SU895694A1

SU895694A1 - Unit for producing sheets from foamed thermoplasts

Info

Publication number: SU895694A1
Application number: SU792798511A
Authority: SU
Inventors: Николай Иванович Маляренко
Original assignee: Предприятие П/Я В-8406
Priority date: 1979-07-20
Filing date: 1979-07-20
Publication date: 1982-01-07

Description

Изобретение относится к области переработки полимерных материалов и может быть использовано для изготовления пенопластов.The invention relates to the field of processing of polymeric materials and can be used for the manufacture of foams.

Известна установка для изготовления листов из вспененных термопластов, содержащая экструдер с кольцевой го<ловкой, охлаждающее устройство, ножи для резки получаемого рукава на ленты и приемные валки ГТ]. _1(J A known installation for the manufacture of sheets of foamed thermoplastics containing an extruder with an annular head, a cooling device, knives for cutting the resulting sleeve into tapes and receiving rolls GT]. _{1 (J}

Недостаток известной установки состоит в том, что она позволяет изготавливать только тонкие листы из вспененного материала.A disadvantage of the known installation is that it allows you to produce only thin sheets of foam material.

Ближайшей по технической сущности и достигаемому результату к изобретению является установка для получения листов из термопластов, содержащая валки для подачи заготовки листов, приводные приемные валки, камеру на- _игрева заготовки и аэрационное устройство, размещенное в зоне вспенивания заготовки ниже выходной щели камеры нагрева t2].The closest in technical essence and the achieved result to the invention is a plant for producing sheets of thermoplastics containing rolls for feeding the blanks, drive receiving rollers, a chamber for heating _and heating the blanks and an aeration device located in the foaming zone of the blank below the exit slit of the heating chamber t2] .

В описанной установке экструдируют смесь полиэтилена, содержащего твердый органический порообразователь с температурой разложения, превышающей температуру экструдирования термопласта. Полученную пленку обрабатывают ионизирующим облучением. При помощи валков подачи и приемных валков заготовку пропускают сверху вниз через камеру нагрева с электронагревателями.In the described installation, a mixture of polyethylene is extruded containing a solid organic blowing agent with a decomposition temperature exceeding the extrusion temperature of the thermoplastic. The resulting film is treated with ionizing radiation. Using feed rolls and receiving rolls, the workpiece is passed from top to bottom through a heating chamber with electric heaters.

Нагрев производится до температуры разложения порообразователя. Выделяющиеся газы придают размягченной пленке пористую структуру. Регулирование температуры в камере нагрева осуществляется так, чтобы положение начала преобразования не изменялось по высоте. Для устранения неровностей, возможных после разогрева, поро-. образования и охлаждения, пористый лист подвергают одноосной поперечной вытяжке ширительным устройством.Heating is performed to the decomposition temperature of the blowing agent. The evolved gases impart a porous structure to the softened film. The temperature in the heating chamber is controlled so that the position of the start of conversion does not change in height. To eliminate the bumps that are possible after warming up, poro-. formation and cooling, the porous sheet is subjected to uniaxial transverse drawing with a shirochny device.

Недостатком известной установки состоит в том, что она не обеспечивает изготовление листов необходимого качества, особенно толстых листов, Объясняется это тем, что заготовка листа перемещается вертикально,вспенивание заготовки происходит в камере, где не исключена возможность контакта разогретой заготовки с конструктивными элементами (вспенивающийся термопласт имеет высокую адгезионную способность и при малейшем соприкосновении с каким либо предметом прочно приваривается). Кроме того, низкое качество листов обусловлено влиянием гравитационных сил на заготовку в зоне вспенивания, отсутствием средств управления процессом вспенивания и вытяжкой заготовки после процесса вспенивания, что затрудняет этот процесс и приводит к неравномерной вытяжке и неравномерной толщине листов.A disadvantage of the known installation is that it does not provide the production of sheets of the required quality, especially thick sheets. This is explained by the fact that the blank of the sheet moves vertically, foaming of the blank occurs in the chamber, where the possibility of contact of the heated blank with structural elements (foaming thermoplastic high adhesive ability and at the slightest contact with any object is firmly welded). In addition, the low quality of the sheets is due to the influence of gravitational forces on the workpiece in the foaming zone, the lack of controls for the foaming process and the drawing of the blank after the foaming process, which complicates this process and leads to uneven stretching and uneven sheet thickness.

