CN207825405U - A kind of injection moulding apparatus of natural-fiber composite material - Google Patents

Abstract

The utility model discloses an injection molding device for a natural fiber composite material, which comprises a plasticizing barrel, the end of the plasticizing barrel is provided with a nozzle, and a rotatable screw body is arranged inside the plasticizing barrel. The end of the screw body is provided with a screw head; the length-to-diameter ratio L/D of the screw body ranges from 18 to 23, and the compression ratio of the screw body ranges from 1.5 to 1.95. The length-to-diameter ratio L/D ratio range of the screw body of the utility model is 18-23, and the ratio range of the compression ratio of the screw body is 1.5-1.95. This design can effectively carry out the shear heat of the material when the screw rotates. Control to ensure that the long fiber part is not excessively sheared, and meet the stringent requirements for injection molding production of high-filling natural fiber biocomposites, with high quality of finished products and high injection molding efficiency, so as to realize and break through the injection molding production process of high-filling natural fiber biocomposites Bottlenecks and solving production safety problems.

Description

A kind of injection molding device of natural fiber composite material

【Technical field】

The utility model belongs to the technical field of moulds, in particular to an injection molding device for natural fiber composite materials.

【Background technique】

Natural fiber composite reinforced material is a highly renewable cellulose reinforced material, which has low density, good sound insulation effect, good mechanical properties, high specific strength and specific modulus, is a renewable resource, and is an environmentally friendly material that can be naturally degraded; use Highly filled natural fiber composite reinforced materials can reduce the use of petroleum and reduce the damage to the forest environment; with the gradual improvement of environmental protection requirements in various countries around the world, this polypropylene-based high-filled natural fiber composite material injection molding products and green The manufacturing process will definitely have a profound impact on related application fields. The production process of the products produced by injection molding of economical and affordable natural fiber composite materials also has the characteristics of low energy consumption and low VOC emissions, which can achieve the green environmental protection of the injection molding manufacturing process and injection molding products.

The widespread use of this polypropylene-based high-fill natural fiber composite reduces the use of petroleum and is fully recyclable or can be burned to reduce forest damage. However, since the content of paper fiber in this polypropylene-based high-filled natural fiber composite material is 40% to 50%, the problem of poor fluidity in injection molding production of the material is more prominent.

This kind of polypropylene-based high-filled natural fiber composite material has a prominent problem of poor fluidity during injection molding, and its injection speed must be fast, so as to improve the marble-like floating fiber effect existing on the product surface, especially for products with large sizes and For products with thick walls ranging from 5mm to 20mm, this phenomenon will be more prominent; due to the addition of a high proportion of reinforcing natural fibers, the temperature of the injection unit and plasticizing device of the injection molding machine and the shear rate of the sol must be accurately analyzed and analyzed. For control, the injection unit and plasticizing device system of the injection molding machine must meet the following three conditions:

1. The materials required for injection molding products in the injection unit and plasticizing device must be quickly injected into the plastic mold within 3S, otherwise it is prone to insufficient filling and serious floating fibers on the product surface, and the product function and appearance cannot meet the use requirements;

2. The temperature of the molten material cannot be lower than 190°C. Too low melting temperature will reduce the fluidity of the material, and the same adverse phenomenon as in 1 will appear;

3. The temperature of the material in the injection unit and the plasticizing device should not be higher than 210°C. If the temperature is too high, the paper cellulose fibers in the material will spontaneously ignite, resulting in the failure of injection molding production and serious safety hazards.

The utility model is produced based on the above problems.

【Content of utility model】

The purpose of this utility model is to provide an injection molding device for natural fiber composite materials in view of the deficiencies of the prior art, which has high product quality and high injection molding efficiency.

In order to solve the above technical problems, the utility model provides the following technical solutions: an injection molding device for natural fiber composite materials, which is characterized in that it includes a plasticizing barrel, the end of the plasticizing barrel is provided with a nozzle, the A rotatable screw body is arranged inside the plasticizing barrel, and the end of the screw body is provided with a screw head; the length-to-diameter ratio L/D of the screw body ranges from 18 to 23, and the compression of the screw body The ratio ranges from 1.5 to 1.95.

A kind of injection molding device of natural fiber composite material as above is characterized in that it also includes a non-return ring and a thrust ring, the non-return ring and the thrust ring are between the screw head and the screw body, and the thrust ring and the screw The body is fixedly connected, and the non-return ring is located between the screw head and the thrust ring.

The above-mentioned injection molding device for natural fiber composite materials is characterized in that the diameter a of the nozzle hole of the nozzle ranges from 5 mm to 25 mm.

The above-mentioned injection molding device for natural fiber composite materials is characterized in that the end of the nozzle is spherical, and the radius r of the spherical surface is in the range of 25 mm to 35 mm.

