Molding device and molding method for polymer extrusion products containing transverse inner locking tooth structure

Abstract

The present invention discloses a molding device for polymer extrusion products containing a transverse inner locking tooth structure, and also discloses a molding method for polymer extrusion products containing a transverse inner locking tooth structure based on the molding device. The molding method of the present invention is realized based on a molding and stamping integrated device, the device contains a punching head with three stamping teeth and an arc-shaped molding groove with a swivel. After being extruded from the die head, the extruded material is introduced into the arc-shaped molding groove by the swivel to form a semi-solid material and gradually obtain an inner locking tooth structure after being intermittently subjected to the up and down impact and pressing action of the punching head. The obtained product has an inner locking angle of 75 to 85 degrees, excellent mechanical properties, and after being locked during operation, the inner locking teeth are not damaged first, and the size error of the obtained product is small.

Description

Technical Field

[0001] The present invention relates to a molding device for polymer extrusion products with a transverse inner locking tooth structure, and also relates to a molding method for polymer extrusion products with a transverse inner locking tooth structure based on the molding device. Background Art

[0002] At present, polymers and their composite materials are widely used. Among them, extrusion molding is one of the most widely used molding methods in the field of polymer material processing. This method can mold polymer products of any length, and the production process can be fully automated with high production efficiency. Generally, the cross-sectional shapes of extrusion molded products are mostly the same or show regular periodic changes. At the same time, in the design of polymer extrusion products, it is often necessary to consider the convenience of its molding processing and design corresponding chamfers, demoulding angles, etc. At the same time, in the design of the shaping device of the extruder, the extrusion shaping part is generally designed as a straight-through structure for the convenience of processing. Take strapping as an example. As a representative fastening product, it is a typical extruded product. Ordinary strapping contains a corresponding toothed structure. In order to facilitate shaping and demoulding, the angle between its teeth and the bottom is generally 90 degrees or more. The raw materials used for this type of strapping are mainly polyolefins and nylon. Among them, nylon is mainly used under the condition of high requirements for the mechanical properties of the product.

[0003] However, in actual use, even if this type of tooth structure reaches 90 degrees, it will often fail due to compression and deformation of the material, thus affecting its use. When this type of product is damaged, it is mainly the root of the tooth, that is, the tensile strength that the root of the tooth can withstand is lower than that of the product itself. But if the teeth are changed to an internal locking type, that is, the angle between the teeth and the bottom is less than 90 degrees, the slippage after the teeth are locked will be significantly improved, but this type of product will encounter more difficulties in the molding process.

[0004] At the same time, for nylon materials, their dimensions change greatly during the processing, and the performance of the product is also greatly affected by the subsequent moisture absorption performance. The dimensional accuracy of the material must be carefully controlled. Summary of the invention

[0005] Purpose of the invention: One of the purposes of the present invention is to provide a molding device for polymer extruded products containing a transverse internal locking tooth structure. Another purpose of the present invention is to provide a molding method for polymer extruded products containing a transverse internal locking tooth structure based on the above-mentioned molding device. The product obtained by this method has a special internal locking angle, thereby ensuring that it is not easy to fall off after being pressed. The product has high dimensional accuracy and excellent mechanical properties.

[0006] Technical solution: The molding device of the polymer extruded product with a transverse inner locking tooth structure described in the present invention comprises a molding and stamping integrated device and an extrusion mechanism located at the front end of the molding and stamping integrated device and a traction mechanism located at the rear end of the molding and stamping integrated device; the molding and stamping integrated device comprises a support frame, an arc-shaped molding groove fixed on the support frame and a mounting frame fixed on the support frame, and the molding and stamping integrated device is fixed on a wall or a base through the support frame; the mounting frame is provided with a stamping cylinder, a stamping head fixedly connected to the driving end of the stamping cylinder and a ball screw mechanism for driving the stamping cylinder to move laterally (the ball screw mechanism comprises a motor fixed to the mounting frame, a ball screw fixedly connected to the driving end of the motor, and the stamping cylinder is fixed on the slider of the ball screw); the arc-shaped molding groove comprises a stamping head with a top opening The arc-shaped shaping groove has an opening and a through hole that penetrates horizontally, and a vacuum hole is also arranged on the inner wall of the cavity of the arc-shaped shaping groove. The vacuum hole is connected to an external vacuum pump through a pipeline (the pipeline extends from the opening on the side wall and is connected to the vacuum hole, so as to control the vacuum degree of the product when it passes through the arc-shaped shaping groove). The side wall of the arc-shaped shaping groove includes a hollow cavity area, and an external cooling medium enters the hollow cavity of the side wall through a pipeline (the pipeline enters the hollow cavity area from the cold water opening on the side wall, so as to achieve rapid cooling of the product when it passes through the arc-shaped shaping groove to form a semi-solid material); it also includes a swivel that is rotatably connected to the arc-shaped shaping groove through a through hole that penetrates horizontally, and a gear located inside the swivel, the inner ring side wall of the swivel has a toothed structure, the swivel is meshed with the gear through the internal toothed structure, and the gear rotates under the drive of the external driving mechanism, thereby driving the swivel to rotate relative to the arc-shaped shaping groove.

