Thermoplastic Molding Process and Apparatus

Abstract

A system and method for forming an article from thermoplastic material and fiber. The method includes heating thermoplastic material to form a molten thermoplastic material for blending with the fiber. The molten thermoplastic material is blended with the fibers to form a molten composite material having a concentration of fiber by weight. The molten composite material may then be extruded through dynamic dies to deliver discrete controlled material that is gravitated onto a lower portion of a mold. The lower portion of the mold may be moved in space and time while receiving the flow of composite material to deposit a predetermined quantity of molten composite material thereon conforming to mold cavities of the lower and an upper portion of the mold. The upper portion of the mold may be pressed against the predetermined quantity of molten composite material and closing on the lower portion of the mold to form the article.

1 . A method for forming an article from thermoplastic material, said method comprising:
 a. heating thermoplastic material to form a molten thermoplastic material,   b. extruding the molten thermoplastic material to form a flow of thermoplastic material gravitating onto a lower portion of a mold for forming the article; moving the lower portion of the mold in space and time while receiving the flow of thermoplastic material to deposit a predetermined quantity of molten thermoplastic material thereon conforming to mold cavities of the lower and an upper portion of the mold; and   c. pressing the upper portion of the mold against the predetermined quantity of molten thermoplastic material and closing on the lower portion of the mold to form the article.   
     
     
         2 . The method according to  claim 1 , further comprising controlling the flow of thermoplastic material to vary the quantity of molten thermoplastic material being delivered to the lower portion of the mold. 
     
     
         3 . The method according to  claim 1 , wherein said moving of the lower portion of the mold forms a predetermined quantity of molten thermoplastic material of varying thickness on the mold. 
     
     
         4 . The method according to  claim 1 , wherein said moving of the lower portion of the mold is along a single axis. 
     
     
         5 . The method according to  claim 1 , wherein the gravitating flows the thermoplastic material with a volumetric flow rate substantially the same onto the lower portion of the mold. 
     
     
         6 . The method according to  claim 1 , wherein the gravitating flows the thermoplastic material with different volumetric flow rates onto the lower portion of the mold. 
     
     
         7 . The method according to  claim 1 , further comprising controlling said extruding to vary the volumetric flow rate of the molten thermoplastic material being gravitated onto the lower portion of the mold. 
     
     
         8 . The method according to  claim 1 , wherein the gravitating of the molten thermoplastic material is performed directly onto the lower portion of the mold. 
     
     
         9 . The method according to  claim 1 , wherein the molten thermoplastic material is extruded on to an insert contained within the lower portion of the mold. 
     
     
         10 . The method according to  claim 9 , wherein the insert is partially embedded within the thermoplastic material. 
     
     
         11 . The method according to  claim 9 , wherein the insert is completely embedded within the thermoplastic material. 
     
     
         12 . The method according to  claim 1 , wherein a first layer of thermoplastic material is extruded into the lower portion of the mold. 
     
     
         13 . The method according to  claim 12 , wherein a second layer of thermoplastic material is layered on top of the first layer. 
     
     
         14 . The method according to  claim 12 , wherein an insert is placed on the first layer. 
     
     
         15 . The method according to  claim 14 , wherein said insert is partially embedded within the first layer. 
     
     
         16 . The method according to  claim 14 , wherein said insert is completely embedded within the first layer. 
     
     
         17 . The method according to  claim 14 , wherein a second layer of thermoplastic material is layered on top of the insert. 
     
     
         18 . A system for forming an article from thermoplastic material and fiber, said system comprising:
 a. a heater operable to pre-heat reinforced thermoplastic material to form a molten thermoplastic material;   b. an extruder coupled to the heater and operable to melt and blend the molten thermoplastic material for gravitating onto a lower portion of a mold to form the article;   c. a movable structure coupled to the lower portion of the mold and operable to be moved in space and time while receiving the flow of thermoplastic material to deposit a predetermined quantity of molten thermoplastic material thereon conforming to mold cavities of the lower and an upper portion of the mold; and   d. a press coupled to the upper portion of the mold and capable of receiving said movable structure with the lower portion of the mold, said press operable to press the upper portion of the mold against the predetermined quantity of molten thermoplastic material on the lower portion of the mold to form the article.   
     