Цель изобретения - повышение качества листов»The purpose of the invention is improving the quality of the sheets "

Достигается указанная цель благодаря тому, что в установке для получения листов из вспененных термопластов, содержащей валки для подачи заготовки листов, приводные приемные валки, камеру нагрева заготовки и аэрационное устройство, размещенное в зоне вспенивания ниже выходной;щели камеры нагрева, камера нагрева, выполнена изогнутой по форме провисающей заготовки, а аэрационное устройство смонтировано в зоне наибольшего провисания заготовки и снабжено поворотными форсунками»This goal is achieved due to the fact that in the installation for producing sheets of foamed thermoplastics containing rolls for feeding the billet sheets, drive receiving rollers, a heating chamber of the workpiece and an aeration device located in the foaming zone below the exit; the slots of the heating chamber, the heating chamber, is made curved in the form of a sagging workpiece, and the aeration device is mounted in the zone of the greatest sagging of the workpiece and is equipped with rotary nozzles "

Кроме того, аэрационное устройство снабжено размещенными по периметру его в заборных карманах дросселями.In addition, the aeration device is equipped with chokes placed around its perimeter in the intake pockets.

Установка снабжена также размещенными над аэрационным устройством фотоэлементами положения заготовки, связанными с приводом приемных валков.The installation is also equipped with photocells of the position of the workpiece located above the aeration device, associated with the drive of the receiving rolls.

Благодаря такому выполнению установки процесс вспенивания начинается на выходе из камеры нагрева и происходит на воздушной подушкеJ которую создает аэрационное устройство, при этом потоки воздуха направляются и в поперечном направлении, что обеспечивает равномерное растяжение заготовки в поперечном направлении по мере вспенивания. Кроме того, в предложенном решении исключен контакт свободно провисающей заготовки с элементами камеры нагрева, т.е. исключено повреждение заготовки, исключено вредное влияние гравитационных сил в зоне вспенивания за счет размещения аэрационного устройства,обеспечено автоматическое управление процессом вспенивания.Due to such an installation, the foaming process starts at the outlet of the heating chamber and takes place on an air cushion J which creates an aeration device, while air flows are also directed in the transverse direction, which ensures uniform stretching of the workpiece in the transverse direction as it foams. In addition, the proposed solution excludes the contact of a freely sagging workpiece with elements of the heating chamber, i.e. damage to the workpiece is excluded, the harmful effect of gravitational forces in the foaming zone is eliminated due to the placement of the aeration device, automatic control of the foaming process is ensured.

На фиг. 1 дана принципиальная схема предложенной установки; на фиг. 2 - разрез А-А на фиг»1; на фиг. 3 вид по стрелке Б-Б на фиг. 1; на фиг. 4 - форсунка аэрационного устройства, разрез.In FIG. 1 is a schematic diagram of the proposed installation; in FIG. 2 - section aa in FIG. 1; in FIG. 3 is a view along arrow BB in FIG. 1; in FIG. 4 - nozzle aeration device, section.

Установка состоит из обрезиненных валков 1 для подачи заготовки и приводных приемных валков 2, камеры 3 нагрева, аэрационного устройства 4, фотоэлементов 5,6,7 и источников 8, 9, 10 света.The installation consists of rubberized rolls 1 for feeding the workpiece and drive receiving rolls 2, a heating chamber 3, an aeration device 4, photocells 5,6,7 and light sources 8, 9, 10.

Фотоэлементы электрически (через промежуточное реле и задатчик скорости с реверсивным электродвигателем) связаны с приводом (на чертеже не показан) приемных валков 2. Фотоэлементы 5,6,7 и источники 8,9,10 света установлены в вертикальной плоскости. Перед приемными валками 2 установлена камера 11 охлаждения.The photocells are electrically (through an intermediate relay and a speed controller with a reversible electric motor) connected to a drive (not shown) of the receiving rollers 2. Photocells 5,6,7 and light sources 8,9,10 are mounted in a vertical plane. In front of the receiving rolls 2, a cooling chamber 11 is installed.

