CN115012121A

CN115012121A - Production method and equipment of automotive carpet

Info

Publication number: CN115012121A
Application number: CN202210679833.XA
Authority: CN
Inventors: 潘峻俊; 赵俊; 陈铭
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-06-16
Filing date: 2022-06-16
Publication date: 2022-09-06
Anticipated expiration: 2042-06-16

Abstract

The invention relates to the technical field of automotive carpets, in particular to a production method and equipment of an automotive carpet, wherein the method is sequentially carried out according to the following steps: the method comprises the following steps: finishing raw materials, namely compressing the raw materials, wherein the raw materials are a mixture of pet fibers and pp fibers; step two: heating the compressed raw materials; step three: the automobile carpet produced by the method has the advantages of simple process, high efficiency and large-scale production, and the obtained carpet is compact, firm, good in quality and free of pollutants.

Description

Production method and equipment of automotive carpet

Technical Field

The invention relates to the technical field of automotive carpets, in particular to a production method and equipment of an automotive carpet.

Background

At present, the magnitude of the car noise already reflects the quality and technical performance of the car. The higher the automobile is, the less the noise and vibration of the automobile are transmitted to the passenger compartment, that is, the NVH performance of the whole automobile is matched. NVH is a comprehensive problem for measuring the manufacturing quality of automobiles, the NVH gives the most intuitive feeling to automobile users, and is an important ring in the design and manufacture of automobiles, and the automobile noise is from many sources, such as an engine, a gearbox, a drive axle, a transmission shaft, a compartment, a glass window, a tire, a relay, a loudspeaker, a sound box and the like, and the parts generate noise during working.

In order to prevent the noise of the automobile from entering the automobile, except reducing the noise source as much as possible, the sealing structure in the automobile is also designed up and down, especially the sealing and sound insulation performance of the front panel and the floor, the automobile cushion is generally used on the floor in the automobile, is an environment-friendly automobile interior decoration which integrates the five main functions of water absorption, dust absorption, decontamination, sound insulation and protection of a main machine carpet, and the current automobile carpet mainly comprises a wool carpet, a cashmere carpet, a PVC carpet, a flax carpet, a rubber carpet, a nylon carpet, a high-temperature heat insulation anti-blocking cotton and a super-fiber leather-like carpet,

the traditional automobile carpet manufacturing process also has certain defects and can be improved: the traditional automobile carpet production process is complex, the manual automobile carpet product needling manufacturing method is complex, the working efficiency is low, and the phenomenon of matching with an automobile internal structure part is easy to occur; the automobile carpet produced by the machine has the disadvantages of serious resource waste, complex process, large material consumption and low benefit, and is not suitable for large-scale production and use; for some carpet products such as spinning carpets and the like, the service life is short, the carpet products are easy to rot and break under the premise of poor ventilation effect in an automobile, and water is easy to accumulate at the lower part of the carpet, so that the bottom plate in the automobile is rotten, and the safety performance of the automobile is influenced; although some once-forming carpets appear in the market at present, the carpets have complex production process, parameters in the process are not easy to control, the safety factor is low during use, and potential safety hazards exist.

Therefore, the automobile carpet is designed, the production and manufacturing process is simple, the efficiency is high, and the large-scale production can be realized.

Disclosure of Invention

The invention aims to provide a production method and equipment of an automobile carpet, which are used for realizing the technical effects of simple process, high efficiency and large-scale production of the automobile carpet.

The invention is realized by the following technical scheme:

the production method of the automotive carpet sequentially comprises the following steps:

the method comprises the following steps: finishing raw materials, namely compressing the raw materials, wherein the raw materials are a mixture of pet fibers and pp fibers;

step two: heating the compressed raw materials;

step three: cooling after heating, and then discharging.

The polypropylene fiber is a synthetic fiber spun by taking isotactic polypropylene obtained by propylene polymerization as a raw material, is sold under the trade name of polypropylene in China, can be divided into long fiber, short fiber, spun-bonded non-woven fabric, melt-blown non-woven fabric and the like, is light and has the density of 0.90-0.92g/cm ³ The fiber is the lightest of all chemical fibers, has high strength, good elasticity, wear resistance and corrosion resistance, and has the advantages of electrical insulation, heat retention, sound insulation, strong covering power, good wear resistance, microorganism resistance, moth-eaten resistance, easy cleaning, low price, stain resistance, moth-eaten resistance, easy washing, good rebound resilience and the like.

pet fiber, commonly known as "dacron", is polyester fiber having good crease resistance and shape retention, high strength, elastic recovery and sound insulation, and is durable, crease resistant, easy to iron, and non-sticky.

