SOCIETY OF PLASTICS ENGINEERS
GOLDEN GATE SECTION
SERVING NORTHERN CALIFORNIA AND NORTHERN NEVADA
www.spe-ggs.org

DECEMBER 2017





 
 



 

 
 
        


If your company is interested in becoming a sponsor here, please email: spear-head@spe-ggs.org for details..


Holiday Board Dinner


Friday December 8th, 2017
CREOLA BISTRO
San Carlos, CA


   
 CREOLA BISTRO
   
 Location 
  344 Camino Real, San Carlos, CA 94070   
 Date  Friday December 8th, 2017
   
 Time   6:30 PM 
 
 Cost
 $40 per person
 PayPal or cash/check at the door
 Contact
 RSVP to: Jennifer Hoffman JHoffman@airexpanders.com 
 RSVP by Friday December 1st

PLEASE state in the email how you wish to pay: CHECK, CASH OR PAYPAL



I am honored to have the opportunity to represent SPE GGS as the President this year. I’m excited to share my passion about polymer science and re-energize this Section with new events and activities.


My main goal is to provide our members with many interesting tours, workshops and networking opportunities. We recently hosted a networking event at EAG Laboratories, which included a short technical lecture followed by food and conversation. This was a fantastic opportunity for our members to interact and get to know each other better. We are planning to host several such events in the upcoming year.


I am also pleased to annouce that we are in the process of creating a new Mentorship program between students and senior engineers/scientists. Once we have compiled directories of potential mentors and mentees, we will help match those with common interests and professional aspirations. Please contact me at yschneider@eag.com if you would like to be involved.


The mentorship program is just one part of our larger effort to foster a strong relationship between the student chapters and the SPE community at large. We are working very closely with the student leadership on co-sponsored events and have welcomed several new professors to our Board of Directors. We are planning to host a Professional SPE Career panel in February as well as revamping our Education Expo so that more students are involved.


Finally, we are updating our website and becoming more present in social media with a new Facebook account. We hope this will help our members stay aware of our upcoming activities. We have always had a presence of LinkedIn and are continuing to post articles and share events.

As I share my excitement about the upcoming year, I hope that you feel free to reach out to me with any questions or concerns. My door is always open and I’d love to know how our organization can do better to serve you and your needs.

 

Warmest regards,

Yanika Schneider
SPE GGS President
yschneider@eag.com


The GGS wishes to thank Design Octaves for their hospitality and informative tour. The board continues to prepare the calendar for 2017-2018. Special thanks to Yanika & Jennifer for their efforts. Check back here often for more details on future events and join us on LinkedIn. Should you be able to host a tour or can suggest one, if you know of an interesting topic, event, speaker, etc.. please let us know. We appreciate any assistance from both members and non-members to improve our monthly content. Thanks!


Our next scheduled event will be in January 2018. Look for more diverse topics and speakers in 2018. We have scheduled more meetings, tours, and luncheons. Check the CALENDAR section of our web site for our future meetings and social events. We hope to see you at one of our monthly meetings.


Tech Tip December 2017

Documentation

 

There should be two basic types of documentation that any processor keeps. The first is the machine set up documentation and the second is the process documentation. Why, because the first is for setting up the machine and the second is to confirm that the process is now the same.


If one were to use a standard setup sheet or one that is on the machines, within the computer that one finds within most new machines and pieces of equipment, it allows all the machine set points to be recorded. These may include temperatures, pressures, times, speeds and so forth on the machine. These are great, and should be used and hopefully there is even a notes section within the computer so that one may add comments and so forth to the actual setup. On newer machines sometimes one is even allowed to place pictures or data sheets and other electronic forms within the machine memory so that the technician can than review and access.


All this set up data is great to get the process within the operational sphere of processing and may at some point even produce great parts.
  But this documentation does not guarantee a good part or one which was produced last time. The reason being is that there are no results.


The process sheet has the results data, meaning the actual melt temperature, steel temperature, fill time, pressure at transfer, cycle time and hopefully shot weight at transfer.
  Some may even go as far as to record pressure of cooling system and or flow of cooling system.


The reason for the two sheets (which may be combined into one) is that one allows for the setting of the machine, and other allows for setting the process.


