201139096 六、發明說明： 【發明所屬之技術領域】 本發明係有關於一種用於吹塑成型製程製造中空物體 的改良型預製件，特別是任何型式及尺寸的瓶子。 【先前技術】 如同熟知此領域之人士所知曉的，現今塑膠瓶或罐的 製造幾乎都是採用二階段製程，其中包括製造及使用稱爲 預製件或型坯之具有實質上圓柱狀的中空半完工原料件。 在此製程中的第一階段中，其係幾乎都採用射出成型來以 一種極度集中化的方式，亦即僅在少數特定的製造廠商處 ’進行大厚度中空預製件的製造，該預製件所具有的縱向 及橫向尺寸’相對於已完工之瓶體尺寸的比値約爲1 : 2至 1 : 4。在該製程的第二階段中，其通常係在與裝瓶液體包 裝相同之工廠處進行的，該中空預製件會被加熱至一個足 以達到所需之軟化效果的溫度、插入至一吹塑模內、由— 插入至該預製件內之拉伸桿加以拉伸至最終瓶體長度、以 及將一股或多股壓縮空氣流導入至該加熱並拉伸後的預製 件來加以吹塑成型。 此種製造系統在整個製造鏈中提供顯著而多樣的優點 ，此係熟知此領域之人士所熟知者，故在此無需重述，這 些優點使得此種製造系統在全球性層級上幾乎是普遍採用 來製造中空物體’特別是任何型式、形狀及尺寸的瓶。 具體地說，前面所述的製程在使用結晶塑膠材料，例 -5- 201139096 如PET (聚乙烯對苯二甲酸酯），可以特別有效地加以應 用，該材料在吹塑的過程中會經歷晶體結構的定向，使得 該瓶體具有特別合宜的機械特徵，即使是僅具有極低的最 終材料厚度。 特別是針對此種型式的瓶體，不斷地有硏究被開發出 來，以將此製造程序加以最佳化，以供在最終瓶體容量相 同的條件下將所使用的塑膠材料的量加以減少，此塑膠材 料佔瓶體最終成本的約90%。一直到現在，此等硏究一方 面主要在於最終瓶體的形狀變化（以供創造出較佳的形狀 穩定性），另一方面則是在於各種模製參數（預製件拉伸 比、加熱溫度、吹塑空氣的壓力、以及類似者）的施行。 長時間以來，預製件的形狀實質上是沒有改變過，如 所提過的，此形狀包含有一具有固定或可變厚度的中空圓 柱狀本體，其開放端係已具有瓶頸區域之最後形狀者，故 而因此亦具有所需用來與螺紋蓋相結合用的螺紋，而其封 閉末端在大部份的情形中則是具有球形形狀。 爲供減少在完成後的瓶體中會留存在其底部中心區域 內的塑膠材料的量，亦有非球形頭部之預製件曾被提出過 ，並有部份被採用過，特別是具有錐狀、橢圓、或拋物線 形狀之頭部者。但是，雖然此種型式的預製件就預製件的 模製而言會有實際上的優勢，且可因依據預製件的不同幾 何形狀而僅射出較少量之塑膠融熔材料而在模製時間上有 著適度的縮短效果，但是他們對於前述瓶體底部中心區域 內的重量減輕並不會有著可以看得到的效果，這是因爲完 -6- 201139096 成後之瓶體內的材料分佈最後並不會與由具有球形頭部之 預製件所製得之瓶體有重大的差異。 再更近年來，在本申請人的歐洲專利EP-2077934中， 其建議一種具有突出的圓滑中心附加件的預製件，藉由之 其可以在預製件上得到極顯著的重量減輕效果，但其性能 則沒改變。 【發明內容】 因此本發明的目的在於提供另一種型式的改良預製件 ’其相對於目前使用之已知型式預製件而言，具有明顯減 輕的重量，而由其所製得之瓶體的尺寸及抗力特徵則維持 相同，相同於歐洲專利E P - 2 0 7 7 9 3 4中所描述之預製件所發 生的情形，但是是一種不同結構的方案，其可以更立即地 用來取代傳統的預製件，且其對於被影響之部位內的改變 僅會有較小的抵制作用。 本發明的另一目的是提供一種改良的預製件，其可用 以取代傳統已知的預製件，而同時能不改變吹塑過程中的 拉伸比値。 本發明的再一目的是提供一種改良的預製件，其可以 在由其製成的瓶體上達成重量減輕的效果，而減輕的作係 集中於瓶體底部的中心區域內。 根據本發明，這些目的係由一種預製件來加以達成的 ’該預製件具有隨附申請專利範圍第1項中所界定的特徵 。本發明之預製件的其他特徵則是定義於申請專利範圍的 201139096 附屬項內。 本發明的其他特徵及好處可以自下面有關於一較佳實 施例的說明中得知’這些純係供做爲非限制性的範例，並 係顯示於隨附圖式中。 【實施方式】 如自圖式中可以清楚看到的，就以已知方式設置螺紋 及用以包覆及抵靠瓶蓋的肋部的開放端2，以及預製件本 體3之長圓柱形形狀而言，本發明的預製件1是完全具有傳 統的結構。 事實上，本發明之預製件的創新之處主要是在於預製 件中與開放端2相對之封閉末端或頭部4的形狀，其一般係 爲半球形。如前所述，預製件頭部也可以具有錐狀、橢圓 形或拋物線形狀，也可以具有如歐洲專利E P · 2 0 7 7 9 3 4中所 描述之突出的中心附加件；但是，爲簡化起見，下文中將 只針對半球形頭部說明，因此此詞彙係意欲涵蓋所有前面 所提及的可能的頭部形狀。 事實上，頭部4具有一系列的凹陷5，最好是平均地分 佈於頭部4的側邊表面上，對應於該頭部中的一個球形片 段，也就是一個位於二互相平行平面之間而垂直於預製件 軸心的區域，該凹陷5係適切地接合至該頭部4的其餘側邊 部位上，而具有朝向預製件內部的相對應突出部6，因此 預製件在該凹陷5處的厚度是實質上等於該預製件頭部4在 其餘鄰接部位處的厚度。將預製件在對應於的凹陷5處保 -8- 201139096 持實質上固定的厚度，事實上是由本發明之預製件製得較 佳性能瓶體的較佳需求。首先，預製件頭部對應於該凹陷 處的較狹小截面會在預製件射出成型階段中造成預製件的 部份結晶化；第二，預製件頭部在不同部位具有不同厚度 會造成瓶體在其底部具有不固定的厚度；第三，在吹塑成 型製程的預熱步驟中，預製件頭部中較薄的部位會在太短 的時間內軟化，因此必須要調整模製參數，以避免在完成 的瓶體中造成任何不均勻或瑕疵的情形，特別是考量到完 成之瓶體的爆裂抵抗性及應力碎裂抵抗性。頭部4的其餘 側邊部分可以具有前面所述之已知形狀的任一者，但最好 是具有半球形。 凹陷5的形狀，其數量及小，並沒有特別的限制，只 要在對應於該凹陷之處不會有實質性的預製件厚度變化， 且突出部6中朝向頭部4內部最突出的部位能留下夠大之中 心空間以供預製件拉伸桿（未顯示）在模製階段開始之時 通過即可。在以剖面形式顯示出來的各種實施例中，其分 別具有凹陷5具有內凹形狀（第2 A圖）、平直形狀（第2 B 圖）、以及雙凸形狀（第2 C圖）。其他的形狀當然也是可 行的，例如說前述各者中的各種曲面的組合，當然也可以 大幅度地改變設置著凹陷5之球形部位的高度，其也可以 延伸至占滿整個頭部4。換言之，凹陷5的一側可以延伸至 頭部4的頂端，而另一側延伸至連接著頭部4及圓柱狀本體 3的圓周。 在前述的變化範圍內’大小及形狀’以及凹陷5的數 -9 - 201139096 量可以依所需的結果隨意變化，例如說爲了將預製件重量 的減損集中在由於預製件所製成之瓶體底部中心區域，或 是爲了其他可能會對於個人或各種應用有用或方便的目的 〇 由於前述本發明之預製件的特殊形狀之故，可以獲致 預製件相較於相同厚度及高度之已知預製件具有大幅減低 之重量的非凡結果，這是因爲考量到在頭部4之每一點處 ，受到凹陷5影ϋ到的區域係沿著較內部周邊展開，故而 較相對應之球形表面者爲短，所以本發明之預製件的整體 表面很顯然具有較傳統有著完整球形頭部及相同高度之相 對應預製件爲小的展開面積。進一步而言，此種非凡的結 果可以在一點也不需要改變預製件其他結構來達成，特別 是其軸向的拉伸比値，因爲拉伸桿可以直接通過突出部6 ，直到碰觸到預製件的內部頂點，故其可以將本發明預製 件的伸長量設定爲與相同高度之具有球形頭部的習用預製 件所可設定者相同。 