无碱玻纤胎基的应用研究.doc

无碱玻纤胎基的应用研究

美国佳斯迈威公司 Ruben G. Garcia

早在二十世纪九十年代初期，中国就已经开始了以新型防水材料替代传统油毛毡的进程。 在过去的十余年间， 中国市场上先后出现了各种不同的沥青屋面防水材料，其中一些重要应用的产品与国外的同类产品极其相似。 但与其它成熟市场或新兴市场相比，中国防水材料更新进程的一个比较明显的不同点在于以玻纤毡为胎基的品质防水卷材之用量甚低。直到最近，这种情况才开始有所转变。
过去十余年间，中国在沥青瓦和防水卷材生产中开始大量采用玻纤毡，目睹中国防水行业的飞速发展，作为一个见证人， 我应中国防水材料协会的邀请撰写并发表本论文，对此我深感荣幸。同时， 我也愿借此机会，与广大的中国同行分享我过去二十年间在北美地区屋面防水行业的研究成果和工作经验，并将其视为我的责任和义务。
正如大家所知， 在广阔的全球沥青防水卷材市场上，品质优异的无碱玻纤毡（E-glass Mat）被一致公认为是生产优质沥青屋面防水材料的最合适、也是最经济的胎基材料。无碱玻纤毡（E-glass Mat）以其良好的加工性能、防水性能和杰出的性价比，奠定了其作为纸胎替代用材的牢固地位。
那么， 什么是无碱玻纤毡（E-glass Mat）？ 它采用什么材料制成？ 又有哪些性能？ 它与有机毡有什么区别？ 与中碱玻纤毡（Ｃ-glass Mat）或高碱玻纤毡（Ａ-glass Mat）又有什么区别？ 这些性能上的差异对于采用不同胎基生产的沥青屋面防水材料有什么影响？无碱玻纤毡（E-glass Mat）的用途到底是什么？ 在回答这些问题之前， 一方面让我们来简朴回顾一下世界屋面防水工业的发展历程和现状。
一、世界屋面防水工业——历史与现状
在世界各地， 人们为了保护建筑物自身和建筑物内的设施免遭破坏，习惯于采用各种屋面防水材料作为防水保护层。在长达一百五十年的时间里，从将沥青涂在纸胎上防水， 一直发展到今天， 耐久性更好的玻纤毡和聚酯毡与SBS或APP改性沥青结合，构成了性能更为先进的优质防水材料。
在开始阶段的很长一段时间内， 人们使用品有各类纤维素的有机毡来制作沥青屋面防水材料。 这种成本低廉的替代产品重要由打坏的木料和纸毡构成。 最早的时候，还具有打坏的“旧布”， 这也是破布毡这一名称的由来。后来，重要采用纸质材料。 今天，虽然在屋面防水材料、衬垫材料和沥青瓦中仍可不时发现有机毡的踪迹，但毕竟已成昨日黄花。玻纤毡和聚酯毡材料正以其经久耐用的显著优点迅速取代并占领传统的屋面防水材料市场。
人们对于更优越生活品质的追求呼唤优质的居住环境，这不仅对屋面防水材料的耐久性提出了更高的规定，同时也对沥青防水材料的防水性能寄寓了更大的希望。此外， 为了保护人们享受优质居住环境的权利，在今天，广泛采用的沥青屋面系统不再仅仅是为了满足建筑物和屋内设施的防水需要， 同时也要满足本地建筑标准的需要。此类标准都规定成品材料有足够的强度以便抵御房屋形变、火灾、风暴和冰雹等灾害的侵袭。许多沥青屋面防水材料都采用品有防水性能的改性沥青涂层，无论是在卷材生产制造过程中，还是在现场直接铺设应用过程中，玻纤毡或聚酯毡都要与这类较粘稠的涂盖料结合。
二、无碱玻纤毡（E-glass Mat）——制作原料
玻璃纤维最早于1935年出现在美国。 1942年， 玻璃纤维初次使用于航天领域。 今天， 玻璃纤维的用途得到了极大的拓展，从玻璃钢到沥青屋面防水材料，直至电池隔板和石膏纤维材料等等，不一而足。从世界范围来说， 在屋面防水材料中，无碱玻纤是最常见的玻璃纤维成分。这种玻璃是一种“铝-钙硼硅酸盐玻璃”， 就其成分而言，其碱性物质(Na2O, K2O, Li2O)的含量最高仅达2%。在某些规定具有良好强度和电阻性能的场合，通常用无碱玻纤。
1、玻璃纤维、玻纤毡和沥青屋面防水材料的制造
就制造工艺而言， 一方面， 运用熔化工艺将一定配方的原材料熔化成性状均一的熔融玻璃，然后使熔融玻璃液通过细小的抽丝孔，形成我们所见到的玻璃纤维。 当熔融状的纤维流出抽丝孔时，急速冷却并切断（参见图1），供生产玻纤毡用。
通过切断的玻璃纤维用作湿法生产玻纤毡的原材料（参见图2）。 在生产玻纤毡时， 先在切断的玻璃纤维中加入各类粘接剂，充足拌和成网， 然后将混和有粘接剂的玻璃纤维网送入烘房干燥。通过烘房干燥工艺，粘接剂被加热并粘结纤维。 图1 切断的玻璃纤维

