阅读说明：本技术 一种复合热熔胶网膜的制备方法 (Preparation method of composite hot melt adhesive net film ) 是由 刘卫峰 于 2021-07-09 设计创作，主要内容包括：本发明涉及一种复合热熔胶网膜的制备方法,具体步骤包括如下：S1、按重量份数计,选取70-80份的聚乙烯-醋酸乙烯酯、8-10份的萜烯树脂、5-8份的石蜡、2-3份的成核剂、2-3份的抗氧化剂、1-2份的无机填料、1-2份增容剂、1-2份扩链剂；S2、形成复合热熔胶液b；S3、特氟龙网带在受到复合热熔胶液b向下的冲击力以及抽风机的压力而发生上下振动,从而实现对超细纤维网膜层内部分子均匀化重组；S4、对步骤S中形成的超细纤维网膜层经过水雾喷淋,烘箱烘干后收卷,制得复合热熔胶网膜。本发明具有如下优点：通过对各个成分的选取以及在专用的热熔胶喷射装置的高压超细纤维化喷射成型下,提高了复合热熔胶网膜的弹性及平整度,提高其粘结强度。(The invention relates to a preparation method of a composite hot melt adhesive net film, which comprises the following specific steps: s1, selecting 70-80 parts of polyethylene-vinyl acetate, 8-10 parts of terpene resin, 5-8 parts of paraffin, 2-3 parts of nucleating agent, 2-3 parts of antioxidant, 1-2 parts of inorganic filler, 1-2 parts of compatibilizer and 1-2 parts of chain extender according to parts by weight; s2, forming a composite hot melt adhesive solution b; s3, the Teflon mesh belt vibrates up and down under the action of the downward impact force of the composite hot melt adhesive liquid b and the pressure of an exhaust fan, so that the molecule homogenization recombination in the superfine fiber mesh film layer is realized; and S4, spraying water mist on the superfine fiber net film layer formed in the step S, drying in an oven and then rolling to obtain the composite hot melt adhesive net film. The invention has the following advantages: through the selection of each component and the high-pressure ultrafine fiber injection molding of the special hot melt adhesive injection device, the elasticity and the flatness of the composite hot melt adhesive net film are improved, and the bonding strength of the composite hot melt adhesive net film is improved.)

1. The preparation method of the composite hot melt adhesive net film is characterized by comprising the following steps of: the method comprises the following specific steps:

s1, selecting 70-80 parts of polyethylene-vinyl acetate, 8-10 parts of terpene resin, 5-8 parts of paraffin, 2-3 parts of nucleating agent, 2-3 parts of antioxidant, 1-2 parts of inorganic filler, 1-2 parts of compatibilizer and 1-2 parts of chain extender according to parts by weight;

s2, stirring and mixing the polyethylene-vinyl acetate and the terpene resin in the step S1 at the temperature of 60-80 ℃ to obtain a prepolymer, adding the paraffin, the nucleating agent, the antioxidant, the non-polar filler, the compatibilizer and the chain extender in the step S1 into the prepolymer to be stirred and mixed, vacuumizing to remove bubbles to preliminarily form a composite hot melt adhesive liquid a, pouring the composite hot melt adhesive liquid a into a preheated mold, and curing at the temperature of 100-120 ℃ to form a composite hot melt adhesive liquid b;

s3, the composite hot melt adhesive liquid b in the step S2 is impacted and sprayed on a Teflon mesh belt through a hot melt adhesive spraying device to form a superfine fiber mesh film layer, an exhaust fan for exhausting and cooling the superfine fiber mesh film layer on the Teflon mesh belt is arranged at the lower end of the Teflon mesh belt, and the Teflon mesh belt vibrates up and down under the action of the downward impact force of the composite hot melt adhesive liquid b and the pressure of the exhaust fan, so that the molecule homogenization recombination in the superfine fiber mesh film layer is realized;

and S4, spraying water mist on the superfine fiber net film layer formed in the step S, drying in an oven and then rolling to obtain the composite hot melt adhesive net film.

