201000298 六、發明說明： 【發明所屬之技術領域】 本發明有關藉由吹模法製造由塑膠材料所製成之容器 【先前技術】 大致上’由塑膠材料所製成之容器，諸如由PET (聚 對苯二甲酸乙二醇酯）所製成之瓶子能以下列方式製造。 一預製件係藉由射出成形法所製成，於射出成形期間，一 部份係塑形在該預製件上，該部份係意欲形成該容器之頸 部。然後，該預製件被加熱（至大約攝氏1 1 0度，用於 PET )，且被插入一模具之彼此分開的二部份之間。然後 ’該模具係藉由將該二部份放置成彼此接觸再次被關閉， 而允許該預製件之頸部由該被關閉之模具浮現。然後，一 密封式噴嘴係施加至該頸部，加壓氣體、諸如空氣係經過 該噴嘴吹出。此氣體造成該熱的預製件膨脹，並以此一便 於將其壓抵靠著該模具之壁面的方式，在該塑膠材料中建 立一空的內部空間，以將該預製件轉變成一容器。當該材 料已使用一用於冷卻該模具之裝置被冷卻時，該密封之噴 嘴被移去，一夾緊裝置夾緊由該模具浮現之頸部，且該模 具之壁面被分開，以釋放該容器。該容器係接著被移除， 以遭受其製造之隨後階段。 傳統上，該預製件於吹模法期間之模製係藉由機械式 伸展系統所輔助。該機械式伸展系統傳統上包括一伸展桿 -5- 201000298 棒，亦即一在該預製件上沿著其縱軸施加壓力之桿棒’以 便結合該吹模法促成其延伸。此伸展桿棒之使用有助於在 吹模法期間將該預製件正確地中心定位在該模具中’且如 此獲得該最後容器之令人滿意的形狀° 傳統上，該模製操作以一習知爲“預先吹製”之操作 開始，在此操作期間’該空氣係在一壓力（10至2 0巴） 噴射至該預製件上，該壓力係低於該實際吹模相位期間之 壓力（2 5至4 0巴）。該預先吹製相位之持續時間係大致 上大約該吹模相位之持續時間的兩倍。該伸展桿棒係該預 先吹製製程之開始即作動。 不同型式之裝置大致上被用於該伸展桿棒之位移。 一氣壓控制可被使用。然而，其具有該桿棒的位置或 其操作動力之不允許精確控制的缺點。 一液壓控制可被使用。相對於氣壓控制，位移之速率 係更有限制的，但一較大之操作動力可被施加。以該等操 作參數之準確性的觀點，其缺點係類似於該氣壓控制之那 些缺點。 一機械式控制可被使用，但將此型式之系統放在適當 位置係笨重的。 最後一電子系統可被使用，包括滾珠螺桿驅動器。在 獲得該伸展桿棒之控制的速率之改良控制中，此系統具有 一勝過氣壓及液壓系統之優點，然而，該速率依然受限於 大約2米/秒。其具有該等零件之相當顯著程度的磨損之 缺點，而限制其沒有維修之使用壽命。 -6 - 201000298 大致上，現存系統在該等裝置之操作中達成一生產力 及精確性’其可能爲想要的，以改良之。 【發明內容】 本發明之目的係提出用於藉由在模具內側吹模一熱預 製件而製造由塑膠材料所製成之容器的方法及裝置，並藉 由該預製件之同時伸展所輔助，在該控制及該等結果中達 成改良之生產力及比現在方法與裝置較大的精確性。 爲此目的，本發明之主題係一以吹模法製造塑膠材料 製成之容器的方法，根據此方法，一預先加熱之預製件被 放入模具，允許該預製件之意欲形成該容器的頸部之一部 份由該模具浮現，且加壓氣體被吹至該預製件上，藉由伸 展機構輔助其變形，以便使得該預製件順應該模具之內部 壁面，其特徵爲在開始該伸展製程之後，該伸展機構在最 多1 /3 0秒的持續時間之後施加至少4牛頓之伸展力至該 預製件，以便在此期間造成至少1 /1 〇 〇毫米之預製件的材 料之位移。 在開始該伸展製程之後，該至少4牛頓之伸展力較佳 地係在最多1 /1 0 0秒的持續時間之後獲得。 該吹模法可在單一步驟中進行。 該吹模法可在1 5及2 5巴間之壓力下進行。 該預製件可爲由PET所製成。 本發明之另一主題係一以吹模法製造塑膠材料製成之 至少一容器的裝置，包括至少一模具，一由該塑膠材料所 201000298 製成之預先加熱預製件可被放入該模具；用於伸展該預製 件之機構及用於其控制之機構；及用於將氣體吹至該預製 件上之機構’其包括一能夠施加至該預製件之噴射噴嘴， 其特徵爲當該預製件係由PET所製成及被預先加熱至攝氏 11 〇度時，該伸展機構使其可能在開始該伸展製程之後， 在最多1/3 0秒的持續時間之後施加至少4牛頓之伸展力 至該預製件’以便在此期間造成至少1 /1 〇 〇毫米之預製件 的材料之位移。 該吹模機構可允許一加壓至1 5至2 5巴之氣體被噴射 至該預製件上。 該伸展機構可包括一可被施加至該預製件之伸展桿棒 〇 該伸展桿棒可被電磁機構所控制。 該電磁機構可包括一固定至該伸展桿棒之線性馬達、 及一用於傳送力量至該線性馬達之磁性軌道。 該裝置可包括複數模具及伸展桿棒，該等伸展桿棒被 固定至一支撐支臂，其本身藉由控制機構之單一組件所控 制。 如將被了解，根據本發明之方法，在開始該伸展操作 之後，在經過一極短時期（最大1 / 3 0秒，較佳地是最大 1/100秒）之後，一相當高、亦即至少4牛頓之伸展力係 施加至該預製件，及以便在此期間造成該預製件之材料的 至少1/100毫米之位移。 本發明家已經確定就算此條件將被考慮，其將可能藉 -8 - 201000298 由在該吹模製程期間施加一壓力達成一很高品質之吹模產 品，該壓力可爲相當適當的（典型I5至25巴），且尤其 藉由提供消除預先吹製相位之可能性。於此案例中，該吹 模法於單一相位期間發生（然而’在此期間，該空氣之壓 力、及該伸展桿棒之推力與推動速率亦可能以一逐漸及控 制下之方式變化），且該容器之製造製程的持續時間大體 上被縮短，如此該裝置之生產力係增加，且該吹模裝置及 其附接件之設計可被簡化。 這些條件可使用根據本發明之裝置被獲得，其中該伸 展機構、譬如伸展桿棒係藉由電磁機構所控制，該電磁機 構包括一固定至該伸展機構之線性馬達、及一未彼此接觸 之磁性軌道。如此，沒有該運轉零組件之磨損的問題。再 者，此型式之系統使其可能幾乎馬上獲得該增加之推力， 這是施行根據本發明之方法所需要者。最後，其係易於以 一精密之方式、尤其藉由電腦機構控制，以便將精密之支 承力量及位移之速率強加在該伸展機構上，使它們保持恆 定或造成它們以一預定之方式根據諸曲線變化，該等曲線 已被該使用者之經驗所顯示，以導致一最佳品質之產品。 相同地，其允許建立用於該伸展機構之不同操作參數及位 移的精確計量之機構。這使其可能於反應中微調該操作參 數，譬如，相對該預製件之黏性的一預料中或意外之修改 ，譬如，由於其溫度中之變化，其可能未如理論上所預料 般精確者。 201000298 【實施方式】 圖1及2係由該前面（圖1 )及從側面（圖2)所觀 看，且槪要地顯示根據本發明之吹模裝置的一範例之基本 元件，以下之元件係可看見的： -該模具之二零件1,2，其係在彼此分開之位置中，且 以傳統方式設計該等零件內部空間之輪廓3、4的形狀， 以界定待藉由吹模法所模製之容器的形狀；該等模具零件 1，2具有用於該運動之結構細節及所附配備，且其加熱/冷 卻係一傳統設計及未被顯示； -一預製件5，其以傳統方式由意欲形成待製造之容器 的材料、譬如P E T之一部份所組成，而用於食物使用之瓶 子；如係習知者’此預製件被預先加熱至一溫度，該溫度 允許其模製件被吹模（用於PET大約攝氏1 1 〇度），且藉 由一未不出之裝置被固持在適當位置中；其上部6傳統上 已被設計形狀，以便形成待模製的容器之頸部； -一空氣噴射噴嘴7’其由一可滲透氣體之材料所形成 ，且被連接至傳統機構（未示出），使其可能在其中噴射 加壓空氣，該加壓空氣可由該處經過其下面8浮現；不用 說異於空氣之氣體可被使用’空氣具有不貴及以壓縮形式 輕易可用之優點； -伸展桿棒9 ’其能以受控制之方式在一縱向孔口內側 滑動，並通過該噴嘴7; -用於根據本發明控制該伸展桿棒9之機構，其具有 以下之性質：它們允許該伸展桿棒9將4牛頓或更多之變 -10- 201000298 形力施加至該預製件，這是在3 /1 0秒的最大持續時間、 較佳地是最多1/100秒之後所獲得，以便在該3/1〇秒之後 、較佳地是在該1 /1 〇 〇秒之後，同時以該吹模法獲得該桿 棒9在該預製件6中之至少1 /1 0 0毫米的位移（如此該預 製件5之材料的一對應位移）：這些條件代表所必需獲得 者係能夠在相當低之壓力（10至20巴）下免除一預先吹 製操作’隨後必需是一在大體上較大額定壓力（25至40 巴）之吹模操作，及藉由單一吹模相位替換此製程，該吹 模相位可在一相當平均之壓力範圍中進行，典型大約15 至2 5巴’且仍然獲得令人滿意之產品品質。 