图2 玻纤毡的生产

然后， 将加工好的玻纤毡送往防水材料厂涂覆各类沥青，制成屋面防水材料（图3所示为典型生产工艺）。
图3 SBS/APP改性沥青卷材典型生产工艺
2、无碱玻璃（E-Glass）、中碱玻璃(C-Glass)和高碱玻璃(A-Glass)之间的差异
除了上面介绍的“铝-钙硼硅酸盐玻璃（无碱玻璃）”之外， 在玻纤毡生产工艺中所使用的其它玻璃尚有“钙硼硅酸盐玻璃（中碱玻璃）”和“碳酸硅酸盐玻璃（高碱玻璃）”
Table 1 – Fiber Glass Properties Check
表1 玻璃纤维的性能比较

A- Glass
C-Glass
E- Glass
Oxide 氧化物:
%
%
%
SiO2
63-72
64-68
52-56
Al2O3
0-6
3-5
12-16
B2O3
0-6
4-6
5-10
MgO
0-4
2-4
0-5
Tensile Strength 拉伸强度(@ 23C, MPa)
3310
3310
3445
Durability 耐久性 (% Weight Loss in Water at 166hrs) 166h下水重量损失
4.7
2.9
0.9
各种工业产品都极其强调材料性能和指标。所以，在比较多种工业产品时都免不了要比较它们的材料成分、物理特性、下道工序的加工性能以及实际使用过程中的应用特点。 同样地， 在比较无碱玻璃、中碱玻璃和高碱玻璃时， 我们也需要从上述这些方面来进行比较。
戴维R哈特曼在《 玻璃研究——卷5第一册，1995》刊物上发表了“高强度玻璃的演化与应用”一文。 表1所示各类数据即引自该文。 它比较了三种玻璃的氧化物含量、拉伸强度以及耐水性能。 而表2数据引自《玻璃纤维，Auburg & Wolf》一文，它介绍了各种氧化物对玻璃制品物理特性和应用特性的影响。

表2所示各种资料从材料科学的角度解释了导致高碱玻璃和中碱玻璃耐久性差的因素。正是由于高碱玻璃和中碱玻璃的耐久性差，使得用高碱玻璃和中碱玻璃制成的玻纤毡也表现为耐久性差——特别是当玻纤毡暴露于潮湿和/或酸性环境中时。
3、玻纤毡与有机毡之间的差异
在对玻纤毡和有机毡进行比较时， 可以对照美国ＡＳＴＭ标准中列出的各种产品比较它们的具体标准。表3给出了不同胎基的ASTM标准数据以及其他性能指标。
Table 3 Organic Felts and Fiber Glass Felts
表3 有机毡和玻纤毡

Organic Felts有机毡
(ASTM D 226)
Glass Mat玻纤毡
(ASTM D 2178)
Average Breaking Strength
平均断裂强度 Lbf/in (kN/m)
- Machine Direction纵向
- Cross Direction横向

30-40 (5.35-7.00)
15-20 (2.63-3.50)