Pure pet fibre can be chooseed for use to pet fibre in this scheme, and is pollution-free from impurity, and the car carpet wear-resisting crease-resistant acoustic insulation performance of making is better, also can choose for use materials such as the cloth felt that pet fibre made such as non-woven fabrics, felt, also can be with the waste recovery material of these cloth felts, and the pp fibre also can choose for use the cloth of making or its waste recovery thing, with energy recovery, resources are saved.

The pet fibers and the pp fibers are arranged, non-pet fibers such as impurities and miscellaneous materials and the pp fibers are mainly removed, other materials except the pet fibers and the pp fibers are avoided in the subsequent production process, the mass ratio of the pet fibers to the pp fibers is 1: 0.5-0.7, the pet fibers are mainly used, the pet fibers and the pp fibers are more fastened during compression and heating, and the obtained automobile carpet is good in sound insulation and water resistance.

And (3) compressing the trimmed pet fibers and the pp fibers together, so that the pet fibers and the pp fibers are compressed together, and the volume after mixing is reduced, thereby facilitating feeding and subsequent fastening and bonding together.

In order to better realize the invention, the pet fiber is a sheath-core composite fiber, the sheath-core composite fiber comprises a sheath fiber and a core fiber, and the melting point of the sheath fiber is lower than that of the core fiber.

According to the technical scheme, the pet fiber is a sheath-core composite fiber, the sheath-core composite fiber is a composite fiber with two component polymers respectively and continuously forming a sheath layer and a core layer along the longitudinal direction of the fiber, the melting point of the core layer fiber is higher than that of the sheath layer fiber, in the mixing process of the pet fiber and the pp fiber, the sheath layer fiber of the pet fiber is melted to form an adhesive to bond the mixed pp fibers together, and the strength, the modulus, the heat resistance and the surface hardness of the pp fiber can be improved by the pet fiber; the pp fiber can improve the processing, impact, environmental stress cracking resistance, separation and other performances of the pet fiber, and the pp fiber can also adopt composite fiber, namely the molten pp skin layer fiber with a low melting point is mutually bonded with the molten low melting point pet skin layer fiber, the pet fiber and the pp fiber are bonded together, the bonding is stable, no bonding agent is needed to be added, the prepared automotive carpet is purer in component and better in performance.

In order to better implement the invention, further, the heating temperature is 160-180 ℃, and the cooling temperature is 30-50 ℃.

Through the technical scheme, the pet fibers and the pp fibers which are compressed together are put into a mold to be heated at the temperature of 160 DEG and 180 DEG, the purpose of heating is to melt the skin fibers in the pet fibers or/and the pp fibers, after the skin fibers are melted, the pet fibers and the pp fibers are bonded together to form an automobile carpet in the mold, and the automobile carpet formed after heating is cooled, demolded, discharged and conveyed out.

The equipment used in the production method of the automotive carpet comprises a compression assembly, a mold assembly and a conveying belt, wherein the compression assembly is used for pressing the finished raw materials together, the mold assembly is used for heating and cooling the pressed raw materials, and the conveying belt is used for conveying the cooled and molded finished products out of the mold assembly.

Through above technical scheme, the raw materials after the arrangement compress tightly through the compression subassembly earlier, make the raw materials fastening together, then heat and cool in the mould subassembly, and fashioned carpet passes through the conveyer belt at last and carries away, and equipment is simple, and the shaping is fast.

In order to better realize the invention, the compression assembly further comprises a feeding bin, two first compression rollers, two second compression rollers, two third compression rollers and a feeding roller which are arranged in sequence.

