200848332 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種包裝盒，尤其係關於用於運送玻璃 基板之包裝盒。 【先前技術】 玻璃是一種脆性材料，當受到外力碰撞或是掉落地面 時，很容易破裂以致於不能使用。而在製作液晶顯示面板 的過程中，彩色濾光片基板及薄膜電晶體基板的運送問題 至關重要。對於液晶顯示面板的製作過程而言，在上述基 板的運送過程中，其易受化學污染，且當基板與其他包裝 物摩擦時，極易因靜電造成彩色濾光片基板及薄膜電晶體 基板表面電路或者元器件受損。 先前技術之玻璃基板運送主要是將玻璃基板放置在包 裝盒中以運送。請參閱圖1，係先前技術一種玻璃基板之包 裝構造立體分解示意圖。該包裝構造10包括一包裝盒100、 一抗靜電薄膜200及一玻璃基板疊合體300。該抗靜電薄膜 200包設於該玻璃基板疊合體300外侧，並與該玻璃基板疊 合體300—起收容於該包裝盒100内。 該包裝盒100係採用發泡倍率為3-30倍之樹脂發泡材 料製成。該包裝盒100包括一盒體120及一蓋體140，該盒體 120與該蓋體140相互嵌套配合，形成一收容該抗靜電薄膜 200及該玻璃基板疊合體300之收容空間（未標示）。 該抗靜電薄膜200係一種採用高密度聚乙烯樹脂材料 與靜電防止性物質摻雜製得之具抗靜電功能之膜片。該抗 7 200848332 靜電薄膜200具有四個彎折區域210、一主區域220及彎折輪 -廓線230。該主區域220之輪廓與該盒體120之底部輪廓相匹 .配，該彎折區域210可以沿該彎折輪廓線230自由彎折。 該玻璃基板疊合體300係由複數平面玻璃基板310疊置 而成，每一平面玻璃基板310均係尺寸大小一致之矩形平 板。 再請參閱圖2，係該玻璃基板疊合體300收容於該包裝 盒100之盒體120之立體示意圖。當該玻璃基板疊合體300 f 收容於該包裝盒100之盒體120與蓋體140形成之收容空間 内時，該抗靜電薄膜200對應夾設於該盒體120與該玻璃基 板疊合體300之間。 當利用該包裝盒100對該玻璃基板疊合體300進行包裝 時，係採用如下步驟進行包裝： 首先，將該複數平面玻璃基板310依次層疊設置，形成 一玻璃基板疊合體300 ; 接著，將該抗靜電薄膜200對應鋪設於該盒體120之收 ' 容空間内，使得該抗靜電薄膜200之主區域220貼附於該收 容空間之底面，其彎折區域210對應貼附於該收容空間之侧 面； 然後，將該玻璃基板疊合體300收容於該盒體120之收 容空間内，並使得該玻璃基板疊合體300與該盒體120藉由 該抗靜電薄膜200間隔； 最後，蓋合該蓋體140以運送。 在該包裝盒100包裝玻璃基板疊合體300之包裝構造10 8 200848332 中，由於該包裝盒100之盒體120係由樹脂發泡材料所製 ，成，雖然該結構具有緩衝性能佳、重量輕之優點，但仍然 .具有以下缺點： 首先，製得該盒體120之内層與外層發泡材料之發泡倍 率一致，所以該包裝盒100之整體發泡倍率不能太高或者太 低，如果其發泡倍率太高雖然該包裝盒100具較佳之緩衝性 能，但是其承載強度則降低；相反，如果其發泡倍率太低， 雖然滿足對該包裝盒100之強度要求，卻往往不能滿足緩衝 ’ 性能之要求，所以採用該包裝盒100對該玻璃基板疊合體 300進行包裝運送，勢必會因不能兼顧滿足運送過程中的承 載強度與緩衝性能之要求而影響玻璃基板疊合體300運送 過程中的安全可靠性。 其次，採用該種包裝方式，由於該包裝盒100不具抗靜 電性能，故需要增加該抗靜電薄膜200將該包裝盒100之盒 體120與該玻璃基板疊合體300間隔開來，避免該玻璃基板 疊合體300與該包裝盒120接觸摩擦導致靜電累積造成對玻 λ 璃基板之破壞，如：因靜電釋放導致薄膜電晶體基板邊緣 表面之金屬線斷路，從而降低玻璃基板疊合體300運送過程 中的安全可靠性。 另外，因為在包裝過程中需要單獨提供抗靜電薄膜 200,並將該抗靜電薄膜200鋪設於該盒體120内，故增加 包裝成本及包裝工序，造成包裝之不放便。 【發明内容】 有鑑於上述内容，有必要提供一種玻璃基板運送過程 9 200848332 中之安全可靠性高、包裝方便且成本低之用於運送玻璃基 板之包裝盒。 . 一種用於運送玻璃基板之包裝盒，其包括一盒體，該 盒體包括一外層緩衝材及一内層缓衝材，該外層緩衝材位 於該内層緩衝材外側，該内層緩衝材圍成一收容空間，其 中該内層緩衝材之發泡倍率大於該外層緩衝材之發泡倍 率，且該内層緩衝材摻雜有靜電防止性物質。 相較於先前技術，於上述用於運送玻璃基板之包裝盒 中，設置該盒體之内層缓衝材之發泡倍率大於該外層緩衝 材之發泡倍率，使得該外層緩衝材具高承載強度以滿足承 載複數玻璃基板疊合形成之玻璃基板疊合體之需求，該内 層缓衝材具高發泡倍率，使得該包裝盒能夠有效缓衝外力 作用造成對該玻璃基板疊合體之衝擊，提高其缓衝性能， 保證玻璃基板運送過程之安全可靠性。另，通過一定摻雜 工藝使得該内層緩衝材具抗靜電特性，減少使用單獨的抗 靜電薄膜來滿足該包裝盒之抗靜電需求，不但有效避免靜 電累積造成對該玻璃基板疊合體之破壞，而且減少包裝元 件，方便包裝，進而降低包裝成本。 【實施方式】 請參閱圖3,係本發明用於運送玻璃基板之包裝盒之一 種較佳實施方式之立體分解示意圖。該包裝盒40包括一盒 體42及一蓋體44，且該盒體42與該蓋體44相互嵌套配合形 成一收容空間（未標示），該收容空間用以收容待運送之玻 璃基板。 200848332 該盒體42包括一外層緩衝材422及一内層緩衝材424。 、該外層緩衝材422位於該盒體42之外側，該内層緩衝材424 _位於該盒體42之内側，且該外層緩衝材422與該内層缓衝材 424均係由四個首位相接之側壁配合一底壁圍成，該内層緩 衝材424高於該外層緩衝材422,同時該内層緩衝材424還圍 成一矩形無蓋收容空間（未標示）。 該盒體42係採用樹脂發泡材料通過雙料射出工藝製得 之具緩衝性能包裝材料，如作為聚烯烃系發泡體之高密度 聚乙烯、聚丙烯、低密度聚乙烯、乙烯-乙酸乙烯酯共聚合 物等。在雙料射出工藝中，其中該外層缓衝材422係採用低 倍率原材或者回收之二次樹脂發泡材料射出，並控制其發 泡倍率介於3〜15倍之間，其電阻系數介於103〜109Ω·ογπ 之間；該内層緩衝材424係採用高倍率樹脂發泡材料摻雜靜 電防止性物質射出，並控制其發泡倍率介於15〜30倍之 間，其電阻系數介於1〇9〜1〇12Ωχιη之間。如此獲得該外層 缓衝材422與該内層缓衝材424 —體成型之盒體42,且該内 〜層缓衝材424之發泡倍率大於該外層緩衝材422之發泡倍 率，該内層緩衝材424具抗靜電性能。 該蓋體44同樣係採用樹脂發泡材料製得之包裝材料， 其蓋合於該盒體42之上，並與該盒體42相互嵌套配合圍成 一封閉收容空間（圖未示）。 再請參閱圖4,係採用該包裝盒40包裝玻璃基板之包裝 構造之立體分解示意圖。該玻璃基板包裝構造50包括一包 裝盒40(請參閱圖3)及一玻璃基板疊合體60。該玻璃基板疊 11 200848332 合體60收容於該包裝盒40之收容空間内。 . 該玻璃基板疊合體60係由複數玻璃基板62配合複數間 隔緩衝材64層疊設置而成。該玻璃基板62可以為液晶顯示 面板、電聚顯不用玻璃基板及一般玻璃基板，同時逛可以 用來運送背光板、彩色濾光片基板及薄膜電晶體基板等。 取該玻璃基板62為薄膜電晶體基板為例，在該玻璃基板6 2 的邊緣區域通常設置有薄膜電晶體引腳、積體電路晶片及 軟性電路板等重要元件，在運送過程中，需要避免受到外 " 力撞擊以及相互摩擦造成對上述重要元件的損壞。 該間隔緩衝材64輪廓大小與該玻璃基板62之大小基本 相匹配，形狀可以為平板形或者框形，且該間隔緩衝材64 與該玻璃基板62相接觸的表面具有空氣可流通之凹凸圖 案，同時，該間隔緩衝材64具有一定彈性，起到緩衝外力 衝擊作用。 考慮運送過程中貨櫃之重量及搬運方便性，通常將十 片至三十片玻璃基板62配合間隔緩衝材64層疊設置為一疊 〜合體60。