[0007] The arc-shaped shaping groove cavity is also provided with an arc-shaped area consistent with the curvature of the rotating ring. The circle corresponding to the contour line of the arc-shaped area is concentric with the rotating ring. The radius R1 of the circle corresponding to the contour line of the arc-shaped area is equal to the outer circle radius R of the rotating ring, the product thickness H and the contraction value δ in the thickness direction of the product. l sum.

[0008] Among them, the punching head is provided with three punching teeth at equal intervals, namely, the right punching tooth, the middle punching tooth and the left punching tooth. After the semi-solid material enters from the right, it is first affected by the right punching tooth. The bottom edge B1 of the right punching tooth is parallel to the tangent direction of the contour of the arc-shaped shaping groove, and the right punching tooth has a right cutting angle X1. The bottom edge B3 of the left punching tooth is also parallel to the tangent direction of the contour of the arc-shaped shaping groove, and the left punching tooth has a left cutting angle X3. The distances S1 and S2 between the punching teeth are consistent. After the angles of the left and right cutting angles are determined, the lengths of S1 and S2 can be used to obtain the relationship between them and the radius R1 of the circle corresponding to the arc contour line according to the trigonometric relationship, that is, the length of S1 = cos(X1)*R1.

[0009] Among them, the extrusion mechanism includes an extruder and an extrusion die; the high-temperature melt extruded by the extrusion die is introduced into the rotating ring, and enters the arc-shaped shaping groove cavity under the drive of the rotating ring; the traction mechanism includes a direction wheel, a traction belt and a traction roller in sequence. After the material passes through the arc-shaped shaping groove, the forward direction is adjusted by the direction wheel. The position of the direction wheel can be adjusted and adapted to the angle of the inner locking angle. The shaped product is gradually cooled into a product after the drawing action of the traction belt. The cooled product can be stretched by the traction roller and then wound for standby use.

[0010] Driven by the gear, the swivel rotates counterclockwise at a determined speed. At this time, the extruded high-temperature melt is introduced onto the swivel, and driven by the swivel, enters the molding and stamping integrated device, and gradually cools down to form a semi-solid material when passing through the arc-shaped molding groove, and then the shape is stabilized under moderate vacuum conditions. At the same time, a punch head is installed on the upper part of the molding and stamping integrated device, and three cutters of different shapes are installed on the punch head. The inclination angles of the three cutters are adapted to the inner locking angle to be obtained and the inclination angle of the arc-shaped molding groove. The semi-solid material is intermittently subjected to the up and down impact and pressing action of the punch head, and gradually obtains an inner locking tooth structure. In addition, the punch head can also move left and right with the material when it moves up and down, to ensure that the inner locking angle after punching out is not damaged, that is, the rotation speed of the gear is consistent with the lateral movement speed of the ball screw mechanism.