Through above technical scheme, pet fibre and the pp fibre after the arrangement get into whole process from the feeding storehouse, after first compression roller, second compression roller and third compression roller cubic compression in proper order, make the mixture compacter, the density of carpet reaches 50kg/m3 at minimum, under the same thickness, the syllable-dividing effect of carpet is better, simultaneously because it is high to use pet fibre and pp fibre matter light strength, under the same density, the high wearability of carpet intensity of this scheme is better.

In order to better realize the invention, the distance between the two first compression rollers is larger than the distance between the two second compression rollers, the distance between the two second compression rollers is larger than the distance between the third compression roller, a plurality of square pressing strips are arranged on the outer circumference of the first compression roller, a plurality of circular pressing strips are arranged on the outer circumference of the second compression roller, and a plurality of dentate cutters are arranged on the outer circumference of the third compression roller.

Through above technical scheme, first compression roller, second compression roller and third compression roller, mixture compress between the interval from big to little in proper order, the feeding of being convenient for on the one hand, and on the other hand can let the mixture press more tightly more, and square layering, circular layering and dentate cutter press inseparabler to the mixture in proper order, and the efficiency that compresses tightly is higher.

In order to better realize the invention, a feeding belt is arranged at the lower side of the feeding roller, a material return pipe is arranged at one side of the feeding roller, which is far away from the feeding belt, and a suction fan is arranged on the material return pipe.

Through above technical scheme, in the compression pet fibre and the pp fibre were sent into mould subassembly to feed roll and pay-off area, material return pipe and suction fan when the feed roll was to mould subassembly pay-off, the pet fibre and the suction of pp fibre that will compress after with partial scattering of pp fibre surface and do not compress tightly together can be sent to the feed bin and recycle once more.

In order to better realize the invention, the mold assembly further comprises an outer roller, an inner roller, a hot air blower and an air cooler, wherein the outer roller is sleeved outside the inner roller, and the hot air blower and the air cooler are respectively used for conveying hot air and cold air to the inner roller at one side of the inner roller.

Through above technical scheme, the raw materials after the compression get into outer cylinder rotatory, hot-blast and cold wind are carried to inner drum and outer cylinder respectively to air heater and air-cooler, and rotatory raw materials heats the bonding when the heating zone is distinguished firmly, cools off the shaping when the cooling zone is distinguished.

In order to better realize the invention, the outer roller comprises an outer cylinder, a gauze, a carpet mould and a shell which are sequentially arranged from inside to outside, the outer cylinder is provided with a plurality of supporting tubes, and the shell is provided with an inlet and an outlet.

Through above technical scheme, the stay tube of outer barrel supports the gauze, installs into the carpet mould in the gauze, and the raw materials in the mould of being convenient for advances through the zone of heating and the cooling zone time, heating and cooling efficiency that can be fine are high, and the import is used for compressing tightly the raw materials entering, exports the finished product output after being used for the cooling.

In order to better realize the invention, a hot air inlet pipe, a cold air outlet pipe and a hot air outlet pipe are further sequentially arranged in the inner roller, the hot air inlet pipe and the hot air outlet pipe are connected through a hot air connecting pipe outside one side of the inner roller, and the cold air inlet pipe and the cold air outlet pipe are connected through a cold air connecting pipe outside one side of the inner roller.

Through above technical scheme, hot-blast and cold wind are after heating and cooling, discharge from hot-blast exit tube and cold wind exit tube, can recycle once more.

The invention has the beneficial effects that:

(1) the automotive carpet that this scheme adoption pet fibre and pp fibre were made gives sound insulation effectually, light in weight, and wear resistance is excellent, and waterproof nature is good, and the carpet dust is few.

(2) The process for producing the automobile carpet by the method is simple, the efficiency is high, the large-scale production can be realized, and the obtained carpet is compact, firm, good in quality and free of pollutants.

(3) The equipment used in the application is simple to operate, energy-saving and efficient, and can be used for continuous large-scale production.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings that are required to be used in the present invention will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and it will be apparent to those skilled in the art that other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic view of an apparatus for producing a carpet for automobile according to the present invention;

FIG. 2 is a schematic view of an outer drum provided by the present invention;

fig. 3 is a schematic view of a screen provided by the present invention.

Icon: 100-compression assembly, 110-feed bin, 120-first compression roller, 130-second compression roller, 140-third compression roller, 150-feed roller, 160-feed belt, 170-return pipe, 180-suction fan, 200-die assembly, 210-outer drum, 211-outer drum, 212-support pipe, 213-gauze, 214-housing, 2141-inlet, 2142-outlet, 215-belt, 216-motor, 220-inner drum, 221-hot air inlet pipe, 222-hot air outlet pipe, 223-cold air inlet pipe, 224-cold air outlet pipe, 225-hot air connecting pipe, 226-cold air connecting pipe, 230-hot air blower, 240-cold air blower, 250-support, 260-heating zone, 270-cooling zone, 300-conveying belt.

Detailed Description

The technical solution of the present invention will be described below with reference to the drawings.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Meanwhile, in the description of the present invention, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance.

Example 1

The production method of the automotive carpet sequentially comprises the following steps: the method comprises the following steps of (1) finishing raw materials, compressing the raw materials, wherein the raw materials are a mixture of pet fibers and pp fibers, the pet fibers are sheath-core composite fibers, the sheath-core composite fibers comprise sheath fibers and core fibers, and the melting point of the sheath fibers is lower than that of the core fibers;

step two: putting the compressed raw materials into a die for heating, wherein the heating temperature is 160 degrees;

step three: cooling after heating, wherein the cooling temperature is 30 degrees, and then discharging.

Example 2

step two: putting the compressed raw materials into a die for heating, wherein the heating temperature is 180 degrees;

step three: and cooling after heating, wherein the cooling temperature is 50 ℃, and then discharging.

Example 3

The production method of the automobile carpet sequentially comprises the following steps: the method comprises the following steps of (1) finishing raw materials, compressing the raw materials, wherein the raw materials are a mixture of pet fibers and pp fibers, the pet fibers are sheath-core composite fibers, the sheath-core composite fibers comprise sheath fibers and core fibers, and the melting point of the sheath fibers is lower than that of the core fibers;

step two: putting the compressed raw materials into a die for heating, wherein the heating temperature is 170 degrees;

step three: cooling after heating, wherein the cooling temperature is 40 degrees, and then discharging.

Referring to fig. 1 to 3, as shown in fig. 1, the apparatus for manufacturing the carpet for automobiles in the present embodiment includes a compression assembly 100 and a mold assembly 200, the compression assembly 100 includes a feeding bin 110, two first compression rollers 120 arranged side by side, two second compression rollers 130 arranged side by side, two third compression rollers 140 arranged side by side, and a feeding roller 150, the trimmed pet fibers and pp fibers enter the entire process from the feeding bin 110, the two first compression rollers 120 arranged side by side are below the feeding bin 110, the two second compression rollers 130 arranged side by side are below the two first compression rollers 120, the two third compression rollers 140 are below the two second compression rollers 130, the feeding roller 150 is below the two third compression rollers 140, the pet fibers and the pp fibers in the feeding bin 110 pass between the two first compression rollers 120 in sequence and are compressed by the two first compression rollers 120 for the first time, and then compressed a second time between two second compression rollers 130 by two second compression rollers 130, and then compressed a third time between two third compression rollers 140 by two third compression rollers 140, and the compressed pet and pp fibers are fed into the die assembly 200 through feed rollers 150.

Preferably, the distance between the two first compression rollers 120 is greater than the distance between the two second compression rollers 130, the distance between the two second compression rollers 130 is greater than the distance between the third compression rollers 140, the outer diameter of the first compression roller 120 is greater than that of the second compression roller 130, the outer diameter of the second compression roller 130 is greater than that of the third compression roller 140, a plurality of square beads are provided on the outer circumference of the first compression roller 120, a plurality of circular beads are provided on the outer circumference of the second compression roller 130, a plurality of toothed cutters are provided on the outer circumference of the third compression roller 140, the two first compression rollers 120 primarily compress the pet fibers and the pp fibers, the two second compression rollers 130 further compress the pet fibers and the pp fibers to enable the pet fibers and the pp fibers to be compressed more tightly, the two third compression rollers 140 finely compress the pet fibers and the pp fibers, the first compression roller 120, the second compression roller 130 and the third compression roller 140 enable the pet fibers and the pp fibers to be compressed more tightly, and the subsequent heating and forming in a die are facilitated.

The feeding belt 160 is arranged on the lower side of the feeding roller 150, the feeding belt 160 and the feeding roller 150 both rotate towards the direction of the die assembly 200, the compressed pet fibers and pp fibers are fed into the die assembly 200 through the feeding roller 150 and the feeding belt 160, a material return pipe 170 is arranged on one side of the feeding roller 150, which is far away from the feeding belt 160, a suction fan 180 is arranged on the material return pipe 170, and when the feeding roller 150 feeds the die assembly 200, the pet fibers and the pp fibers, which are scattered and not compressed together, on the surface parts of the compressed pet fibers and the pp fibers are sucked out and can be fed into the feeding bin 110 for recycling again.

The mold assembly 200 includes an outer drum 210, an inner drum 220, a hot air blower 230, and an air blower 240, the outer drum 210 rotates along the outer circumference of the inner drum 220, i.e. the outer drum 210 is sleeved outside the inner drum 220, the hot air blower 230 and the air blower 240 are at one side of the inner drum 220 for respectively delivering hot air and cold air to the inner drum 220, the outer drum 210 includes an outer cylinder 211, a gauze 213, a carpet mold, and a housing 214, the outer cylinder 211 is provided with a plurality of support pipes 212, i.e. the plurality of support pipes 212 are uniformly arranged on the outer cylinder 211, the gauze 213 is arranged outside the support pipes 212 and mounted along the circumference of the outer drum 210, the carpet mold is arranged outside the gauze 213, i.e. the support pipes 212, the gauze 213, and the carpet mold (not shown in the figure) are arranged on the outer drum 210 from inside to outside, the housing 214 is wrapped outside the outer cylinder 211, the gauze 213, and the carpet mold is a part of the housing 214 as shown in figure 2, when the outer drum 210 rotates, the outer cylinder 211, the support pipe 212, the gauze 213 and the carpet mold rotate together, the outer shell 214 does not rotate, an inlet 2141 is arranged on one side of the outer shell 214, namely the side close to the feed roller 150, and is used for feeding the compressed pet fibers and pp fibers into the carpet mold of the outer roller 210 by the feed roller 150, the mold is designed according to the required shape of the carpet, the preferred cavity thickness of the mold is 5-350mm, and the injection speed of the pet fibers and the pp fibers into the mold is 30 seconds and 6 kilograms are injected.

The inner drum 220 is provided therein with a hot air inlet pipe 221, a hot air outlet pipe 222, a cold air inlet pipe 223, and a cold air outlet pipe 224. The inner roller 220 is fixed and does not rotate, the hot air blower 230 is used for producing hot air and conveying the hot air to the hot air inlet pipe 221 through a pipeline, the hot air inlet pipe 221 and the hot air outlet pipe 222 are connected through a hot air connecting pipe 225 outside one side of the inner roller 220, the cold air inlet pipe 223 and the cold air outlet pipe 224 are connected through a cold air connecting pipe 226 outside one side of the inner roller 220, the hot air enters from the hot air inlet pipe 221, a heating area 260 is formed in the corresponding outer roller area, pet fibers and pp fibers are heated, preferably, the hot air temperature in the hot air inlet pipe 221 is 180 degrees, the heated air is sent out from the hot air outlet pipe 222, the sent air can be sent to the hot air blower 230 to be heated and reused, the cold air inlet pipe 223 is arranged on one side of the hot air inlet pipe 221, a cooling area 270 is formed in the corresponding outer roller area, the heated carpet is cooled and molded, the cold air temperature in the cold air inlet pipe 223 is 30-50 degrees, and the cold air outlet pipe 224 is arranged on the other side of the cold air inlet pipe 223, the hot air outlet pipe 222 is arranged on the other side of the cold air outlet pipe 224.

After the pet fibers and the pp fibers enter the mold from the inlet 2141, the pet fibers and the pp fibers sequentially pass through the heating area 260 of the hot air inlet pipe 221 and the cooling area 270 of the cold air inlet pipe 223 under the rotation action, the compressed pet fibers and the pp fibers in the mold are sequentially heated and cooled, the pet fibers and the pp fibers are heated and firmly bonded to form an automotive carpet, the automotive carpet is cooled and shaped to form an automotive carpet finished product, the bottom of the outer shell 214 is provided with an outlet 2142, the automotive carpet after being shaped and cooled rotates to the outlet 2142 and then is discharged from the outlet 2142, the outlet 2142 is externally provided with a conveyer belt 300, and the finished automotive carpet is conveyed to a corresponding position.