Compared with the prior art, an injection molding device of a natural fiber composite material of the utility model has the following beneficial effects:

The length-to-diameter ratio L/D ratio range of the screw body of the utility model is 18-23, and the ratio range of the compression ratio of the screw body is 1.5-1.95. This design can effectively carry out the shear heat of the material when the screw rotates. Control to ensure that the long fiber part is not excessively sheared to meet the stringent requirements for injection molding production of high-fill natural fiber biocomposites, high-quality finished products and high injection molding efficiency, thereby achieving and breaking through the injection molding production process of high-fill natural fiber biocomposites Bottlenecks and solving production safety problems.

【Description of drawings】

Below in conjunction with accompanying drawing, the specific embodiment of the present utility model is described in further detail, wherein:

Fig. 1 is a structural representation of the utility model;

Fig. 2 is the enlarged view of M place in Fig. 1;

Fig. 3 is the structural diagram of the screw rod body of the present invention;

Description of drawings: 1. Plasticizing barrel; 2. Nozzle; 3. Screw body; 4. Screw head; 5. Check ring; 6. Thrust ring; L, length of screw body; D, diameter of screw body; Feed section; L2, compression section; L3, homogenization section; h1, screw groove depth of feed section; h3, screw groove depth of homogenization section.

【Detailed ways】

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

As shown in Figures 1 to 3, in this embodiment, an injection molding device for natural fiber composite materials includes a plasticizing barrel 1, and a nozzle 2 is provided at the end of the plasticizing barrel 1, and the plasticizing barrel 1 is provided with a nozzle 2. The plasticizing barrel 1 is provided with a rotatable screw body 3, and the end of the screw body 3 is provided with a screw head 4; the length-to-diameter ratio L/D of the screw body 3 has a ratio range of 18 to 23, so The compression ratio of the screw body 3 ranges from 1.5 to 1.95.

The length of the screw body is the length from the threaded part of the screw head to the midline of the hopper; the diameter of the screw body is D.

The compression ratio is the ratio of the volume of the first thread groove in the feed section L1 of the screw body to the volume of the last thread groove in the homogenization section L3. In the equidistant gradual deformation screw, it can also be understood as the depth of the first thread groove in the feed section L1 The ratio of h1 to the depth h3 of the last thread groove of the homogenizing section L3, that is, the compression ratio = h1/h3. The compression ratio of the screw has a great influence on the process control conditions of extruding plasticized raw materials. When extruding different resins, the compression ratio of the screw should be selected according to the physical properties of different plastics.

As shown in Figures 1 to 3, in this embodiment, a non-return ring 5 and a thrust ring 6 are also included, and the non-return ring 5 and the thrust ring 6 are between the screw head 4 and the screw body 3, and the thrust The ring 6 is fixedly connected with the screw rod 3 , and the non-return ring 5 is located between the screw head 4 and the thrust ring 6 . The function of the non-return ring is to prevent the melt from flowing backward; when the melt is melted, the screw body rotates, and the material is squeezed to the front end through the thread of the screw body. There is a gap, and the material can flow along the gap, then flow through the screw head, and then flow to the front of the barrel. When the glue is injected, the screw body moves forward, and the thrust ring and the thrust ring will be locked, closing the channel, thus playing the role of sealing glue.

As shown in Figures 1 to 3, in this embodiment, the diameter a of the nozzle hole of the nozzle 2 ranges from 5 mm to 25 mm. It is far beyond the design size of the injection molding device commonly used at present, so as to meet the injection speed requirements of high-fill natural fiber biocomposite injection molding production.

As shown in FIG. 1 to FIG. 3 , in this embodiment, the end of the nozzle 2 is a spherical surface, and the radius r of the spherical surface is in the range of 25 mm to 35 mm.

Claims (4)

1. a kind of injection moulding apparatus of natural-fiber composite material, which is characterized in that include plasticizing charging barrel (1), the plasticizing material The end set of cylinder (1) has nozzle (2), and rotatable screw body (3), the screw rod sheet are equipped in the plasticizing charging barrel (1) The end set of body (3) has screw head (4)；The ratio range of the draw ratio L/D of the screw body (3) is 18~23, described The ratio range of the compression ratio of screw body (3) is 1.5~1.95.

2. a kind of injection moulding apparatus of natural-fiber composite material according to claim 1, which is characterized in that further include having only Inverse ring (5) and thrust ring (6), check ring (5) and thrust ring (6) are described as between screw head (4) and screw body (3) Thrust ring (6) is fixedly connected with screw body (3), and check ring (5) is located between screw head (4) and thrust ring (6).

3. a kind of injection moulding apparatus of natural-fiber composite material according to claim 1, which is characterized in that the nozzle (2) ranging from 5mm~25mm of the diameter a of nozzle bore.

4. a kind of injection moulding apparatus of natural-fiber composite material according to claim 3, which is characterized in that the nozzle (2) end is spherical surface, and ranging from 25mm~35mm of spherical radius r.