自然地，這不排除使用較高之吹模壓力，當大尺寸或 由難以模製的材料所製成之預製件5可爲想要的時，該等 壓力係能夠高達譬如4 0巴。 於該被喜好但不須專有、且被本發明家所可預見的範 例中’該控制機構係電磁機構’包括· -一磁性馬達（線性馬達）1 0與其導引機構（未示出 )，並藉由一磁性軌道1 1未接觸地移動； -一路徑分析器1 2，其被固定至該線性馬達1 0 ’且使 其可能決定與調整其位置及其位移； 在所有使用一線性馬達的裝置之型式中’這些構件係 傳統的，且不會在此被較大詳細地揭示。 圖3及4顯示與圖1及2相同之元件，如以相同之方 式觀看，雖然該裝置係正好在其操作之開始處° 換句話說： -11 - 201000298 -該模具之壁面1，2已被再次關閉至該預製件5上，僅 只留下該頸部6保持在該模具外側； -該伸展桿棒9隨著支撐它之線性馬達1 0被降低直至 與該預製件5內側之底部接觸，以提前進行該桿棒9相對 該吹模製程之開始的降低； -該噴射噴嘴7已被放置成與該預製件5之頸部6接 觸；一外殼（未示出）可被選擇性地形成在該噴嘴7之下 面8上，以在此承接該頸部6之至少該上端；該噴嘴7及 該預製件5間之接觸的密封可如此被改善，以確保該方法 之較佳控制。 然後該加壓空氣被噴射進入該噴嘴7，且該伸展桿棒 9係降低進入該預製件5，並遠至該模具1，2之底部，以 輔助該模製操作。根據本發明，如藉由使用控制該桿棒9 用之電磁裝置而變成可能的，該桿棒9係藉由一在最多 1/30秒、較佳地是甚至最多1/100秒之後所獲得的相當高 之力量、亦即至少4牛頓馬上位移，且以此一便於造成該 預製件5之材料的至少1 / 1 〇 〇毫米位移（換句話說該桿棒 9貫穿進入該預製件5)之方式。由於此條件之結果，對 比於慣例，其係可能避免必需將該吹模製程分爲二步驟， 其第一步驟已在一相當適度的壓力下進行，且該第二步驟 在一相當高壓下進行。根據本發明的方法之使用有利地是 藉由採用一電磁系統1 0、1 1以控制該桿棒9之位移而成 爲可能，使其可能以單一吹模步驟達成該容器1 3之模製 ，該吹模步驟能夠在一平均之壓力範圍、譬如15至25巴 -12- 201000298 中進行。 圖5及6顯示該裝置於其最後狀態中，使所模製之容 器13及該伸展桿棒9已抵達該容器13之底部附近。在此 之後，該模具係藉由分開該零件1,2被打開，該桿棒9及 該馬達10被舉起，且藉由該頸部6夾緊該容器13，以被 移除供其處理之隨後階段。 一裝置已被顯示在圖1至6中，在此一馬達10控制 單一伸展桿棒9。然而，該馬達1 0當然能控制一支撐支臂 ，該支撐支臂本身承載複數桿棒9，使用將與該等桿棒有 關聯的相等數目之模具1,2，輔助相等數目之容器1 3的形 成。如此能以同時之方式形成複數容器1 3，這增加該裝置 之生產力。 使用藉由電磁機構1 〇、1 1所控制之桿棒9以獲得該 預製件5之伸展係一伸展裝置之有利的範例，但其係可能 使用其他型式之伸展裝置，用於施行本發明之方法，由施 加至該預製件5的力量及它們將強加於形成該預製件5的 材料上之位移的觀點，該等伸展裝置在功能上係相同的。 根據本發明之方法的優點之一亦爲其可允許一用於預 先加熱該預製件5之溫度係低於該等傳統方法，典型較低 達攝氏1及20度之間’視所處理之材料而定。 於二步驟中施行該吹模法將留在本發明之精神內，如 傳統上所常有的，而且在已被討論的條件之下施加該伸展 力。這樣一來’本發明之一些優點將喪失，亦即該吹模法 製程之簡化及生產力中之增加。然而，比於該傳統方法中 -13- 201000298 較低之吹模壓力可被使用，及/或用於預先加熱該預製件 5之溫度可被減少’及/或使用與該等傳統方法中所使用 者不同之材料’對比於根據本發明之方法，該等傳統方法 中所使用之材料將不會允許其在合適之條件中變形。 【圖式簡單說明】 本發明將藉由閱讀以下之敘述、參考以下之附圖而更 佳了解： -圖1及2係由該前面（圖1 )及從側面（圖2 )所觀 看’並在實施根據本發明的方法之前槪要地顯示根據本發 明之裝置的一範例； -圖3及4在根據本發明的方法之實施的開始處顯示 相同之裝置； -圖5及6在根據本發明的方法之實施的結束處顯示 相同之裝置。 【主要元件符號說明】 1 :零件 2 :零件 3 :輪廓 4 :輪廓 5 :預製件 6 :上部 7 :空氣噴射噴嘴 -14 - 201000298 8 :下面 9 :伸展桿棒 1 0 :馬達 1 1 :軌道 1 2 =路徑分析器 13 :容器 -15201000298 VI. Description of the Invention: [Technical Field] The present invention relates to a container made of a plastic material by blow molding [Prior Art] A container substantially made of a plastic material, such as PET ( A bottle made of polyethylene terephthalate can be produced in the following manner. A preform is formed by injection molding, and during injection molding, a portion is formed on the preform which is intended to form the neck of the container. The preform is then heated (to approximately 110 degrees Celsius for PET) and inserted between two separate portions of a mold. The mold is then closed again by placing the two parts in contact with one another, allowing the neck of the preform to emerge from the closed mold. Then, a sealed nozzle is applied to the neck through which a pressurized gas, such as air, is blown. This gas causes the hot preform to expand and thereby establish an empty interior space in the plastic material to press the preform into a container in a manner that presses it against the wall of the mold. When the material has been cooled using a means for cooling