[0011] The method for molding a polymer extruded product having a transverse inner locking tooth structure based on the above molding device comprises the following steps:

[0012] (1) preparing a mixed material: by weight, 100 parts of thermoplastic polymer PA66, 5 to 15 parts of polyester reinforcement, 3 to 5 parts of compatibilizer, 3 to 8 parts of micro-nano particle reinforcement, 1 to 3 parts of dispersant and lubricant, 1 to 2 parts of auxiliary lubricant and 0.5 parts of antioxidant are mixed at high speed to obtain a mixed material;

[0013] (2) Through preliminary experiments, determine the shrinkage rate δ of the tensile and compressive body of the mixed material and the rebound angle γ of the material after being compressed by the punching teeth in the arc-shaped shaping groove;

[0014] (3) Determine the values ​​of the left and right cutting angles X3 and X1 as the internal locking angle α-the rebound angle γ, wherein the internal locking angle α is 75 to 85 degrees;

[0015] (4) adding the mixed material into the extruder, and passing through the melt pump at the processing temperature after plasticization, and the melt pump controls the extrusion speed V1 and volume flow rate Q1 of the mixed material;

[0016] (5) After the extrudate passes through the extruder head, it enters the arc-shaped shaping groove driven by the rotating ring and is pressed by three different front and rear stamping teeth at a specified shaping temperature, and a transverse inner locking tooth structure is obtained with the assistance of a steering wheel;

[0017] (6) The extrudate is then pulled out of the arc-shaped shaping groove, and the stretching ratio is obtained by adjusting the extrusion speed and the stretching speed. V1 is the linear speed of the material when it is extruded from the die head, and V2 is the linear speed of the material when it leaves the arc-shaped shaping groove. V2 / V1 is 0.8 to 0.9;

[0018] (7) The extrudate is post-processed to fully determine its size, and is dried and cooled twice before being wound to obtain the product.

[0019] Among them, in step (1), PEN is the best polyester reinforcement, which is mainly because the melting point difference between the two (thermoplastic polymer PA66 and PEN) is very small, which is convenient for extrusion processing and molding control; the compatibilizer is preferably ethylene-methyl acrylate-glycidyl methacrylate random terpolymer (E-MA-GMA), which can not only improve the compatibility between PA and PEN, but also improve the compatibility between PA and other inorganic fillers; the micro-nano particle reinforcement is preferably an inorganic filler; the dispersant and lubricant is preferably high-temperature resistant vinyl bis-stearamide EBS, and the auxiliary lubricant is preferably molybdenum disulfide. The addition of these two types of additives can significantly improve the material's feeding characteristics and the lubricity when entering the shaping groove after extrusion from the die; the antioxidant is preferably 1098 specifically for nylon.

[0020] Wherein, in step (2), by determining the volume shrinkage of the product when it is extruded from the die head and when it leaves the arc-shaped shaping groove, after the speed ratio is converted, the tensile and compressive body shrinkage δ of the mixed material is determined, and then the linear shrinkage of the product thickness direction when the material is extruded from the die to the arc-shaped shaping groove is determined. The tensile and compressive body shrinkage here takes into account the influence of stretching, compression and temperature change on material shrinkage, and its main influencing factors include: the ratio of extrusion speed to stretching speed (controlling the dimensional change under the stretching rate); the amount of punching and the amount of rebound after punching; the shrinkage of the material itself when it changes at two different temperatures; the specific calculation method of the tensile and compressive body shrinkage is: δ = Q1 / Q2*V1 / V2, wherein: Q1 is the volume flow rate of the material when it is extruded from the die head, Q2 is the volume rate of the material when it leaves the arc-shaped shaping groove, V1 is the linear speed of the material when it is extruded from the die head, and V2 is the linear speed of the material when it leaves the arc-shaped shaping groove. As a preference, for nylon and its composites, V2 / V1 is preferably controlled between 0.8 and 0.9. At this time, the material is mainly driven by the rotating ring and compressed in the arc-shaped shaping groove. The main principle is that the expansion effect of the material after extrusion can be fully released, which is conducive to the subsequent dimensional stability in all directions.

[0021] Among them, in step (2), the right cutting angle X1 of the right punching tooth is pre-determined to any value between 75 and 85 degrees, and then the final angle obtained after the material is extruded and shaped is measured. This angle is generally smaller than the pre-set value, and the difference between the two is determined as the rebound angle γ.