44-60 (7.7-10.5)
44-60 (7.7-10.5)
Ash Content 灰分含量
10%
70-88%
Loss on Heating @105C
105℃下加热时的损失
4%
<1%
由于无碱玻纤毡具有良好的加工性能、防水性能以及优越的性价比，所以在世界各地的各大屋面防水材料市场上都成了替代纸胎的首选材料。
三、沥青瓦和改性沥青防水材料中所使用的无碱玻纤毡——应用一瞥
推动沥青防水材料胎基进一步发展的真正动力来自于世界各地的地方标准。 这些标准都无一例外地规定成品防水材料具有更长的保质期、更好的防火、防风、防水以及抗紫外线性能。
无论是坡面屋顶还是平面屋顶，随着时间的推移， 不仅胎基材料已经逐渐改用更加经久耐用的玻璃纤维毡和聚酯毡，沥青涂层材料也发生了变化。这种以沥青为基本材料的涂层是沥青与SBS或APP的混合体， 内含防火剂、紫外线稳定剂和/或填充料。 这些涂层材料可以满足最终屋面系统对当今建筑环境的必要防护规定。

1、 坡面屋顶
无碱玻璃纤维毡几乎是沥青瓦的首选胎基。沥青瓦不仅规定强度高、经久耐用，并且规定具有一定的硬挺度，以保证屋面轮廓挺括美观，又便于安装施工。
三片式沥青瓦（参见图4）是屋面材料行业的标准形式，在中心的玻璃纤维毡的上下两面涂沥青，表面覆盖矿物粒料，并裁成三片。

此外， 为了获得独特的三维外观效果， 可以把两层沥青瓦粘合起来，形成叠层瓦（参见图5）。 这样做尽管增长了总体重量， 但可以提高设计的灵活性，因而也被称为“建筑美”沥青瓦。

无碱玻纤毡不仅有助于展现沥青瓦的美学效果， 同时也可以提高沥青瓦在各种恶劣环境下的强度和耐久性，从而全面提高沥青瓦的综合性能。
2、平面屋顶
世界各地的地方标准都对竣工以后的屋面防护系统制订了相应的规定，这些规定又推动着防水材料胎基的创新设计。尽管无碱玻璃纤维毡不具有像聚酯毡那样好的弹性，但它良好的加工性、尺寸稳定性、各种恶劣环境下的耐久性以及杰出的材料强度都使它成为制造经济型优质屋面系统的首选材料。假如与SBS和APP改性材料结合使用，只要施工恰当， 无碱玻纤毡制成的防水卷材完全可以保护建筑物免遭漏水侵害。
四、用于生产经济、优质屋面防水材料的无碱玻璃纤维毡——前景展望
过去150年的历史证明， 人们对于民用住宅、商业用房和工业建筑物的品质、舒适和美观正在提出越来越高的规定。 对优质建筑物的规定也就是对优质屋面防水材料的规定，而追求优质的屋面防水材料， 无疑将提高沥青屋面防水材料产品中所使用胎基材料的质量规定。
全球市场的发展趋势正不断证明着这样一个事实： 在沥青屋面系统中，成本低廉的有机毡产品（例如破布毡、麻布毡、纸胎和复合胎等）正逐渐被防水性能好、使用寿命长的玻纤毡和聚酯毡产品所代替。 尽管这种替代过程在不同的市场合需时间长短不一，但就其趋势而言，已然不可逆转。
目前，中国经济一日千里，发展潮流浩浩荡荡。 中国政府推广使用优质建筑材料的决心不可动摇。 面对这一大好形势，我们完全有理由相信： 中国的防水材料市场必将是优质产品的天下。这一天， 固然不会一蹴而就，但也决非遥不可期！
注：术语
Ｅ－glass mat　无碱玻纤毡
C-glass mat中碱玻纤毡
A- glass mat高碱玻纤毡
shingle沥青瓦
rag felt纸胎
plastic reinforced　玻璃钢
roofing material屋面防水材料

发言人简介

Ruben G. Garcia
公司：佳斯迈威公司
职位：工程产品部门的六西格玛新产品负责人
教育背景：
化学工程学学士-新墨西哥州立大学，新墨西哥州，1974
化学工程学硕士-新墨西哥州立大学，新墨西哥州，1977
工商管理学硕士-丹佛大学，1982

美国SPRI成员，1990-1994任SPRI董事会成员
美国化学工程师协会会员
美国防水卷材征询协会会员
美国化学工程征询董事会成员
美国RURSI大学教员
2023年10月成为DFSS六西格玛黑带大师

