JPH0778287B2 - Lightweight helmet cap manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to impact resistance and light weight for protecting the safety of a driver of a high-speed body such as a motorcycle, an automobile, an aircraft, and a high-speed boat and passengers in the event of an accident. About excellent Helmet.

(Prior Art) A helmet is a simple helmet with low impact resistance, which is used for a small impact in an accident like a vehicle moving at a relatively low speed, and a vehicle moving at a high speed has a very large impact in an accident. There are helmets having a high impact resistance used for various purposes, and there are also those used for various purposes such as sports, military, and construction and civil engineering.

The present invention mainly relates to a light weight and high impact resistance helmet that protects the head of a person riding a vehicle moving at high speed.

Conventionally, the Hermet used for this purpose mainly uses unsaturated polyester resin as a matrix, and uses a mat in which glass fibers are laminated in the outermost layer and the innermost layer. It is generally made by heating and curing. The finished product, which is made by applying this method to the hermet cap body, which has been coated with cushion materials and fittings, generally weighs 1600 g.
Due to the above weight and the problem of physical fatigue during long-term use, there has been a strong demand for weight reduction.

(Problems to be Solved by the Invention) In order to achieve this weight reduction, it is indispensable to reduce the weight of the cap body, and various studies such as reduction of the amount of reinforcing material or resin and change of material have been made. However, the decrease in the amount of roving cloth and the amount of resin causes performance deterioration such as drop impact performance and penetrating weight drop, and in order to prevent performance deterioration, it is necessary to make the roving cloth material significantly stronger and have a higher modulus. It is not a realistic improvement measure because it is expensive and it has been a long-standing problem in the industry.

The present invention provides a fundamental improvement to a conventional manufacturing method using a roving cloth to achieve satisfactory performance and cost, and to achieve an epoch-making weight reduction.

(Means for Solving the Problem) The present inventor has conducted a research on the relationship between the reinforcing material structure of the FRP plate and the falling ball impact property, and found a very interesting phenomenon. That is, when an FRP plate with the same thickness is made, a roving cloth of the same weight, the same area made with fibers of the same type, the same thickness, and the same performance as the structure of the reinforcing material, and the monofilament uniformly dispersed laminated mat ( FRP with non-woven mats)
Comparing the performance of the plates, the roving cloth reinforced FRP plate shows higher values in bending strength and bending rigidity, but the non-woven mat reinforced FRP plate shows much higher values in bending fracture deformation amount and falling ball impact resistance. Found out to show. This phenomenon can be effectively utilized in various fields of use of FRP (Japanese Patent Application No. 62-213838).

The present inventor has conducted research to apply this knowledge to hermet.

The method of the present invention is generally applied to a bag molding method. For the molding, a lower hemispherical, medium-thick cylindrical outer shell mold with the crown of the Helmet as the lowermost part of the mold and the neck as the uppermost part is used. The press die on the inner shell side cannot be inserted because the cross section is narrower than the center of the die. Therefore, the pressing from the inner shell side is performed by the expansion of the balloon inserted from the top. A glass mat is placed on the entire inner surface of the outer shell mold, a roving cloth made of organic synthetic fiber is placed in the middle layer, and the glass mat is placed in the innermost layer, and then a required amount of resin is poured. Next, the bag in a deflated state is inserted through the opening corresponding to the neck of the Hermet neck at the top of the mold, and air is applied to the bag to expand it (pressure 3).
~6kg / cm ^2). The resin liquid accumulated at the bottom of the mold is pressed by the expanding bag and penetrates into the reinforcing material layer, and further penetrates into the entire surface of the hermet reinforcing material layer pushed up. In this state, the mold is heated (100 to 150 ° C x 10 to 20 minutes), and the resin is cured by the curing agent added in advance to the resin. When the curing is completed, the bag is deflated and pulled out from the mold, the outer shell mold is removed, and the hermet cap body is taken out.

The present inventor made a hermet with a non-woven mat having various thicknesses and densities in which the fiber performance, the fiber thickness, and the like were changed in place of the roving cloth of the intermediate layer, and the weight, the drop impact property, the drop weight penetrability, etc. We carry out experiments on hermet performance and moldability to pursue the possibility of weight reduction and performance improvement of Hermet, and provide Hermet with amazing weight reduction and sufficient performance considered impossible in the industry. Was successful.

That is, according to the present invention, when a hermetic cap body is manufactured by impregnating a fiber-reinforced material with a thermosetting resin, molding and hardening it, at least a part of the reinforcing material has a thickness of 1 denier or more and a modular 100 g / denier. 50 to 500 g / m ^{2 of} a unit weight of a bundled yarn that is integrated and integrated with a resin so that the organic synthetic fiber has a total denier of 2000 denier or less,
A method for manufacturing a lightweight hermetic hat body, which comprises using non-woven mats having a density of 0.015 to 0.08 g / cm ^{3 in} a single layer or a plurality of layers.

The unsaturated polyester resin is most suitable as the thermosetting resin, but resins such as epoxy resin, phenol resin, melamine resin and urea resin may be used.

The non-woven mat used for reinforcement is made of organic synthetic fibers 20
Consists of fiber bundles of less than 00 single fibers bundled with resin,
It has a structure in which short fibers or long fibers are mainly uniformly dispersed / laminated in a planar state, and the fiber bundle is entangled by a method such as needle punching or hydroentanglement, or by a suitable resin. It may be bonded to form a sheet, and these are also included in the non-woven mat referred to in the present invention.

