Liquid Silicone Rubber Basics LSR Specific Options Dosing

Liquid Silicone Rubber Basics LSR Specific Options Dosing

Liquid Silicone Rubber Basics LSR Specific Options Dosing Equipment Control system Closed loop metering control Minimum - maximum material pressure limits Capacity Amount of material to be processed per hour 5 gallon / 55 gallon capabilities Molding controls Feed system sized correctly for injection unit size Static mixer, filter pack, material dosing valve

LSR vs. HCR vs Thermoplastics Vacuum Feed Injection Mold LIMS Molding Process Mold Heated electrically or with fluid: 300 - 430F Cold Runner: 70 F Vacuum

Liquid Silicone Rubber Viscous fluid, centipoise from 500,000 2,000,000 5 gal or 55 gal drum Mixing ratio 1:1 Component A Methyl Vinyl Polymer Platinum Catalyst Silica Filler Additives A

Injection Molding Machine Standard Injection Molding Machine Special injection unit Optimized non-return valve B LSR Mixing Unit Pneumatic, hydraulic or servo Material pressure 100 - 200 bar Third stream additive Component B Methyl Vinyl

Polymer Hydride Crosslinker Inhibitor Silica Filler Additives LSR Dosing Equipment Equipment Mounted on the Injection Molding Machine (IMM) Mixing block Equipped with non-return valves Static Mixer Water cooled, sized properly

Pressure reducing valve Stabilizes pump pressures Material isolation valve Isolate material pump pressures from the injection unit Filter assembly With pressure transducer LSR Dosing Equipment Static Mixers Static Mixers work by splitting/folding the A, B & third stream option(s) with the desired result being a

homogenous mix Cooled mixer is preferred to slow the vulcanization of the mixed silicone Static mix is the preferred method of mixing as dynamic tends to create heat Ratio of mixing elements will need to be considered for proper utilization; Too many = residence time of mixed material & pressure drop Too less = incorrect ratio of LSR LSR Specific Requirements Injection unit Water cooled static mixer

Dosing Valve Pressure Transducer mounted below filer element Water cooled abrasion resistant barrel Pneumatic shut-off nozzle Zero compression screw

LD 16:1, 20:1 Spring loaded check assembly LSR Specific requirements Injection barrel LSR Plasticizing Assembly Flange Plasticizing barrel Standard, M3 Bimetallic barrel Cooling sleeve

Material seal with brass back plate BSPP ORB feed throat interface Barrel flange with M36 x 1.5 thread Cooling sleeve Material seal, brass back plate LSR Specific Requirements - Screw LSR Plasticizing Screw Zero compression, feeding only, minimal mixing

LD = 20/1, ideally not less than 16/1 Surface hardened 2 mm thickness, except for smaller diameters Screw specifications: S8 through hardened chromium steel LSR Screw: LD16 without compression Plasticizing screw LSR Specific Requirements - NRV LSR Non-Return Valve Valve body Shut off platen Coil spring

Assembly nut Advantages No injection movement needed to shut off LSR Plate NRV with spring Nut Spring Platen Valve body LSR Specific Requirements Injection Units Hydraulic drive Standard injection drive system

Proven repeatability & precision Profiled speed control for process control Improved performance with the addition of servo valve Operating range of 20 75% capacity for best resolution Lower Initial investment LSR Specific Requirements Injection Units Servo Electric drive Best possible resolution for shot to shot consistency Dynamic speed control Force transducer for actual injection pressure

display Due to Servo drive, injection unit works independent from clamping system Zero hydraulics, no heat up time or fluctuations resulting in parameter changes Larger operating range due to higher resolution measurement Higher initial investment LSR Specific Requirements Clamping Unit Clamping Unit Mold area for peripheral equipment, core pulls, automation, connections Tonnage Requirements for Silicone, part surface area, 2-3

tons per square inch. Clamp force is required to overcome expansion of LSR during vulcanization Thicker parts need higher clamp to overcome expansion Thinner parts have less expansion Always discuss mold construction with mold builder, preloaded inserts, springs and needed land size of cavities Hydraulic or Electric clamping unit Tie-bar vs. Tie-barrless design LSR Specific Requirements Vacuum System with Monitoring Vacuum system