[0022] Wherein, in step (3), the general principle for determining the inner locking angle is: if the material strength is high and the compression modulus is small, the angle can take a large value; if the material strength is low and the compression modulus is large, the angle can take a large value. The upper and lower limits of the inner locking angle are determined according to the tensile strength and compression modulus of the material. Preferably, the upper limits of the tensile strength and compression modulus of the material are 60MPA and 5000MPA, and the lower limits are 30MPA and 2000MPA. When the tensile strength of the material exceeds 60MPA and the compression modulus exceeds 5000MPA, that is, when both reach or exceed the upper limit, the angle is 85 degrees. When the tensile strength of the material is lower than 30MPA or the compression modulus is lower than 2000MPA, that is, when both are lower than the lower limit, the angle is 75 degrees. When either the tensile strength or the compression modulus of the material is between the upper and lower limits, the tensile strength and the compression modulus with a larger gap from the upper limit are selected, and the inner locking angle is determined by converting the ratio between the tensile strength and the compression modulus and the upper limit. In order to ensure that the material can smoothly enter the arc-shaped shaping groove, the size of the entrance is slightly larger than the inner part by 1 to 2 mm. According to the rebound angle γ of the material after being compressed in the shaping groove, the inclination angles X1 and X3 of the cutter are set to the angle of the inner locking angle minus the rebound angle γ.

[0023] Wherein, in step (4), the processing temperature is 5 to 20 degrees above the melting temperature of the thermoplastic polymer PA66.

[0024] Wherein, in step (5), the setting temperature is between the melting temperature and the glass transition temperature of the thermoplastic polymer PA66; preferably, the setting temperature is 30 to 80 degrees below its melting temperature.

[0025] Wherein, in step (7), post-treatment refers to passing through a retaining rack in water at 70 to 110°C.

[0026] The internal locking angle α of the obtained product is 75 to 85 degrees, which can ensure that it is not easy to slip after being compressed. In addition, for ease of use, the internal locking groove width L1 is more than 10% larger than the groove spacing L2. At the same time, in order to take into account both use and ensure product strength, the internal locking groove depth h is 0.4 to 0.5 times the product wall thickness H.

[0027] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The molding method of the present invention is implemented based on a molding and stamping integrated device, which comprises a punch head with three stamping teeth and an arc-shaped molding groove with a rotating ring. After the extruded material is extruded from the die head, it is introduced into the arc-shaped molding groove by the rotating ring to form a semi-solid material and gradually obtain an inner locking tooth structure after being intermittently subjected to the up and down impact and pressing action of the punch head. The obtained product has an inner locking angle of 75 to 85 degrees and excellent mechanical properties. After working locking, the inner locking teeth are not first damaged, and the size error of the obtained product is small; (2) The raw material ratio fully considers the synergistic effect of each component, and the raw material combination has excellent mechanical properties. Compared with pure materials and non-synergistic ratios, it has better tensile strength and elongation at break; at the same time, the melting points of the two main raw materials are close, which is conducive to the implementation of the molding process, and the addition of auxiliary agents also effectively improves the molding processing performance of the raw materials; in addition, the synergistic effect of the components of the formula is obvious, and the shrinkage deformation of the obtained mixed material is small, which is conducive to the dimensional stability of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The structure diagram of the polymer extrusion product with the transverse inner locking tooth structure prepared by the present invention, wherein α is the transverse inner tooth angle, which is 75 to 85 degrees; L2 / L1=0.85 to 0.95; h / H=0.4 to 0.5;

[0029] Figure 2 It is a structural schematic diagram of the molding device of the present invention;

[0030] Figure 3 It is a structural schematic diagram of the shaping and stamping integrated device;

[0031] Figure 4 It is a schematic diagram of the internal shape when the arc-shaped shaping groove and the swivel are cut apart after being matched;

[0032] Figure 5 It is a schematic diagram of the internal structure of the arc-shaped shaping groove after it is cut open;

[0033] Figure 6 It is a schematic diagram of the punching teeth and arc-shaped forming grooves after the punching head rises;

[0034] Figure 7 It is a schematic diagram of the dimensional relationship between the stamping teeth and the arc-shaped forming groove. DETAILED DESCRIPTION