E-Glass Mat --- The World’s Most Popular Economic Substrates for Quality Bitumen Roofing Products
Johns Manville Corporation Ruben G. Garcia

China started its rag felt replacement process in the early 1990s’. In the past dozen of years, different new bitumen roofing substrate materials are becoming available in the market, and the major types present are fairly similar to those of other countries’. However one remarkable difference to many other developed or emerging markets is that the participation of Glass Mat in this paper carrier substitution process is much less until very recently.
Having observed the change of the Chinese waterproofing industry in the past decade, and seeing increasing amount of glass mat products used in shingle and roofing sheets production; I felt honored to get the invitation from China Waterproofing Association to write this paper, and also felt obligated to share my 20 years experience in waterproofing industry in North America with my colleagues in China.
In many global markets, high quality E-glass Mat is unanimously chosen as the most suitable economic substrate for quality bitumen roofing product. With its excellent processibility, resistance to moisture, and positive economic position, E-Glass mat is the best choice substrate for rag felt replacement.
Before further study on “What is E-Glass mat, its materials and properties?”, “How it is compared with organic substrates or with C-Glass or A-Glass mat?”, “How these property differences in the mat will influence the bitumen sheets process based on them?”, or “What can E-Glass mat be used for?”; we will first take a quick glance at the history and status of waterproofing industry world-wide.
Ⅰ. World Waterproofing Industry – History and Status
Roofing materials are installed on buildings world-wide to provide a water-tight layer to protect the building and the occupants from damage. Over the last 150 years, these roofing materials have evolved from asphalt coatings on paper or Rag Felt carriers to today’s more durable fiber glass or polyester mats used in conjunction with SBS or APP modified bitumen systems.
For many years at the beginning, organic felts containing cellulose fibers have been used to make bitumen roofing products. These low cost substrates were made from shredded wood and felted paper. Some of the earliest organic felts also contained shredded “rags”, which gave these products the name of Rag Felt. Later on, these organic felts are made primarily from paper based products. Although, you can still find these organic felts used world–wide in roofing felts, underlayments and shingles, their use is significantly declining and they are being quickly replaced by more durable fiber glass mats and polyester mats.
The need for more durable substrates has been driven by people’s increasing demand on quality of life that requires decent quality of home, and therefore good performance of the bitumen roofing products. Furthermore, to protect the people’s right to quality living, today’s bitumen roofing systems are required not only to provide a water-tight system for the building and it’s occupants, but also to meet local building codes as well. Such code requires the strength of the finished membrane to such an extent that it will sufficiently withstand building movement, fire, wind and hail, etc.. Many bitumen roofing products are being made with water resistant modified bitumen coatings, which require substrates like fiber glass and polyester mats to be used with more viscous coatings, both in the manufacturing process and in the field application steps.
Ⅱ.E-Glass Mat – A Look on Material
Fiber glass was first developed in 1935 in U.S.. The first use for fiber glass was in 1942 in structural aerospace parts. Today, fiber glass is used in many applications, from plastic reinforcements to bitumen roofing product substrates, battery separators and gypsum fibers – just to name a few. World-wide, the most common fiber glass formulation used in roofing products is E-Glass. This glass is an “alumina-calcium-borosilicate glass” with a maximum alkali (Na2O, K2O, Li2O) content of 2% by weight. E-Glass is used as general purpose fibers where strength and high electrical resistivity are required.
1. The Making of Glass Fiber, Glass Mat and Bitumen roofing product
Fiber glass fibers are first made by a process where various raw materials are converted over to a homogeneous melt, which can then be formed into a fiber as the molten glass flows through tiny orifices. As the molten fibers flow out of the orifices, they are quickly cooled and chopped (see picture 1), for use in the formation of a fiber glass mat.
Such chopped glass fiber will then be used as raw material for producing (see picture 2) wet laid glass mat. These chopped fibers are blended with various binders to make a web. The web is then processed through a drier where the binder is heated and set onto the fiber.
The finished mat is then sent to a bitumen roofing product plant where the mat is coated with various asphalt coatings for use in roofing products (see picture 3 for typical process). Typically, the coatings used to make low slope roofing materials are either oxidized asphalt (Built-Up Roofing BUR) or a modified bitumen coating which consists of bitumen blended with either an SBS or APP polymer. The polymers in the modified bitumen products give the asphalt various flexibility, low temperature flexibility or waterproofing characteristics.
2. Difference among E-Glass, C-Glass, and A-Glass
Besides “alumina-calcium-borosilicate glass” (E-Glass), the other types of glass used in glass mat production are “calcium borosilicate glass” (C-Glass) and soda lime silicate glass (A-Glass).
Table 1 – Fiber Glass Properties Check

