SU952631A1

SU952631A1 - Mould for making articles of polymeric materials

Info

Publication number: SU952631A1
Application number: SU813266260A
Authority: SU
Inventors: Роман Павлович Занин; Эмма Сергеевна Виноградова; Игорь Серафимович Пушкин; Валерий Александрович Масолов
Original assignee: Всесоюзный Научно-Исследовательский Технологический Институт Приборостроения
Priority date: 1981-03-27
Filing date: 1981-03-27
Publication date: 1982-08-23

Description

Изобретение относитс к переработке пластмасс и может быть использовано при переработке пластмасс методом лить под давлением в многргнездных формдх.The invention relates to the processing of plastics and can be used in the processing of plastics by injection molding in multi-cavity molds.

Известна литьева форма с основной и дополнительной литниковой плоскост ми разъема. Дл предотвращени образовани обло в основной плоскости разъема в литниковой плите выполнены небольшой глубины выборки (карманы |, имеющие площадь больше общей площади отливки. Под действием давлени расплава плиты формы разжимаютс . Но, так как площадь карманов больше общей площади отливки, то и разжимающее усилие расплава в литниковой плоскости больше усили в основной плоскости разъема формы. Разность этих усилий прижимает литниковую плиту к подвижной форме и не позвол ет образоватьс заэору в.основной плоскости разъема формы t .A casting mold is known with the main and additional gating planes of the connector. To prevent the formation of an overflow in the main plane of the connector in the gating plate, a small sampling depth is made (pockets | having an area larger than the total casting area. Under the influence of the melt pressure, the plates of the mold expand. But since the pocket area is larger than the total casting area, the pressure of the melt in the gating plane there is more force in the main plane of the form connector. The difference of these efforts presses the gating plate to the movable form and does not allow the formation of a gap in the main plane of the form connector. t.

Недостаток такого технического решени заключаетс в том, что его мож- но использовать только в формах с дополнительной литниковой плоскостью разъема формы. Кроме того, формы такой конструкции требуют повышенной .нормы расхода пластмассы.The disadvantage of this technical solution is that it can only be used in forms with an additional gating plane of the form's connector. In addition, forms of this design require increased plastic consumption rates.

Наиболее близкой к предлагаемой по технической сущности и достигае- мому эффекту вл етс литьева форма Дл изделий из полимерных материалов, содержаща неподвижную полуформу и подвижную, имеющую плиты иатриц .и выталкивсцощей системы, опорную плиту , упоры, основание и хвостовику,f 2J.Closest to the proposed technical essence and the achieved effect is a casting mold For products made of polymeric materials, containing a fixed half-form and a movable one having plates and matrices and extruded systems, a base plate, supports, base and shank, f 2J.

Однако в центральной части плос10 кости разъема формы во врем вспрыска расплава возможно образование обло . Это происходит из-за тоги, что в плитах, образукнцих плоскость смыкани формы, напр жени сжати , However, in the central part of the plane of the shape plug during the melt injection, an oblo formation is possible. This is due to the fact that in the plates, forming the plane of the closure of the form, the stress of compression,

15 воз икак дие под воздейотвием усили смыкани термопластавтомата, распредел ютс неравномерно. В местах расположени упоров они будут максимальными, а в зонах отсутст20 ви упоров минимальными или даже отсутствовать вообще, т.е. минимгшьные напр жени будут в самом центре формы, где давление расплава максимальное . Давление расплава плиты 15, air blow molding forces are unevenly distributed. At the locations of the stops, they will be maximum, and in areas where there are no stops, the stops are minimal or even absent altogether, i.e. The minimum stresses will be in the very center of the mold, where the melt pressure is maximum. Melt pressure plate

25 разожмет, изгиба их в разные стороны по плоскости смыкани . В зазор между плитами будет подтекать расплав , образу облой.25 will open, bending them in different directions along the closing plane. In the gap between the plates will melt melt, forming bald.

Claims

The aim of the invention is oats30, the ability to manufacture articles without oblo in multi-cavity form. The goal is achieved by the fact that the casting mold for products made of polymeric materials, comprising a stationary half-mold and a movable one, having matrix plates and an ejector system, a base plate, stops, bushing and shank, is provided with a plate placed between the matrix plate and the base plate and made with a convex surface, in contact with the base plate, the latter being made of hardened spring steel. FIG. 1 shows a casting mold, in a closed state. FIG. 2 the same, in the open state. The casting mold comprises a fixed mold 1, a movable mold, comprising a plate 2 of dies and with sockets 3, a plate 4 with a convex surface, contacting with a support plate 5 made of hardened spring steel, stops b rigidly connected to the base 7 and base plate 5, e |: Vostovik 8, fixed in the plates 9 of the ejector system, with the ejector 10. The form works as follows. In the open position of the form Po. the top of the 2 matrix plate is convex. Since a plate 4 is placed between it and the base plate 5 made of hardened spring steel. Under the form of a plate 2. the matrices under the force of the closing force of the injection molding machine is straightened, but the base plate 5 is accordingly deformed, since it is made of hardened steel, then bending stresses arise in it, which tend to straighten it and, thereby, increase the contact density of the fixed half-form. 1 and plate 2 matrices. The convexity of the plate 4 and the rigidity of the base plate 5 are selected so that the deformation force of the base plate 5 is greater than the force generated by the molten plastic. Under this condition, the force generated by the pressure of the melt cannot overcome the force arising in the base plate 5 as a result of its deformation, and the contact surface of the holder of the matrix plates 2 remains tightly pressed against the fixed half-form 1. Thus, the burr does not occur. After the casting solidifies, the mold is opened. By the shank 8, by means of an abutment by an injection molding machine, the ejector system is set in motion and ejected by means of the ejector; the bodies 10 of the article are removed from the mold; The use of the proposed form will make it possible to exclude from the technological process operations associated with the separation of waste from the product. Claims. A mold for products made of polymeric materials, containing a fixed half-form and a movable one, having plates of matrices and an ejector system, a support plate, an insert, a base and a shank, characterized in that plate placed between the matrix plate and the base plate and made with a convex surface in contact with the base plate, the latter is made of hardened spring steel. Sources of information taken into account in the examination 1. Authors certificate of the USSR 753658, cl. B 29 C 5/00, 1978.

2. Manikhin Yu.P. Multi-cavity automated injection molds for products from thermoplastics .. L., Leningrad House of Scientific and Technical Propaganda, 1970, p. 5, fig. 1 (prototype).

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