當玻璃基板62與該間隔緩衝材64層疊時，該間隔 緩衝材64與該玻璃基板62彼此交錯層疊，每一玻璃基板62 夾設於二相鄰間隔缓衝材64之間，且該玻璃基板疊合體60 最外層係間隔緩衝材64。 在該玻璃基板包裝構造50中，藉由該内層緩衝材424 之發泡倍率大於該外層緩衝材4 2 2之發泡倍率，使得與該玻 璃基板疊合體60相接觸之内層緩衝材424具較佳之緩衝性 能，當在運送過程中遇到外力撞擊或者震動時，該内層緩 12 200848332 衝材424能夠有效緩衝該外力衝擊，避免造成對玻璃基板62 .之損壞。而該外層緩衝材422因發泡倍率較小，即其密度大 _於内層緩衝材424之密度，故其具較強之承載能力，能夠有 效承載一定數量之玻璃基板62，提高該玻璃基板62在運送 過程中之安全可靠性。 另，因為該内層缓衝材424係採用摻雜靜電防止性物質 製得，故當該玻璃基板疊合體60收容於該盒體42時，與該 玻璃基板疊合體60直接接觸之内層缓衝材424能夠有效避 ， 免該玻璃基板疊合體60與該盒體42之内層缓衝材424因摩 擦產生靜電，破壞玻璃基板62之性能。 木较於先前技術，在該實施方式中，採用該包裝盒40 對玻璃V板62進行包裝運送，藉由該内層緩衝材424之缓衝 性能及抗靜電特性有效提高該玻璃基板62在運送過程中之 安全可靠性。 採用該包裝盒40包裝該玻璃基板疊合體60之步驟為： 首先，提供該包裝盒40之盒體42 ; ^ 然後，將該間隔緩衝材64及該玻璃基板62交叉層疊放 置獲得一玻璃基板疊合體60,其中該玻璃基板疊合體60之 最外層為間隔缓衝材64 ; 接著，將該玻璃基板疊合體60收容於該盒體42内； 最後，將該蓋體44蓋合於該盒體42上，並使得該玻璃 基板疊合體60之最上層間隔緩衝材64抵接於該蓋體44頂部 内表面。當玻璃基板62不滿時，通過填加其他填充物補充 來避免包裝盒40之鬆動。 13 200848332 相較於先前技術，採用該包裝盒40包裝該玻璃基板疊 .合體60時，可以直接將該玻璃基板疊合體6〇置放於該包穿 .盒40之盒體42内，而不必另外單獨鋪設抗靜電薄膜 體42内以分隔該玻璃基板疊合體6〇與該盒體“，減少包= 元件，方便包裝的同時，降低了包裝成本。 0衣 綜上所述，本發明確已符合發明專利之要 A 、 ^ Hi. 如出專利申請。惟，以上所述者僅為本發明之較佳實施例， 本發明之範圍並不以上述實施例為限，舉凡熟習本突技蓺 之人士援依本發明之精神所作之等效修飾或變比巧 .. ’皆應涵 風於以下申請專利範圍内。 14 200848332 【圖式簡單說明】 .圖1係一種先前技術之玻璃基板包裝構造立體分解示意 圖。 圖2係圖1所示玻璃基板疊合體收容於包裝盒之立體示意 圖。 圖3係本發明一種較佳實施方式玻璃基板包裝盒之立體分 解示意圖。 圖4係採用圖3所示包裝盒包裝玻璃基板之立體分解示意 ' 圖。 【主要元件符號說明】 包裝盒 40 玻璃基板包裝構造 50 盒體 42 玻璃基板疊合體 60 外層缓衝材 422 玻璃基板 62 内層緩衝材 424 間隔緩衝材 64 蓋體 44 15200848332 IX. Description of the Invention: [Technical Field] The present invention relates to a package, and more particularly to a package for transporting a glass substrate. [Prior Art] Glass is a brittle material that is easily broken so that it cannot be used when it is hit by an external force or dropped to the ground. In the process of fabricating a liquid crystal display panel, the problem of transporting the color filter substrate and the thin film transistor substrate is critical. For the manufacturing process of the liquid crystal display panel, during the transportation of the above substrate, it is susceptible to chemical contamination, and when the substrate is rubbed with other packages, the color filter substrate and the surface of the thin film transistor substrate are easily caused by static electricity. The circuit or component is damaged. The prior art glass substrate transport is primarily by placing the glass substrate in a package for shipping. Referring to FIG. 1, a perspective exploded view of a packaging structure of a glass substrate according to the prior art. The package construction 10 includes a package 100, an antistatic film 200, and a glass substrate laminate 300. The antistatic film 200 is disposed outside the glass substrate laminate 300, and is housed in the package 100 together with the glass substrate laminate 300. The package 100 is made of a resin foamed material having a foaming ratio of 3 to 30 times. The package 100 includes a box body 120 and a cover body 140. The box body 120 and the cover body 140 are nested with each other to form a receiving space for receiving the antistatic film 200 and the glass substrate stack body 300 (not labeled) ). The antistatic film 200 is a film having an antistatic function prepared by doping a high-density polyethylene resin material and an antistatic substance. The anti- 7 200848332 electrostatic film 200 has four bending regions 210, a main region 220, and a bending wheel-profile 230. The contour of the main area 220 is matched to the bottom contour