[0035] like Figures 1 to 7As shown, the present invention comprises a forming device for a polymer extruded product having a transverse inner locking tooth structure, the forming device comprising a forming and stamping integrated device 3 and an extrusion mechanism located at the front end of the forming and stamping integrated device 3 and a traction mechanism located at the rear end of the forming and stamping integrated device 3; the forming and stamping integrated device 3 comprises a support frame 35, an arc-shaped forming groove 34 fixed on the support frame 35 and a mounting frame 36 fixed on the support frame 35, the forming and stamping integrated device 3 is fixed to a wall or a base through the support frame 35; the mounting frame 36 is provided with a stamping cylinder 31, a stamping head 33 fixedly connected to the driving end of the stamping cylinder 31 and a ball screw mechanism 32 for driving the stamping cylinder 31 to move transversely, the ball screw mechanism 32 comprises a motor fixed to the mounting frame 36 and a ball screw fixedly connected to the driving end of the motor, and the stamping cylinder 31 is fixed on a slider of the ball screw; the arc-shaped forming groove 34 comprises a stamping port 343 with a top opening and a through hole 343 which penetrates transversely 41, a vacuum hole 51 is also provided on the inner wall of the arc-shaped shaping groove 34 cavity, and the vacuum hole 51 is connected to an external vacuum pump through a pipeline, and the pipeline extends from an opening 53 on the side wall and is connected to the vacuum hole 51, so as to control the vacuum degree of the product when it passes through the arc-shaped shaping groove 34; the side wall of the arc-shaped shaping groove 34 includes a hollow cavity area, and an external cooling medium enters the hollow cavity of the side wall through a pipeline, and the pipeline enters the hollow cavity area from a cold water opening 52 on the side wall, so as to achieve rapid cooling of the product when it passes through the arc-shaped shaping groove 34 to form a semi-solid material; the shaping and stamping integrated device 3 also includes a swivel 9 rotatably connected to the arc-shaped shaping groove 34 through a transverse through hole 341 and a gear 10 located inside the swivel 9, the inner ring side wall of the swivel 9 is a toothed structure 91, and the swivel 9 is meshed with the gear 10 through the internal toothed structure 91, and the gear 10 rotates under the drive of the external driving mechanism, thereby driving the swivel 9 to rotate relative to the arc-shaped shaping groove 34.

[0036] The arc-shaped shaping groove 34 is provided with an arc-shaped area 342 with the same arc as the rotating ring 9. The circle corresponding to the arc-shaped area contour line is concentric with the rotating ring 9. The radius R1 of the circle corresponding to the arc-shaped area contour line is equal to the outer circle radius R of the rotating ring 9, the product thickness H and the contraction value δ in the product thickness direction. l sum.

[0037] Among them, three punching teeth are equidistantly arranged on the punch head 33, namely, the right punching tooth 37, the middle punching tooth 38 and the left punching tooth 39. After the semi-solid material enters from the right, it is first affected by the right punching tooth 37. The bottom edge B1 of the right punching tooth 37 is parallel to the tangent direction of the contour of the arc-shaped shaping groove, and the right punching tooth 37 has a right cutting angle X1. The bottom edge B3 of the left punching tooth 39 is also parallel to the tangent direction of the contour of the arc-shaped shaping groove, and the left punching tooth 39 has a left cutting angle X3. The distance S1 between the punching teeth is consistent with S2, the length of S1 = cos (X1) * R1, R1 is the radius of the circle corresponding to the contour of the arc region 342, and the right cutting angle X1 and the left cutting angle X3 of the right punching tooth 37 and the left punching tooth 39 correspond to the inner locking angle to be obtained.

[0038] Among them, the extrusion mechanism includes an extruder 1 and an extrusion die 2; the high-temperature melt extruded by the extrusion die 2 is introduced onto the rotating ring 9, and enters the cavity of the arc-shaped shaping groove 34 under the drive of the rotating ring 9; the traction mechanism includes a direction wheel 4, a traction belt 5 and a traction pair of rollers 6 in sequence. After the material passes through the arc-shaped shaping groove, the forward direction is adjusted by the direction wheel 4. The position of the direction wheel 4 can be adjusted and adapted to the angle of the inner locking angle. The shaped product is stretched by the traction belt 5 and gradually cooled into a product 8. The cooled product 8 can be stretched by the traction pair of rollers 7 and then wound for standby use. The swivel 9 is driven by the gear 10 to rotate in the counterclockwise direction at a determined speed. At this time, the extruded high-temperature melt is introduced onto the swivel 9, and is driven by the swivel 9 to enter the shaping and stamping integrated device 3. When passing through the arc-shaped shaping groove 34, it is gradually cooled to form a semi-solid material, and then the shape is stabilized under moderate vacuum conditions. At the same time, a punch head 33 is installed on the upper part of the shaping and stamping integrated device 3. Three cutters of different shapes are installed on the punch head 33. The inclination angles of the three cutters are mutually adapted to the inner locking angle to be obtained and the inclination angle of the arc-shaped shaping groove. The semi-solid material is intermittently subjected to the up and down impact and pressing action of the punch head 33, and gradually obtains an inner locking tooth structure. In addition, the punch head 33 can also move with the left and right movement of the material when moving up and down, to ensure that the inner locking angle after punching out is not damaged, that is, the rotation speed of the gear 10 is consistent with the lateral movement speed of the ball screw mechanism.

