JPH09216240A - Mask cushion and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mask cushion with an integrally molded thick wall section and a uniform thin wall section by the rotary molding to be carried out by using a powder of vinyl chloride plastisol or the like or a paste-like plastic material for molding and injecting quantitatively a material of required minimum amount and also provide a manufacturing method thereof. SOLUTION: This mask cushion is provided with a thick wall section and a uniform thin wall section formed by a powder of vinyl chloride plastisol or the like or a paste-like plastic material, and the wall thickness of the thick wall section is 1-20mm, and the wall thickness of the thin wall section is 0.2-0.8mm. In the molding method, the material of a required minimum amount is injected quantitatively, and the mask cushion is molded integrally by the rotary molding in which two directions of revolutions on its axis and around the sun are combined together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for integrally manufacturing a plastic mask cushion having a thick portion and a uniform thin portion by rotational molding.

[0002]

2. Description of the Related Art Conventionally, mask cushions for resuscitation masks used to secure airways in the fields of anesthesia and emergency have often used rubbers such as natural rubber and silicone rubber, and plastic products such as vinyl chloride resin and polyethylene resin. There is. Rubber is molded by dip molding, compression molding, and rim molding, and then post-processing such as adhesion is performed to make a cushion, but due to the mold structure, it is necessary to bond the cushion seam, which requires man-hours. It also causes defects such as air leakage. Material costs are also higher than those of plastic products.

Among the plastic products, vinyl chloride resin is known to be produced by dip molding with vinyl chloride plastisol or by a combination of injection molding and slush molding. The mask cushion has a thick part for adhering and fixing the mask body made of, for example, polycarbonate by injection molding, and a thin part having flexibility so as to be in close contact with the face and airtight. It is normal, but it is normal to make dips, slushes, and rotational moldings with vinyl chloride plastisols of the same thickness, and to try to make parts with partially different thicknesses as a unit. In this case, the thin part is over-burned and the thick part is semi-burned (raw burn)
Sometimes became. Therefore, if you want to create a mask cushion with a shape with a difference in wall thickness, make the thick part by injection molding and the thin part by dip molding and stick it together, or make the thick part by injection molding or cast molding. However, it has been unavoidable to take a troublesome forming method such as inserting the material into the slush molding die, feeding the material again, and slush molding.

In addition, blow molding is performed with polyethylene resin, and cushion molding can be performed at low cost.
It was difficult to make a complicated shape suitable for the face, and it was also difficult to make a thin portion with a uniform thickness, and the feeling was bad. In order to solve such a problem, the inventors of the present invention have invented an integrated molding method for a mask cushion, which is a combination of cast molding and slush molding.
However, as many molds are opened and closed, the number of man-hours required is high, and the risk of foreign matter entering is high.Moreover, in slush molding for producing thin-walled parts, more materials are required than in other molding methods, so once used Since the surplus material cannot be reused because the physical properties of the material change, it cannot always be said that the molding method is satisfactory.

[0005]

SUMMARY OF THE INVENTION The present invention is a method for manufacturing a mask cushion in the related art, and in particular, molding by using a powdered or pasty plastic material such as vinyl chloride plastisol is carried out by a fixed quantity injection of a required minimum amount of material. Provided are a mask cushion having a thick portion and a uniform thin portion integrally formed by molding, and a method for manufacturing the mask cushion.

[0006]

SUMMARY OF THE INVENTION The present invention is a mask cushion characterized by integrally molding a mask cushion having a thick portion and a thin portion by rotational molding with a powder or paste plastic material such as vinyl chloride plastisol. A mask cushion which is a manufacturing method, wherein the rotational molding is rotational molding in which a powder or paste-like plastic material such as vinyl chloride plastisol is quantitatively injected, and rotation and revolution 2 directions of rotation and rotation (horizontal) only are combined. And the manufacturing method thereof, wherein the thickness of the mask cushion is 1 to 20 mm in the thick portion and 0.2 to 0.
A mask cushion having a size of 8 mm and a manufacturing method thereof.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings. FIG. 1 is a view showing a mold (electroforming mold) used in the present invention, which is an embodiment of the present invention. FIG.
(B) is a port part mold assembly drawing, (c) is a cushion part mold opening state figure, (d) is a mask main body junction part mold opening state figure.

The mold used in the present invention is an electroforming mold as shown in FIG. 1, and it is largely composed of a mask body joining mold (1), a cushion mold (2) and a port mold (7).
It is composed of A thick part is made in the mask body joining part mold (1), and a thin part is made in the cushion part mold (2). The mask body joint part mold (1) and the cushion part mold (2) are electroforming molds and are made of a material such as copper having good thermal conductivity. The port die (7) is shown in Fig. 1-
As shown in (c), it is fitted into the cushion mold (2),
In the cushion molded product, hollow port portions for injecting and exhausting air are made. The port part mold (7) needs to be made of a material having good thermal conductivity such as brass, or a material such as stainless steel needs to have a hole inside to improve heat transfer. The shape of the port mold (7) has a blade at the tip, and while removing the port mold (7) at the time of demolding, the material of the hollow part of the mask cushion molded product port is put on the port mold (7). If the structure is such that the mask cushion is pulled out so that the mask cushion port can be easily manufactured.

