The blasting equipment is produced to deliver, reclaim and contain the media, contain the part to be blasted and collect the dust from the blasting process.
17 pages
539 KB – 17 Pages
PAGE – 2 ============
THE REFERENCE IN SURFACE TREATMENTwww.istsurface.com 2Blasting Technical Informations TABLE OF CONTENTS BLAST FINISHING ..3FACTORS THAT AFFECT BLAST FINISHING .4FACTORS THAT AFFECT BLAST FINISHING ˜ CONT ™D˚ ..5FACTORS THAT AFFECT BLAST FINISHING ˜ CONT ™D˚ ..6FACTORS THAT AFFECT BLAST FINISHING ˜ CONT ™D˚ ..7FACTORS THAT AFFECT BLAST FINISHING ˜ CONT ™D˚ ..8FACTORS THAT AFFECT BLAST FINISHING ˜ CONT ™D˚ ..9ALL IN DUSTRIAL BLAST SYSTEMS HAVE THE FOLLOWING COMPONENTS : 9BLAST ME DIAS 10BLAST ME DIAS ˜ CONT™D˚ . 11BLAST ME DIAS ˜ CONT™D˚ . 12BLAST ME DIAS ˜ CONT™D˚ . 13BLAST ME DIAS ˜ CONT™D˚ . 14BLAST ME DIAS ˜EN D˚ ..15HOW TO MEASURE SURFACE PROFILE USING TESTE X TAPE ..16OUR MISSION .. 17
PAGE – 3 ============
THE REFERENCE IN SURFACE TREATMENTwww.istsurface.com 3Blasting Technical Informations BLAST FINISHING Blasting is the process where small angular or spherical particles are propelled at a part by compressed air, or mechanical high speed rotating wheels or water pumps. The blast media type, shape, size, density, and hardness, along with media acceleration and volume of media, combined with blasting distance from the workpiece, angle of impact and time cycles are important factors in the blast process capabilities. The blasting equipment is produced to deliver, reclaim and contain the media, contain the part to be blasted and collect the dust from the blasting process. Parts can be processed individually as a batch process or can be automated thru the system. SURFACE AFFEC TS FROM THE BLAS TING PROCESS ARE : VISUAL Bright Matte ˜nish Dull Matte Finish Satin ˜nish Satin luster ˜nish Blending of tool marks Removal of weld discoloration Surface cleaning Glass frosting and etching Pre plate and anodize ˜nishes MECHANICAL Deburring De-˚ashing Paint and coating removal Peening Pre paint and coating adhesion Heat treat, mill scale removal Weld splatter removal Thermal metal spray preparation Rust removal Mold cleaning
PAGE – 4 ============
THE REFERENCE IN SURFACE TREATMENTwww.istsurface.com 4Blasting Technical Informations MEDIA DELIVERY SYSTEMSThere are three media delivery systems that propel and deliver media for high speed impact to the part being processed : Air Blasting (Pneumatic) Mechanical Wheel (Airless blasting) Hydro blasting (Pumped water )AIR BLASTING utilizes an air compressors energy to deliver air/media mix at speeds and volumes to impact the parts being processed. The air speed or pressure of an air compressor is controlled by a pressure regulator. The regulator can increase or decrease the speed of the media delivery. Air pressure is measured by pounds per square inch (psi), industrial blasting is e˛ectively done between 20 and 90 PSI. The higher the PSI the higher the air speed. The volume delivered of the air/media mix is determined by the ori˝ce or opening diameter of the nozzle with pressure blast systems or air jet diameter of the suction blast gun body. Air volumes are measured by surface cubic feet per minute (scfm). The larger the ori˝ce I D opening the larger volume of air/media. Other factors that a˛ect volume of air into the blast system is media and air hose diameter. Increased air pressure (PSI) also increases the SCFM with a given size ori˝ce. Industrial blasting gun bodies of suction cabinet blast systems range between 12 to 38 SCFM. The pressure blast cabinet systems range between 12 to 68 scfm and the pressure blast room systems use up to 254 scfm. Industrial air compressors produce approximately 4.5 SCFM per horse power (hp). Blasting cabinets require 3 to15 hp compressors per nozzle and blast rooms can use up to 53 h.p. per man