the mold, the sealed nozzle is removed, a clamping device clamps the neck emerging from the mold, and the wall of the mold is separated to release the container. The container is then removed to suffer from the subsequent stages of its manufacture. Traditionally, the molding of the preform during the blow molding process was aided by a mechanical stretching system. The mechanical stretching system conventionally includes a stretching rod -5 - 201000298 rod, i.e., a rod " on the preform that exerts pressure along its longitudinal axis to facilitate its extension in conjunction with the blowing method. The use of this stretching rod helps to position the preform correctly in the mold during the blow molding process 'and thus obtains a satisfactory shape of the final container. Traditionally, the molding operation is a habit The operation known as "pre-blowing" begins during which the air is injected onto the preform at a pressure (10 to 20 bar) which is lower than the pressure during the actual blow phase ( 2 5 to 40 bar). The duration of the pre-blowing phase is approximately twice the duration of the blown phase. The stretch bar is actuated at the beginning of the pre-blowing process. Different types of devices are generally used for the displacement of the stretching rod. A pressure control can be used. However, it has the disadvantage that the position of the rod or its operating power does not allow precise control. A hydraulic control can be used. The rate of displacement is more limited than for air pressure control, but a larger operating power can be applied. From the standpoint of the accuracy of these operational parameters, the disadvantages are similar to those of the air pressure control. A mechanical control can be used, but placing this type of system in place is cumbersome. The last electronic system can be used, including ball screw drives. In the improved control of the rate at which the control of the stretch rod is obtained, the system has the advantage over the pneumatic and hydraulic system, however, the rate is still limited to about 2 meters per second. It has the disadvantage of a significant degree of wear of the parts and limits their service life without maintenance. -6 - 201000298 In general, existing systems achieve a productivity and accuracy in the operation of such devices 'which may be desirable to improve. SUMMARY OF THE INVENTION The object of the present invention is to provide a method and apparatus for manufacturing a container made of a plastic material by blow molding a hot preform on the inside of a mold, and assisting by simultaneous stretching of the preform, Improved productivity and greater precision than current methods and devices are achieved in this control and in these results. For this purpose, the subject of the invention is a method for producing a container made of a plastic material by blow molding, according to which a preheated preform is placed in a mould, allowing the preform to be intended to form the neck of the container One portion of the portion emerges from the mold, and pressurized gas is blown onto the preform, and the deformation mechanism assists the deformation thereof so that the preform conforms to the inner wall surface of the mold, which is characterized by starting