The non-woven mat is produced by a card web, a uniform shake in the width direction (a method used in the production of SMC), a suction lamination method (a method in which fibers are dispersed in air and suction laminated on a moving suction net). ), A method such as a wet papermaking method may be used as long as it is a method of uniformly dispersing / stacking fiber bundles in a plane. Also, mats in which the fiber bundles are not bonded to each other may be used.

The fibers used for the non-woven mat are polyvinyl alcohol fiber, polyethylene terephthalate fiber, polyamide fiber, polyacrylonitrile fiber, polypropylene fiber, polyethylene fiber, aramid fiber, polyarylate fiber, ultra high strength. It has a performance of 100 g / denier or more of module selected from organic synthetic fibers such as polyethylene fiber, and the temperature at the time of Hermet molding (100-150 ° C)
Therefore, a bundled yarn having a thickness of 1 denier or more and a bundled yarn thickness of 2000 denier or less, which is not substantially affected by deterioration of strength, is suitable. In particular, polyvinyl alcohol fiber (vinylon) is very suitable in terms of specific modulus, cost per unit, resin affinity, heat resistance and the like.

When the modulus of the fiber is 100 g / denier or less, the reinforcing effect is small and the drop impact resistance as a helmet is low, so the reinforcing layer becomes thick and the weight cannot be reduced. Desirably, a module of 150 g / denier or more is required.

In the case of the non-woven mat, impact resistance is better when the bundled yarn in the non-woven mat is defocused to some extent and divided into a state close to a single fiber, and the single fiber has a thickness of 1.0 denier or less. The liquid holding amount of the resin increases, which causes an increase in the weight of the hermet. Further, if the bundled yarn thickness is 2000 denier or more, a large amount of fiber bundles need to be laminated in order to cover the entire surface of the fiber uniformly even if the bundled state is divided, which leads to an increase in the weight of the hermet. The thickness of the bundled yarn is more preferably 600 denier or less, but may be thicker if appropriately divided.

As the adhesive resin used for producing the bundle, polyvinyl acetate resin, polyester resin, polystyrene resin, polyurethane resin, melamine resin, epoxy resin, vinyl ester resin, unsaturated polyester resin, An acrylic resin, a polyamide resin, a phenol resin, or the like can be used, and the amount of adhesion thereof is preferably 0.1 to 20% by weight based on the fiber. Further, in order to improve the adhesiveness between the resin and the organic synthetic fiber, an appropriate amount of a polymerization promoter, a silane coupling agent, a resin penetrant, etc. may be mixed with the adhesive resin.

As the structure of the non-woven mat, when the basis weight is 50 g / m ² or less, the amount of fibers is small and the influence of the basis weight is large, and the number of laminated layers is very large, which is troublesome in manufacturing. If the density is 500 g / m ² or more, the thickness will be extremely large if a proper density is adopted, and the amount of resin impregnated will be large, which will increase the weight of the hermet and be difficult to handle.

If the density of the non-woven mat is 0.015 g / cm ³ or less, the amount of resin absorbed is large, and even if the bag is pressed, the resin does not fill the whole area, and the resin is not impregnated on the upper part of the mold, resulting in a "blurred" portion and poor appearance. . In order to prevent "blurring", it is necessary to increase the amount of resin, which causes a significant increase in the weight of the helmet. When the density is 0.08 g / cm ³ or more, the liquid retention is small and the appearance is good, but the drop impact resistance and drop weight penetration resistance are poor, and if the number of laminated nonwoven mats is increased to improve, The weight increases.

The density of the non-woven mat is the average weight of 10 samples of 30 cm × 30 cm and the average value of the thickness of 5 points in one sample, and the average value of 10 sheets is calculated to obtain the average weight (g / g cm ² ) /
The average thickness (cm) is the average density (g / cm ³ ). The thickness is measured by using a 6 cm × 6 cm compressor under a pressure of 5 g / cm ² by using a Pekotko thickness gauge.

In the Hermet of the present invention, it is needless to say that the non-woven mat may be used as a reinforcing layer by itself, but the non-woven mat made of fibers having a modulus of 100 to 400 g / denier and a high modulus of 400 g / denier or more. A non-woven mat made of fibers or a woven cloth (roving cloth) may be laminated and used. In particular, the outermost layer of the helmet is polished during the finishing process, so that the glass fiber, which breaks the fiber, is finished more beautifully.

Example Using the reinforcing material shown in Table 1, the resin shown in Table 1 was used as the matrix resin, and a hermetic hat body was manufactured by the bag molding method. The performance of the obtained cap body was measured.
The results are shown in Table 1.

As is clear from this result, it will be understood that the Hermet obtained by the method of the present invention can be significantly reduced in weight as compared with the conventional one and can greatly contribute to the industry.

Claims (1)

[Claims] 1. When manufacturing a hermet cap body by impregnating a fiber-reinforced material with a thermosetting resin, molding and hardening it, at least a part of the reinforcing material has a thickness of 1 denier or more and a module 100 g / denier. A weight per unit area of 50 to 500 g / m ² , a density of 0.0, which is made of a bundled yarn in which the above organic synthetic fibers are bundled and integrated with a resin so that the total denier is 2000 denier or less
A method for producing a lightweight hermetic hat body, which comprises using a non-woven mat of 15 to 0.08 g / cm ^{3 in} a single layer or a plurality of layers.