2. The method for preparing a composite hot melt adhesive web according to claim 1, wherein: the hot melt adhesive injection device comprises a plurality of transmission rollers and a spinneret assembly arranged right above any one of the transmission rollers, the Teflon mesh belt is coated on the transmission rollers for transmission, the transmission rollers arranged right below the spinneret assembly can realize up-down buffer type vibration through a vibration group, and the transmission rollers arranged right below the spinneret assembly are higher than other transmission rollers.

3. The method for preparing a composite hot melt adhesive web according to claim 2, wherein: the vibration group includes that support, axostylus axostyle and cover establish the outside live-rollers of axostylus axostyle, the both ends of axostylus axostyle run through the support, have the perforation that the side that holds the axostylus axostyle runs through on the support, the side that runs through the axostylus axostyle has the fixed axle, the fixed axle is fixed to be set up in the perforation, and the fixed axle is located the upper and lower position of axostylus axostyle and all overlaps and be equipped with first spring, the one end and the fenestrate inner wall fixed connection of first spring, the other end of first spring and the side fixed connection of axostylus axostyle, the axostylus axostyle is receiving the effect of external impact force and along with the buffering of first spring direction vibration about in the perforation.

4. The method for preparing a composite hot melt adhesive web according to claim 3, wherein: the spinneret assembly comprises a plurality of spinnerets arranged right above a transmission roller, the spinnerets are distributed along the extension direction of the transmission roller, hot melt adhesive inlet runners and hot melt adhesive outlet runners are arranged in the spinnerets, an upper ejector rod and a lower ejector pin are further arranged, the upper ejector rod and the lower ejector pin are connected in a wrapping type buffering mode through a buffering connection set, the lower end of the lower ejector pin vertically extends into the outlet position of the hot melt adhesive outlet runners, the upper end of the upper ejector rod is impacted with the lower ejector pin at high pressure through a piezoelectric brake, composite hot melt adhesive liquid b in a melting state at the outlet of the hot melt adhesive outlet runners is ejected from the tips of the spinnerets due to instantaneous high pressure, the outer wall of the hot melt adhesive outlet runners is provided with a preheating pipe, and the outer wall of the hot melt adhesive outlet runners is provided with heating pipes.

5. The method for preparing a composite hot melt adhesive web according to claim 4, wherein: the constant temperature of the preheating pipe is controlled to be 80-90 ℃, and the constant temperature of the heating pipe is controlled to be 100-110 ℃.

6. The method for preparing a composite hot melt adhesive web according to claim 5, wherein: the buffer connection group comprises a convex block arranged at the upper end of the lower thimble and a clamping block arranged at the lower end of the upper thimble, a cavity for accommodating the convex block to be embedded is arranged in the clamping block, the height of the cavity is larger than that of the convex block, a movable cavity for providing space for the joint of the upper thimble and the lower thimble is arranged in the spinneret, the clamping block is coated outside the convex block and is arranged in the movable cavity, a second spring is arranged between the clamping block and the bottom of the movable cavity, the second spring is sleeved outside the lower thimble, a third spring is sleeved outside the upper thimble, the third spring is arranged between the upper end of the upper thimble and the upper end of the movable cavity, the movable cavity is communicated with a hot melt adhesive outlet runner, a convex rib is arranged on the outer side wall of the convex block, and a limit groove for accommodating the convex rib to be embedded and capable of sliding up and down is arranged on the inner wall of the cavity.

7. The method for preparing a composite hot melt adhesive web according to claim 6, wherein: the cavity inner wall is arranged at a position right above the lug and is provided with an arc-shaped bulge, an opening of the arc-shaped bulge is arranged back to the lug, and the cavity inner wall is provided with a rubber buffer layer.

