RU2004450C1

RU2004450C1 - Method for making tubular products from foamed polyethylene

Info

Publication number: RU2004450C1
Authority: RU
Inventors: В чеслав Николаевич Чалов; Николай Андреевич Власов; Юрий Иванович Терентьев; Андрей Александрович Гришин; Тать на Евгеньевна Григина; Юрий Митрофанович Кузовлев; Александр Викторович Шашков; Алексей Викторович Лобанов
Priority date: 1991-11-26
Filing date: 1991-11-26
Publication date: 1993-12-15

Description

Отвержденна оболочка 13 (см. фиг. 3) надеваетс с нат гом на металлический кра- сконанос щий вал 14.The cured sheath 13 (see FIG. 3) is tensioned on a metal kraanosaning shaft 14.

Способ осуществл етс следующим образом .The method is carried out as follows.

Пример1.В формующую полость формы дл спекани заготовки 5 трубчатой оболочки (см. фиг. 1) засыпают композицию полиэтилена пенообразующего вулканизующегос марки 108-58П (ТУ 6-06-1753-79) или 108-59П (ТУ 6-54.0203492-30-89) в виде гранул с насыпной плотностью около 0,50- 0,60 г/см3 в количестве 4,1 кг. Сверху в формующую полость формы устанавливают вставку 4 и с помощью пресса (на фигурах не показан) уплотн ют композицию до плотности 0,74-0,76 г/см3.Example 1. In the molding cavity of the mold for sintering the preform 5 of the tubular shell (see Fig. 1), a composition of polyethylene foam-forming vulcanizing grade 108-58P (TU 6-06-1753-79) or 108-59P (TU 6-54.0203492-30- 89) in the form of granules with a bulk density of about 0.50-0.60 g / cm3 in an amount of 4.1 kg. Insert 4 is mounted on top of the mold cavity and the composition is compacted to a density of 0.74-0.76 g / cm3 using a press (not shown in the figures).

После уплотнени композиции хомутом 6 фиксируют вставку 4 и форму помещают в термопечь дл полного прогревани уплот- ненной композиции при температуре 70- 90°С в течение 20-40 мин, не допуска ее плавлени . По окончании прогревани форму с композицией охлаждают на воздухе, а затем вновь нагревают дл спекани зато- товки 5 9 течение 2-3 ч при температуре (185± 5)°С. После спекани форму охлаждают до комнатной температуры, распрессо- вывают и извлекают заготовку 5. Заготовка 5 имеет вид трубчатого издели с размера- ми: наружный диаметр 125, внутренний диаметр 80 мм, длина 750 мм.After the composition is densified with a clamp 6, insert 4 is fixed and the mold is placed in a thermal furnace to completely heat the densified composition at a temperature of 70-90 ° C for 20-40 minutes, preventing its melting. After warming up, the mold with the composition is cooled in air and then heated again to sinter the stock 5 9 for 2-3 hours at a temperature of (185 ± 5) ° C. After sintering, the mold is cooled to room temperature, the workpiece 5 is pressed out and the blank 5 is prepared. The blank 5 has the form of a tubular product with dimensions: outer diameter 125, inner diameter 80 mm, length 750 mm.

Спеченную заготовку 5 обтачивают на токарном станке по наружной поверхности на глубину 2-3 мм дл удалени корки и контрол качества поверхности, после чего помещают в термопечь дл свободного вспенивани при температуре (130 ± 5)°С в течение 2-3 ч. В результате свободного вспенивани заготовка 5 становитс зла- стичной и увеличивает свои размеры примерно в 2 раза до размеров оболочки 10.The sintered preform 5 is turned on a lathe along the outer surface to a depth of 2-3 mm to remove the crust and control the quality of the surface, and then placed in a thermal furnace for free foaming at a temperature of (130 ± 5) ° C for 2-3 hours. As a result by free foaming, the preform 5 becomes malleable and increases in size by about 2 times to the dimensions of the sheath 10.

Сразу после вспенивани , пока оболочка 10 находитс в гор чем эластичном состо нии , ее надевают на калибрующую оправку 9 и закрепл ют на концах оправки 9 по ее периметру посредством хомутов 11, после чего оправку 9 насаживают на ось 8 в камере дл обжати (фиг. 2). Врем пребывани вспененной оболочки 10 в эластич- ном состо нии на открытом воздухеImmediately after foaming, while the sheath 10 is in a hot elastic state, it is put on a calibrating mandrel 9 and secured to the ends of the mandrel 9 along its perimeter by means of clamps 11, after which the mandrel 9 is mounted on the axis 8 in the compression chamber (Fig. 2). The residence time of the foamed shell 10 in a flexible state in the open air

Claims

The claims

METHOD FOR PRODUCING TUBULAR PRODUCTS FROM FOAMABLE POLYETHYLENE, including sintering a tubular preform, its subsequent foaming with the formation of about 2 minutes. In this state, the sheath 10 is easily deformed and freely put on a mandrel 9 having a diameter of 165 mm corresponding to the desired inner diameter of the finished product.

Then the chamber body 7 is hermetically sealed and connected through the nozzle 12 to a compressed gas system to seal the shell 10, which is carried out at a pressure of compressed gas of 0.5 kgf / cm2 for 40 minutes. The shell 10, under the action of the pressure of the compressed gas, is compacted in the radial direction, keeping its length unchanged, it cools and hardens, while its inner diameter becomes equal to the outer diameter of the mandrel 9.

Inert gases (argon, nitrogen, etc.) are preferably used to slow down the oxidation processes in the curing stage of shell 10.

After curing of the shell 10, the chambers are removed together with the mandrel 9, the clamps 11 are disconnected and visual inspection is carried out, after which the outer crust is removed by a groove on the lathe and hardness is measured.

In this example, the hardness of the shell is 36 il units. Shore.

After grooving, the sheath 10 is removed from the mandrel 9 and the ends of the sheath 10 are cut off, as a result of which it takes the form of a finished product 13 and can be supplied to the consumer, where it is pulled onto the ink-bearing shaft 14, machined cleanly on a lathe to the required outer diameter and ground .

The quality of the resulting shell is good, the surface is smooth, without areas with variable hardness and heterogeneous structure.

This method expands technological capabilities, is distinguished by the simplicity of technology and technological equipment, can be easily implemented in specialized industries of various industries. (56) Copyright certificate of the USSR Nfe 770825. cl. B 29 F 5/02, 1380.

USSR copyright certificate No. 1729783. cl. B 29 C 67/20, 1990.

lower elastic shell and curing the latter on a metal gauge. the diameter of which corresponds to the inner diameter of the tubular product, characterized in that. that before curing the shell is fixed at the ends of the caliber, and curing is carried out under pressure of compressed gas.

4 1 153

9 1011

Fig. I

Figure 1

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