A- Glass
C-Glass
E- Glass
Oxide:
%
%
%
SiO2
63-72
64-68
52-56
Al2O3
0-6
3-5
12-16
B2O3
0-6
4-6
5-10
MgO
0-4
2-4
0-5
Tensile Strength (@ 23C, MPa)
3310
3310
3445
Durability (% Weight Loss in Water at 166hrs)
4.7
2.9
0.9
While comparing industrial products where material performance and properties are emphasized, we always need to compare the composition of the material, its physical property, its processibility during next step production, and its application properties during actual usage. Same applies when we try to make an objective comparison among E-Glass, C-Glass and A-Glass.
Table 1 is quoted from David R. Hartman’s “Evolution and Application of High Strength Fibers” published in the <<Glass Research – Vol5 no.1, 1995>>. It has compared the level of Oxide content in the 3 different glasses, as well as their Tensile Strength and Durability in exposure to water. While Table 2 is quoted from <<Glass Fibers Auburg & Wolf>>, and illustrates the impact of various Oxides on the physical and application properties of glass products.
The information include in Table 2 has explained, from the material science point of view, the cause of the low durability of A-Glass and C-Glass. And consequently, glass mat based on A-Glass and C-Glass will have low durability as well, especially when the mat is in exposure to water and/or acid.
3. Difference between Glass Mat and Organic Rag Felts
In trying to compare fiber glass felts to organic rag felts, the detailed comparison can be made by reviewing the various standards for each of the products as listed in ASTM. Table 3 illustrates some of the data from the various ASTM standards along with other performance criteria for roofing membranes used world-wide.

Table 3: Organic Felts and Fiber Glass Felts

Organic Felts
(ASTM D 226)
Glass Mat
(ASTM D 2178)
Average Breaking Strength Lbf/in (kN/m)
- Machine Direction
- Cross Direction

30-40 (5.35-7.00)
15-20 (2.63-3.50)

44-60 (7.7-10.5)
44-60 (7.7-10.5)
Ash Content
10%
70-88%
Loss on Heating @105C
4%
<1%

Due to its excellent processibility, resistance to moisture, and positive economic position, E-Glass mat is the best choice substrate for rag felt replacement in all major roofing markets in the world.
Ⅲ. E-Glass Mat used in Shingle and Modified Bitumen Sheets – A Look on Application
The future of bitumen roofing product substrates is being driven primarily by local codes world-wide. These codes are requiring the materials to have longer warranties, better fire and wind resistance as well as water and UV resistance of the finished water-proofing membrane.
For both slope roofs and flat roofs, not only have the bitumen roofing products’ substrates changed over time to the more durable fiber glass and polyester mats, so have the coatings that are used to coat the substrates. These bitumen based coatings are blends of bitumens with SBS or APP polymers along with fire retardants, UV stabilizers and fillers. These coatings will provide the necessary protections the final roofing system is demanding of today’s construction environment.
1. Slope Roofs
E-Glass mat is almost the best choice for shingle products, which require not only good strength and durability, but also a certain level of stiffness which will provide good visual aesthetics and ease at installation.
Three-tab shingles (see picture 4) are the roofing industry's standard, consisting of two layers of asphalt around a glass fibers mat core covered with ceramic mineral granules, notched into three integrated pieces, or tabs.

Other than that, in order to achieve a distinct three-dimensional appearance, Laminated Shingle (see picture 5) was created by bonding two asphalt shingles together. Though generally heavier in weight, this product allows for greater design flexibility, and was therefore called “architectural” shingles.

E-Glass Mat not only supports good aesthetics for the shingle products, but also adds strength and durability to many premium and high performance roofing shingles.
2. Flat Roofs
Substrates design today is driven by the requirements of finished roof