8. The method of making a composite hot melt adhesive web of claim 7, wherein: the hot melt adhesive outlet flow passage comprises an upper longitudinal portion, a middle longitudinal portion and a lower cone portion which are sequentially connected from top to bottom, the upper longitudinal portion, the middle longitudinal portion and the lower cone portion are of an integrated forming structure, the width of the upper longitudinal portion is larger than that of the middle longitudinal portion, and the outlet end of the hot melt adhesive inlet flow passage is connected with the middle longitudinal portion.

9. The method of making a composite hot melt adhesive web of claim 8, wherein: the bottom of the inner side of the upper longitudinal portion is provided with a sealing gasket, a filler is arranged above the sealing gasket, the bottom of the movable cavity is provided with a filler pressing plate, and the filler is pressed tightly on the inner wall of the upper longitudinal portion by the filler pressing plate.

The technical field is as follows:

the invention belongs to the field of hot melt adhesive net films, and particularly relates to a preparation method of a composite hot melt adhesive net film.

Background art:

the hot melt adhesive net film is a non-woven fabric-shaped high-molecular thermoplastic adhesive, and along with the aggravation of market competition, each industry needs a more efficient composite adhesive to promote the production efficiency and the product quality, and the hot melt adhesive net film is an innovative product of a hot melt adhesive technology.

At present, in the process of preparing the hot melt adhesive net film, because the functional groups of various polymers are different in property, viscosity difference exists between high molecular weights, the activity is poor, and the situation that the polymers are incompatible exists before each other, the prepared hot melt adhesive net film has the defect of low bonding strength.

The invention content is as follows:

the invention aims to overcome the defects and provides a preparation method of a composite hot melt adhesive net film, which improves the elasticity and the flatness of the composite hot melt adhesive net film and the bonding strength of the composite hot melt adhesive net film by selecting various components and carrying out high-pressure ultrafine fiber injection molding by a special hot melt adhesive injection device.

The purpose of the invention is realized by the following technical scheme: a preparation method of a composite hot melt adhesive net film comprises the following specific steps:

s1, selecting 70-80 parts of polyethylene-vinyl acetate, 8-10 parts of terpene resin, 5-8 parts of paraffin, 2-3 parts of nucleating agent, 2-3 parts of antioxidant, 1-2 parts of inorganic filler, 1-2 parts of compatibilizer and 1-2 parts of chain extender according to parts by weight;

s2, stirring and mixing the polyethylene-vinyl acetate and the terpene resin in the step S1 at the temperature of 60-80 ℃ to obtain a prepolymer, adding the paraffin, the nucleating agent, the antioxidant, the non-polar filler, the compatibilizer and the chain extender in the step S1 into the prepolymer to be stirred and mixed, vacuumizing to remove bubbles to preliminarily form a composite hot melt adhesive liquid a, pouring the composite hot melt adhesive liquid a into a preheated mold, and curing at the temperature of 100-120 ℃ to form a composite hot melt adhesive liquid b;

s3, the composite hot melt adhesive liquid b in the step S2 is impacted and sprayed on a Teflon mesh belt through a hot melt adhesive spraying device to form a superfine fiber mesh film layer, an exhaust fan for exhausting and cooling the superfine fiber mesh film layer on the Teflon mesh belt is arranged at the lower end of the Teflon mesh belt, and the Teflon mesh belt vibrates up and down under the action of the downward impact force of the composite hot melt adhesive liquid b and the pressure of the exhaust fan, so that the molecule homogenization recombination in the superfine fiber mesh film layer is realized;

and S4, spraying water mist on the superfine fiber net film layer formed in the step S, drying in an oven and then rolling to obtain the composite hot melt adhesive net film.

The invention is further improved in that: the hot melt adhesive injection device comprises a plurality of transmission rollers and a spinneret assembly arranged right above any one of the transmission rollers, the Teflon mesh belt is coated on the transmission rollers for transmission, the transmission rollers arranged right below the spinneret assembly can realize up-down buffer type vibration through a vibration group, and the transmission rollers arranged right below the spinneret assembly are higher than other transmission rollers.

