Skip to main content
Sister Publication Links
  • Sustainable Plastics
  • Rubber News
Subscribe
  • Sign Up Free
  • Login
  • Subscribe
  • News
    • Processor News
    • Suppliers
    • More News
    • Digital Edition
    • End Markets
    • Special Reports
    • Newsletters
    • Videos
    • Podcasts
    • Injection Molding
    • Blow Molding
    • Film & Sheet
    • Pipe/Profile/Tubing
    • Rotomolding
    • Thermoforming
    • Recycling
    • Machinery
    • Materials
    • Molds/Tooling
    • Product news
    • Design
    • K Show
    • Mergers & Acquisitions
    • Sustainability
    • Public Policy
    • Material Insights Videos
    • Numbers that Matter
    • Automotive
    • Packaging
    • Medical
    • Consumer Products
    • Construction
    • Notable Leaders in Sustainability
    • Processor of the Year
    • Best Places to Work
    • Women Breaking the Mold
    • Rising Stars
    • Diversity
    • Most Interesting Social Media Accounts in Plastics
  • Opinion
    • The Plastics Blog
    • Kickstart
    • One Good Resin
    • Pellets and Politics
    • All Things Data
    • Viewpoint
    • From Pillar to Post
    • Perspective
    • Mailbag
    • Fake Plastic Trees
  • Shop Floor
    • Blending
    • Compounding
    • Drying
    • Injection Molding
    • Purging
    • Robotics
    • Size Reduction
    • Structural Foam
    • Tooling
    • Training
  • Events
    • Plastics News Events
    • Industry Events
    • Injection Molding & Design Expo
    • Livestreams/Webinars
    • Editorial Livestreams
    • Ask the Expert
    • Plastics News Events Library
    • Plastics News Executive Forum
    • Injection Molding & Design Expo
    • Plastics Caps + Closures: A Global Online Event
    • Women Breaking the Mold Networking Forum
    • Bioplastics Live
    • Numbers that Matter Live
    • PFAS Live
    • Plastics in Politics Live
    • PN Live: Mergers and Acquisitions
    • Polymer Points Live
    • Sustainable Plastics Live
    • Plastics Caps & Closures Library
    • Plastics in Healthcare Library
    • Women Breaking the Mold Networking Forum Library
  • Rankings & Data
    • Injection Molders
    • Blow Molders
    • Film Sheet
    • Thermoformers
    • Pipe Profile Tubing
    • Rotomolders
    • Mold/Toolmakers
    • LSR Processors
    • Recyclers
    • Compounders - List
    • Association - List
    • Plastic Lumber - List
    • All
  • Directory
  • Resin Prices
    • Resin Prices Overview
    • Commodity Thermoplastics
    • High Temperature Thermoplastics
    • Engineering Thermoplastics
    • Recycled Plastics
    • Thermosets
    • Europe - Virgin
    • Europe - Recycled
    • Europe - Feedstock
  • Custom
    • Sponsored Content
    • LS Mtron Sponsored Content
    • Conair Sponsored Content
    • KraussMaffei Sponsored Content
    • ENGEL Sponsored Content
    • White Papers
    • Classifieds
    • Place an Ad
    • Sign up for Early Classified
MENU
Breadcrumb
  1. Home
  2. News
May 06, 2019 02:00 AM

Massive growth leading to LSR resin shortages

Bill Bregar
Senior Staff Reporter
  • Tweet
  • Share
  • Share
  • Email
  • More
    Reprints Print
    Bill Bregar
    Boy Machine Inc. hosted an open house April 9-11 in Exton, Pa.

    Exton, Pa. — Liquid silicone rubber, used in automotive, medical and other markets, is a small niche in the plastics industry, but it's growing so quickly that molders are experiencing resin shortages, according to Rick Ziebell, vice president of technology for R.D. Abbott Co. Inc.

    Ziebell, the first speaker at an April 9-11 open house at Boy Machine Inc. in Exton, called the shortages "the elephant in the room."

    The last major shortage happened back in 1992, he said, when a lot of new applications in the automotive industry — the biggest LSR market — drove up demand for materials. New uses for LSR included coatings for airbags and parts where anti-flammability is critical.

    Add in ever-growing electronic connectors, where durable silicone seals are superior to rubber ones, engine seals, and new optical silicone applications, and "the need for silicones has expanded greatly," Ziebell said.

    Glues and adhesives also use the same raw ​ materials. It adds up to a tripling of sales of silicones in the last five years, he said.

    Ziebell delivered some good news: Major manufacturers are planning a total investment of about $1.4 billion over the next few years.

    LSR is a thermoset elastomer that gets pumped into a mold through a water-cooled nozzle and gets cured quickly inside a heated mold. The very fast curing is why LSR systems keep Part A and Part B separated, until just before they come together and go into the mold.

    Medical offers big growth rates because LSR has good biocompatibility, Ziebell said.

    "We're starting to see more LSR implantable medical devices," he said, especially diagnostic products.