因此，本發明的預製件可以取代傳統的預製件而不需 要對吹塑成型製程做新的校驗，這也是因爲頭部4中位在 相鄰凹陷5之間的半球形區域是一種連接至位在下方之圓 柱狀本體3上的網狀結構，故而他們可以一種實質上相等 於習用預製件中所發生之方式將拉伸桿造成的拉伸動作加 以傳遞，因此能以簡單而直接的方式獲致預製件重量及完 成之瓶體的重大減低’所以可以達成本發明的第一及第二 目的。 -10- 201139096 再者，透過適當地調整凹陷5的尺寸參數 '形狀、及 數量，其亦可以將重量的減低集中在藉由吹塑成型該預製 件而得到之瓶體底部的中心部位處，因此可達成本發明的 第三目的。 如前所述，本發明之預製件的頭部亦可配合歐洲專利 EP-2077 93 4中所述之圓滑中心附加件使用，因此可以在預 製件上得到更加顯著的重量減低。 前文中係配合本發明的一較佳實施例來加以說明，但 很明顯的，仍有許多其他使用本發明原則的實施例係與之 不同。因此本發明絕不應受到所述之實施例的結構加以限 制’僅能由下附申請專利範圍所提供的本發明的定義來加 以限定。 【圖式簡單說明】 第1圖是根據本發明之一改良式預製件的一示意側視 圖。 第2A圖、第2B圖、以及第2C圖係根據本發明之預製 件的各種實施例的縱向剖面的部份視圖。 【主要元件符號說明】 1 :預製件 2 :開放端 3 :本體 4 :頭部 -11 - 201139096 5 :凹陷 6 :突出部BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved preform for producing a hollow object for a blow molding process, particularly a bottle of any type and size. [Prior Art] As is known to those skilled in the art, the production of plastic bottles or cans today is almost always a two-stage process, including the manufacture and use of a substantially cylindrical hollow half called a preform or parison. Finished raw materials. In the first stage of the process, almost all of them were injection molded to produce a large-thickness hollow preform in an extremely centralized manner, that is, only at a few specific manufacturers. The ratio of the longitudinal and transverse dimensions 'with respect to the finished bottle size is about 1:2 to 1:4. In the second stage of the process, it is typically carried out at the same plant as the bottling liquid package, which is heated to a temperature sufficient to achieve the desired softening effect, inserted into a blow mold. The inside, by - the stretching rod inserted into the preform is stretched to the final length of the bottle, and one or more streams of compressed air are introduced into the heated and drawn preform to be blow molded. Such manufacturing systems provide significant and diverse advantages throughout the manufacturing chain and are well known to those skilled in the art, so there is no need to repeat them here, and these advantages make such manufacturing systems almost universal at the global level. To make hollow objects 'especially any type, shape and size of bottles. Specifically, the above-described process is particularly effective in the use of a crystalline plastic material, such as PET-5 (Purylene Terephthalate), which is experienced during the blow molding process. The orientation of the crystal structure gives the bottle a particularly desirable mechanical character, even with only a very low final material thickness. In particular, for this type of bottle, continuous research has been developed to optimize this manufacturing procedure to reduce the amount of plastic material used under the same conditions of the final bottle capacity. This plastic material accounts for about 90% of the final cost of the bottle. Until now, on the one hand, these studies mainly focused on the shape change of the final bottle (to create better shape stability), and on the other hand, various molding parameters (preformer draw ratio, heating temperature). , the pressure of blown air, and the like). The shape of the preform has not changed substantially for a long time. As mentioned, the shape comprises a hollow cylindrical body having a fixed or variable thickness, the open end of which