The invention is further improved in that: vibration group includes the support, axostylus axostyle and cover establish the outside live-rollers of axostylus axostyle, the support is run through at the both ends of axostylus axostyle, the perforation that the side that holds the axostylus axostyle to run through has on the support, the side that runs through the axostylus axostyle has the fixed axle, the fixed setting of fixed axle is in perforating, and the fixed axle is located the upper and lower position of axostylus axostyle and all overlaps and be equipped with first spring, the one end and the fenestrate inner wall fixed connection of first spring, the other end of first spring and the side fixed connection of axostylus axostyle, the axostylus axostyle is receiving the effect of external impact force and along with the buffering of first spring orientation vibration about in perforating.

The invention is further improved in that: the spinneret assembly comprises a plurality of spinnerets arranged right above a transmission roller, the spinnerets are distributed along the extension direction of the transmission roller, hot melt adhesive inlet runners and hot melt adhesive outlet runners are arranged in the spinnerets, an upper ejector rod and a lower ejector pin are further arranged, the upper ejector rod and the lower ejector pin are connected in a cladding type buffering mode through a buffering connection set, the lower end of the lower ejector pin vertically extends into the outlet position of the hot melt adhesive outlet runners, the upper end of the upper ejector rod realizes high-pressure impact on the lower ejector pin through a piezoelectric brake, composite hot melt adhesive liquid b in a molten state at the outlet of the hot melt adhesive outlet runners is ejected from the tip of the spinnerets due to instantaneous high pressure, the outer wall of the hot melt adhesive outlet runners is provided with a preheating pipe, and the outer wall of the hot melt adhesive outlet runners is provided with heating pipes.

The invention is further improved in that: the temperature of the preheating pipe is controlled to be 80-90 ℃ at constant temperature, and the temperature of the heating pipe is controlled to be 100-110 ℃.

The invention is further improved in that: the buffering connection group is including arranging the lug of thimble upper end down in and arranging the fixture block of last ejector pin lower extreme in, the cavity that holds the lug embedding has in the fixture block, the height that highly is greater than the lug of cavity, have in the spinneret to last ejector pin, the thimble junction provides the activity cavity in space down, the fixture block cladding is in the outside of lug and places the activity cavity in, the second spring has between the bottom of fixture block and activity cavity, the outside of thimble under is established to the second spring housing, the outside cover of going up the ejector pin is equipped with the third spring, the upper end of last ejector pin and the upper end of activity cavity are placed in to the third spring, activity cavity and hot melt adhesive outlet runner intercommunication, the lateral wall of lug has protruding muscle, the inner wall of cavity has the spacing groove that holds protruding muscle embedding and gliding from top to bottom.

The invention is further improved in that: the inner wall of the cavity is provided with an arc-shaped bulge at a position right above the lug, the opening of the arc-shaped bulge is arranged back to the lug, and the inner wall of the cavity is provided with a rubber buffer layer.

The invention is further improved in that: the hot melt adhesive outlet flow passage comprises an upper longitudinal portion, a middle longitudinal portion and a lower cone portion which are sequentially connected from top to bottom, the upper longitudinal portion, the middle longitudinal portion and the lower cone portion are of an integrated forming structure, the width of the upper longitudinal portion is larger than that of the middle longitudinal portion, and the outlet end of the hot melt adhesive inlet flow passage is connected with the middle longitudinal portion.

The invention is further improved in that: the bottom of the inner side of the upper longitudinal portion is provided with a sealing gasket, a filler is arranged above the sealing gasket, the bottom of the movable cavity is provided with a filler pressing plate, and the filler is pressed tightly on the inner wall of the upper longitudinal portion by the filler pressing plate.