or nozzle. THERE ARE TW O TY PES OF AIR BLAS T DELIVER Y SYSTEMS :SUCTION (used in blast cabinets) PRESSURE (used in blast cabinets, blast rooms, and outdoor blasting) SUCTION Blasting uses the venture principle sucking media from a hopper. The air jet is 1/2 the ID of the nozzle and as the air stream is passed through both, it creates a suction which sucks the media from the hopper into the air stream. The media acceleration distance is very short ( from the nozzle to the workpiece (approximately continuously blast as long as there is blasting media in the hopper. Suction systems have limits on their suction capacity and on propelling heavier media. Very heavy blasting media (larger steel media) cannot be conveyed into the air stream with suction blasting. However, most industrial blast cabinets use suction systems due to their lower cost and because work well for most applications. FACTORS THAT AFFECT BLAST FINISHING
PAGE – 5 ============
THE REFERENCE IN SURFACE TREATMENTwww.istsurface.com 5Blasting Technical Informations PRESSURE The pressure pot contains the media, and as it is energized with compressed air, it pressurizes the pot. When the air/media mix is released from the pot, it accelerates from the pot through at least 5-10 feet of hose and then even faster as it travels through the Venturi of the nozzle. The acceleration rates of air/ media mix are much higher in pressure blasting than suction blasting. When the pressure pot empties of the media, it has pressure blasting systems are much more productive than suction systems. Pressure systems can blast all medias regardless of their weight or size, but they require a minimum of 25 psi to operate .AIR BLAS T SYSTEMS – AIR CONSUMP TION RA TES Below are charts of air volume (SCFM) used in blasting with pressure and suction systems utilizing various pressures (PSI) and orifice sizes. CABINET BLAS T SYSTEMS – AIR REQUIREMENTS (scfm) SUCTION S YSTEM S P RE SS URE S YSTEM SFACTORS THAT AFFECT BLAST FINISHING ( CONT™D) Pressure (psi) 30405060708090100 1/4fl nozzle 3/32 jet6781011121315 1/4fl nozzle 1/8 jet1012151719212326 5/16fl nozzle 5/32 jet1519232731373842 7/16fl nozzle 7/32 jet3138455259667380 Pressure (psi) 2030 40506080100120 1/8fl nozzle 68101314172025 3/16fl nozzle 1518 222630484555 1/4fl nozzle 2732414955688197 5/16fl nozzle 4250 647888113137152 3/8fl nozzle 557391109126161196220
PAGE – 6 ============
THE REFERENCE IN SURFACE TREATMENTwww.istsurface.com 6Blasting Technical Informations BLAST ROOMS AND OUTDOOR SYSTEMS – AIR REQUIREMENTSAir consumption and media delivery rates are much higher on blast rooms and outdoor blasting systems than in pressure blast cabinets. The air supply hose ID, the media blast hose ID, the nozzle ID, the pressure pot and pot piping are all much larger on the blast rooms than cabinet systems. The increase in production is also due to the further distance that the nozzle is from the work piece in blast rooms creating a larger blast pattern. PRESSURE -BL AST REQUIREMENTS ( BL AST ROOMS )FACTORS THAT AFFECT BLAST FINISHING ( CONT™D) Pressure Nozzle ID60708090100120 3/16™™ #3AIR (CFM )3033384145 ˜/˜Air compressor hp 77.589.510 ˜/˜Lbs Sand hour171196216238264 ˜/˜1/4™™ #4AIR (CFM )546168748197 Air compressor hp 1213.51516.51821.5 Lbs Sand hour312354406448494582 5/16™™ #5AIR (CFM )89101113126137152 Air compressor hp 20.022.525.528.030.534.0 Lbs Sand hour534604672740812912 3/8™™ #6AIR (CFM )126143161173196220 Air compressor hp 28323638.54449 Lbs Sand hour7548649601 0521 1521 320 7/16™™ #7AIR (CFM )170194217240254300 Air compressor hp 3843.548.553.556.567 Lbs Sand hour1 0231 1761 3121 4481 5841 800 1/2™™ #8AIR (CFM )224252280390338392 Air compressor hp 505662.5697587.5 Lbs Sand hour1 3361 5121 6801 8562 0242 352
PAGE – 8 ============
THE REFERENCE IN SURFACE TREATMENTwww.istsurface.com 8Blasting Technical Informations BLAST ROOM AND OUTDOOR BLAS T PRO DUCTION RA TESMECHANICAL WHEEL BLASTINGFor more information on blast specifications contact info@istblast.com BLAS T SPECIFICA TIONS (Approx. Sq. Ft. Cleaning Per Hour at 90 PSI)ESTIMA TED BLAS T CLEANING RA TES (#7 nozzle) No.1 WHITE METAL BLAS TSSPC-SP5#7 N OZZLELoose Mill Scale 170 Sq. Ft Tight Mill Scale 140 Sq. Ft Pitted Paint 85 Sq. Ft. Layered Paint 70 Sq. Ft. No.2 NEAR WHITE BLASTSSPC-SP10#7 N OZZLELoose Mill Scale 180 Sq. Ft Tight Mill Scale 146 Sq. Ft Pitted Paint 90 Sq. Ft. Layered Paint 72 Sq. Ft. No.3 COMMERCIAL BLAS TSSPC-SP6#7 N OZZLELoose Mill Scale 420 Sq. Ft Tight Mill Scale 270 Sq. Ft Pitted Paint 200 Sq. Ft. Layered Paint 140 Sq. Ft. No.4 BRUSH – OFFSSPC-SP7#7 N OZZLELoose Mill Scale 420 Sq. Ft Tight Mill Scale 835 Sq. Ft Pitted Paint 200 Sq. Ft. Layered Paint 825 Sq. Ft. FACTORS THAT AFFECT BLAST FINISHING ( CONT™D) Wheel blast system utilizes a high speed rotation wheel using centrifugal force to propel the media. The wheel size design and rotation speed affect the velocity and pattern of the media. The abrasive is fed into the rotating wheel. The impact on the media by the hard rotating wheel usually restricts media selection to a very tough steel or stainless steel shot or grit. Machines can be built with multiple wheels for automation. Automated systems include basket, table, spinner hangers and continuous conveyor processing. Wheel blast systems are a less expensive way to blast (due to higher media recycleability and automation) than air blasting by a factor of 10. Their disadvantage are restrictions to very few media. Media Loading
PAGE – 9 ============
THE REFERENCE IN SURFACE TREATMENTwww.istsurface.com 9Blasting Technical Informations HYDRO BLAS TINGFACTORS THAT AFFECT BLAST FINISHING ( CONT™D) ALL IN DUSTRIAL BLAST SYSTEMS HAVE THE FOLLOWING COMPONENTS : This blasting system uses a pressurized water stream generated by pumps that are capable of pumping an abrasive charged water supply at high rates of speed. The Hydro Systems are good for conveying very fine abrasives. They are also used in cleaning gunky, greasy parts, and containing toxic materials. The wet blast systems are very good at blasting surfaces without damage and blasting internal surfaces. Delivery Systems (Air or Wheel Blasting) Containment Systems (Hand cabinets, Automated enclosures, and Blast rooms) Reclaim Systems Dust Collection CONTAINMENT S YSTEM SHand cabinets, automated enclosures and blast rooms are built to handle various size and shapes of parts. The containment systems are built to control and contain the blast media and parts within the enclosures. The enclosure systems use gravity for the blasted media to drop down to a collection area so the media can be conveyed to the reclaim system. Blast systems can have inexpensive or premium containment systems. Matching the right containment system to the application is very important. MEDIA RECLAIM S YSTEM SRecoverable medias used in industrial blast systems will run from 5 to 100 times through the blast system. These recoverable medias need to be cleaned, sized and returned to the blast system after being blasted. The media reclaim system accomplishes this. The reclaimer keeps finish and production rates consistent. Media reclaim systems can be Air Cyclones or Mechanical Systems. DUST COLLECTION All Industrial blast systems utilize dust collectors to allow blast systems to be indoors. The dust collector removes the fine blasting dust keeping the media clean and operators safe through visibility and breathable air. Dust collectors remove 99% of 1 micron or larger material. Hepa filters can be added to remove dust particles down to 1/2 micron. Dust collectors are sized to the cabinet size, media type, and amount of blast nozzles or wheels being used.