of the casing 120. The bending area 210 can be freely bent along the bending contour 230. The glass substrate laminate 300 is formed by stacking a plurality of planar glass substrates 310, and each of the flat glass substrates 310 is a rectangular plate having a uniform size. Referring to FIG. 2, a perspective view of the glass substrate stack 300 housed in the casing 120 of the package 100 is shown. When the glass substrate assembly 300 f is received in the housing 120 formed by the casing 120 and the cover 140 of the package 100, the antistatic film 200 is correspondingly disposed between the casing 120 and the glass substrate assembly 300. between. When the glass substrate laminate 300 is packaged by the package 100, the packaging is performed by the following steps: First, the plurality of planar glass substrates 310 are sequentially laminated to form a glass substrate laminate 300; The electrostatic film 200 is disposed in the receiving space of the casing 120, so that the main area 220 of the antistatic film 200 is attached to the bottom surface of the receiving space, and the bending area 210 is attached to the side of the receiving space. Then, the glass substrate laminate 300 is received in the receiving space of the casing 120, and the glass substrate laminate 300 and the casing 120 are separated by the antistatic film 200; finally, the cover is covered. 140 to ship. In the packaging structure 10 8 200848332 of the package 100 for packaging the glass substrate stack 300, since the case 120 of the package 100 is made of a resin foam material, although the structure has good cushioning performance and light weight Advantages, but still have the following disadvantages: First, the inner layer of the casing 120 is made to have the same expansion ratio as the outer layer foaming material, so that the overall expansion ratio of the package 100 cannot be too high or too low, if it is The bubble ratio is too high. Although the package 100 has better cushioning properties, its load-bearing strength is lowered. On the contrary, if the expansion ratio is too low, although the strength requirement for the package 100 is satisfied, the cushioning performance is often not satisfied. Therefore, the packaging of the glass substrate stack 300 by the package 100 is inevitably affected by the inability to meet the requirements of bearing strength and cushioning performance during transportation, and the glass substrate stack 300 is safely and reliably transported. Sex. Secondly, in the packaging method, since the package 100 does not have antistatic properties, the antistatic film 200 needs to be added to space the box 120 of the package 100 from the glass substrate stack 300 to avoid the glass substrate. The friction between the laminated body 300 and the package 120 causes electrostatic accumulation to cause damage to the glass substrate, such as: the metal wire of the edge surface of the thin film transistor substrate is broken due to electrostatic discharge, thereby reducing the transportation process of the glass substrate laminate 300. Safety and reliability. In addition, since the antistatic film 200 needs to be separately provided in the packaging process and the antistatic film 200 is placed in the casing 120, the packaging cost and the packaging process are increased, resulting in uncomfortable packaging. SUMMARY OF THE INVENTION In view of the above, it is necessary to provide a packaging box for transporting a glass substrate with high safety and reliability, convenient packaging, and low cost in the glass substrate transportation process 9 200848332. A package for transporting a glass substrate, comprising a box body, the box body comprising an outer cushioning material and an inner cushioning material, the outer cushioning material is located outside the inner cushioning material, and the inner cushioning material is enclosed The accommodating space, wherein an expansion ratio of the inner cushioning material is larger than an expansion ratio of the outer cushioning material, and the inner cushioning material is doped with a static electricity preventing substance. Compared with the prior art, in the above package for transporting a glass substrate, the expansion ratio of the inner cushioning material of the casing is set to be larger than the expansion ratio of the outer cushioning material, so that the outer cushioning material has high bearing strength. To meet the demand of the glass substrate stack formed by stacking a plurality of glass substrates, the inner buffer material has a high expansion ratio, so that the package can effectively buffer the impact of the external force on the laminated body of the glass substrate, and improve the slowness thereof. Punching performance, ensuring the safety and reliability of the glass substrate transportation process. In addition, the inner layer buffer material has antistatic property by a certain doping process, and the use of a separate antistatic film to meet the antistatic requirement of the package is not only effective to avoid the accumulation of static electricity, but also the destruction of the glass substrate laminate. Reduce packaging components, facilitate packaging, and reduce packaging costs. [Embodiment] Please refer to Fig. 3, which is a perspective exploded view of a preferred embodiment of a package for transporting a glass substrate of the present invention. The package 40 includes a box body 42 and a cover body 44. The box body 42 and the cover body 44 are nested with each other to form a receiving space (not shown) for receiving the glass substrate to be transported. 200848332 The casing 42 includes an outer cushioning material 422 and an inner cushioning material 424. The outer cushioning material 422 is located on the outer side of the casing 42. The inner cushioning material 424_ is located inside the casing 42, and the outer cushioning material 422 and the inner cushioning material 424 are connected by four first positions. The side wall is surrounded by a bottom wall, and the inner cushioning material 424 is higher than the outer cushioning material 422, and the inner cushioning material 424 is also enclosed by a rectangular uncovered receiving space (not shown). The box body 42 is a cushioning performance packaging material obtained by a two-shot injection process using a resin foaming material, such as high density polyethylene, polypropylene, low density polyethylene, ethylene vinyl acetate as a polyolefin foam. Copolymers, etc. In the two-material injection process, the outer cushioning material 422 is sprayed with a low-magnification raw material or a recycled secondary resin foaming material, and the expansion ratio is controlled to be between 3 and 15 times, and the resistivity thereof is between 103 to 109 Ω·ογπ; the inner buffer material 424 is made of a high-rate resin foaming material doped with an antistatic substance, and the expansion ratio is controlled to be between 15 and 30 times, and the resistivity is between 1 and 〇9~1〇12Ωχιη between. Thus, the outer cushioning material 422 and the inner cushioning material 424 are integrally formed, and the foaming ratio of the inner buffering material 424 is greater than the foaming magnification of the outer cushioning material 422. Material 424 has antistatic properties. The cover 44 is also made of a resin foamed material, which is covered on the casing 42 and nested with the casing 42 to form a closed receiving space (not shown). Referring to Fig. 4, a perspective exploded view of the packaging structure of the glass substrate packaged by the package 40 is shown. The glass substrate package construction 50 includes a package 40 (see Fig. 3) and a glass substrate stack 60. The glass substrate stack 11 200848332 is integrated into the housing space of the package 40. The glass substrate laminate 60 is formed by laminating a plurality of glass substrates 62 in combination with a plurality of spacer buffer members 64. The glass substrate 62 can be a liquid crystal display panel, a non-glass substrate and a general glass substrate, and can be used to transport a backlight panel, a color filter substrate, a thin film transistor substrate, and the like. Taking the glass substrate 62 as an example of a thin film transistor substrate, important elements such as a thin film transistor lead, an integrated circuit chip, and a flexible circuit board are usually provided in the edge region of the glass substrate 62, and it is necessary to avoid during transportation. Damage to the above important components caused by external "force impact and mutual friction. The size of the spacer buffer material 64 is substantially matched with the size of the glass substrate 62, and the shape may be a flat plate shape or a frame shape, and the surface of the spacer buffer material 64 in contact with the glass substrate 62 has an air permeable concave and convex pattern. At the same time, the spacer cushioning material 64 has a certain elasticity and functions to cushion external force. In consideration of the weight of the container during transportation and the ease of handling, ten to thirty glass substrates 62 are generally laminated with the spacer buffer 64 as a stack-to-body 60. When the glass substrate 62 and the spacer buffer 64 are stacked, the spacer buffer 64 and the glass substrate 62 are alternately stacked with each other, and each of the glass substrates 62 is sandwiched between two adjacent spacer buffers 64, and the glass substrate is The outermost layer of the laminate 60 is a spacer buffer 64. In the glass substrate packaging structure 50, the inner layer cushioning material 424 is in contact with the inner layer cushioning material 60 by the expansion ratio of the inner layer cushioning material 424 being larger than the expansion ratio of the outer cushioning material 42. The cushioning performance is good. When an external force is struck or vibrated during transportation, the inner layer is slowed down. 200848332 The punching material 424 can effectively buffer the external force and avoid damage to the glass