    "In about two years, you're going to see all kinds of things coming out. If you think the FitBit and the iPhone Watch is super, wait till you're taking a pill and it's measuring digestive systems. There'll be a little chip inside the pill that'll be communicating to your watch. Not only that, but on the therapeutic side, you'll get pulses back from various other devices implanted in your body to control and regulate metabolism throughout the body. It's amazing where we're headed," he said.

    Ziebell, who outlined the chemistry behind liquid silicone rubber, spelled out one fundamental challenge with molding LSR: The huge change in viscosity that goes on throughout the pumping and molding cycle.

    "The varying degree of shear mixing changes the silicone's viscosity attributes," he said. As shear increases, viscosity goes down.

    When the two components come together, they start to set up and cure right away. Silicone goes from paste to water inside the injection press machine, he said, which means molding machines have to do "phenomenal things" to compensate when running LSRs. Precise cycle times and the flow speed are very important, he added.

    "A good injection press applies its force in a very repeatable manner. But LSR changes its viscosity all the time! You never know what it's going to do," Ziebell said.

    R.D. Abbott is a full-service distributor of LSR and rubber in Cerritos, Calif. In addition to Ziebell's talk, representatives from pumping equipment companies, mold makers and material suppliers took a deep dive into the world of liquid silicone rubber during a conference held at the open house. The event drew 125 attendees.

    Boy Machine ran five injection molding machines at the event, molding LSR and thermoplastic products like medical micromolded items, baby bottle nipples and a bottle cap opener showing molding of a metal insert with polypropylene.

    A highlight was the U.S. launch of the largest-ever Boy, the Boy 125 E, with 137 tons of clamping force, molding two-component coffee mugs made of polypropylene and overmolded with a soft thermoplastic elastomer. The bolt-on second injection unit, built by parent company Dr. Boy GmbH of Fernthal, Germany, was set up in an L-configuration, mounted horizontally at the rear of the machine.

    Bill Bregar

    Ziebell

    Importance of metering

    Bob and Mike Pelletier, brothers who work for competing pumping equipment companies, explained the importance of metering the two components.

    "You have to look at the big picture when you look at silicon processing," said Bob Pelletier, operations manager for Elmet North America Inc.

    Pelletier said the company's new Top 5000 P dosing system makes sure you use 99 percent of the LSR components in the drums.

    For clean room molding, a molder can gain space by isolating the pumping system outside the room, set up on levels above and below.

    One big issue is the skill level of operators, who may have come from thermoplastics molding — the exact opposite of thermoset LSR processing, Pelletier said.

    "We spend a lot of money on machinery, we spend a lot on the dosing system and molds, and then we pull someone off the street to run it," he said.

    Elmet set up a timer on its controller, giving operators advance notice that levels are getting low and it's time to get materials prestaged in new drums. Another feature allows only authorized employees to set up production and shows who made what changes. He said video instructions show how to hook up the A and B components, and a bar code scanner checks the drums before they ever get hooked up — making sure the system is set up correctly.

    Elmet North America is in Dimondale, Mich., near Lansing.

    Mike Pelletier, business development manager for LSR and medical systems at Graco-Fluid Automation Inc., said the company's F4-5 and F4-55 metering systems automatically adjust the pumping ratio to ensure equal material consumption of the two components.

    Graco-Fluid Automation is based in North Canton, Ohio.

    Tooling a specialty for LSR

    Officials from two LSR mold makers described their craft.

    Dana King, business development manager of Kipe Molds Inc., said some critical areas are a balance of fill and valve gate control and proper mold venting on parting lines. By minimizing the pressure drop across the cavity, the mold maker can minimize the possibility of trapping air and flash, he said.

    Kipe Molds is in Placentia, Calif.

    Rick Finnie, president of M.R. Mold & Engineering Corp. in Brea, Calif., said silicone can tear when it's too hot and not fully cured. "It can be easily damaged when coming out of the tools," he said. Deformation can also be a problem.

    "The most common defect with silicone is flash, and it's hard to stop because silicone can flash easily," Finnie said. "It's an ongoing challenge." Other challenges include air-trap, non-fill or short shot areas, as well as "backrind" a ragged indention at the parting line.

    Finnie said gate location and the parting line are very important. Sharp corners in the mold can cause tearing of the part, he said. A mold maker can add undercuts, if they're properly designed, he added.

    Careful mold design is also needed for venting. One option could be adding a small reservoir or "dump area" for excess material, he said.

    "We don't need draft. In fact, you can have negative draft in the mold and it wouldn't hurt anything at all if it wasn't too bad. Silicone does an excellent job of replicating texture that's in the tool," Finnie said.

    Vincent Colarossi, senior application development engineer of elastomers for Momentive Performance Materials Inc., said several techniques can be used for two-component LSR molding, including chemical bonding of the two materials or a mechanical interlock with holes and undercuts.

    Two-component parts can be molded in one injection press, with a mold rotating between two injection units — one for thermoplastic and the other overmolding silicone. Or a molder could use two machines, molding the substrate on one press and moving or over to another machine for LSR processing, Colarossi said.

    "The real driver is the high-performance products — waterproofing and durability," he said.

