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The Manufacturing Process- The differences begin with where and how the three types of conductive materials
are produced. The impregnated material is manufactured at one paper mill location which is computer controlled for consistent high quality manufacturing whereas typically the coated/printed material can be applied at several different locations by a roller coater process or on a printing press.
The impregnated material material is made on a cylinder type paper machine. A
cylinder paper machine makes paper in different layers (usually 6-8 layers). This allows the impregnated material to have a buried conductive layer of <10 to 4 ohms/square 5 layers down from the top surface. Additionally the top layer is treated to be permanently static dissipative measuring 10 to 7 -10 to 10 ohms/square.
The coated/printed material, after being coated or
printed with carbon loaded black ink must then be coated or printed again with a clear sealer. This is to help prevent the coating from rubbing off. Although some manufactures have tried to make the top layer static dissipative, the results have been very poor and inconsistent because the carbon layer is to close to the surface and the high carbon content bleeds through the sealer to measure 10 to 4 ohms/square or conductive.
Since the impregnated material is manufactured on one paper machine at one single location and because the impregnated material is made
of 100% recycled paper; the sulfur content of the impregnated material is consistently low. This is because the sulfur is washed out during the refining, filtering, and pulping process.
Because of the paper trading within the corrugated industry, it is
difficult to know if the paper which is coated or printed is made from recycled, virgin, or ma combination of these materials. Therefore, the sulfur content of coated material can vary. This is because sulfur is used in the pulping process to make virgin paper. Sulfur can cause corrosion to leads and circuits, causing problems and failures.
Consequently utilizing 100% recycled paper becomes an important factor for eliminating sulfur because the majority of the sulfur is
filtered out during pulping. Conversely virgin paper can exceed the FED-STD-101, method 3005 for reducible sulfur which is less than 8 parts per million in content.
Sloughing and Durability - Impregnated materials are far more durable over ink coated materials. Teledyne Tabor Abrasion Test, ASTM D4060 (1000 grams CS-17 wheel @ 70 RPM) has demonstrated results of a 50% loss of the coated/printed conductive surfaces area in 10 cycles, 1% loss for 200 cycles and 60% loss for 500 cycles. Since the conductive layer is buried, conductive particle sloughing is dramatically minimized compared to coated/printed materials. Circuit board leads have a tendency to scrape off the conductive coated/printed surface, which may short out your circuit board.
CDM Danger (Charged Device Model) - Conductive surfaces (whether paper or plastic) are too surface conductive and may pose a danger to components stored in open bin boxes, open in- plant handlers, open shippers, totes, or nesting trays. Burying the conductive layer (<10 to 4 ohms/square) under a dissipative surface (10 to 7 10 10 to 10 ohms/square) reduces the potential for a "rapid discharge" or "sparking".
Current Carrying Hazard - Conductive surfaces (whether paper or plastic) are susceptible to drawing a dangerous current. Impregnated materials with static dissipative and buried shielding layer reduces the likelihood of any current carrying hazard.
Shielding Effectiveness - The ability to attenuate high voltage discharge is about the same between impregnated and coated conductive materials. However, some coated products shield poorly due to inconsistent application procedures by some manufactures.
Recyclability - The impregnated and the coated/printed conductive corrugated materials are 100% recyclable. However, there can be a problem with the scrap value of the material when heavy concentrations of black materiel are visible in the bales. The large concentration of black become an aesthetic issue in making new recycled paper. This is a problem no matter what colors are baled in bales in heavy concentration (i.e. red, blue, green, etc.) because the colors are not completely filtered out during the recycling process and color specs may be visible on the surface of new recycled paper. However, they are all 100% recyclable, but potentially at a discount scrap value.
*All data and recommendations contained herein are to our knowledge and belief accurate and reliable. They are furnished, however, without
guarantee because Protektive Pak has no control over their utilization. Protektive Pak disclaims any liability for the loss or damage resulting from use of these products.
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