An example is that of fill time which is a result of the speed of injection, pressure available, melt temperature, mold temperature, shot size, with suck back, transfer point and lot of material.
  If the material temperature is too cold than it does not flow as good as last time, thus taking more pressure and possibly more time, thus the shear induced upon the material is different and the flow pattern into the cavities is different thus yielding possibly a part which is not the same, as last time.


Another example is that of weight at transfer, if for example one has the same fill time, but not the same weight at transfer, than yes the fill time is correct but the volume of material injected is different thus again shear is different and flow is different and relationship of what is filled and packed on pack/hold is different.


In this day and age I have run into too many issues that the documentation is not available, or that the OEM has specified that the machine conditions cannot be changed after all of their testing has been completed. Yes they may specify that they can only run in this machine, but like everything there is always a wear and tear, and if unfortunately one is not robust enough with the initial setup, and a new lot of material comes into the plant which is at the opposite end of the melt flow range from the one tested initially problems shall arise.
 The other issue is that the processor, whom originally set up the testing and process, has put themselves into a corner due to their ISO procedures and what they wrote. Be aware that ISO is a procedure; allow yourselves as big a window as you may.


Thanks for the time

TA


Steven L Silvey

Silveys’ Plastic Consulting

360-882-3183

www.silveysplasticconsulting.com

Silveysplastics@hotmail.com



The Microfluidics Corner  -- by Rey Parel rparel@parelengineeringllc.com
 

Imagine a world where disease could be predicted before it happens, instead of diagnosed and cured by drugs or surgery.  Where doctors could change a patient’s life style, diet and exercise, and prevent the disease.

 

A Bishop once told me, long ago before the advent of the diagnostics revolution, that God designed the human body to produce very small amounts of antigens to signal the advent of diseases, and was just waiting for man to rise to the level of intelligence to create devices that would be able to detect these.

 

Flashback to 1989, when I met Kary Mullis, who won the Nobel Prize in Chemistry in 1993 for a technology called Polymerase Chain Reaction, and he said:  “I want you to design a tube that is so thin and so uniform in thickness, it has never been done before in plastic!”  And we asked, why plastic?

 

Because we will produce millions and millions of these “thermocycler tubes”, and it has to be manufacturable and cheap, robust and accessible to ordinary folks.  It blew our minds, because the concept of amplifying (making copies) of DNA was not only foreign to us young plastics engineers but mind-boggling in its concept.

 

The way he explained PCR to our “primitive” minds was like this:  Imagine our DNA chain as a railroad track twisted like a helix.  Under heat, this railroad track unravels into a straight track.  The polymerase enzyme takes base pairs from other sections of this railroad track and puts it in the same sequence as the DNA sequence you want to copy.  And it can do this hundreds, millions, even billions of times.

 

He said the thermocycler tube wall thickness must be incredibly uniform, so uniform in fact that it was well nigh impossible to produce with the state of plastics technology at the time.

 

As I said, it blew our minds!  Fast forward 3 years later, and the first GeneAmp PCR System was developed and the ultra-thin, ultra-uniform PCR thermocycler tube was a reality.  I certified the polypropylene material that is still used today in all your labs.
 

I have a Polaroid photo of myself and the Perkin-Elmer guys kicking the first box of PCR tubes out the door.  One of its first applications, even before it was ever mass-produced, came about from a very tragic incident in Petaluma in 1993.

 

The FBI approached Perkin-Elmer and said: “We heard you have a new method for making copies of DNA.  We have a very small spec of blood on the scene where a little girl by the name of Polly Klaas was abducted and subsequently murdered, and which we believe was of the perpetrator.  The spec is so minute, we can’t identify it.”

 

I have to tell that when the District Attorney held up that tube on TV and said:  “This is Polly’s blood!”, I ran up and down my neighborhood and yelled, “That’s my tube!  That’s my tube!”  When I recount this story today, it still gives me goose bumps almost 25 years later.



Fast forward to 2000, when we made the very first microfluidics chip in plastic at Aclara Biosciences.  Seventeen years ago, advances in materials, machinery, equipment, and software were still in their early stages to enable replication of micron plastic features.  It was a struggle.