Камера 3 нагрева (см. фиг. 2) выполнена по форме провисающей лисФовой заготовки, в ней установлены электронагреватели 12 с зеркальными отражателями 13.Внутренняя поверхность камеры 3 покрыта теплоизоляционным материалом.The heating chamber 3 (see Fig. 2) is made in the form of a sagging lisF blank, electric heaters 12 with mirror reflectors 13 are installed in it. The inner surface of the chamber 3 is covered with heat-insulating material.

Аэрационное устройство 4 состоит из воздуходувки 14, распределительной камеры 15, электронагревателей 16, заборных карманов 17 и нагнетающих поворотных форсунок 18. Карманы 17 и поворотные форсунки 18 снабжены регулируемыми дросселями 19. Поворотные форсунки 18 имеют шарообразную горловину 20 (см. фиг. 4) и крепятся к корпусу 21 при помощи фасонного фланца 22, винтов 23 и уплотнения 24. Поворотные форсунки 18 могут поворачиваться в пределах кривизны шарообразной горловины 20 и фиксируются затяжкой винтов 23.The aeration device 4 consists of a blower 14, a distribution chamber 15, electric heaters 16, intake pockets 17 and forcing rotary nozzles 18. The pockets 17 and rotary nozzles 18 are equipped with adjustable chokes 19. The rotary nozzles 18 have a spherical neck 20 (see Fig. 4) and fastened to the housing 21 by means of a shaped flange 22, screws 23 and seals 24. The rotary nozzles 18 can be rotated within the curvature of the spherical neck 20 and are fixed by tightening the screws 23.

Работает установка следующим образом.The installation works as follows.

Листовая заготовка 25 через валки 1 поступает в камеру 3 нагрева, где она нагревается до температуры разложений порофора с таким расчетом, чтобы процесс вспенивания заготовки ,25 начинался при выходе ее из каме5 ры. Это достигается путем согласования скорости вращения валков 1 и суммарной мощности электронагревателей 12. Температурный режим регулируется выключением или включением соответствующего количества электронагревателей 12. На выходе из камеры 3 нагрева порофор разлагается и заготовка 25 вспенивается со значительным увеличением объема, т.е. происходит ее утолщение, расширение и удчинение. Разложение порофора экзотерАичное, что дополнительно разогревает заготовку 25, и предел текучести ее настолько снижается, что под действием гравитационных сил она сильно деформируется. Поток воздуха из поворотных форсунок 18 ориентируется для противодействия гравитационным силам и в направлении растяжения вспенивающейся заготовки по ширине. Температура нагнетаемого в поворотные форсунки 1-8 воздуха устанавливается включением соответствующего количества электронагревателей 16 с таким расчетом, чтобы обеспечивалась заданная степень вспенивания. Дросселями 19 устанавливается сечение поворотных форсунок 18 и заборных карманов 17» обпеспечивающее равномерное силовое и тепловое поле, а также .'минимальный унос тепла в окружающую среду. Фотоэлементы 5,6,7 электрически связаны с приводом приемных валков 2 так, что при открытии потока света οϊ источника 8 фотоэлемент 5 через промежуточные реле воздействует на привод и скорость вращения приемных валков 2 уменьшается, при перекрытии заготовки 25 потока света от источника 9 фотоэлемент 6 дает сигнал стабилизироваιь достигнутую скорость вращения приемных валков 2. При перекрытии потока света от источника 10 фотоэлемент 7 подает сигнал на увеличение скорости вращения приемных валков 2. Перед прием- .Sheet billet 25 through rolls 1 enters the heating chamber 3, where it is heated to the decomposition temperature of the porophore so that the process of foaming the billet 25 begins when it leaves the chamber5. This is achieved by coordinating the speed of rotation of the rolls 1 and the total power of the electric heaters 12. The temperature mode is controlled by turning off or on the corresponding number of electric heaters 12. At the exit from the heating chamber 3, the porophore decomposes and the workpiece 25 foams with a significant increase in volume, i.e. it thickens, expands, and grows. The porophore decomposition is exothermic, which additionally heats the workpiece 25, and its yield strength is so reduced that under the influence of gravitational forces it is strongly deformed. The air flow from the rotary nozzles 18 is oriented to counter the gravitational forces and in the direction of expansion of the expandable workpiece in width. The temperature of the air injected into the rotary nozzles 1-8 is set by turning on the appropriate number of electric heaters 16 so as to ensure a given degree of foaming. The throttles 19 set the cross-section of the rotary nozzles 18 and the intake pockets 17 ”providing a uniform force and heat field, as well as.” Minimum heat transfer to the environment. Photocells 5,6,7 are electrically connected to the drive of the take-up rolls 2 so that when the light flux οϊ of the source 8 is opened, the photocell 5 through the intermediate relays acts on the drive and the rotation speed of the take-up rolls 2 decreases, when the blank 25 of the light flow from the source 9 of the photo-cell 6 is blocked gives a signal to stabilize the achieved rotation speed of the receiving rolls 2. When the light stream from the source 10 is blocked, photocell 7 sends a signal to increase the speed of rotation of the receiving rolls 2. Before receiving.