[0039] The molding method of the polymer extrusion product containing the transverse inner locking tooth structure of the present invention uses raw materials including: nylon 66 (PA66), PEN, E-MA-GMA, nano-montmorillonite, high temperature resistant EBS, molybdenum disulfide, antioxidant 1098, all of which are commercially available.

[0040] Weigh them according to the following mass ratio:

[0041] Formula 1: PA66: 100 parts; PEN: 5 parts; E-MA-GMA: 3 parts; nano-montmorillonite: 3 parts; EBS: 1 part; molybdenum disulfide: 1 part; antioxidant 1098: 0.5 parts.

[0042] Formula 2: PA66: 100 parts; PEN: 10 parts; E-MA-GMA: 4 parts; nano-montmorillonite: 6 parts; EBS: 2 parts; molybdenum disulfide: 1.5 parts; antioxidant 1098: 0.5 parts.

[0043] Formula 3: PA66: 100 parts; PEN: 15 parts; E-MA-GMA: 5 parts; nano-montmorillonite: 8 parts; EBS: 3 parts; molybdenum disulfide: 2 parts; antioxidant 1098: 0.5 parts.

[0044] The above raw materials were dried, mixed at high speed, and granulated, and then tested according to standard ASTM-D638. The results are shown in Table 1. It can be seen from Table 1 that formulas 1 to 3 have better tensile strength and elongation at break than pure PA66 and other formulas. In the present invention, they are used as raw materials for subsequent implementation plans.

[0045] Table 1 Performance comparison of several materials

[0046]

[0047] Note: The shrinkage rate of the tensile and compressive body is the volume shrinkage rate obtained by converting the speed ratio of the product when it is extruded from the die head and when it leaves the arc-shaped shaping groove. This value is the measured value. Those marked with * cannot be extruded through this device because the material has poor lubricity and unstable dimensions. Through offline simulation tests, the shrinkage rate of the tensile and compressive body of the materials marked with * is more than 5%.

[0048] The molding device used is as follows Figure 2 As shown, a preliminary experiment was carried out using the forming device to determine the tensile and compressive shrinkage of the material, wherein the results obtained for formulations 1 to 3 are also listed in Table 1. At the same time, it was also determined that the rebound angle γ of the material after being stamped in the shaping groove was between 1.60 and 1.65 degrees.

[0049] According to the results in Table 1, it can be seen that the materials obtained by formulations 1 to 3 have low shrinkage rates, which is conducive to dimensional stability.

[0050] Since the tensile strength of the materials in formulas 1 to 3 is mostly between 70 and 75 MPA, the application strength of 30 MPA can meet the requirements after calculation based on all cross sections. At the same time, after actual measurement, the compression modulus of the material is about 4000 MPA, so the compression modulus is lower than the upper limit of the internal locking angle evaluation of 5000 MPA. According to the difference between the compression modulus and its upper and lower limits, the internal locking angle α is determined to be 85-(85-75)*(5000-4000) / (5000-2000)=81.67 degrees. Furthermore, the rebound amount of the material after being compressed in the arc-shaped shaping groove determines the inclination angle of the right cutting angle X1 and the left cutting angle X3 of the right punching tooth and the left punching tooth to be between 81.67-(1.6~1.65)=80.02~80.07 degrees.

[0051] The linear shrinkage of the material can be calculated from the shrinkage of the tension and compression body. Figure 7 , it can be determined that the radius R of the arc-shaped shaping groove is the outer radius of the swivel 9, the product thickness H and the linear contraction value δ in the product thickness direction l In order to ensure that the material can smoothly enter the arc-shaped shaping groove, the size of the entrance is slightly larger than the inner size by 1 to 2 mm.