has the final shape of the bottleneck region, Therefore, there is also a thread which is required for use in combination with the screw cap, and the closed end has a spherical shape in most cases. In order to reduce the amount of plastic material remaining in the bottom center of the bottle after completion, there are also preforms of non-spherical heads that have been proposed and partially used, especially with cones. The head of a shape, ellipse, or parabolic shape. However, while this type of preform has practical advantages in terms of molding of the preform, it can be produced by molding only a small amount of plastic melt material depending on the geometry of the preform. There is a moderate shortening effect, but they do not have a visible effect on the weight reduction in the center of the bottom of the bottle. This is because the material distribution in the bottle after the completion of -6-201139096 will not last. There is a significant difference from a bottle made from a preform having a spherical head. In a more recent year, in the applicant's European patent EP-2077934, it proposes a preform having a protruding sleek center attachment, whereby it can achieve a very significant weight reduction effect on the preform, but Performance has not changed. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improved preform of another type which has a significantly reduced weight relative to the known types of preforms currently in use, and the size of the bottle produced therefrom And the resistance characteristics remain the same, as is the case with the preforms described in European Patent EP - 2 07 7 9 3 4, but a different structural scheme that can be used more immediately to replace the traditional prefabrication. And it will only have a small offset for changes in the affected part. Another object of the present invention is to provide an improved preform that can be used in place of conventionally known preforms while not changing the draw ratio in the blow molding process. It is a further object of the present invention to provide an improved preform that achieves a weight reduction effect on the bottle body made therefrom, with a reduced focus on the central portion of the bottom of the bottle body. According to the invention, these objects are achieved by a preform which has the features defined in item 1 of the appended patent application. Other features of the preform of the present invention are defined in the 201139096 sub-item of the patent application. Other features and advantages of the present invention will become apparent from the following description of a preferred embodiment. These pure lines are provided as non-limiting examples and are shown in the accompanying drawings. [Embodiment] As can be clearly seen from the drawings, the thread and the open end 2 for covering and abutting the rib of the cap are provided in a known manner, and the long cylindrical shape of the preform body 3 In terms of the preform 1 of the present invention, it has a completely conventional structure. In fact, the innovation of the preform of the present invention is primarily in the shape of the closed end or head 4 opposite the open end 2 in the preform, which is generally