Compared with the prior art, the invention has the following advantages:

1. the paraffin selected by the invention has lower surface tension, improves the crystallinity of the polyethylene-vinyl acetate, relatively improves the compatibility among a plurality of polymers, thereby improving the elasticity of the polyethylene-vinyl acetate, improves the heat resistance of the hot melt adhesive liquid and reduces the heat shrinkage, prevents the self-adhesion of the hot melt adhesive liquid by controlling the fluidity of the hot melt adhesive, avoids the self-adhesion of the hot melt adhesive liquid, ensures the compatibility among the polymers, and provides a foundation for the subsequent injection of the hot melt adhesive liquid.

2. The invention adopts a special hot melt adhesive injection device to realize high-speed ultrafine fiber injection molding of hot melt adhesive, wherein micro-droplet molecules of the hot melt adhesive impact a Teflon mesh belt at high speed and high pressure, a certain downward impact force is generated on the Teflon mesh belt and a transmission roller arranged right below a spinning nozzle assembly, and the transmission roller generates certain vibration under the suction action of an exhaust fan, so that hot melt adhesive injection molecules are more closely attached to the Teflon mesh belt, the flatness of a composite hot melt adhesive net film is improved, and meanwhile, the hot melt adhesive injection molecules are rapidly dispersed and recombined under the action of gravity and the impact force through certain vibration, and the bonding strength of the hot melt adhesive net film is improved; the exhaust fan plays a role in vibrating the conveying roller up and down, and rapidly cools the sprayed hot melt adhesive molecules to realize rapid cooling forming.

3. The piezoelectric brake in the spinning nozzle assembly is used as a power source to output certain force and impact speed, the certain force and the certain impact speed are acted on the upper ejector rod, the force and the impact speed are acted on the lower ejector pin by the upper ejector rod, the lower ejector pin subjected to high-pressure impact impacts the spinning nozzle at high speed to jet the hot melt adhesive liquid in a molten state in the spinning nozzle, the high impact speed and the small movement displacement of the hot melt adhesive liquid are realized through the secondary impact between the upper ejector rod and the lower ejector pin, the small volume of the jet is realized, the jet with higher viscosity can be realized, and the bonding strength of the composite hot melt adhesive net film is improved.

4. The connection part of the upper ejector rod and the lower ejector pin in the invention adopts a buffer connection group to realize cladding type buffer connection, the second spring and the third spring are arranged to realize the quick rebound of the upper ejector rod and the lower ejector pin, the lug at the upper end of the lower ejector pin is clamped in the cavity of the fixture block at the lower end of the upper ejector pin, and the lower ejector pin is prevented from rotating or swinging circumferentially when being impacted by the upper ejector pin from top to bottom at high speed through the matching of the convex rib and the limiting groove, and the quality of the composite hot melt adhesive net film is influenced by the tiny rotation or swinging of the hot melt adhesive liquid spray adhesive.

Description of the drawings:

fig. 1 is a schematic view of the connection of the teflon mesh belt and the hot melt adhesive injection device in the present invention.

FIG. 2 is a schematic view of the structure of the vibration unit and the conveying roller of the present invention.

FIG. 3 is a schematic diagram of the construction of a spinneret assembly according to the present invention.

Reference numbers in the figures:

1-Teflon mesh belt, 2-exhaust fan, 3-transmission roller, 4-spinneret assembly and 5-vibration group;

41-spinneret, 42-hot melt adhesive outlet flow channel, 43-hot melt adhesive inlet flow channel, 44-upper ejector rod, 45-lower ejector pin, 46-buffer connection group, 47-piezoelectric brake, 48-preheating tube, 49-heating tube;

421-upper longitudinal part, 422-middle longitudinal part, 423-lower cone part, 424-sealing gasket, 425-packing and 426-packing pressing plate;

461-convex block, 462-clamping block, 463-cavity, 464-movable cavity, 465-second spring, 466-third spring, 467-convex rib, 468-limiting groove, 469-arc-shaped bulge and 4610-rubber buffer layer;

51-bracket, 52-shaft lever, 53-rotating roller, 54-perforation, 55-fixed shaft, 56-first spring.