895694 6 ными валками 2 вспененная листовая заготовка в охлаждающем устройстве 11 обдувается холодным воздухом и приобретает устойчивую структуру.895694 6 rolls 2 foamed sheet stock in the cooling device 11 is blown with cold air and acquires a stable structure.

₅ Экономическая целесообразность использования изобретения заключается в повышении производительности,_ улучшении качества изделий, особенно толстых листов из вспененного термо10 пласта. _{5 The} economic feasibility of using the invention is to increase productivity, _ improve the quality of products, especially thick sheets of foamed thermo 10 layer.

Claims

(5t) INSTALLATION FOR OBTAINING SHEETS FROM REMOVED THERMOPLASTES The invention relates to the field of processing of polymeric materials and can be used for the manufacture of foams. A known plant for the manufacture of sheets of thermoplastic-foamed extruder with an annular head, a cooling device, knives for cutting the resulting sleeve into ribbons and pick-up rolls P. The disadvantage of the known apparatus is that it allows only thin sheets of foam to be made. The closest in technical essence and the achieved result to the invention is an installation for producing sheets from thermoplastic materials comprising rolls for feeding sheet blanks, driving take-up rollers, a billet heating chamber and an aeration device located in the foaming zone of the billet below the exit slit of the heating chamber t2. In the described installation, a mixture of polyethylene is extruded containing a solid organic blowing agent with a decomposition temperature exceeding the extrusion temperature of the thermoplastic. Poluennuyu film treated with ionizing radiation. With the help of feed rolls and take-up rolls, the workpiece is passed from top to bottom through a heating chamber with electric heaters. Heating is performed to the decomposition temperature of the blowing agent. The emitted gases impart a porous structure to the softened film. The temperature in the heating chamber is controlled so that the transformation start position does not change in height. To eliminate irregularities that may occur after warming up, poro-. formation and cooling, the porous sheet is subjected to uniaxial transverse stretching with a spreading device. A disadvantage of the known installation is that it does not ensure the manufacture of sheets of the required quality, especially thick sheets. This is explained by the fact that the sheet blank is moved vertically, the foaming of the blank occurs in the chamber, where it is possible that the heated blank can come into contact with structural elements (foaming thermoplastic it has a high adhesive ability and is strongly welded on the slightest contact with any object). In addition, the poor quality of the sheets is due to the influence of gravitational forces on the workpiece in the foaming zone, the lack of means to control the foaming process and stretching of the workpiece after the foaming process, which complicates this process and leads to uneven stretching and uneven thickness of the sheets. The purpose of the invention is to improve the quality of the sheets. This goal is achieved due to the fact that in an apparatus for producing sheets of foamed thermoplastic materials comprising rolls for feeding sheet blanks, driving take-up rollers, a heating chamber for the workpiece and an aeration device located in the foaming zone below the exit slit of the heating chamber, the heating chamber is bent in the shape of a sagging workpiece, and the aeration device is mounted in the zone of greatest sagging of the workpiece and equipped with rotatable nozzles. In addition, the aeration device is equipped with throttles placed around its perimeter in the intake pockets. The installation is also equipped with photovoltaic cells positioned above the aeration device, associated with the drive receiver. Due to this installation, the foaming process starts at the exit of the heating chamber and occurs on the airbag that the aeration device creates, while the air flows are directed in the transverse direction. direction, which ensures uniform stretching of the workpiece in the transverse direction as it foams. In addition, in the proposed solution, the contact of a freely sagging workpiece with 4 elements of the heating chamber, i.e. damage to the workpiece is excluded, the harmful influence of gravitational forces in the foaming zone is eliminated due to the placement of the aeration device, automatic control of the foaming process is provided. FIG. 1 is a schematic diagram of the proposed installation; in