RU2641918C1 - Method for moulding article by direct of premix pressing with use of reinforcing element - Google Patents

Abstract

FIELD: machine engineering.

SUBSTANCE: according to the method, the reinforcing element is preliminarily installed on a platform of the mould lower portion contacting with the central portion of the reinforcing element lower surface. The upper surface, the ends and edges of the reinforcing element lower surface are left open for contacting the premix. The premix is loaded into the lower mould portion and the upper and lower mould portions are closed. The reinforcement element is compressed.

EFFECT: increased strength of produced article.

5 cl, 5 dwg

Description

Technical field

The invention relates to the field of manufacture by molding polymer products with fittings or embedded part (element) to enhance strength, reduce weight, reduce costs, for example, sanitary products: sinks for the kitchen and bathroom, bathtub, shower tray, or furniture details: doors, countertops, etc.

State of the art

The molding of polymer products is widely used for the manufacture of sanitary products and furniture parts. In these applications, it is especially important that the molded products have strength, high resistance to mechanical and thermal loads.

A known method of molding articles from a press material in the form of a roll composite material based on unsaturated polyester resins, fiberglass and mineral fillers (SMC - Sheet Molding Compound). The manufacture of products from SMC is carried out mainly by direct (compression) pressing in heated molds, the design of which involves the implementation of stiffeners. The disadvantages of this molding method are: the high cost of the source material, the high cost of tooling, molds and equipment.

From patent JP 4998783, published August 15, 2012, there is a known method of molding a product by direct compression of a premix using a reinforcing element - fiber-filled plastic (FRP). This known method is a prototype of the claimed method.

The disadvantage of this known method is that it is used for the manufacture of light sinks and is not applicable for the manufacture of shower trays and bathtubs, the strength requirements of which are much higher.

Disclosure of invention

The technical result of the claimed invention consists in hardening and cheapening of products. The claimed invention allows to strengthen the design of the product, which allows you to use instead of the expensive prepreg SMC cheaper premix Navy (Bulk Molding Compound) and a cheaper reinforcing element.

The specified technical result is achieved in the method of molding products with a reinforcing element by direct compression of the premix, in which:

pre-installing a reinforcing element, for example a plate made of plastic or metal, or a chipboard on a platform of the lower part of the mold in contact with the central part of the lower reinforcing element, and the upper surface, ends and edges of the lower surface of the reinforcing element are left open for contact with the premix,

then the premix is loaded into the lower part of the mold and the upper and lower parts of the mold are closed, while

compress the reinforcing element.

A stiffener can be formed along the edge of the lower surface of the reinforcing element.

When using a particleboard as a reinforcing element, compressing it, it is reduced in thickness by 10-20%. In this case, you can use a chipboard, laminated only from the side facing the platform of the lower part of the mold.

Brief Description of the Drawings

In FIG. 1 shows the lower part of the mold with a vacuum platform and a reinforcing plate mounted on it.

In FIG. 2 shows the interface element of the reinforcing plate with the platform at the bottom of the mold.

In FIG. 3 shows the open upper and lower parts of the mold; the lower part of the mold with a platform mounted on it with a reinforcing plate and a premix located on the reinforcing plate.

In FIG. 4 shows a mold with closed upper and lower parts and a molded product with a reinforcing plate located between them.

In FIG. 5 shows the finished product - a shower tray.

The implementation of the invention

In accordance with the claimed invention, when directly pressed in heated molds (dies), a reinforcing element is used as a reinforcer of the product structure, for example, a shower tray, bathtub, sink, a plastic, metal plate, or chipboard.

The molding is carried out as follows:

pre-heat the mold to the required operating temperature (120-150 ° C);

dose the IUD premix by weight;

mounted inside the mold, in its lower part 1, as shown in FIG. 1, the reinforcing element 2, for example, of chipboard with one-side lamination on the platform 3, while combining, as shown in FIG. 2, technological blind holes in the chipboard with protrusions on the platform 3 in the form of bushings 4, see FIG. 2, connected to channels 5 for expelling the finished product from the lower part of the mold by air, made in the lower part 1 of the mold along with channels 6, which serve to exhaust air;

the prepared premix 7 is loaded as shown in FIG. 3; if necessary, before loading the premix and reinforcing element, the surfaces of the mold can be processed by means that prevent sticking of the material, such as calcium stearate, zinc stearate or high temperature silicone lubricants;

mold closure as shown in FIG. four; at the moment of closing of the upper 8 and lower 1 parts of the mold, the premix takes the shape of the product (cavity of the mold) and closes the raw ends of the reinforcing element 2, the edges of its lower surface, and also forms a stiffener 9 around the perimeter of the embedded element. In the process of closing the mold, the reinforcing element from chipboard is deformed, compressing by 10-20% in thickness, while it does not delaminate, but rather, significant hardening is observed;

the filled premix mold is warmed up and can withstand the premix under high pressure; holding time from 15 sec to 1 min per 1 mm of the thickness of the product, depending on the used press material;

finished product 10, see FIG. 5, removed from the mold and cleaned from burr.

Applicable Materials

Premix (Navy) is a non-flowing thermoset, which is a special paste containing resin, fillers, reinforcing fibers. Typical composition of the premix Navy: fiberglass (5-30 mm) - 10-30%; filler (talc, microcalcid) - 45-60%; resin (polyester, vinyl ester) - 20-30%; other technological additives - 5%.

The main characteristics of the Navy: the content of fiberglass 10-30%; density: 1400-2400 kg / m ³ ; technological shrinkage (-0.1) - (+ 0.25); bending strength 70-140 MPa; bending modulus of 8-15 GPa; tensile strength 20-60 MPa; impact strength 10-60 kJ / m ² ; water absorption of 0.03-0.05%.

Chipboard (particle board): lamination (coating with paper-resin film) on one side, the second side without coating (preferably not sanded), thickness: 10-20 mm; density: 580-700 kg / m ³ ; bending strength 10-14 MPa.

Pressing is carried out on a press, which provides a pressing force of up to 70 kg / cm ² , a high degree of parallelism of closure of the upper and lower parts of the mold, as well as a controlled closure speed and pressure resistance when pressing up to 1 min per 1 mm of the thickness of the product.

The metal heated molds are made of chrome steel. Pressure is from 30 to 70 kg / cm ² , heating temperature is 100-160 ° C. Uniform heating is provided by steam, electricity or oil. The closing time of the forms is up to 7 minutes, at this time the heating and polymerization reaction are carried out.

Claims (5)

1. The method of forming the product by direct compression of the premix using a reinforcing plate, characterized in that the reinforcing plate is pre-installed on the platform of the lower part of the mold in contact with the Central part of the lower surface of the reinforcing plate, the upper surface, ends and edges of the lower surface of the reinforcing plate are left open to contact the premix, then load the premix into the lower part of the mold and close the upper and lower parts of the mold, while compressing the reinforcing plate. 2. The method according to claim 1, characterized in that a stiffener is formed from the premix along the edge of the lower surface of the reinforcing plate. 3. The method according to p. 1, characterized in that for the reinforcement use a chipboard, which is compressed when the upper and lower parts of the mold are closed and reduced in thickness by 10-20%. 4. The method according to p. 3, characterized in that they use a chipboard, laminated only from the side facing the platform of the lower part of the mold. 5. The method according to p. 1, characterized in that for the reinforcement use a plate of plastic.

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