JPH02113923A - Production of mat - Google Patents

Abstract

PURPOSE:To economically prepare a mat according to a mass production system by a method wherein a carpet is pressed through a diaphragm without heating a mold when closely brought into contact with a rubber sheet but directly pressed by compressed air when at the time of vulcanization. CONSTITUTION:An upper heating plate 2 falls and the under surface of the lower mold 5 of a mold 3 is closely brought into contact with a belt conveyor 13 and the under space 8 of a diaphragm 6 is reduced in pressure to be held to 30mmHg for 1min. Next, compressed air of pressure of 3kg/cm<2> is introduced into the upper space of the diaphragm 6 and a carpet 21 is closely brought into contact with an unvulcanized rubber sheet 20 by pushing down the diaphragm 6 to be held for 1min and, after the compressed air is discharged, compressed air of pressure of 3kg/cm<2> is continuously introduced into the lower space of the diaphragm 6 to perform vulcanization at mold temp. of 160 deg.C for 15min. The upper space 7 is reduced to 50mmHg in pressure to bring the diaphragm 6 into contact with the ceiling of the upper mold 4 and a mat completed in vulcanization is taken out behind a lower heating plate 1 and, at the same time, the unvulcanized rubber sheet 20 and carpet 21 prepared in front are drawn in above the lower heating plate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing a mat in which a carpet is placed on a rubber sheet.

(Prior art) As a method of manufacturing Mano 1 by bonding a rubber sheet to the back side of a carpet, an unvulcanized rubber sheet and a carpet are placed in advance on a smooth metal plate, and the metal plate is placed in a press. The method of heating unvulcanized rubber sheets and carpets under pressure under pressure is known. In addition, a sealed space is formed at the mating part of a pair of upper and lower molds, an unvulcanized rubber sheet and a carpet are stacked and mounted in this sealed space, and pressurized air is supplied to the sealed space to uncure the carpet. A method is known in which the above mold is heated while being pressed against a vulcanized rubber sheet to perform vulcanization and adhesion at the same time.

(Problems to be Solved by the Invention) The method of directly pressing the unvulcanized rubber sheet and carpet by sandwiching them between upper and lower heating plates has the disadvantage that the above-mentioned rubber sheet and carpet are firmly bonded.

The pile of the carpet is pressurized by the upper heating plate and falls down, and is heat-set in the fallen state, which causes a problem in that the carpet loses its cushioning properties and the appearance of the carpet deteriorates. Even when the vulcanized carpet is placed in a napping machine, not only is sufficient nap not obtained, but the fibers of the pile are damaged and the number of steps increases.

On the other hand, in the method of compressing the carpet to the unvulcanized rubber sheet using air pressure, if the base fabric of the carpet is breathable, the air pressure is balanced at the interface between the carpet and the unvulcanized rubber sheet, and therefore the necessary bonding is Pressure could not be obtained, and it was necessary to change the mold depending on the height of the pile, and it was troublesome to attach the carpent and unvulcanized rubber seam to the mold.

This invention enables the carpet to be firmly vulcanized and bonded to a rubber sheet without knocking down the pile of the carpet,
Moreover, there is no need to change the mold depending on the pile height, the carpet and the unvulcanized rubber sheet can be easily attached to the mold, and multiple sets of the carpet and the unvulcanized rubber sheet can be bonded at the same time if necessary. This is what makes it possible.

(Means for solving 3% 1 problem) First, place unvulcanized rubber sheets and carpets of a predetermined size on a belt conveyor, and heat the unvulcanized rubber sheets and carpets above and below. Transfer to the lower heated platen of a press with a smooth surface. The above-mentioned unvulcanized rubber sheet is a composition made of rubber such as natural rubber or synthetic rubber, and its thickness is preferably 0.5 to 2.0 m. Further, the carpet may have cant pile or loop pile, and may be provided with or without backing.

The above-mentioned belt conveyor has excellent heat resistance, high thermal conductivity, no air permeability, and good release properties after vulcanization.1 For example, a belt made of glass fiber fabric coated with fluororesin. is preferred.

Next, the press is closed, and a diaphragm is placed on the belt conveyor above the lower heating platen, which is fixed to the upper heating platen of the press and has an open cavity on the lower surface and a diaphragm that divides the cavity into upper and lower halves. A mold equipped with a mold is brought into close contact to form a closed space surrounding the unvulcanized rubber sheet and the carpet on the belt conveyor. In this case, the air pressure in the space above the diaphragm is 10
It is desirable to reduce the pressure to ~1100rrtn11 to prevent the diaphragm from sagging.

Next, the pressure in the space below the diaphragm of the mold is preferably reduced to 1 to 50 ioHg for 20 to 60 seconds.