[0052] After assembling the arc-shaped shaping groove according to the above dimensions, add the material of formula 3 into the extruder, and after plasticization, pass through the melt pump at the specified processing temperature: 275 degrees, and control its extrusion speed V1 and volume flow rate Q1; after that, after the extrudate passes through the extruder head, it enters the arc-shaped shaping groove driven by the swivel and is punched by three different punching teeth at the specified shaping temperature of 200 degrees, and obtains the transverse inner locking tooth structure under the action of the direction wheel; the punching speed of the high-speed arc-shaped shaping groove matches the extrusion speed, and the extrudate is then pulled out of the shaping groove, and the product size is basically fixed, at this time, the pulling speed V2 and the product volume flow rate Q2; after repeated experiments, it is known that keeping the ratio of V2 / V1 between 0.8 and 0.9 is conducive to the dimensional stability of each part. The extrudate passes through the retainer in 95-degree high-temperature pressure water, and the size is completely determined, and after drying, it is wound after cooling again to obtain the produced product.

[0053] The dimensions of the product are Figure 1 As shown, it has the following dimensions: inner locking groove width L1 = 0.7mm, groove spacing L2 = 0.5mm, inner locking angle α is 81.67 degrees, inner locking groove depth h = 0.6mm and product wall thickness H = 1.3mm; after actual measurement, the dimensional error level of each part of the produced product meets the MT1 level.

[0054] The tensile strength calculated by the total area of ​​the product after direct stretching (the inner lock teeth are not stressed at this time) and tensile testing under application conditions (the inner lock teeth are mainly stressed at this time) is more than 30MPA, and the former is lower than the latter, indicating that the inner lock teeth will not slip off after being locked in the working state. Therefore, this type of product has excellent mechanical properties.

Claims

1. A molding device for polymer extrusion products containing a transverse inner locking tooth structure, characterized in that: The forming device comprises a shaping and stamping integrated device (3), an extrusion mechanism located at the front end of the shaping and stamping integrated device (3), and a traction mechanism located at the rear end of the shaping and stamping integrated device (3); the shaping and stamping integrated device (3) comprises a support frame (35), an arc-shaped shaping groove (34) fixed on the support frame (35), and a mounting frame (36) fixed on the support frame (35); the mounting frame (36) is provided with a stamping cylinder (31), a stamping head (33) fixedly connected to the driving end of the stamping cylinder (31), and a ball screw mechanism for driving the stamping cylinder (31) to move laterally; the arc-shaped shaping groove (34) comprises a stamping opening (343) with a top opening and a through hole (341) extending laterally therethrough. The inner side wall of the arc-shaped shaping groove (34) is also provided with a vacuum hole (51), the vacuum hole (51) is connected to an external vacuum pump through a pipeline, the side wall of the arc-shaped shaping groove (34) includes a hollow cavity area, and the external cooling medium enters the hollow cavity of the side wall through the pipeline; it also includes a rotating ring (9) rotatably connected to the arc-shaped shaping groove (34) through a transverse through hole (341) and a gear (10) located inside the rotating ring (9), the inner side wall of the rotating ring (9) is a toothed structure (91), the rotating ring (9) is meshed with the gear (10) through the internal toothed structure (91), and the gear (10) rotates under the drive of an external driving mechanism, thereby driving the rotating ring (9) to rotate relative to the arc-shaped shaping groove (34); The punch head (33) is provided with three punch teeth at equal intervals, namely a right punch tooth (37), a middle punch tooth (38) and a left punch tooth (39). The bottom edge of the right punch tooth (37) is parallel to the tangent direction of the contour of the arc-shaped shaping groove, and the right punch tooth (37) has a right cutting angle X1. The bottom edge of the left punch tooth (39) is also parallel to the tangent direction of the contour of the arc-shaped shaping groove, and the left punch tooth (39) has a left cutting angle X3.

2. The molding device for polymer extruded products with a transverse inner locking tooth structure according to claim 1, characterized in that: The cavity of the arc-shaped shaping groove (34) is also provided with an arc-shaped area (342) having the same arc as the rotating ring (9), the circle corresponding to the contour line of the arc-shaped area is concentric with the rotating ring (9), and the radius R1 of the circle corresponding to the contour line of the arc-shaped area is equal to the outer circle radius R of the rotating ring (9), the product thickness H and the contraction value δ in the thickness direction of the product l sum.

