Understanding_ the_Cleaning_Process_for_Automatic_Stencil_Printers.pdf - 第20页

Hydr o - Ent angl ed, Singl e - Fiber Polymer • A new material consisting of a hydr o- ent a ngled, single -f iber polymer based on regener a ted cellulos e was d evelop ed. • This fabric, which is comple tely sy nthetic…

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Hydro-Entangling
• Some paper is made using a process called “hydro-entangling”
• This process involves laying raw fibers of polyester and cellulose onto a conveyor belt and intertwining the fibers with high-pressure jets
of water
• Heat and pressure then are used to dry the slurry into the proper configuration
• Lacking glue, hydro-entangled papers have a softer feel
• They are more absorbent, thicker and stronger than ordinary paper
• The flat, rough cellulose fibers (thin, top layer) are highly absorbent, but
weak and prone to lifting
• The rounder polyester fibers (middle and bottom) provide structural
strength and open space to pick up solder paste
Understanding the Cleaning Process for Automatic Stencil Printers
Hydro-Entangled, Single-Fiber Polymer
• A new material consisting of a hydro-entangled, single-fiber polymer based on
regenerated cellulose was developed.
• This fabric, which is completely synthetic, contains no natural fibers or binders.
• Under a microscope, the long, thin, hard fibers are identical and homogenous,
giving the fabric an open structure.
• The material is a pale, off-white color and highly absorbent.
• The fabric scores well on the solder paste pick-up tests for non-liquid
contamination.
• The fibers are smooth, consistent and hard.
• The paper includes extensive voids and cavities to pick up solder paste.
• There is no cellulose to rip or shred, or binders to dissolve and contaminate the
stencil.
Understanding the Cleaning Process for Automatic Stencil Printers
Paper Compared (Dry Wipe Data Only)
High End Paper Typical Paper Paper Using Glue
Base Weight (oz/per yd²) 1.87 1.56 1.11
Tensile Strength (LB’s) 29 31 16
Thickness (Mils) 15 12 11
Absorption (ML H²O/M²) 391 290 231
Fiber Shedding (particles >0.5
mm/m². x103)
127 1,130 20
Extractable IPA % 0.08% 0.07% 0.98%
Solder Paste Pick-up Test 77% 61% 33%
Understanding the Cleaning Process for Automatic Stencil Printers