    RECOMMENDED FOR YOU
    Documentary looks at how ‘we love to hate' packaging
    Letter
    to the
    Editor

    Do you have an opinion about this story? Do you have some thoughts you'd like to share with our readers? Plastics News would love to hear from you. Email your letter to Editor at [email protected]

    Most Popular
    1
    An 8,000-ton dream for Milacron, 20/20 Custom Molded Plastics
    2
    Braskem stops production on a PP line at Pennsylvania plant
    3
    Resin Prices - North America
    4
    Report: Tekni-Plex may be for sale
    5
    National bottle bill ‘could make sense,' senator says
    SIGN UP FOR OUR FREE NEWSLETTERS
    EMAIL ADDRESS

    Please enter a valid email address.

    Please enter your email address.

    Please verify captcha.

    Please select at least one newsletter to subscribe.

    Find more newsletters at plasticsnews.com/newsletters.

    You can unsubscribe at any time through links in these emails. For more information, see our Privacy Policy.

    Get our newsletters

    Staying current is easy with Plastics News delivered straight to your inbox, free of charge.

    Subscribe today

    Subscribe to Plastics News

    Subscribe now
    Connect with Us
    • LinkedIn
    • Facebook
    • Twitter
    • Instagram

    Plastics News covers the business of the global plastics industry. We report news, gather data and deliver timely information that provides our readers with a competitive advantage.

    Contact Us

    1155 Gratiot Avenue
    Detroit MI 48207-2997

    Customer Service:
    877-320-1723

    Resources
    • About
    • Staff
    • Editorial Calendar
    • Media Kit
    • Data Store
    • Digital Edition
    • Custom Content
    • People
    • Contact
    • Careers
    • Sitemap
    Related Crain Publications
    • Sustainable Plastics
    • Rubber News
    • Tire Business
    • Urethanes Technology
    Legal
    • Terms and Conditions
    • Privacy Policy
    • Privacy Request
    Copyright © 1996-2023. Crain Communications, Inc. All Rights Reserved.
    • News
      • Processor News
        • Injection Molding
        • Blow Molding
        • Film & Sheet
        • Pipe/Profile/Tubing
        • Rotomolding
        • Thermoforming
        • Recycling
      • Suppliers
        • Machinery
        • Materials
        • Molds/Tooling
        • Product news
        • Design
      • More News
        • K Show
        • Mergers & Acquisitions
        • Sustainability
        • Public Policy
        • Material Insights Videos
        • Numbers that Matter
      • Digital Edition
      • End Markets
        • Automotive
        • Packaging
        • Medical
        • Consumer Products
        • Construction
      • Special Reports
        • Notable Leaders in Sustainability
        • Processor of the Year
        • Best Places to Work
        • Women Breaking the Mold
        • Rising Stars
        • Diversity
        • Most Interesting Social Media Accounts in Plastics
      • Newsletters
      • Videos
      • Podcasts
    • Opinion
      • The Plastics Blog
      • Kickstart
      • One Good Resin
      • Pellets and Politics
      • All Things Data
      • Viewpoint
      • From Pillar to Post
      • Perspective
      • Mailbag
      • Fake Plastic Trees
    • Shop Floor
      • Blending
      • Compounding
      • Drying
      • Injection Molding
      • Purging
      • Robotics
      • Size Reduction
      • Structural Foam
      • Tooling
      • Training
    • Events
      • Plastics News Events
        • Plastics News Executive Forum
        • Injection Molding & Design Expo
        • Plastics Caps + Closures: A Global Online Event
        • Women Breaking the Mold Networking Forum
      • Industry Events
      • Injection Molding & Design Expo
      • Livestreams/Webinars
      • Editorial Livestreams
        • Bioplastics Live
        • Numbers that Matter Live
        • PFAS Live
        • Plastics in Politics Live
        • PN Live: Mergers and Acquisitions
        • Polymer Points Live
        • Sustainable Plastics Live
      • Ask the Expert
      • Plastics News Events Library
        • Plastics Caps & Closures Library
        • Plastics in Healthcare Library
        • Women Breaking the Mold Networking Forum Library
    • Rankings & Data
      • Injection Molders
      • Blow Molders
      • Film Sheet
      • Thermoformers
      • Pipe Profile Tubing
      • Rotomolders
      • Mold/Toolmakers
      • LSR Processors
      • Recyclers
      • Compounders - List
      • Association - List
      • Plastic Lumber - List
      • All
    • Directory
    • Resin Prices
      • Resin Prices Overview
      • Commodity Thermoplastics
      • High Temperature Thermoplastics
      • Engineering Thermoplastics
      • Recycled Plastics
      • Thermosets
      • Europe - Virgin
      • Europe - Recycled
      • Europe - Feedstock
    • Custom
      • Sponsored Content
      • LS Mtron Sponsored Content
      • Conair Sponsored Content
      • KraussMaffei Sponsored Content
      • ENGEL Sponsored Content
      • White Papers
      • Classifieds
        • Place an Ad
        • Sign up for Early Classified