3. The molding device for polymer extruded products with a transverse inner locking tooth structure according to claim 1, characterized in that: The distances S1 and S2 between the right punching tooth (37) and the middle punching tooth (38) as well as between the middle punching tooth (38) and the left punching tooth (39) are consistent, and the lengths of S1 and S2 are cos(X1)*R1.

4. The molding device for polymer extruded products with a transverse inner locking tooth structure according to claim 1, characterized in that: The extrusion mechanism comprises an extruder (1) and an extrusion die (2); the high-temperature melt extruded by the extrusion die (2) is introduced onto a rotating ring (9) and driven by the rotating ring (9) into a cavity of an arc-shaped shaping groove (34); the traction mechanism comprises a direction wheel (4), a traction belt (5) and a traction pair of rollers (6) in sequence; after the material passes through the arc-shaped shaping groove (34), the forward direction of the material is adjusted by the direction wheel (4); the shaped product is stretched by the traction belt (5) and gradually cooled into a product (8); the cooled product (8) is stretched by the traction pair of rollers (7) and can be wound up for standby use.

5. A method for molding a polymer extruded product having a transverse inner locking tooth structure based on the molding device according to claim 1, characterized in that: The steps include: (1) Preparing a mixed material: by weight, 100 parts of thermoplastic polymer PA66, 5-15 parts of polyester reinforcement, 3-5 parts of compatibilizer, 3-8 parts of micro-nano particle reinforcement, 1-3 parts of dispersant and lubricant, 1-2 parts of auxiliary lubricant and 0.5 parts of antioxidant are mixed at high speed to obtain a mixed material; (2) Through preliminary experiments, determine the shrinkage rate δ of the tensile and compressive body of the mixed material and the rebound angle γ of the material after being compressed by the punch teeth in the arc-shaped shaping groove; (3) Determine the values ​​of the left and right cutting angles X3 and X1 as the internal locking angle α-springback angle γ, where the internal locking angle α is 75~85 degrees; (4) The mixed material is added to the extruder, and after plasticization, it passes through a melt pump at the processing temperature. The melt pump controls the extrusion speed V1 and volume flow rate Q1 of the mixed material; (5) After the extrudate passes through the extruder head, it enters the arc-shaped shaping groove driven by the rotating ring and is pressed by three different front and rear stamping teeth at a specified shaping temperature, and a transverse inner locking tooth structure is obtained with the assistance of a steering wheel; (6) The extrudate is then pulled out of the arc-shaped shaping groove, and the stretching ratio is obtained by adjusting the extrusion speed and the stretching speed. V1 is the linear speed of the material when it is extruded from the die head, and V2 is the linear speed of the material when it leaves the arc-shaped shaping groove. V2 / V1 is 0.8~0.9; (7) The extrudate is post-processed to fully determine its size, and then it is dried twice and cooled before being wound to obtain the product.

6. The method for forming a polymer extruded product having a transverse inner locking tooth structure according to claim 5, characterized in that: In step (1), the polyester reinforcement is PEN; the compatibilizer is a random terpolymer of ethylene-methyl acrylate-glycidyl methacrylate; the micro-nano particle reinforcement is nano-montmorillonite; the dispersant and lubricant is vinyl bisstearamide; the auxiliary lubricant is molybdenum disulfide; and the antioxidant is antioxidant 1098.

7. The method for forming a polymer extruded product having a transverse inner locking tooth structure according to claim 5, characterized in that: In step (2), the calculation method of the tensile and compressive shrinkage rate δ of the mixed material is: δ=Q1 / Q2*V1 / V2, wherein: Q1 is the volume flow rate of the material when it is extruded from the die head, Q2 is the volume velocity of the material when it leaves the arc-shaped shaping groove, V1 is the linear velocity of the material when it is extruded from the die head, and V2 is the linear velocity of the material when it leaves the arc-shaped shaping groove.

8. The method for forming a polymer extruded product having a transverse inner locking tooth structure according to claim 5, characterized in that: In step (4), the processing temperature is 5 to 20 degrees above the melting temperature of the thermoplastic polymer PA66; in step (5), the setting temperature is between the melting temperature and the glass transition temperature of the thermoplastic polymer PA66.

9. The method for forming a polymer extruded product having a transverse inner locking tooth structure according to claim 5, characterized in that: In step (7), post-treatment refers to passing through a retaining rack in water at 70 to 110°C.

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