cold forming at the second time.  
      While the invention has been described with referencing to preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims.