久久九九有精品国产尤物-久久九色综合九色99伊人-久久久91麻豆精品国产一区-久久久97精品一区蜜桃-久久久97丨国产人妻熟女-久久久99精品成人片

Your Current Position:  Common problem
  • Glas transition temperature

    The glass transition temperature (TG) is the temperature at which the adhesive becomes brittle. It is important that the application temperature is distinctly above the TG of the adhesive (e.g. resealable bags that are stored in the fridge or freezer as it can prevent a safe reclosure of the bag).


  • Hard adhesive

    10.jpg

    Term usually used to characterize highly cohesive PSA tapes.

    Advantages (compared to soft adhesives):

    higher holding power withstands

    higher sustained loads good temperature resistance

    less edge picking

    improved die cuttability

     

    Disadvantages:

    low initial tack and adhesion;

    requires higher contact pressure

    not suited for rough surfaces


  • Hot melt pressure-sensitive adhesive

    Types of pressure sensitive adhesive that can be coated without use of solvents or water. Today PSA tapes based on synthetic rubber as well as acrylics are available for hot melt coating.


  • Humidity resistance

    Moisture or even humidity can affect the performance of an adhesive. Especially if applied under wet or very humid conditions the adhesive absorbs the humidity, which leads to reduced adhesion performance. This effect occurs especially with water-based acrylics, which should not be used under those conditions.

    In general a PSA tape is humidity resistant when it resists contact with humid air or even water without negative effects on the adhesion properties 

    All acrylics have a good humidity resistance. Humidity can damage paper liners and lead to “bubbles” on the surface of the tape. Basically, filmic liners are more dimensionally stable than paper ones.

     

    1.jpg


  • liner

    Anti-adhesive material which covers the adhesive on almost all d/s and some s/s tapes and prevents the adhesive from sticking to itself. The liner is used as a protection aid during handling/processing and storage. Most commonly used liner types are

    1. Paper liners (e.g. Glassine paper, PE-coated paper, Clay-coated paper)

    2. Film liners (e.g. PP, PET, PE) Silicone is used as release system to avoid adhesion between liner material and adhesive.

     

    11.jpg


  • migration

    The molecular movement over a long period of time of an ingredient from one surface to another when both are in contact. Migration may occur between tape components and the surface to which applied. Some plastic films (e.g. PVC) contain plasticizers which are apt to migrate into the tape adhesive, causing the adhesive to soften. Other ingredients like foaming, vulcanisation, age-resistant agents used for flexible seals migrate into the tape and can compromise the bond.


  • Non-polar substrates

    Critical surfaces to adhere to due to low surface energy. The lower the surface energy the lower the molecular attraction to the adhesive (adhesion). Typical materials are polyolefins such as PP and PE, but also PS, EVA and many powder painted surfaces. By surface pretreatment (e.g. corona treatment) the polarity can be modified to achieve higher surface energy and improved adhesion. Use of primers will also act as adhesion promoters.


  • Outgassing

    Amount of chemical ingredients evaporating from adhesives (e. g. monomer residues, solvents, etc.) especially under elevated temperature conditions. Often a concern in the Automotive, Aerospace and Electronics industries, where chemical residues could affect e. g. electric circuits.

     

    1.jpg

  • Polar substrates

    Uncritical surfaces to adhere to due to high surface energy. On these substrates the high molecular attraction between adhesive and substrate leads to increased adhesion. Most common materials are PET, PC, PVC, ABS, steel, aluminum, glass etc.


  • Primer

    A coating applied to a surface (e. g. backing or a substrate) prior to the application of an adhesive, improving bond performance between backing and adhesive or between tape and substrate


主站蜘蛛池模板: 狠狠色丁香婷婷久久 | 欧美三极| 久久久久成人片免费观看蜜芽 | 亚洲精品一区二区三区在线看 | 国产午夜在线观看视频 | 久久九九久精品国产免费直播 | 亚洲av丰满熟妇在线播放 | 插一插射一射视频 | 国产福利精品在线观看 | 亚洲av日韩av无码a一区 | 欧洲无码八A片人妻少妇 | 国产一区二区三区四区五区VM | 亚洲精品黑牛一区二区三区 | 99精品国产99久久久久久97 | 久草国产精品 | 成人免费视频在线观看 | 天天插天天干 | 八武将免费完整版在线观看 | 国产精成人品日日拍夜夜免费 | 日本免费观看日本高清视频 | 国产精品无码aⅴ嫩草 | 亚洲欧美日韩久久精品第一区 | 欧美天堂在线 | 久久艹精品 | 国产高清在线精品 | 熟妇人妻久久中文字幕 | jizz.日本 | 成人精品一区二区激情 | 色综合久久久久久中文网 | 五月婷婷电影网 | 久色中文| 无码精品国产一区二区三区免费 | 狠狠草视频 | xx小视频| 久久婷五月综合 | 久久久久亚洲精品无码网址 | 公粗挺进了我的密道在线播放贝壳 | 欧洲精品码一区二区三区免费看 | 牛和人交videos欧美冫3d | 欧美99视频| 小明成人永久视频在线观看 |