The specific implementation mode is as follows:

for the purpose of enhancing the understanding of the present invention, the present invention will be further described in detail with reference to the following examples and the accompanying drawings, which are only used for explaining the present invention and are not to be construed as limiting the scope of the present invention.

In the description of the present invention, it is to be understood that the terms indicating an orientation or positional relationship, such as one based on the drawings, are used only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the structure or unit indicated must have a specific orientation, and thus, are not to be construed as limiting the present invention.

In the present invention, unless otherwise specified and limited, terms such as "connected," "provided," "having," and the like are to be understood in a broad sense, and may be, for example, fixedly connected, detachably connected, or integrally connected, mechanically connected, or directly connected, and may be connected through an intermediate medium, so that those skilled in the art can understand the basic meaning of the above terms in the present invention according to specific situations.

The invention relates to a preparation method of a composite hot melt adhesive net film, which comprises the following specific steps:

s1, selecting 70-80 parts of polyethylene-vinyl acetate, 8-10 parts of terpene resin, 5-8 parts of paraffin, 2-3 parts of nucleating agent, 2-3 parts of antioxidant, 1-2 parts of inorganic filler, 1-2 parts of compatibilizer and 1-2 parts of chain extender according to parts by weight;

s2, stirring and mixing the polyethylene-vinyl acetate and the terpene resin in the step S1 at the temperature of 60-80 ℃ to obtain a prepolymer, adding the paraffin, the nucleating agent, the antioxidant, the non-polar filler, the compatibilizer and the chain extender in the step S1 into the prepolymer to be stirred and mixed, vacuumizing to remove bubbles to preliminarily form a composite hot melt adhesive liquid a, pouring the composite hot melt adhesive liquid a into a preheated mold, and curing at the temperature of 100-120 ℃ to form a composite hot melt adhesive liquid b;

s3, as shown in figure 1, the composite hot melt adhesive liquid b in the step S2 is impacted and sprayed on the Teflon mesh belt 1 through a hot melt adhesive spraying device to form a superfine fiber mesh film layer, the lower end of the Teflon mesh belt 1 is provided with an exhaust fan 2 for exhausting and cooling the superfine fiber mesh film layer on the Teflon mesh belt 1, and the Teflon mesh belt 1 vibrates up and down under the downward impact force of the composite hot melt adhesive liquid b and the pressure of the exhaust fan 2, so that the molecule homogenization recombination in the superfine fiber mesh film layer is realized;

and S4, spraying water mist on the superfine fiber net film layer formed in the step S, drying in an oven and then rolling to obtain the composite hot melt adhesive net film.

Further, hot melt adhesive injection apparatus includes a plurality of transmission rollers 3 and arranges spinneret assembly 4 directly over arbitrary transmission roller 3 in, and the cladding of special fluorine dragon guipure 1 is carried out the transmission on a plurality of transmission rollers 3, arranges transmission roller 3 directly under spinneret assembly 4 in and can realize the vibration of upper and lower buffering formula through vibration group 5, arranges transmission roller 3 directly under spinneret assembly 4 in and is higher than other transmission roller 3.

Further, as shown in fig. 2, the vibration unit 5 includes a bracket 51, a shaft 52, and a rotating roller 53 sleeved outside the shaft 52, two ends of the shaft 52 penetrate through the bracket 51, the bracket 51 has a through hole 54 for allowing a side end of the shaft 52 to penetrate through, the side end penetrating through the shaft 52 has a fixing shaft 55, the fixing shaft 55 is fixedly disposed in the through hole 54, the fixing shaft 55 is sleeved with a first spring 56 above and below the shaft 52, one end of the first spring 56 is fixedly connected to an inner wall of the through hole 54, the other end of the first spring 56 is fixedly connected to the side end of the shaft 52, and the shaft 52 vibrates in the up-and-down direction in the through hole 54 along with the buffering of the first spring 56 when being subjected to an external impact force.