Thereafter, pressurized air is sent into the space above the diaphragm to push down the diaphragm, and the diaphragm is preferably pressed down at a pressure of 2 to 15 kg/cd for 10 to 60 seconds to bring the carpet into close contact with the unvulcanized rubber sheet.

Thereafter, the pressure in the space above the diaphragm is reduced, pressurized air is introduced into the space below, and this pressurized air is used to directly blow the carpet onto the unvulcanized rubber sheet, preferably at a rate of 2 to 10 kg/a.
Pressure bonding is carried out at a pressure of J, and vulcanization is preferably carried out at a temperature of 120 to 180°C for 3 to 20 minutes.

This allows the rubber sheet described above to be adhered to the back surface of the carpet.

After vulcanization and adhesion are completed, the space below the diaphragm is returned to normal pressure and the press is opened.

(Function) By closing the press to form a sealed space on the lower heating plate and pushing down the diaphragm, the back side of the carpet comes into close contact with the top surface of the unvulcanized rubber sheet, and the contact surfaces of the two become familiar.

At this time, by reducing the pressure in the space below the diaphragm, the affinity between the carpent and the unvulcanized rubber sheet is further improved. In addition, since the diaphragm is pushed down without directly heating the mold, even if the carpet pile falls down, it will not be heated to a collapsed state, and the next time the diaphragm is raised, A pile stands up. However, the downward pressure of the diaphragm is 2 kg/a.
If the pressure is less than J or the pressing time is less than 10 seconds, the adhesion between the carpet and the unvulcanized rubber sheet will be insufficient.On the other hand, if the pressing pressure exceeds 15 kg/cJ or the pressing time is less than 60 seconds. If it exceeds seconds, the pile tends to be set in a collapsed state due to the influence of residual heat of the mold, etc., which is not preferable.

During vulcanization, the diaphragm is separated from the carpet and the carpet is pressed directly onto the unvulcanized rubber sheet using pressurized air, so the pile will not collapse and the back side of the carpet will stick tightly to the top of the rubber sheet. As a result, the pressurized air does not pass through the fiber voids of the carpet, and therefore all of the pressure of the pressurized air is used for crimping the carpet, and no loss of bonding pressure occurs.

(Example) FIG. 1 shows a large press machine (Nf L 200 mm, length 3500 na when the width direction is perpendicular to the plane of the paper).

Heating temperature 120-180℃, mold clamping pressure 5-30kg
/ ad ), an upper heating plate 2 is provided on the −E side of the lower heating plate 1, and this upper heat! ! A mold 3 is fixed to the lower surface of 2. This mold 3 consists of an upper mold 4 having a recess 4a on the lower surface, and a frame-shaped lower mold 5 connected to the four circumferential edges of the upper mold 4. The four circumferences of a diaphragm 6 made of a heat-resistant silicone rubber sheet (thickness 2+n++) are sandwiched, and the cavity of the lower opening formed at the bottom of the mold 3 is partitioned into upper and lower parts by the diaphragm 6, and an upper space 7 and a lower space are created. 8 is formed. A seal rubber 5a is fixed to the lower surface of the lower mold 5, and ventilation holes 4b and 5b are formed in the upper mold 4 and the lower mold 5, respectively.

A belt pulley 11.11 and a guide pulley 12.1.2 are provided before and after the lower heating plate 1.

Belt pulleys 11.11 are arranged so that an endless belt conveyor 13 passes along the upper surface of the lower heating platen 1 in its length direction.
, wrapped around the guide pulley 12.1.2. The above-mentioned bell 1 conveyor 13 is a heat-resistant conveyor (width: 11.0 mm, length: 15,000 nm+n) made of a glass fiber fabric coated with a fluororesin, and rotates intermittently in the direction indicated by the arrow.

On the belt conveyor 13, an unvulcanized rubber sheet (JIS-A rubber hardness after vulcanization of NBR1, 65 degrees, 770 ann, length: 9
20m1. Four sheets of 1.5 m+)2Q with a thickness of 1.5 m+) were placed at equal intervals, and a carpet 21 was layered on each. The carpet 21 used was a non-woven fabric as a base fabric, a pile thread made of nylon composite fibers was tufted to form a cut pile with a height loa+, and the carpet was backed with NBR.

With the upper and lower heating plates 1.2 open, the belt conveyor 13 is driven to convey a 4 m long unvulcanized mat consisting of an unvulcanized rubber sheet 20 and a carpet 21 above the lower heating plate 1, and then The lower heat glt is raised, and 4ffl of uncured mat 2 is placed on the upper surface of the lower heating plate 1 via a belt conveyor 13.
Supports 0.21.