     
         19 . The system according to  claim 18 , further comprising a dynamic die having at least one flow control element and operable to control the flow of thermoplastic material in a varied amount of molten thermoplastic material being delivered to the lower portion of the mold. 
     
     
         20 . The system according to  claim 18 , further comprising a controller coupled to said moveable structure and operable to move of said moveable structure to position the lower portion of the mold to form a predetermined quantity of molten thermoplastic material of varying thickness on the mold. 
     
     
         21 . The system according to  claim 18 , wherein said moveable structure includes wheels operable to move the moveable structure. 
     
     
         22 . The system according to  claim 18 , further comprising a die coupled to said extruder and operable to gravitate the flow of the thermoplastic material with a volumetric flow rate substantially the same across a plane onto the lower portion of the mold. 
     
     
         23 . The system according to  claim 18 , further comprising a dynamic die coupled to said extruder and operable to gravitate the thermoplastic material with different volumetric flow rates across a plane onto the lower portion of the mold. 
     
     
         24 . The system according to  claim 18 , further comprising a controller coupled to said extruder and operable to vary the volumetric flow rate of the molten thermoplastic material from the extruder and gravitate the molten thermoplastic material onto the lower portion of the mold. 
     
     
         25 . The system according to  claim 24 , wherein said controller moves said movable structure directly below said extruder for gravitating the extruded thermoplastic material onto the lower portion of the mold. 
     
     
         26 . A system for forming an article from thermoplastic material and fiber, said system comprising:
 a. means for heating thermoplastic material to form a molten thermoplastic material for blending with the fiber;   b. means for blending the molten thermoplastic material with the fibers to form a molten thermoplastic material having a concentration of fiber by weight;   c. means for extruding the molten thermoplastic material to form a flow of thermoplastic material gravitating onto a lower portion of a mold for forming the article;   d. means for moving the lower portion of the mold in space and time while receiving the flow of thermoplastic material to deposit a predetermined quantity of molten thermoplastic material thereon conforming to mold cavities of the lower and an upper portion of the mold; and   e. means for pressing the upper portion of the mold against the predetermined quantity of molten thermoplastic material and closing on the lower portion of the mold to form the article.   
     
     
         27 . The system according to  claim 26 , further comprising means for controlling the flow of thermoplastic material to vary the quantity of molten thermoplastic material being delivered to the lower portion of the mold. 
     
     
         28 . The system according to  claim 26 , further comprising means for controlling said means for extruding to vary the volumetric flow rate of the molten thermoplastic material being gravitated onto the lower portion of the mold. 
     
     
         29 . A method for forming a thermoplastic structural component, said method comprising:
 a. receiving a thermoplastic material;   b. heating the thermoplastic material;   c. extruding the thermoplastic material;   d. dynamically outputting the extruded thermoplastic material at different volumetric flow rates across a plane;   e. positionally synchronizing a mold to receive the extruded thermoplastic material in relation to the different volumetric flow rates across the plane; and   f. pressing the extruded thermoplastic material into the mold to form the thermoplastic structural component.   
     
     
         30 . The method according to  claim 29 , wherein said heating includes melting the thermoplastic material. 
     
     
         31 . The method according to  claim 29 , wherein said outputting of the different volumetric flow rates ranges between approximately zero and 3000 pounds per hour. 
     
     
         32 . The method according to  claim 29 , wherein said flow rate ranges between approximately 2500 and 3000 pounds per hour. 
     
     
         33 . The method according to  claim 29 , wherein said positionally synchronizing includes translating the mold with respect to the volumetric rates. 
     
     
         34 . The method according to  claim 29 , further comprising predetermining the different volumetric flow rates based on cavity volume of the mold across the plane. 
     
     
         35 . The method according to  claim 29 , wherein the forming of thermoplastic structural component includes forming a pallet. 
     
     
         36 . The method according to  claim 29 , further comprising configuring an element in the mold to be encapsulated by the thermoplastic material. 
     
     
         37 . The method according to  claim 29 , wherein said dynamic outputting of the extruded thermoplastic material is performed by controlling discrete flow control elements. 
     
     
         38 . A system for forming a thermoplastic structural component, said system comprising:
 a. means for receiving a thermoplastic material;   b. means for heating the thermoplastic material;   c. means for extruding the thermoplastic material;   d. means for dynamically outputting the extruded thermoplastic material at different volumetric flow rates across a plane;   e. means for positionally synchronizing a mold to receive the extruded thermoplastic material in relation to the different volumetric flow rates across the plane; and   f. means for pressing the extruded thermoplastic material into the mold to form the thermoplastic structural component.   
     