the stretching process Thereafter, the stretching mechanism applies a stretching force of at least 4 Newtons to the preform after a duration of up to 1 / 30 seconds to cause a displacement of the material of the preform of at least 1 / 1 mm during this period. After the stretching process is initiated, the stretching force of at least 4 Newtons is preferably obtained after a duration of up to 1/100 seconds. The blow molding process can be carried out in a single step. The blow molding method can be carried out under a pressure of between 15 and 25 bar. The preform can be made of PET. Another subject of the present invention is a device for producing at least one container made of a plastic material by blow molding, comprising at least one mold, and a preheated preform made of the plastic material 201000298 can be placed in the mold; a mechanism for extending the preform and a mechanism for controlling the same; and a mechanism for blowing a gas onto the preform, which includes an injection nozzle that can be applied to the preform, characterized in that the preform is When made of PET and preheated to 11 degrees Celsius, the stretching mechanism makes it possible to apply a stretching force of at least 4 Newtons after a duration of up to 1/3 0 seconds after starting the stretching process. The preform 'to cause a displacement of the material of the preform of at least 1 / 1 mm during this period. The blow molding mechanism allows a gas pressurized to 15 to 25 bar to be sprayed onto the preform. The stretching mechanism can include a stretch bar that can be applied to the preform. The stretch bar can be controlled by an electromagnetic mechanism. The electromagnetic mechanism can include a linear motor secured to the extension rod and a magnetic track for transmitting power to the linear motor. The apparatus can include a plurality of dies and extension bars that are secured to a support arm that is itself controlled by a single component of the control mechanism. As will be appreciated, the method according to the present invention, after the start of the stretching operation, after a very short period of time (maximum 1 / 30 seconds, preferably 1/100 second maximum), is quite high, ie A stretching force of at least 4 Newtons is applied to the preform and to cause at least a 1/100 millimeter displacement of the material of the preform during this period. The inventors have determined that even if this condition is to be considered, it would be possible to apply a pressure during the blow molding process to achieve a very high quality blow molded product by -8 - 201000298, which pressure can be quite appropriate (typical I5 Up to 25 bar), and in particular by providing the possibility of eliminating pre-blowing phases. In this case, the blow molding method occurs during a single phase (however, during this period, the pressure of the air, and the thrust and pushing rate of the stretching rod may also vary in a gradual and controlled manner), and The duration of the manufacturing process of the container is substantially shortened, so that the productivity of the device is increased, and the design of the blow molding device and its attachment can be simplified. These conditions can be obtained using a device according to the