The paraffin selected by the invention has lower surface tension, improves the crystallinity of the polyethylene-vinyl acetate, relatively improves the compatibility among a plurality of polymers, thereby improving the elasticity of the polyethylene-vinyl acetate, improves the heat resistance of the hot melt adhesive liquid and reduces the heat shrinkage, prevents the self-adhesion of the hot melt adhesive liquid by controlling the fluidity of the hot melt adhesive, avoids the self-adhesion of the hot melt adhesive liquid, ensures the compatibility among the polymers, and provides a foundation for the subsequent injection of the hot melt adhesive liquid.

Secondly, the invention adopts a special hot melt adhesive injection device to realize the high-speed ultrafine fiber injection molding of the hot melt adhesive, the micro-droplet molecules of the hot melt adhesive impact the Teflon mesh belt 1 at high speed and high pressure, a certain downward impact force is generated on the Teflon mesh belt 1 and the transmission roller 3 arranged right below the spinneret component 4, and the transmission roller 3 generates a certain vibration under the suction action of the exhaust fan 2, so that the hot melt adhesive injection molecules are more closely attached to the Teflon mesh belt 1, the flatness of the composite hot melt adhesive net film is improved, and meanwhile, the hot melt adhesive injection molecules are rapidly dispersed and recombined under the action of gravity and the impact force through the certain vibration, so that the bonding strength of the hot melt adhesive net film is improved; the exhaust fan plays a role in vibrating the conveying roller up and down, and rapidly cools the sprayed hot melt adhesive molecules to realize rapid cooling forming.

Further, as shown in fig. 3, the spinneret assembly 4 includes a plurality of spinnerets 41 disposed directly above the conveying roller 3, the spinnerets 41 are distributed along the extending direction of the conveying roller 3, each spinneret 41 has a hot melt adhesive inlet flow passage 43 and a hot melt adhesive outlet flow passage 42, and further has an upper ejector rod 44 and a lower ejector pin 45, the upper ejector rod 44 and the lower ejector pin 45 are buffer-connected in a cladding manner through a buffer connection set 46, the lower end of the lower ejector pin 45 vertically extends into the outlet position of the hot melt adhesive outlet flow passage 42, the upper end of the upper ejector rod 44 realizes high-pressure impact on the lower ejector pin 45 through a piezoelectric actuator 47, so that the composite hot melt adhesive liquid b in a molten state at the outlet of the hot melt adhesive outlet flow passage 42 is ejected from the tip of the spinnerets 41 due to instant high pressure, the outer wall of the hot melt adhesive outlet flow passage 42 has a preheating pipe 48, and the outer wall of the hot melt adhesive outlet flow passage 42 has a heating pipe 49.

Further, the temperature of the preheating pipe 48 is controlled to be 80-90 ℃ at constant temperature, and the temperature of the heating pipe 49 is controlled to be 100-110 ℃ at constant temperature.

The piezoelectric brake 47 in the spinning nozzle assembly 4 of the invention is used as a power source to output a certain force and impact speed, the force and the impact speed are acted on the upper ejector rod 44, the upper ejector rod 44 acts on the lower ejector pin, the lower ejector pin 45 subjected to high-pressure impact impacts the spinning nozzle 41 at a high speed to jet the hot melt adhesive liquid in a molten state in the spinning nozzle 41, the high impact speed and small movement displacement of the hot melt adhesive liquid are realized through the secondary impact between the upper ejector rod 44 and the lower ejector pin 45, the small volume of the jet is realized, the jet with higher viscosity can be realized, and the bonding strength of the composite hot melt adhesive omentum is improved.

