CN112388936B - Single core mask line manufacturing process - Google Patents

Abstract

The invention discloses a manufacturing process of a single-core mask wire in the field of mask nose clip wire. The extrusion die is improved by design, a protruding edge structure is adopted, the extrusion performance is improved, and the surface of the single-core mask nose clip wire is guaranteed to be smooth after extrusion molding. It is flat and free of burrs, which greatly improves the production efficiency, and effectively solves the problems of low production speed and limited production efficiency in the prior art due to structural reasons for the nose clip of the mask.

Description

Single core mask line manufacturing process

technical field

The invention relates to the field of manufacturing a mask nose clip line, in particular to a manufacturing process for a single-core mask thread.

Background technique

Masks are sanitary products used to filter the air entering the nose and mouth. They can effectively filter harmful bacteria, dust, particles, etc. in the air. They are often used in hospitals, factories and other places. However, with the increase of urban air haze and some airborne viruses With the outbreak of the epidemic, more and more masks are used in people's daily travel. In addition to the filtering protection effect of the mask mainly depends on the filtering ability of its own material, the fitting effect after it is attached to the face is also very important. In order to ensure that the mask can better fit the contours of the human face, mask lines, also known as nose bridge strips, nose clip lines, etc., are set on the existing masks, which are used to attach the mask to the human face.

The mask line is mostly made of plastic metal sheet or polyolefin resin. The metal sheet is mostly aluminum sheet, which is mainly used for thicker masks, and the polyolefin resin mask line is mainly used for thinner medical disposable masks. In order to ensure the setting performance of polyolefin resin mask line, thin metal wires are often embedded in it. Such mask lines are extruded and packaged with resin on the outside of the metal wire during the production process. However, the production efficiency of such a mask line in the prior art is relatively low, mainly because the mask line is used on a mask with a light and thin material, and the thickness of the mask line is limited, usually 1-2mm, and requires a smooth surface to When assembling on the mask, it will not hang with the main body of the mask such as non-woven fabric and meltblown cloth, so as to ensure that the mask is flat and usable. In order to meet the above requirements, the extrusion speed of the mask nose clip line of the existing structure cannot exceed 120 m/min. The mask thread with brushed surface will inevitably pull the mask filter cloth during the process of sewing it into the mask, causing the assembled mask to wrinkle and unable to provide effective filtering protection. This limits the production efficiency of the mask line, especially when there is a large demand for masks such as influenza and infectious diseases, which seriously affects the production and supply of masks.

SUMMARY OF THE INVENTION

The present invention intends to provide a single-core mask wire manufacturing process to solve the problems of low production speed and limited production efficiency of the mask nose clip wire in the prior art due to structural reasons.

In order to achieve the above-mentioned purpose, the basic technical scheme of the present invention is as follows: the single-core mask wire manufacturing process comprises the following steps:

A. Prepare materials, prepare metal core wires and insulating materials;

B. Open the mold and prepare to extrude the mold. There is a discharge port on the extrusion mold. The discharge port includes a rectangular hole. The left and right ends of the rectangular hole are connected with a circular hole, and the diameters of the two circular holes are larger than The distance between the upper and lower walls of the rectangular hole, the middle of the upper wall of the rectangular hole is upwardly recessed to form a semi-circular through groove;

C. Extrusion, assemble the extrusion die on the screw extruder, heat the screw extruder and the extrusion die, and simultaneously extrude the metal core wire and the insulating material through the extrusion die on the screw extruder;