invention, wherein the stretching mechanism, such as a stretching rod, is controlled by an electromagnetic mechanism comprising a linear motor fixed to the stretching mechanism and a magnetic element that is not in contact with each other. track. As such, there is no problem with the wear of the running components. Moreover, this type of system makes it possible to obtain this increased thrust almost immediately, which is required to carry out the method according to the invention. Finally, it is easy to control in a sophisticated manner, in particular by a computer mechanism, to impose precise support forces and displacement rates on the stretching mechanism, keeping them constant or causing them to follow the curves in a predetermined manner. Changes, these curves have been shown by the experience of the user to result in a product of the best quality. Similarly, it allows for the establishment of a mechanism for precise metering of different operating parameters and displacements of the stretching mechanism. This makes it possible to fine tune the operating parameters in the reaction, for example, an unexpected or unexpected modification of the viscosity of the preform, for example, due to changes in its temperature, which may not be as accurate as theoretically expected. . 201000298 [Embodiment] Figs. 1 and 2 are viewed from the front (Fig. 1) and from the side (Fig. 2), and schematically show the basic elements of an example of the blow molding apparatus according to the present invention, and the following components are Visible: - the two parts 1, 2 of the mould, which are in a position separated from each other, and the shape of the contours 3, 4 of the interior spaces of the parts are designed in a conventional manner to define the blow moulding method The shape of the molded container; the mold parts 1, 2 have structural details and accompanying equipment for the movement, and the heating/cooling system is a conventional design and is not displayed; - a preform 5, which The conventional method consists of a material intended to form a container to be manufactured, such as a part of PET, which is used for food use; as is known in the art, the preform is preheated to a temperature which allows the mold to be molded. The article is blow molded (for PET approximately 1 degree Celsius) and held in place by a device that is not present; its upper portion 6 has traditionally been shaped to form a container to be molded Neck; - an air jet nozzle 7' Formed by a gas permeable material and connected to a conventional mechanism (not shown) such that it may inject pressurized air therein, which may emerge from there through its lower surface 8; needless to say, is different from air The gas can be used with the advantage that air is inexpensive and readily available in compressed form; - the stretching rod 9' can be slid inside a longitudinal orifice in a controlled manner and passed through the nozzle 7; The present invention controls the mechanism of the stretch rod 9 which has the property that they allow the stretch rod 9 to apply a force of 4 Newtons or more to the 10-201000298 force to the preform, which is at 3/1 The maximum duration of 0 seconds, preferably up to 1/100 second, is obtained after the 3/1 leap second, preferably after