Note that the air pressure in the space 7 above the diaphragm 6 is 50 nin.
The pressure was reduced to 11 g to prevent the diaphragm 6 from sagging.

Next, as shown in FIG. 2, the upper heating platen 2 is lowered, the lower surface of the lower mold 5 of the mold 3 is brought into close contact with the belt conveyor 1, 3.1 m, and the space 8 below the diaphragm 6 is depressurized. 3
The pressure is maintained at zero for one minute, and then pressurized air at a pressure of 3 kg/cd is introduced into the space above the diaphragm 6, and the diaphragm 6 is pushed down to bring the force base 21 into close contact with the unvulcanized rubber sheet 20. .

After holding for 1 minute, the pressurized air was discharged, and then pressurized air at a pressure of 3 kg/J was introduced into the space below the diaphragm 6 (see FIG. 3), and vulcanization was performed at a mold temperature of 160° C. for 15 minutes.

After the above-mentioned vulcanization is completed, the pressurized air in the space 8 below the diaphragm 6 is discharged, and the pressure in the space 7 above is reduced to 50 on) to bring the diaphragm 6 into close contact with the ceiling of the upper mold 4, as shown in FIG. As shown, the upper heating platen 2 and the lower heating platen 1 are opened and the belt conveyor 13 is driven.

The vulcanized mat 22 is taken out to the rear of the lower heating plate 1, and at the same time, the unvulcanized rubber sheet 20 and the carpet 21, which have been pasted in front, are pulled into the upper part of the lower heating plate 1.

When the mat 22 of the above example was cut into a width of 25.4+m+ and a 180 degree peel test was performed, the rubber sheath was broken because the adhesive was strong. On the other hand, in the mat of the comparative example obtained by directly pressing the carpet onto the unvulcanized rubber sheet using a hot platen, the adhesion was strong like in the above example, but the pile fell down and the cushioning did not improve. had disappeared.

In the above example, the pile height is 10 and 1.
When a 5-inch pile was vulcanized at the same time, a mat with strong adhesion was obtained without any piles collapsing. On the other hand, in the comparative example in which pressure was applied directly with a hot platen, the collapse of the higher pile was particularly severe, and the cushioning properties were lost.

(Effects of the Invention) This invention applies pressure to the carpet through a diaphragm without heating the mold when adhering the carpet to the rubber sheet, and pressurizes the carpet directly with pressurized air during vulcanization. Since it is pressurized, the pile will not collapse,
Moreover, a mat in which the carpet and the rubber sheet are firmly bonded can be obtained, and there is no need to raise the pile after vulcanization. Then, the unvulcanized rubber sheet and the carpet are stacked on top of each other on a belt conveyor that passes over the lower heating platen, and the belt conveyor is driven to transport them onto the heating platen, forming an airtight space on the heating platen. However, since it brings the carpet and unvulcanized rubber sheet into close contact and vulcanization bonding, it is easy to attach and remove the unvulcanized rubber sheet and carpet, and it is possible to vulcanize multiple sets of unvulcanized rubber sheet and carpet at the same time. It can be bonded with sulfur to form a mat, and the mat can be mass-produced economically.

[Brief explanation of the drawing]

1 to 4 are vertical cross-sectional views of a preliminary mold for explaining the method of this invention. 1: Lower heating plate, 2: Upper heating plate, 3: Mold, 4: Upper mold, 5
: lower mold, 6: diaphragm, 7: upper space, 8: lower space, 13: belt conveyor, 20: unvulcanized rubber sheet,
21: Carpella 1-122: Matsut. Patent applicant Kureha Rubber Industries Co., Ltd. Agent Patent attorney Yoshi 1) Tsukasa Ryo

Claims (1)

[Scope of Claims] [1] An unvulcanized rubber sheet of a predetermined size and a carpet are stacked on a belt conveyor, and the unvulcanized rubber sheet and carpet are placed on the lower side of a press having heating plates above and below. The mold is transferred onto a heating platen, and then the press is closed, and a mold having a cavity opening at the bottom and a diaphragm dividing the cavity into upper and lower halves is placed on the belt conveyor above the lower heating platen. Closely forming an enclosed space surrounding the unvulcanized rubber sheet and the carpet on the belt conveyor, then pushing down the diaphragm, causing the carpet to adhere tightly to the unvulcanized rubber sheet, and then raising the diaphragm. , by introducing pressurized air into the space below the diaphragm to press the carpet onto the unvulcanized rubber sheet and vulcanizing the unvulcanized rubber sheet, the rubber sheet is adhered to the carpet. and then returning the space below the diaphragm to normal pressure and opening the press.