D. Cooling and molding, water-cooling the extruded single-core mask line to room temperature.

The principle and advantages of this scheme are: in practical application, the extrusion die is installed on the screw extruder, the raw materials are heated and transported to the extrusion die by the screw extruder for extrusion molding, and the raw materials are extruded from the outlet of the extrusion die. Forming, the round holes at both ends of the discharge port improve the passability of the raw material at the edge of the discharge port during the extrusion process, ensuring that the raw material is smoothly extruded from the discharge port, and the surface will not be rough. Compared with the extrusion die in the prior art, such a round hole increases the passage space on both sides of the discharge port, reduces the plane contact of the edge parts, and reduces the plane pulling during the extrusion process of the raw material through the arc surface, effectively To avoid the raw material being pulled to produce burrs, so that the surface of the extruded mask line will not have hair pulling defects. And adopting such a structure improves the passability of raw materials, so that the extrusion molding speed of the mask line can be increased by more than 60% on the existing basis, and the production efficiency is greatly improved. A convex rib is formed on the nose clip line of the extruded mask through the semi-circular through groove, which can cover the metal core wire, and can also easily identify the front and back of the mask during the use of the mask, and can improve the performance of the mask. The shaping performance of the thread ensures that the mask can be effectively fitted to the human face during use.

Further, the insulating material in step A includes 70%-90% polyethylene and 10%-30% polypropylene. As an insulating material mixed with polyethylene and polypropylene in such a proportion, the extruded mask nose clip has excellent bending resistance, flexibility and good heat resistance and low temperature resistance, and can withstand repeated bending The bent part will not turn white, which can meet the needs of various disinfection and sterilization.

Further, the insulating material in step A includes 80% polyethylene and 20% polypropylene. It is preferable to use such a proportion of insulating materials to obtain the best mechanical properties, and effectively ensure that the produced mask nose clips have excellent mechanical properties.

Further, in step B, the two circular holes are processed into the same diameter. Preferably, the passage space at both ends of the discharge port is the same, the flow of raw materials is more uniform and the fluidity is better during the process of passing through the discharge port, which further ensures that there is no fluffing defect on both sides of the extruded mask line. Improve the applicability of the assembly with the mask.

Further, in step B, the chord length of the intersection of each circular hole and the rectangular hole is processed to be equal to the distance between the upper and lower walls of the rectangular hole. In this way, the transition between the round hole and the rectangular hole is relatively smooth, and the surface of the extruded mask line will not be dented or drawn, and the molding quality will be better.

Further, in step B, the centers of the two circular holes are both positioned on the vertical axis of symmetry of the rectangular holes. Preferably, the two circular holes are symmetrically arranged on the vertical axis of symmetry, the circular holes protruding above the rectangular hole and the space outside the lower wall are of the same size, and the raw material flows more smoothly during the extrusion process therefrom.

Further, in step B, the center of the semicircular through groove is positioned on the transverse axis of symmetry of the rectangular hole. As a preference, it is ensured that the discharge port has a symmetrical structure as a whole, and the quality of the extruded mask line is better.

Further, in step B, the metal core wire is arranged coaxially with the semicircular through groove of the extrusion die. Preferably, the metal wire core of the mask nose clip wire formed in this way is covered with insulating material of uniform thickness, the metal wire core can provide stable and reliable shaping performance, and the insulating material can effectively isolate the metal wire core.

Further, in the step C, the whole formed by the screw extruder and the extrusion die adopts six-stage heating, the temperature of the first stage is 150 ° C, the temperature of the second section is 160 ° C, the temperature of the third section is 170 ° C, and the temperature of the machine neck section is 170 ° C. It is 180℃, the temperature of the mold body section is 190℃, and the temperature of the mold section is 190℃. As a preferred method, the temperature is gradually increased by six-stage heating. First, the insulating material entering the screw extruder is gradually heated and heated through three-stage heating, and then the neck and the die body are further heated, so that the insulating material is further melted and mixed, and the flow rate is improved. Then, it is extruded isothermally at the mold part, so that the insulating material can maintain stable and excellent fluidity during the extrusion process, and then the insulating material can be smoothly extruded during the extrusion process without causing edge pulling, burrs, burrs and other defects. The insulating material can also be stably wrapped on the outside of the metal core wire.

Further, the extrusion speed in step C is 120-200 m/min. As a preference, the extrusion speed can be further increased by improving the extrusion die and process, the extrusion efficiency can be increased by more than 60% compared with the original technology, and the production efficiency of the single-core mask line can be greatly improved.