the 1 / 1 leap second, while the blow molding method Obtaining a displacement of the rod 9 in the preform 6 of at least 1 / 10 mm (so a corresponding displacement of the material of the preform 5): these conditions represent that the required winner is capable of being at a relatively low pressure ( 10 to 20 bar) exempt from a pre-blowing operation It is necessary to perform a blow molding operation at a substantially larger rated pressure (25 to 40 bar) and to replace the process by a single blow mold phase which can be carried out in a relatively average pressure range, typically about 15 Up to 2 5 bar' and still get satisfactory product quality. Naturally, this does not preclude the use of higher blow mold pressures which can be as high as, for example, 40 bar when preforms 5 of large size or made of materials that are difficult to mold can be desired. In the example that is preferred but not exclusive and predictable by the inventors, 'the control mechanism is an electromagnetic mechanism' includes a magnetic motor (linear motor) 10 and its guiding mechanism (not shown) And moving by a magnetic track 1 1 without contact; a path analyzer 12 that is fixed to the linear motor 10' and makes it possible to determine and adjust its position and its displacement; In the version of the device of the motor, these components are conventional and will not be disclosed in greater detail herein. Figures 3 and 4 show the same components as Figures 1 and 2, as viewed in the same manner, although the device is just at the beginning of its operation. In other words: -11 - 201000298 - The wall 1, 2 of the mold has Closed to the preform 5 again, leaving only the neck 6 to remain outside the mold; - the stretch rod 9 is lowered with the linear motor 10 supporting it until it contacts the bottom of the inside of the preform 5 To advance the lowering of the rod 9 relative to the beginning of the blow molding process; - the spray nozzle 7 has been placed in contact with the neck 6 of the preform 5; a housing (not shown) can be selectively Formed on the lower surface 8 of the nozzle 7 to receive at least the upper end of the neck portion 6; the sealing of the contact between the nozzle 7 and the preform 5 can be improved to ensure better control of the method. The pressurized air is then injected into the nozzle 7, and the stretch rod 9 is lowered into the preform 5 and as far as the bottom of the mold 1, 2 to assist the molding operation. According to the invention, it is made possible by using an electromagnetic device for controlling the rod 9, which is obtained after a maximum of 1/30 second, preferably even at most 1/100 second. The relatively high force, that is, at least 4 Newtons, is immediately displaced, and as a result, at least 1 / 1 〇〇 mm displacement of the material of the preform 5 is facilitated (in other words, the rod 9 penetrates into the preform 5) The way. As a result of this condition, it is possible to avoid having to divide the blow molding process into two steps, the first step of which has been carried out under a relatively moderate pressure, and the second step being carried out under a relatively high pressure. . The use of the method according to the invention is advantageously made possible by the use of an electromagnetic