     
         39 . The system according to  claim 38 , wherein said means for heating includes means for melting the thermoplastic material. 
     
     
         40 . The system according to  claim 38 , wherein said means for positionally synchronizing includes means for translating the mold with respect to the volumetric rates. 
     
     
         41 . The system according to  claim 38 , further comprising means for predetermining the different volumetric flow rates based on cavity volume of the mold across the plane. 
     
     
         42 . The system according to  claim 38 , further comprising means for setting a non-thermoplastic element in the mold to be encapsulated by the thermoplastic material. 
     
     
         43 . A system for forming a thermoplastic structural component, said system comprising:
 a. a material receiving unit operable to receive a thermoplastic material;   b. a heater unit operable to heat the thermoplastic material;   c. an extruder coupled to the material receiving unit and operable to extrude the thermoplastic material;   d. a dynamic die having a plurality of selectably alterable flow control elements operable to control output of the thermoplastic material;   e. a mobile unit operable to support a mold and to be dynamically positioned below the dynamic die;   f. a controller electrically coupled to said dynamic die and mobile unit, said controller operable to dynamically alter said flow control elements to output the extruded thermoplastic material at different volumetric flow rates across a plane and position said mobile unit in synchronicity with the altering of said flow control elements to apply the extruded thermoplastic material onto the mold;   g. and a press operable to receive said mobile unit and press the extruded thermoplastic material into the mold.   
     
     
         44 . The system according to  claim 43 , wherein said material receiving unit includes at least one feeder. 
     
     
         45 . The system according to  claim 43 , wherein said heater unit is further operable to heat the thermoplastic material to a melted thermoplastic state. 
     
     
         46 . The system according to  claim 43 , wherein said mobile unit has revolving elements coupled thereto. 
     
     
         47 . The system according to  claim 43 , wherein said mobile unit includes at least one dynamic positioning element operable to engage and disengage the revolving elements. 
     
     
         48 . The system according to  claim 43 , wherein said controller is operable to disengage the revolving elements while said mobile unit is positioned in said press for the extruded thermoplastic material to be pressed into the mold. 
     
     
         49 . A method for forming a structural part from thermoplastic material, said method comprising:
 a. positioning an insert in a mold; depositing molten extruded thermoplastic material on the mold;   b. forming extruded thermoplastic material about at least a portion of the insert;   c. removing supports, if any, used to configure the insert in the mold;   d. compressing the extruded thermoplastic material to form the structural part; and removing the structural part with the insert at least partially embedded from the mold.   
     
     
         50 . The method according to  claim 49 , wherein said positioning of the insert is performed in a lower portion of the mold. 
     
     
         51 . The method according to  claim 49 , wherein said depositing the molten extruded thermoplastic material is performed dynamically across a plane. 
     
     
         52 . The method according to  claim 49 , wherein said forming the extruded thermoplastic material includes encapsulating the entire insert within the extruded thermoplastic material. 
     
     
         53 . The method according to  claim 49 , further comprising pressing the extruded thermoplastic material in the mold. 
     
     
         54 . A system for forming a structural part from thermoplastic material and fiber, said system comprising:
 a. means for configuring an insert in a mold;   b. means for depositing molten extruded thermoplastic material on the mold;   c. means for forming extruded thermoplastic material about at least a portion of the insert; means for removing supports, if any, used to configure the insert in the mold;   d. means for compressing the extruded thermoplastic material to form the structural part; and   e. means for removing the structural part with the insert at least partially embedded from the mold.   
     
     
         55 . The system according to  claim 54 , wherein said means for configuring of the insert is coupled to a lower portion of the mold. 
     
     
         56 . The system according to  claim 54 , wherein said means for depositing the molten extruded thermoplastic material includes means for dynamically flowing the extruded thermoplastic material across a plane. 
     
     
         57 . The system according to  claim 54 , wherein said means for forming the extruded thermoplastic material includes means for encapsulating the entire insert within the extruded thermoplastic material. 
     
     
         58 . The system according to  claim 54 , further comprising means for pressing the extruded thermoplastic material in the mold.