Further, the buffer connection set 46 includes a protrusion 461 disposed on the upper end of the lower thimble 45 and a latch 462 disposed on the lower end of the upper support rod 44, the latch 462 has a cavity 463 for the protrusion 461 to be inserted into, the height of the cavity 463 is greater than the height of the protrusion 461, the spinneret 41 has an upper support rod 44, the joint of the lower thimble 45 provides a movable chamber 464 with a space, the fixture block 462 is coated outside the projection 461 and is arranged in the movable chamber 464, a second spring 465 is arranged between the fixture block 462 and the bottom of the movable chamber 464, the second spring 465 is sleeved outside the lower thimble 45, a third spring 466 is sleeved outside the upper ejector rod 44, the third spring 466 is arranged between the upper end of the upper ejector rod 44 and the upper end of the movable chamber 464, the movable chamber 464 is communicated with the hot melt adhesive outlet flow passage 42, the outer side wall of the projection 461 is provided with a convex rib 467, and the inner wall of the cavity 463 is provided with a limiting groove 468 for embedding the convex rib 467 and sliding up and down.

The connection part of the upper ejector rod 44 and the lower ejector pin 45 in the invention adopts the buffer connection group 46 to realize the cladding type buffer connection, the second spring 465 and the third spring 466 are arranged to realize the rapid rebound of the upper ejector rod 44 and the lower ejector pin 45, the lug 461 at the upper end of the lower ejector pin 45 is clamped in the cavity 463 of the fixture block 462 at the lower end of the upper ejector rod 44, and the lower ejector pin 45 is prevented from rotating or swinging circumferentially when being impacted by the upper ejector rod 44 from top to bottom through the matching of the convex rib 467 and the limiting groove 468, and the quality of the composite hot melt adhesive net film is influenced by the tiny rotation or swinging of the hot melt adhesive liquid.

Further, the inner wall of the cavity 463 is provided with an arc-shaped protrusion 469 at a position right above the protrusion 461, an opening of the arc-shaped protrusion 469 is arranged opposite to the protrusion 461, the inner wall of the cavity 463 is provided with a rubber buffer layer 4610, and the arrangement of the arc-shaped protrusion 469 realizes concentrated impact of the fixture block 462 on the middle position of the protrusion 461 at the upper end of the lower thimble 45, so that high-speed impact from top to bottom is ensured, and the rubber buffer layer 4610 plays a role in buffering and protecting contact of the two, so as to avoid abrasion.

Further, hot melt adhesive outlet flow path 42 includes upper longitudinal portion 421, middle longitudinal portion 422 and lower taper portion 423 that are sequentially connected from top to bottom, upper longitudinal portion 421, middle longitudinal portion 422 and lower taper portion 423 are of an integral molding structure, and the width of upper longitudinal portion 421 is greater than that of middle longitudinal portion 422, and the outlet end of hot melt adhesive inlet flow path 43 is connected with middle longitudinal portion 422.

Further, the inner bottom of the upper longitudinal portion 421 has a sealing pad 424, the sealing pad 424 has a packing 425 thereon, the bottom of the movable chamber 464 has a packing pressing plate 426, and the packing pressing plate 426 presses the packing 425 against the inner wall of the upper longitudinal portion 421.

Because lower thimble 45 from top to bottom soaks in the hot melt adhesive solution, lower thimble 45 is at high-speed displacement in-process from top to bottom, the phenomenon that the hot melt adhesive solution climbs the pole appears, make the hot melt adhesive solution the excessive phenomenon of seepage appear, the hot melt adhesive solution that overflows simultaneously produces great resistance to the upper and lower displacement of lower thimble 45, thereby influence the high-speed fiberization of hot melt adhesive solution and spray, in this application, set up sealed fill up 424 between hot melt adhesive outlet runner 42 and movable cavity 464, pack 425 and packing clamp plate 426, effectively play the sealed effect of leak protection, prevent that the hot melt adhesive solution from overflowing.

It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only for the purpose of illustrating the principles of the present invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.