system 10, 1 1 to control the displacement of the rod 9, making it possible to achieve the molding of the container 13 in a single blow molding step, The blow molding step can be carried out in an average pressure range, such as 15 to 25 bar-12-201000298. Figures 5 and 6 show the device in its final state such that the molded container 13 and the stretching rod 9 have reached the bottom of the container 13. After that, the mold is opened by separating the parts 1, 2, the rod 9 and the motor 10 are lifted, and the container 13 is clamped by the neck 6 to be removed for disposal. The subsequent stage. A device has been shown in Figures 1 through 6, where a motor 10 controls a single stretch rod 9. However, the motor 10 can of course control a support arm which itself carries a plurality of rods 9, using an equal number of moulds 1, 2 associated with the rods, to assist an equal number of containers 1 3 Formation. This makes it possible to form the plurality of containers 13 in a simultaneous manner, which increases the productivity of the apparatus. An advantageous example of using the rod 9 controlled by the electromagnetic mechanism 1 〇, 1 1 to obtain an extension-stretching device of the preform 5, but it is possible to use other types of stretching devices for carrying out the invention The method is functionally identical from the standpoint of the force applied to the preform 5 and the displacement they will impose on the material forming the preform 5. One of the advantages of the method according to the invention is that it allows a temperature for preheating the preform 5 to be lower than the conventional methods, typically between 1 and 20 degrees Celsius. And set. Performing the blow molding in the second step will remain within the spirit of the invention, as is conventionally the case, and the stretching force is applied under the conditions already discussed. As a result, some of the advantages of the present invention will be lost, i.e., the simplification of the blow molding process and the increase in productivity. However, a lower blow mold pressure can be used than in the conventional method -13-201000298, and/or the temperature for preheating the preform 5 can be reduced' and/or used in such conventional methods. Different materials for the user 'Compared to the method according to the invention, the materials used in these conventional methods will not allow them to be deformed under suitable conditions. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood by reading the following description, with reference to the following drawings: - Figures 1 and 2 are viewed from the front (Fig. 1) and from the side (Fig. 2) An example of a device according to the invention is shown schematically before carrying out the method according to the invention; - Figures 3 and 4 show the same device at the beginning of the implementation of the method according to the invention; - Figures 5 and 6 are in accordance with the present The same device is shown at the end of the implementation of the inventive method. [Main component symbol description] 1 : Part 2 : Part 3 : Contour 4 : Contour 5 : Preform 6 : Upper 7 : Air jet nozzle - 14 - 201000298 8 : Bottom 9 : Stretch rod 1 0 : Motor 1 1 : Track 1 2 = Path Analyzer 13: Container-15