hemispherical. As mentioned before, the preform head can also have a tapered, elliptical or parabolic shape, and can also have a prominent central attachment as described in European Patent EP 2 0 7 7 3 3; however, to simplify For the sake of the description, only the hemispherical head will be explained below, so this vocabulary is intended to cover all of the possible head shapes mentioned above. In fact, the head 4 has a series of depressions 5, preferably evenly distributed on the side surfaces of the head 4, corresponding to a spherical segment in the head, that is, between two mutually parallel planes. And in a region perpendicular to the axis of the preform, the recess 5 is suitably joined to the remaining side portions of the head 4 with a corresponding projection 6 facing the interior of the preform, so that the preform is at the recess 5 The thickness is substantially equal to the thickness of the preform head 4 at the remaining abutment locations. Maintaining the preform at a substantially constant thickness at the corresponding recess 5 is in fact a preferred requirement for a better performance bottle from the preform of the present invention. First, the narrower section of the preform head corresponding to the depression causes partial crystallization of the preform during the injection molding stage of the preform; secondly, the preform head having different thicknesses at different locations causes the bottle to be The bottom has an unfixed thickness; thirdly, in the preheating step of the blow molding process, the thinner portion of the preform head softens in too short a time, so the molding parameters must be adjusted to avoid Any unevenness or embarrassment in the finished bottle, especially considering the burst resistance and stress crack resistance of the finished bottle. The remaining side portions of the head 4 may have any of the previously known shapes, but preferably have a hemispherical shape. The shape of the recess 5 is small and small, and is not particularly limited as long as there is no substantial thickness variation of the preform corresponding to the recess, and the most prominent portion of the projection 6 toward the inside of the head 4 can A large enough central space is left for the preform stretching rod (not shown) to pass at the beginning of the molding phase. In the various embodiments shown in cross-section, they have recesses 5 having a concave shape (Fig. 2A), a straight shape (Fig. 2B), and a biconvex shape (Fig. 2C). Other shapes are of course also possible. For example, combinations of various curved surfaces in the foregoing may, of course, also greatly change the height of the spherical portion in which the recess 5 is provided, and may extend to occupy the entire head 4. In other words, one side of the recess 5 may extend to the top end of the head 4, and the other side extends to the circumference connecting the head 4 and the cylindrical body 3. Within the aforementioned range of variation, the 'size and shape' and the number of depressions -9 - 201139096 can be varied arbitrarily according to the desired result, for example, in order to concentrate the weight loss of the preform on the bottle body made of the preform. The bottom central