Description of drawings

1 is a front view of an extrusion die in Example 1 of the present invention;

Fig. 2 is the cross-sectional structure schematic diagram of the single-core mask wire produced by the technical solution of the present invention.

Detailed ways

The following is further described in detail by specific embodiments:

Reference numerals in the accompanying drawings include: extrusion die 1 , rectangular hole 2 , round hole 3 , semi-circular through groove 4 , sheath 5 , convex rib 6 , and metal wire 7 .

Embodiment 1, single-core mask line manufacturing process, may further comprise the steps:

A. Prepare materials, prepare metal core wire and insulating material, the metal core wire is steel wire with a diameter of less than 0.5mm, and the insulating material is composed of 80% polyethylene and 20% polypropylene by mass fraction;

B. Open the mold and prepare the extrusion mold 1. As shown in Figure 1, the extrusion mold 1 is provided with a discharge port, and the discharge port includes a rectangular hole 2. The left and right ends of the rectangular hole 2 are connected with a circle Hole 3, the diameters of the two circular holes 3 are larger than the distance between the upper and lower walls of the rectangular hole 2, the two circular holes 3 are processed into the same diameter, and the centers of the two circular holes 3 are located at the vertical position of the rectangular hole 2. On the axis of symmetry, the chord length of the intersection of each circular hole 3 and the rectangular hole 2 is processed to be equal to the distance between the upper and lower walls of the rectangular hole 2; , the center of the semicircular through groove 4 is positioned on the transverse axis of symmetry of the rectangular hole 2, and the metal core wire is coaxially arranged with the semicircular through groove 4 of the extrusion die 1;

C, extrusion, the extrusion die 1 is assembled on the screw extruder, and the screw extruder and the extrusion die 1 are heated, and the whole formed by the screw extruder and the extrusion die 1 adopts six-stage heating, and the first The temperature of the first stage is 150 °C, the temperature of the second stage is 160 °C, the temperature of the third stage is 170 °C, the temperature of the neck section is 180 °C, the temperature of the mold body section is 190 °C, and the temperature of the mold section is 190 °C. The insulating material is synchronously extruded through the extrusion die 1 on the screw extruder, and the extrusion speed is 200 m/min;

D. Cooling and molding, water-cooling the extruded single-core mask line to room temperature.

Example 2, in this example, the insulating material is composed of polyethylene with a mass fraction of 70% and polypropylene with a mass fraction of 30%, and the extrusion speed is 160 m/min.

Embodiment 3, in this embodiment, the insulating material is composed of polyethylene with a mass fraction of 90% and polypropylene with a mass fraction of 10%, and the extrusion speed is 120 m/min.

Comparative Example 1, in this comparative example, the mass fraction of the insulating material is 60% polyethylene and 40% polypropylene.

Comparative example 2, in this comparative example, the mass fraction of the insulating material is 95% polyethylene and 5% polypropylene.

In the production process, the extrusion die 1 is assembled with the screw extruder, and the resin raw materials such as polyethylene are sent into the screw extruder. Mouth extrusion molding. In the process of the raw material passing through the discharge port, because the two sides of the discharge port adopt the concave circular hole 3 structure, the friction effect caused by the arc surface is smaller than the flat friction effect in the middle, and the raw material can pass better, so that the raw material is uniform and synchronized. It is extruded from the discharge port, and the surface of the extruded product is smooth and flat without burrs, and the non-woven fabric and melt-blown cloth will not be pulled during the process of wearing it to the mask filter cloth. While ensuring the extrusion quality, the extrusion speed can be further increased. The original extrusion speed exceeding 120 m/min will produce a large number of fluffing defects. Now the improved extrusion speed can be increased to 200 m/min. There is a problem of hair pulling, and the production quality and production efficiency are greatly improved.

During the extrusion process, the metal wire 7 can also be transported in the extrusion die 1 synchronously, so that the metal wire 7 is embedded in the extruded resin raw material, which can improve the structural strength and bending setting performance of the extruded product, so that the formed Mask line products can effectively fit the mask to the contours of the human face to achieve effective protection.