fig. - section A-A in FIG. 1; in fig. 3 is a view along arrow BB in FIG. one; in fig. - nozzle of aeration device, incision. The installation consists of rubberized rollers 1 for feeding the workpiece and the drive receiving rolls 2, the heating chamber 3, the aeration device 4, the photocells 5, and the sources 8, 9, 10 of light. The photo cells electrically (via an intermediate relay and a speed reference with a reversing electric motor) are connected to a drive (not shown) of the take-up rolls 2. The photo cells 5,6,7 and 8,9,10 light sources are installed in a vertical plane. In front of the take-up rolls 2, a cooling chamber 11 is installed. The heating chamber 3 (see Fig. 2) is made in the form of a sagging sheet blanks; electric heaters 12 with mirror reflectors 13 are installed in it. The internal surface of the chamber 3 is covered with heat insulating material. The aeration device consists of a blower 1, a distribution chamber 15, electric heaters 16, intake pockets 17 and forcing rotary nozzles 18. Pockets 17 and rotary nozzles 18 are equipped with adjustable throttles 19. The rotary nozzles 18 have a spherical neck 20 (see Fig. L) and mounted to the housing 21 by means of a shaped flange 22, screws 23 and a seal 2. The rotary nozzles 18 can be rotated within the curvature of the spherical neck 20 and fixed by tightening the screws 2. The unit works as follows. Sheet billet 25 through rolls 1 enters the heating chamber 3, where it is heated to the decomposition temperature of the porophor in such a way that the foaming of the billet 25 begins at its exit from the chamber. This is achieved by matching the speed of rotation of the rolls 1 and the total power of the electric heaters 12. The temperature mode is controlled by turning off or on the appropriate number of electric heaters 12. At the exit of the heating chamber 3, the porofor decomposes and the workpiece 25 foams with a significant increase in volume ,. there is its thickening, expansion and extension. The decomposition of the porophore exotherm Private, which additionally razhoraafft billet 25, and its yield strength is so reduced that under the action of gravitational forces, it is greatly deformed. The air flow from the rotary nozzles 18 is oriented to counteract the gravitational forces and in the direction of expansion of the foaming preform in width. The temperature of the air injected into the rotary nozzles 1-8 is set by switching on the appropriate number of electric heaters 16 so as to ensure the desired degree of foaming. Drossel 19 establishes the cross section of the rotary nozzles 18 and intake pockets 17 providing an even force and heat field as well as the minimum heat loss into the environment. Photo cells 5, 6, 7 are electrically connected to the drive of the take-up rolls 2 so that when the light flux from the source 8 is opened, the photocell 5 through intermediate relays acts on the drive and the rotation speed of the take-off rolls 2 decreases when the light flux from the source 9 closes The photocell 6 gives a signal to stabilize the reaching rotational speed of the pickup rolls 2. When the light flow is blocked by the source 10, the photocell 7 sends a signal to increase the pickup rolls rotation speed 2. Before the pickup rolls 2, foamed sheet metal Cooking in the cooling device 11 obduvaets cold air and becomes stable structure. The economic feasibility of using the invention is to increase productivity, improve the quality of products, especially thick sheets of foamed thermoplastic. Claims 1. An apparatus for producing sheets of foamed thermoplastic materials comprising rollers for feeding sheet blanks j drive receiving rolls, a heating chamber for a billet, and an aeration device placed in the foaming zone of the billet below the exit slit of the heating chamber, characterized in that sheet quality, the heating chamber is made of a sagging blank bent in shape, and the aeration device is mounted in the zone of the greatest sagging of the workpiece and is equipped with rotary nozzles. 2. The installation according to p.1.0 tl and h ayushchaya with the fact that the aeration device is equipped with throttle placed around its perimeter in the intake pockets. 3. Installation according to claims 1, 2, about tl and so that it is equipped with position of the workpiece placed above the photoelectric device associated with the drive of the take-up rolls. Sources of information taken into account in the examination 1. USSR Patent No. 701523, cl. On 29 D 27/00, 1978.

2.Patent of France №, cl. In 29 About 27/00, published, 1971 (prototype).