PAGE – 10 ============
THE REFERENCE IN SURFACE TREATMENTwww.istsurface.com 10Blasting Technical Informations BLAS T MEDIASRecoverable blasting medias are used in industrial blasting. Indoor blasting systems require medias with extended life. Blast media, type, shape, size and hardness affect the process and materials they are capable of blasting. Spherical medias are used for peening and produce smoother surface finishes. Angular medias chip at a parts surface; removing paint, rust and scale quicker, with better results than round medias. Angular medias produce a rougher surface finish and produce superior anchor patterns for paint and coating adhesions. Higher blast pressures increase production but reduce media life. Blasting harder workpieces also reduces media life. Recoverable blasting medias have two basic shapes. Round (spherical) and angular. The most common recoverable industrial blast medias are : S PHERICAL SHA PED MEDIA ANGULAR SHA PED MEDIA Aluminum Oxide (AL2O3) is a man made fused alumina that is very tough and angular blocky shaped, medium density, with a hardness of 9 on the Mohs scale. This abrasive is designed for high blasting pressures up to 90 PSI. Aluminum oxide is very good for light deburring and surface prep (bonding strength) prior to painting and coating. AO creates a dull matte finish.Aluminum oxide has media life of approximately10-12 times through the blast system. Ceramic Beads Aluminum OxideSilicon Carbide Ceramic GritStainless GritCrushed Glass Steel GritGlass Beads Stainless ShotGrit Size Conversion for AO and SICTYPICAL ALUMINUM OXIDE BLA STING APP LICATION S Cleaning of investment castings Scale removal Thermal spray coating preparation Rust removal Hard oxide removal Heat treat and mill scale removal Glass frosting and etching Monument lettering and carving Aircraft engine overhaul Matte finishing Surface preparation D urability up to 20 passes Grit Size Inches (average) Microns (average) 700.008203 800.0085165 900.0057145 1000.0048122 1200.0048102 1500.003589 1800.003076 2200.002563 Grit Size Inches (average) Microns (average) 160.0431092 200.037942 240.027686 300.022559 360.019443 460.014356 540.012305 600.010254
PAGE – 11 ============
THE REFERENCE IN SURFACE TREATMENTwww.istsurface.com 11Blasting Technical Informations TYPICAL SILICON CARBIDE BLA STING APP LICATION S Blasting hard metals Glass etching Ceramic recast removal Very tough scale removal Heavy profile and metal preparation Before brazing and weld applications requiring no aluminum oxide contamination Glass Beads and Glass Grit are glass beads used in peening and surface finishing on tight tolerance machined surfaces. Glass Beads create a bright matte surface finish with no surface contamination or damage. As a round particle beads are very slow on removal of paint, rust, or scale. Glass grit is the angular counterpart of glass beads. Glass grit is very aggressive on a blasted surface. Glass beads are blasted at pressures between 40-80 psi. Glass bead media life cycles are 9 – 12 times thru the blast system. TYPICAL GLA SS BEAD BLA STING APP LICATION S Ceramic Blast Media Ceramic Beads are spherical shaped media with high mechanical strength and high wear rates. Ceramic is impact resistance creating very little dust. The ceramic beads keeps its round consistency and is chemically inert. Ceramic blast processes produce a smooth bright satin finish. The ceramic beads density creates higher impact speed making it a good choice for deburring and peening. Blast pressure recommendations are between 40-65 psi with media cycle lives between 70-90 times thru the blast system. Ceramic blast media is very versatile and can be blasted with all delivery systems( air, wheel and water). Ceramic beads is a standard peening material for titanium parts. Ceramic grit is angular and is excellent for etching parts with extended media life. TYPICAL CERAMIC MEDIA BLA STING APP LICATION S Peening Titanium Non contamination High impact for deburring Long media life applications Bright surface finish requirements Aircraft and medical parts Grit Size Conversion for AO and SICSIZING : SAME AS ALUMINUM OXIDEBLAS T MEDIAS ˝CONT™D˙ Silicon Carbide (SIC) is a man made abrasive that is very sharp and friable. SIC is very hard at 9.5 on the mohs scale. It is used to blast very hard materials such as tool steels, glass and ceramics. SIC creates a dull matte finish. The grit sizes available are the same sizes as aluminum oxide. SIC blasts at pressures up to 90 psi and has an approximate life of 9-12 times thru the blast system. Grit Size Conversion for glass beads Mil-G- 9954AInches (average) Microns (average) US Screen Size (Mesh)# 3.028272520-30 # 4.018751230-40 # 5.013936340-50 # 6.010525650-70 # 7.008421560-80 # 8.007118170-100 Mil-G- 9954AInches (average) Microns (average) US Screen Size (Mesh)# 9.006015380-120 # 10.0047120100-170 # 11.0039100120-200 # 12.003385140-230 # 13.002668170-325 Light deburring. Surface cleaning. Peening. Blending machine marks. Removal of welding discolor. Blasting tight tolerance parts. Produces a bright matte finish. Pre Anodize finishing.
539 KB – 17 Pages