region, or for other purposes that may be useful or convenient for the individual or for various applications, due to the particular shape of the preform of the present invention, it is possible to obtain a preform having a known thickness and height compared to the same preform. The extraordinary result of the greatly reduced weight is due to the fact that at each point of the head 4, the area affected by the recess 5 is spread along the inner periphery and is therefore shorter than the corresponding spherical surface. Therefore, the overall surface of the preform of the present invention clearly has a smaller expanded area than a conventional preform having a full spherical head and the same height. Further, such extraordinary results can be achieved at one point without changing the other structures of the preform, especially the axial stretch ratio 値 because the stretch rod can pass directly through the projections 6 until it touches the prefabrication The internal apex of the piece, so that the elongation of the preform of the invention can be set to be the same as that of a conventional preform having a spherical head of the same height. Therefore, the preform of the present invention can replace the conventional preform without requiring a new check of the blow molding process, also because the hemispherical region of the head 4 between the adjacent recesses 5 is a connection to The mesh structure on the lower cylindrical body 3, so that they can transfer the stretching action caused by the stretching rod in a manner substantially equivalent to that occurring in the conventional preform, so that it can be carried out in a simple and straightforward manner The first and second objects of the present invention can be achieved by achieving a significant reduction in the weight of the preform and the finished bottle. -10- 201139096 Furthermore, by appropriately adjusting the size parameter 'shape and number of the recess 5', it is also possible to concentrate the weight reduction on the center of the bottom of the bottle obtained by blow molding the preform. Therefore, it is possible to achieve the third object of the invention. As previously mentioned, the head of the preform of the present invention can also be used in conjunction with the sleek center attachment described in European Patent EP-2077 93 4, so that a more significant weight reduction can be achieved on the preform. The foregoing has been described in connection with a preferred embodiment of the present invention, but it is apparent that many other embodiments that utilize the principles of the present invention are different. Therefore, the present invention should in no way be limited by the structure of the described embodiments, which can be limited only by the definition of the invention provided by the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic side elevational view of an improved preform according to one of the present inventions. 2A, 2B, and 2C are partial cross-sectional views of various embodiments of preforms in accordance with the present invention. [Description of main component symbols] 1 : Prefabricated parts 2 : Open end 3 : Main body 4 : Head -11 - 201139096 5 : Depression 6 : Protruding part