The single-core mask nose clip line processed in Comparative Example 1 and Comparative Example 2 is compared with that obtained in Example 1-3, and it is found that the bending resistance performance of the single-core mask nose clip line prepared in Comparative Example 1 is not as good as that in Example 1- 3 The prepared product has a harder texture, and the bending part is prone to whitish fatigue. The texture of the single-core mask nose clip prepared in Comparative Example 2 is softer than that of the products prepared in Examples 1-3, the surface is easy to wear, and the metal wire is easy to wear. In general, the quality of the products produced by the technical solutions of Examples 1-3 of the present invention is better.

The single-core mask thread formed by the technical solution of the present invention is shown in Figure 2. Including a sheath 5, the two sides of the sheath 5 are round bars protruding outward, a metal wire 7 is embedded in the extension direction of the sheath 5, and the diameter of the metal wire 7 is less than or equal to 0.5mm. The middle part of the upper surface of the sheath 5 is provided with a convex rib 6 extending along the length direction.

The above descriptions are only examples of the present invention, and common knowledge such as well-known specific structures and/or characteristics in the solutions are not described too much here. It should be pointed out that for those skilled in the art, some modifications and improvements can be made without departing from the structure of the present invention. These should also be regarded as the protection scope of the present invention, and these will not affect the implementation of the present invention. Effectiveness and utility of patents. The scope of protection claimed in this application shall be based on the content of the claims, and the descriptions of the specific implementation manners in the description can be used to interpret the content of the claims.

Claims (9)

1. single-core mask line manufacturing process, is characterized in that: comprise the following steps: A. Prepare materials, prepare metal core wires and insulating materials; B. Open the mold and prepare the extrusion mold. The extrusion mold is provided with a discharge port, and the discharge port includes a rectangular hole. The left and right ends of the rectangular hole are connected with a circular hole, and the two circular holes are connected with each other. The diameter of the hole is larger than the distance between the upper and lower walls of the rectangular hole, and the middle of the upper wall of the rectangular hole is recessed upward to form a semi-circular through groove; C. Extrusion, assemble the extrusion die on the screw extruder, heat the screw extruder and the extrusion die, and simultaneously extrude the metal core wire and the insulating material through the extrusion die on the screw extruder, extrude The output speed is 120-200 m/min; D. Cooling and molding, water-cooling the extruded single-core mask line to room temperature. 2. The single-core mask wire manufacturing process according to claim 1, wherein the insulating material in the step A comprises 70%-90% polyethylene and 10%-30% polypropylene. 3. The single-core mask wire manufacturing process according to claim 2, wherein the insulating material in the step A comprises 80% polyethylene and 20% polypropylene. 4. The single-core mask wire manufacturing process according to claim 1, characterized in that: in the step B, two circular holes are processed into the same diameter. 5. single-core mask wire manufacturing process according to claim 1, is characterized in that: in described step B, the chord length that each round hole and rectangular hole intersects is all processed to be equal to the length between the upper and lower walls of the rectangular hole. spacing. 6 . The single-core mask wire manufacturing process according to claim 1 , wherein in the step B, the centers of the two circular holes are positioned on the vertical axis of symmetry of the rectangular hole. 7 . 7 . The single-core mask wire manufacturing process according to claim 1 , wherein in the step B, the center of the semicircular through groove is positioned on the transverse axis of symmetry of the rectangular hole. 8 . 8 . The single-core mask wire manufacturing process according to claim 7 , wherein in the step B, the metal core wire is arranged coaxially with the semicircular through groove of the extrusion die. 9 . 9. single-core mask wire manufacturing process according to claim 8, is characterized in that: in the described step C, the whole formed by screw extruder and extrusion die adopts six-stage heating, and the temperature of the first stage is 150 ℃, The temperature of the second stage is 160 °C, the temperature of the third stage is 170 °C, the temperature of the machine neck section is 180 °C, the temperature of the mold body section is 190 °C, and the temperature of the mold section is 190 °C.

Images