The support 250 is arranged below the outer roller 210, the outer roller 210 is supported, the motor 216 is arranged on the support 250, the belt 215 is arranged at the output end of the motor 216, the other end of the belt 215 is connected to the outer barrel 211, and the belt 215 and the outer barrel 211 are driven to rotate through the rotation of the motor 216, so that pet fibers and PP fibers in the die are rotated.

Through this scheme output automotive carpet finished product speed be 600kg/h, hot-blast and the equal recycle of cold wind, the energy saving, and heating efficiency is high, and the shaping is fast, compresses tightly many times before the heating, and the carpet density that obtains is high, and it is effectual to give sound insulation.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The production method of the automobile carpet is characterized by comprising the following steps in sequence:

step two: heating the compressed raw materials;

step three: cooling after heating, and then discharging.

2. The method of claim 1, wherein the pet fiber is a sheath-core composite fiber, the sheath-core composite fiber comprises a sheath fiber and a core fiber, and the sheath fiber has a melting point lower than that of the core fiber.

3. The method for producing an automotive carpet as claimed in claim 1, characterized in that the heating temperature is 160-180 ° and the cooling temperature is 30-50 °.

4. The apparatus for use in the method of manufacturing automotive carpets according to any of claims 1 to 3, comprising a compression module (100), a mold module (200), and a conveyor (300), wherein the compression module (100) is used for pressing the finished materials together, the mold module (200) is used for heating and cooling the pressed materials, and the conveyor (300) is used for conveying the cooled and formed finished products out of the mold module (200).

5. The automotive carpet production plant according to claim 4, characterized in that the compression assembly (100) comprises a feeding bin (110), two first compression rollers (120) arranged side by side, two second compression rollers (130) arranged side by side, two third compression rollers (140) arranged side by side and a feeding roller (150) arranged in sequence.

6. The carpet manufacturing apparatus of claim 5, wherein the distance between the two first compression rollers (120) is greater than the distance between the two second compression rollers (130), the distance between the two second compression rollers (130) is greater than the distance between the third compression rollers (140), the first compression roller (120) is provided with a plurality of square beads on the outer circumference, the second compression roller (130) is provided with a plurality of circular beads on the outer circumference, and the third compression roller (140) is provided with a plurality of tooth-shaped cutters on the outer circumference.

7. The automotive carpet production equipment as claimed in claim 5, wherein a feeding belt (160) is arranged on the lower side of the feeding roller (150), a material return pipe (170) is arranged on one side of the feeding roller (150) far away from the feeding belt (160), and a suction fan (180) is arranged on the material return pipe (170).

8. The automotive carpet production equipment according to claim 5, wherein the mold assembly (200) comprises an outer roller (210), an inner roller (220), a hot air blower (230) and a cold air blower (240), the outer roller (210) is sleeved outside the inner roller (220), and the hot air blower (230) and the cold air blower (240) are respectively used for conveying hot air and cold air to the inner roller (220) on one side of the inner roller (220).

9. The automotive carpet manufacturing apparatus according to claim 8, wherein the outer drum (210) comprises an outer drum body (211), a gauze (213), a carpet mold and a housing (214) which are arranged in sequence from inside to outside, the outer drum body (211) is provided with a plurality of support pipes (212), and the housing (214) is provided with an inlet (2141) and an outlet (2142).

10. The apparatus for producing an automotive carpet as claimed in claim 9, wherein the inner roller (220) is provided therein with a hot air inlet pipe (221), a cold air inlet pipe (223), a cold air outlet pipe (224), and a hot air outlet pipe (222) in sequence, the hot air inlet pipe (221) and the hot air outlet pipe (222) are connected by a hot air connecting pipe (225) outside one side of the inner roller (220), and the cold air inlet pipe (223) and the cold air outlet pipe (224) are connected by a cold air connecting pipe (226) outside one side of the inner roller (220).