Process for preparing prepreg by continuous method

Abstract

The present application relates to a process for preparing a prepreg by a continuous method, including the following steps: S1: preparing a raw material; S2: heating and stirring the raw material, and spinning in a spinning box to form a semi-finished ultra high molecular weight polyethylene fiber; S3: uniformly laying the semi-finished ultra high molecular weight polyethylene fiber into a layer, performing multistage drafting on the layer while immersing in a liquid matrix; S4: solidifying the matrix on the layer of ultra high molecular weight polyethylene fiber to form an ultra high molecular weight polyethylene fiber prepreg; S5: orthogonally aligning two sheets of the ultra high molecular weight polyethylene fiber prepregs with each other in warp and weft directions, and then performing lamination to form a weft-free fabric; and in step S3, performing multistage drafting by using a drafting device, and immersing by using an immersing device.

What is claimed is: 
     
         1 . A process for preparing a prepreg by a continuous method comprising the following steps:
 step S1: preparing a raw material;   step S2: heating and stirring the raw material, and spinning in a spinning box to form a semi-finished ultra high molecular weight polyethylene fiber;   step S3: uniformly laying the semi-finished ultra high molecular weight polyethylene fiber into a layer, performing multistage drafting on the layer while immersing in a liquid matrix;   step S4: solidifying the liquid matrix on the layer of ultra high molecular weight polyethylene fiber to form an ultra high molecular weight polyethylene fiber prepreg; and   step S5: orthogonally aligning two sheets of the ultra high molecular weight polyethylene fiber prepregs with each other in warp and weft directions, and then performing lamination to form a weft-free fabric.   
     
     
         2 . The process for preparing the prepreg by the continuous method according to  claim 1 , wherein, the multistage drafting is performed on a drafting device, and the drafting device comprises a frame rotatably provided with a plurality of drafting rollers parallel to each other, provided with a plurality of drive motors in a same number as that of the drafting rollers and one-to-one connected with the drafting rollers in a transmission way, and provided with a finishing assembly configured for finishing and laying a fiber. 
     
     
         3 . The process for preparing the prepreg by the continuous method according to  claim 2 , wherein, the finishing assembly comprises a mounting frame provided at an outlet end of the frame, and an inlet end of the mounting frame is provided with a pair of driving rollers; two ends of the pair of driving rollers departing from each other are rotatably connected with the mounting frame, and two ends of the pair of driving rollers facing each other extend obliquely in a same direction; a rubber roller is provided between the pair of driving rollers, and each end of the rubber roller is coaxially defined with a connection hole; two ends of the pair of driving rollers facing each other are inserted in two connection holes respectively; an axis of the rubber roller is vertical to a transportation direction of the frame; an outlet end of the mounting frame is rotatably provided with two horizontal pressing rollers parallel to each other, and an axis of each of the two horizontal pressing rollers is vertical to a fiber transportation direction of the frame; the mounting frame is provided with two first finishing motors respectively connected with the pair of driving rollers in the transmission way; and the mounting frame further is provided with a second finishing motor connected with one end of one of the two horizontal pressing rollers. 
     
     
         4 . The process for preparing the prepreg by the continuous method according to  claim 3 , wherein, the mounting frame is rotatably provided with two first mounting blocks, and rotating planes of the two first mounting blocks are parallel to a plane where axes of the pair of driving rollers are located; the pair of driving rollers are rotatably provided on the two first mounting blocks respectively, and the two first finishing motors are provided on the two first mounting blocks respectively; the mounting frame is vertically slidably provided with two second mounting blocks, and both ends of one of the two horizontal pressing rollers are respectively rotatably connected with the two second mounting blocks; and the mounting frame is provided with a first fixing part for fixing the two first mounting blocks and a second fixing part for fixing the two second mounting blocks. 
     
     
         5 . The process for preparing the prepreg by the continuous method according to  claim 4 , wherein, the first fixing part comprises a worm rotatably provided on the mounting frame and having reverse thread directions at two ends of the worm; each of the two first mounting blocks is coaxially provided with a worm gear, and the two worm gears are respectively engaged with both ends of the worm; one end of the worm is coaxially provided with a hand wheel with a pointer, and the mounting frame is provided with a scale coaxial with an axis of the hand wheel and in cooperation with the pointer; the second fixing part comprises a vertical gear rack provided on any one of the two second mounting blocks; and the mounting frame is rotatably provided with a transmission gear engaged with vertical gear rack and transmission connected with the worm. 
     
     
         6 . The process for preparing the prepreg by the continuous method according to  claim 2 , wherein, the immersing in step S3 is performed in an immersing device, and the immersing device comprises a support provided at an outlet end of the frame; the support is vertically slidably provide with a hopper, and a heating part is provided in the hopper; the hopper is provided with a positioning part configured for fixing the hopper on the support; a bottom wall of the hopper is provided with a flat discharge pipe, and an end of the flat discharge pipe is in communication with an inner cavity of the hopper; the flat discharge pipe is rotatably provided with a horizontal first material roller, the support below the hopper is provided with a recovery box, and a vertical projection of the flat discharge pipe is located in the recovery box; a second material roller is rotatably provided in the recovery box, and an upper side of the second material roller is higher than a side wall of the recovery box; the second material roller is located directly below the horizontal first material roller; and a recovery pump is provided in the recovery box, and an outlet end of the recovery pump is in communication with the inner cavity of the hopper through a pipe. 
     
     
         7 . The process for preparing the prepreg by the continuous method according to  claim 6 , wherein, a lower end of the flat discharge pipe bends towards a direction opposite to a fiber transportation direction of the frame. 
     
     
         8 . The process for preparing the prepreg by the continuous method according to  claim 6 , wherein, a horizontal closing roller is rotatably provided in the hopper, and a side wall of the hopper is provided with a closing motor connected with the horizontal closing roller in the transmission way; a side wall of the horizontal closing roller is circumferentially provided with a plurality of closing plates at intervals, and the bottom wall of the hopper is provided with a closing groove in communication with the flat discharge pipe; and a lower side of the horizontal closing roller is located in the closing groove, and a side wall of each of the closing plates abuts against a side wall of the closing groove. 
     
     
         9 . The process for preparing the prepreg by the continuous method according to  claim 6 , wherein, the hopper and the recovery box have funnel-shaped bottom walls. 
     
     
         10 . The process for preparing the prepreg by the continuous method according to  claim 3 , wherein, a side wall of each of the pair of driving roller is circumferentially provided with a plurality of positioning plates at intervals, and a side wall of each of the two connection holes is circumferentially defined with a plurality of positioning grooves at intervals, the positioning grooves are in one-to-one correspondence with the positioning plates, and the positioning plates are one-to-one slidably provided in the positioning grooves.