Dedicated vacuum pump, 25, 40 or 60m3/hr Vacuum valve switchable in machine software System monitoring Vacuum release valve Vacuum Sensor, analog or digital LSR Specific Requirements LSR Tooling Hot Runner Technology Built for low volume Short production runs, mostly operator driven Higher material waste

Extended cycle times to ensure runner is fully cured Sprue bushing on mold, Typically radius nozzle for hot runner molds Lower tooling cost Faster tooling changes LSR Specific Requirements LSR Tooling Cold Runner Technology Open nozzle vs. valve gate design Direct Injection Reduced material waste Reduced cycle time Typically 15mm diving nozzle needed

for cold runner technology Higher tooling cost Increased preventative maintenance LSR Specific Requirements Clamping Unit Tonnage requirements Part Surface area of each cavity needs to be calculated for required machine Example: .520in^2 (x) one cavity = 1.5Tn LSR Specific Requirements Clamping Unit Tonnage requirements Part Surface area of each cavity needs to be calculated for required machine Example: .082in^2 (x) 64 cavity = 16Tn

LSR Specific Requirements Cooling water Water cooling circuits Cooling water manifold, (0-10L & 0-30L), to distribute cooling to plasticizing components & cold runner mold Bulkhead option for convenience, setting up mold Number of circuits required should be considered to ensure enough cooling for all auxiliary equipment Cooling water filter, important for cold runner molds

LSR Specific Requirements Mold heating Euromap 14 Standard Multi pin connector, all zones on one plug Execution in standard, 230V with 12 amps each zone is standard (other specifications are available) Male/Female connectors for heating current and T/C temperature reading Set-up errors reduced

Recently Viewed Presentations

  • Millennial Money Building your business for tomorrow, today

    Millennial Money Building your business for tomorrow, today

    Understanding the various causes and investment styles under the ESG umbrella will help you better understand what your client wants. STEP 2: Enquire into client's interest in the space and ensure it is genuine. ESG investing entails unique risk/return characteristics,...
  • 1 INTRODUCTION Annette Owens-Scarboro Program Manager Small Business

    1 INTRODUCTION Annette Owens-Scarboro Program Manager Small Business

    The best ways to obtain orders for simplified acquisitions are to: ensure you are SAM.gov registered so you are ready to accept PO's, frequent fedbizopps for opportunities, consider becoming a GSA schedule holder, consider negotiating a BPA agreement, keep your...
  • Over/Under-Reaction of Stock Markets

    Over/Under-Reaction of Stock Markets

    Section VIII: Stock Returns Around Earnings Announcement Dates The stocks are ranked in ascending order on the basis of 6-month lagged returns. The stocks in the lowest past return decile are called the losers group and the stocks in the...
  • Conflicting Perspectives - HSC HELP

    Conflicting Perspectives - HSC HELP

    Analyse the ways conflicting perspectives generate diverse and provocative insights.In your response, make detailed reference to your prescribed text and at least ONE other related text of your own choosing. 2008: Compare how the texts you have studied emphasise the...
  • Lower Snake River Fish & Wildlife Compensation Plan: Purpose ...

    Lower Snake River Fish & Wildlife Compensation Plan: Purpose ...

    Lower Snake River Fish & Wildlife Compensation Plan Scott Marshall LSRCP Program Manager US Fish & Wildlife Service Topics Legislative History Goals & Benefits Conservation Actions Operations Budget History Operations Non-recurring maintenance Equipment Summary Pending Legal Obligations Legislative History Public...
  • Safe Sense Technologies

    Safe Sense Technologies

    Shadi A.K Shirazi Jamie Westell Arash Jamalian Arash * Arash * Arash * Arash * Shadi * Arash * Arash * Arash pressure mat * Pressure mat results * The maximum current available for the motor 20 Amps (H-Bridge limitation)...
  • Surviving & Succeding at CCNY

    Surviving & Succeding at CCNY

    Carlito Berlus. Senior Academic Advisor. Gateway Academic Center. Transfer students. Thriving At The City College of New York:what you need to know. Your Academic Record. Resources. Advisement. Advising at CCNY . My degree.
  • 슬라이드 1 - Daum

    슬라이드 1 - Daum

    070609-070610. 선돌회 모임 울진 응봉산(매봉산)에서 모임중 오후 산행중 울진 응봉 산 산행중 12개 다리 중 1번.3번 다리에서 병남이.유득이와 옛 우정을 삼키면서 찰칵