黏度与剪切力
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 – 有优良的剪力性能 Well balanced shear properties
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

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
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
压敏胶的化学构成
Pressure Sensitive Adhesive
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
丙烯酸胶的化学构成
Acrylic Adhesive Chemistry 交联结构 Crosslinking 增粘 Tackification 高分子结构 Various polymer backbones
How PSA Bonds ?

压敏胶具有流动性, 能与背材紧密接合 Adhesive must FLOW to CONTACT substrate

压敏胶与背材间的 相互作用 Adhesive - Substrate INTERACTION
初期与最终粘黏力
Initial and Ultimate Adhesion
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
黏度和黏弹性
Viscosity and Visco-elasticity
Tackification

Adding resins to increase the adhesion to low surface energy materials
No tackifier
Maximum tackifier
Increasing Tackifier: • Increases adhesion • Decreases temperature resistance • Decreases solvent resistance • Increases softness/oozing
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
Ready to use, no mixing or brushing is required


一贯性的胶量 Consistent amount of adhesive 使用方便，快捷
Less messy than super glue and contact cement
可以模切成各种形状
Can be die cut into specific shapes
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
Substrate Adhesive
Substrate
黏度与剪切力
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
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
– 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
Maximization of Contact Area
粘接力和内聚力
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
材料自身的力量 Internal strength of material

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

压敏胶的作用原理与技术
Pressure Sensitive Adhesive Technology
3China General Office
Application Engineer 朱弘 Cory Zhu email:czhu1@
压敏(不乾)胶的定义
Definition of PSA

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

无臭，无味和溶剂 Less odor during use
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 C
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