压敏胶原理

表 面 结 构与不乾胶的厚薄度
Surface Texture
薄
Thin Adhesive
厚
Thick Adhesive
有限度的接触
Limited Contact
最大接触面积
Maximum Contact
粗糙的表面
Textured Surface
不乾胶的化学构成
Pressure Sensitive Adhesive
Ready to use, no mixing or brushing is required


一贯性的胶量 Consistent amount of adhesive 使用上方便，快捷
Less messy than super glue and contact cement
可以模切成各种形状
Rubber vs Acrylic Adhesives Bond Build Up
Adhesion Level 丙烯酸类 Acrylic 橡胶类 Rubber
粘黏力
驻留时间 Dwell Time
粘接不牢的各种因素
What Causes Bond Failure?

不乾胶与背材的相互作用
Adhesive-Substrate Incompatibilty

尘埃, 石粉, 纤维持等
Dust, Talc, Fiber, Particle Contamination
– 影响胶的黏性
Affects tackiness of adhesive
– 减少有效的接触面积
Reduce contact surface area
剥离力与剪力的测试
Peel vs Shear Test 剥离力 Peel
非黏性材料 Non-viscous Materials (e.g. cured adhesives 作用 后的粘黏剂) – 无流动性 No flow characteristics – 无黏性 Not sticky – 有极高的剪力 Maximum shear strength
黏性和黏弹性
Viscosity and Visco-elasticity
黏性
Viscous
黏弹性
Visco-elastic
弹性
Elastic
固体状
Solid
软
Soft
不乾胶
Pressure Sensitive Adhesives
韧
Firm
Maximum
粘黏 性
Adhesion Properties
Maximum
内聚力特性
Cohesion Properties
不 乾 胶 的 运 作 原理

橡胶类 Rubber Adhesives
– 天然胶 Natural Rubber – 人造胶 Synthetic Rubber

丙烯酸类 Acrylic Adhesives
– 纯丙烯酸类 Standard Acrylic – 改良丙烯酸类 Modified Acrylic

矽胶类 Silicone Elastomer Adhesives
How PSA Bonds ?

不乾胶 具有流动 性, 能 与 背 材 紧 密 接合 Adhesive must FLOW to CONTACT substrate 不乾胶与背材间的相互 作用 Adhesive - Substrate INTERACTION
Hale Waihona Puke Baidu

初期与最终粘黏力
Initial and Ultimate Adhesion
– 聚碳 Polycarbonate
表面污染
Surface Contamination

油脂, 指纹, 水, 油 和注 塑用的离型剂
Grease, Finger Print, Moisture, Oil, Mold Release Chemicals
– 防止胶与背材接合
Create a barrier bewteen adhesive and substrate

高黏性材料 Higher Viscous Materials (e.g. Oil, Honey 油, 蜂蜜) – 只需少许压力便可以流动 Require moderate pressure to flow – 低剪力 Little shear strength – 无法持久承受荷重 Fail under continuous shear load
不乾胶的定义
Definition of PSA

拥有持久的高黏度
Aggressively and permanently tacky
应用时只需用手或手指施压
Adheres with finger or hand pressure
不需水, 溶剂或加热过程
Requires no activation by water, solvent or heat

无臭，无味和溶剂 Less odor during use
粘黏力和内聚力
Adhesion and Cohesion
粘黏力Adhesion
存在两种表面之间的力量 Force between dissimilar surfaces
Substrate Adhesive Substrate
内聚力Cohesion
– 较低的初期粘黏力
Low initial bond strength
– 须较长的驻留时间
Requires longer dwell time

软性不乾胶 Soft Adhesive
– 良好的初期接触面积
Good immediate contact
– 较高的初期粘黏力
High initial bond strength
Rubber
Acrylic (Tackified)
Acrylic (Nontackified)
Silicone
Advantages In door Effective “WETTING” properties High initial bond strength Good adhesion to various substrates Low cost In door & Excellent durability Out door Broad performance temperature range (-40 to 350 F) Excellent chemical & UV resistance In door & Significantly improved Out door “WETTING” properties Excellent bond to LSE plastics Good aging characteristics Fills gap between Acrylic and Rubber adhesives In door & Broad temperature Out door performance (-100 to 500 F) Excellent Durability
容易黏接
Easy-to-adhere
低表面能 Low Surface Energy 难以黏接
Hard-to-adhere
金属Metals 聚碳Polycarbonate 聚酯Polyester 聚氯 乙烯PVC 聚氨Polyurethane 丙烯酸 Acrylic
Polyvinyl Acetate 聚乙烯 Polyethylene 聚苯 Polystyrene 聚丙烯 Polypropylene 聚氟Teflon
黏性与剪力
Viscosity and Shear Strength

黏弹性材料 Visco-elastic Materials
(e.g. Pressure Sensitive Adhesive 不乾胶)

– 使用时须施加压力 Require considerable rubdown pressure – 需驻留时间发挥效能 Require dwell time – 有优良的剪力 Well balanced shear properties
– 较短或不须驻留时间
Needs little or no dwell time
软性与韧性的不乾胶
Soft and Firm Adhesives
韧性胶 Firm 软性胶 Soft
粘黏力
Adhesion Level
驻留时间 Dwell Time
如何取得最大的接触面积
Maximisation of Contact Area
衡量 measures
粘黏力 Adhesion
剪力 Shear
衡量 measures
内聚力 Cohesion
剪力
Shear Strength

Shear measures Cohesion - the internal
材料自身的力量 Internal strength of material
Substrate Adhesive
Substrate
黏性与剪力
Viscosity and Shear Strength

低黏性材料 Low Viscous Materials (e.g. Water 水) – 高流动性 Flow easily – 不须施加压力 Do not need rub down pressure – 无剪力 No shear strength
Can be die cut into specific shapes
持久的黏弹性可以避免脆化，断裂等现象
Stays viscoelastic which eliminates brittle fracture possible with epoxies, hot melts and cyanoacrylates

时 间 Time
– 胶需要时间流动For adhesive to flow
温 度Temperature
– 高温可以减低胶的黏性 Decrease
adhesive viscosity
– 促进胶的流动性
Accelerates adhesive flow
– 促进胶的 Improve wetting

初期粘黏力 无驻留时间
Initial Adhesion No Dwell Time
最终粘黏力 驻留时间:
Ultimate Adhesion 72 小 时/ 70 癈
软性与韧性的不乾胶
Soft and Firm Adhesives

韧性不乾胶 Firm Adhesive
– 较小的初期接触面积
Less immediate contact
表面结构 Textured Surface 表面污染 Surface Contamination
– 离型剂 Mold Release, 尘埃 Dust Particles


增塑剂的移行 Plasticiser Migration
– 软质聚氯乙烯 Flexible PVC, 橡胶 Rubber
残留水份 Outgassing of Moisture
压 力Pressure
– 促进胶的流动性
Accelerates adhesive flow
压力
– 促进胶的
Improves surface wetting
– 避免汽泡的产生
Eliminates trapped air
表面能
Surface Energy
高表面能 High Surface Energy
有牢靠的粘黏力
Exerts a strong holding force
有足够的内聚力和弹性
Has sufficient cohesiveness and elasticity
Pressure Sensitive Tape Council
不干胶的好处
Advantages of PSA抯

不须涂布，混合等预处理步骤
各种不干胶 Types of PSAs
Disadvantages Limited temperature performance (-20 to 200 F) Poorer durability Poorer chemical and U.V. resistance Limited “WETTING” characteristics Lower initial bond strength Limited to HSE materials Limited chemical and U.V. resistance Limited temperature performance (-40 to 250 F) High cost