substrate 62. The outer cushioning material 422 has a small expansion ratio, that is, its density is greater than the density of the inner cushioning material 424, so that it has a strong carrying capacity, can effectively carry a certain number of glass substrates 62, and enhance the glass substrate 62. Safety and reliability during transportation. In addition, since the inner buffer material 424 is made of a doping antistatic material, when the glass substrate laminate 60 is housed in the case 42, the inner layer buffer material directly in contact with the glass substrate laminate 60 424 can effectively avoid the static electricity generated by the glass substrate laminate 60 and the inner buffer material 424 of the casing 42 from being rubbed by friction, thereby deteriorating the performance of the glass substrate 62. Compared with the prior art, in the embodiment, the glass V plate 62 is packaged and transported by the package 40, and the cushioning property and the antistatic property of the inner cushioning material 424 effectively improve the glass substrate 62 during transportation. Safety and reliability. The step of packaging the glass substrate laminate 60 by the package 40 is as follows: First, the casing 42 of the package 40 is provided; ^ Then, the spacer buffer 64 and the glass substrate 62 are stacked to form a glass substrate stack. The cover 60, wherein the outermost layer of the glass substrate stack 60 is a spacer buffer 64; then, the glass substrate stack 60 is received in the case 42; finally, the cover 44 is closed to the case 42, and the uppermost layer cushioning material 64 of the glass substrate laminate 60 is brought into contact with the top inner surface of the lid body 44. When the glass substrate 62 is not full, the packing 40 is prevented from being loosened by the addition of other fillers. 13 200848332 Compared with the prior art, when the glass substrate stack 60 is packaged by the package 40, the glass substrate laminate 6 can be directly placed in the box 42 of the package 40 without In addition, the antistatic film body 42 is separately laid to separate the glass substrate laminate 6〇 and the box “to reduce the package=component, and the packaging is convenient, and the packaging cost is reduced. The present invention has indeed been described. The patent application is in accordance with the invention patents A and ^ Hi. However, the above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above embodiments, and is familiar with the prior art. The equivalent modification or variation of the person in accordance with the spirit of the present invention is as follows: 'All should be within the scope of the following patent application. 14 200848332 [Simple description of the drawings] Figure 1 is a prior art glass substrate package Fig. 2 is a perspective view showing the glass substrate stack shown in Fig. 1 in a package. Fig. 3 is a perspective exploded view of a glass substrate package according to a preferred embodiment of the present invention. The three-dimensional exploded schematic view of the packaging glass substrate is shown in Fig. 3. [Main component symbol description] Package 40 Glass substrate packaging structure 50 Box 42 Glass substrate laminate 60 Outer cushioning material 422 Glass substrate 62 Inner cushioning material 424 spacer buffer material 64 cover 44 15