1. Correct the name of the squeegee
In the process of screen printing, squeegee is a kind of gluing tool used to scrape the printing material on the screen plate to make the missing printing on the substrate. It includes two parts, squeegee and squeegee handle.As the name implies, squeegee and squeegee are dependent.For this reason, people often refer to a squeegee as
Scraping is incorrect.In the process of PCB silk-screen printing, a squeezer (also known as a scraper) is used instead of a single squeezer. It is difficult to achieve the purpose of silk-screen printing if the single squeezer does not match the scraper handle.
2. The base material made of glue scraping
The handle and glue that make up the bite scraper are usually made of the following substrates :A. The handle: it has A wooden handle and A metal handle (e.g.Aluminum, stainless steel), etc.B. Squeezes: polyurethane, nitrile, ortonyl and neoprene.C - fine rubber dry silicone rubber, fluorine rubber, natural rubber and other types.But from all aspects of performance, most PCB manufacturers use polyurethane squeezes.Therefore, the squeezes mentioned below are limited to polyurethane squeezes only.
3. Forming method of scraping glue
According to the survey, domestic and foreign manufacturers mainly adopt the following 6 shaping methods (most of which are 3 shaping methods):
(1) Injection (thermoplastic) molding method: The raw materials are heated and melted in the injection machine, mixed evenly, and then injected into a specific mold to cool and form.
(2) Roll molding method: The heated material is formed by rolling the hot kun in a specific equipment.
(3) Casting molding method: the molten material liquid is poured into a Special mold, cooled and formed.
(4) Extrusion molding method: Similar to injection method, the molten material starts to cool in the front part of the machine cavity, extrudes through the machine mouth, and then pulls out to form by external force.
(5) Die pressing: the material is formed by heating up and down and pressing in a specific mold.
4. Simple hardness and marking method
Hardness is a physical measure of the degree of deformation or puncture resistance of a substance under pressure.Hardness can be divided into relative hardness and absolute hardness. Absolute hardness is generally used in the scientific community, but rarely used in production practice.
We usually use the hardness system as the relative hardness, there are roughly the following several marking methods: Xiao's, Luo's, Brinell, Wechsler, Lu's, Mo's, pencil hardness and so on.
The surface wear resistance of a paint film or coating material is measured by pencil hardness, such as ink hardness tests in the PCB industry.
To measure the elastic chamber and elastic body, make use of Shaw hardness. For example, in the test of rubber scraping hardness in THE PCB procedure, the test of Shaw hardness is similar to the mesh tension test: the pointer on the dial is made to connect to a needle by a quickening needle and prick the surface of the measured object. The value shown on the dial is the hardness value.
The Shaw hardness system is usually represented by grade A and Grade D.The grade A hardness of the squeegee is generally between 50 ~ 90KG/MM'.
6. Classification of squeegee:
(1) The squeegee can be divided into polyester type and polyether type according to the molecular structure.
(2) Divided by color: primary colors, green, blue, yu Huang, red, amber, in addition to black, tan, etc.
(3) According to the degree of soft and hard can be divided into:
Soft squeegee (S) 50-65 °
Widely used in printing products with rough/uneven surface, as glass, gold asshole.Plastic, etc.
Neutral squeegee (M)65~75 °
It is mainly used for printing products with light smooth surface or slightly undulate with a little hardness, such as solder wire printing of PCB.
Hard: shaving (H)75 ~90 °
Used for printing surface is very smooth more soft products.Such as the silk screen of rubber products.
(4) According to the processing method can be divided into: pouring type, mixed type, thermoplastic type.
7. Performance of squeegee
The performance of skeleton scraping can be investigated from the following aspects:
1) physical properties: such as hardness.Wear resistance and resilience.Tensile strength, tear strength, etc.
2) chemical properties;Such as resistance to stem agents, oil resistance, weather resistance, no thermal stability, etc.
3) Electrical function: such as antistatic, etc.
For more details and information, welcome to send requirement to sales@paiouscreenmesh.com, or you can reach us at Tel/Whatsapp/Wechat: +86 19932893768