FIG. 2 shows a design example of the continuous molding apparatus used in the present invention. In the die matching, first, the mask body joining portion die (1) is fixed to a disk for moving on the continuous forming apparatus. Next, the cushion part mold (2) is positioned on the mask main body joint part mold (1) while paying attention to the direction of the mold matching parts (9) and (13). 12), and the two mold holding handles (3) of the cushion part mold are firmly fixed to the handle fixing part (15) of the mask body joint part mold (1). Next, the disk is rotated so that the port of the cushion part mold (2) faces upward, and a fixed amount of material is charged from the inlet of the port.
After that, the assembled port portion die (FIG. 1- (b)) is inserted into the port portion, and the die holding handle (8) of the port portion die is inserted into the cushion portion die (FIG. 1- (c)). Firmly fix it to the handle fixing part (11) of 2). After mounting the port mold, in the case of PVC plastisol, insert the mold into a heating furnace and rotate the disk in two directions, rotating and revolving around 260
Bake for 2-3 minutes at ℃. Further, the revolving is stopped so that the mask body bonding die (1) faces downward, and only horizontal rotation is performed, and baking is performed at about 260 ° C. for about 5 minutes and 30 seconds.

First, during rotation in both the autorotation and revolution directions, the vinyl chloride plastisol in the mold hardens while flowing on the wall surface of the mold to form a thin portion having a uniform thickness. Next, during the rotation only in the horizontal direction, the uncured PVC plastisol flows into the mask main body joining portion mold by gravity and is hardened to form a thick portion. At that time, if a uniform heating state can be maintained depending on the fluidity (viscosity) of the PVC plastisol and the shape of the mold, it will not rotate while the resin flowing in due to gravity cures while it is still horizontal in the heating furnace. You can place it. After that, after removing from the furnace and cooling with water, first, the assembled port part mold (FIG. 1- (c)) is extracted, air is made to flow, and then the cushion part mold (2) is opened to open the cushion part mold (2). Remove the cushion molded product attached to. In this embodiment, the step of rotating only in the horizontal direction is to rotate the mold in order to make the heating of the mold uniform. The fact that the heating state differs depending on the performance and method of the heating furnace (electric heating, gas combustion, high frequency) does not limit the present invention.

By carrying out this molding method, compared to slush molding or the like, it is possible to perform molding without waste by reusing powdered material such as vinyl chloride plastisol or in the form of a pasty plastic material without the need to reuse it in a fixed amount. In a series of steps, a thin wall portion can be formed by rotation in two rotation directions, and a thick wall portion can be formed only when rotating, and the number of mold openings and closings can be reduced, the number of work steps can be reduced, and foreign matter can be reduced. The thickness of the mask cushion is such that the thick part is adhesively fixed to the mask body, so it must have strength so that it will not be broken or deformed when pressed from the mask body side. If it is thinner than 1 mm, it may be broken, and if it is thicker than 20 mm, the mask becomes large and it becomes difficult to hold it during use. The thin part should be in close contact with the face and should be flexible enough to maintain airtightness.
About 0.8 mm is preferable, and if it is thinner than 0.2 mm, the burst strength is low and it is easy to burst.

The powdery or pasty plastic materials used include polyvinyl plastisol, olefin-based and silicone rubber-based materials, and are not particularly limited, but the degree of burning of the thick-walled portion and the thin-walled portion is similar. To be
It has good thermal stability, has fluidity to obtain a uniform cushion film, and has excellent safety because it comes into contact with the face in use.
It must have sufficient flexibility without pungent odor.
In the case of PVC plastisol, for example, it can be prepared by the following formulation. PVC paste resin: 100 parts (polymerization degree 1600) Plasticizer (DOP): 80 parts Plasticizer (DNP): 50 parts Stabilizer (Ca / Zn system): 2 parts

[0013]

According to the method of the present invention, a mask cushion having a thick and uniform thin portion made of a plastic material in the form of powder or paste such as vinyl chloride plastisol, which has been time-consuming to prepare, can be formed in a fixed minimum amount. Since it can be integrally molded with the above material, there is no need for extra material, there is no need to make thick molded products in advance or to bond them in post processing, and as an industrial mask cushion and its manufacturing method It is suitable.

[Brief description of drawings]

FIG. 1 is an embodiment of a mold (electroforming mold) used in the present invention (a) Mold matching state diagram (b) Port part mold assembly diagram (c) Cushion part mold open state diagram (d) Mask Main body joint part Mold open state diagram

FIG. 2 is a design example of a continuous molding apparatus used in the present invention.

[Explanation of symbols]

 1. Mask body joint mold 2. Cushion part mold 3.8. Embossing handle 4. Stopping pin 5.6. Spring 7. Port part mold 9.13. Mold matching section 10. Alignment hole 11. Handle fixing part 12. Alignment pin 14. Mask body joint part 15. Handle fixing part

Claims (3)

[Claims] 1. A mask cushion and a method for producing the same, wherein a thick portion and a uniform thin portion are integrally formed by rotational molding from a powder or paste plastic material. 2. The mask cushion according to claim 1, wherein the rotational molding is a rotational molding in which a powder or a pasty plastic material is quantitatively injected, and rotation in two directions of rotation and revolution and rotation only in a rotation (horizontal) direction are combined. And its manufacturing method. 3. The thickness of the mask cushion is 1 at the thick portion.
The mask cushion according to claim 1 or 2, and the method for producing the mask cushion, wherein the mask cushion has a thickness of -20 mm and a thin portion of 0.2-0.8 mm.