 

 

 

 

Fast forward some more to 2010, when we were using injection-compression molding technology, borne out of the CD/DVD industry and morphed by Sony DADC Biosciences for biotech applications, to mold at Illumina a credit-card sized PCR chip with 2.8 million wells, each well 30 microns in diameter.  Who would have thought this was possible 25 years ago!

 



I tell this story about PCR because as the engine that revolutionized research to sprout new fields in DNA sequencing, genomics, bioinformatics and the like, this surging wave spurred the plastics industry to develop new techniques, new machinery, new tools, and new polymers to meet the demanding challenges of replicating increasingly smaller and smaller features.

 

The result was the plastic microfluidic chip embedded in almost every diagnostic medical device today.

 

 Polymer-Based Microfluidic Chips: The Engine That Is Driving a New Generation of Medical Devices Called Prognostic Point-Of-Care Devices

 

The impact of the microfluidic chip in the Life Sciences is similar in magnitude to the impact of the microchip in the Information Sciences.  If the microchip reduced building-size computers to the size of your hand, the microfluidic chip is reducing building-size laboratories and hospitals to the size of your thumb.

 

Why plastic?  Consider this:  It costs around $0.30 cents per sq cm for a silicon-glass chip and $0.03 per sq cm for the same chip molded in Cyclic Olefin Copolymer.  As Kary Mullis said, it must “manufacturable and cheap, robust and accessible” to the masses.

 

The push over the last 15 years is transitioning from glass to polymer substrates, because of the latter’s scalability, manufacturability, lower cost and biocompatibility.  Microfluidics means smaller reagent volumes (some of which can cost several hundred or thousand $ per liter), but also shorter reaction times and faster analyses results (from days in a lab, to hours or even minutes), on-site delivery of test results, smaller sample sizes (blood, cells, etc.), and greater number of iterations (from tens to several millions) – all of these translating to less cost, portability and disposability. 

 

Hence, the development of exciting new devices such the ubiquitous Lab-on-a-Chip, the more recent Organ-on-a-Chip and Body-on-a-Chip, each about the size of your thumb or palm.  All of these devices take advantage of the unique fluidic flow properties at the microfluidic level, and most if not all powered by micro pumps and valves without external power sources except capillary pressure, all integrated into the plastic design.  Did I say moldable?  Yes! 

 

How these are accomplished in fact is due a convergence of teams of researchers with inventions for advanced immunoassay devices and dense arrays (from sample prep, to amplification, to detection, to immunoassays, to sequencing) with teams of plastics engineers who have developed these new techniques to make their scale-up a reality.

 

As Healthcare moves away from curing diseases to predicting diseases via handheld POC (point-of-care) devices, the advent of the polymer-based microfluidic chip is the enabling technology that is making this happen. These new devices are called Prognostic Devices.

 

At the heart of these disease-predicting devices are novel developments in nano-biosensors and ultra-sensitive DNA detection.

 

One Example:  Imagine a microfluidics-based POC device that can detect BNP, a cardiac marker antigen that is produced by the heart in very minute quantities before the advent of Arrhythmia in a patient. Then the doctor can prevent the disease by changing the patient's life style, diet and exercise.

 

There is such a device right now, in production by a China-based company, Micropoint Bioscience (http://www.micropointbio.cn), and was initially funded by the Chinese government, because there are 100 million people with incipient arrhythmia-risk in the Chinese mainland, many without direct access to government hospitals.

 

The device is called mLabs® Precision POC Testing, which is an immunoassay diagnostic platform based on their patented microfluidic technologies and advanced fluorescence detection.

 

According to Micropoint’s CEO, Nan Zhang, the device currently tests for D Dimer (a protein released by blood clots), but more cardiac markers are coming soon, including Troponin I (a marker for heart muscle damage), hs-Troponin I (a marker for acute thrombosis syndrome), and the aforementioned BNP.

 

Why polymer-based microfluidics chips?  Over the last 25 years, microfluidics has been largely silicon-glass based, due to their micron-size features, which was difficult to replicate using conventional molding methods and materials.

 







The state of the art has finally caught up with the exacting demands of the microfluidics field. There are exciting breakthroughs in the following technologies that are enabling microfluidic chip injection molding:

 

(1) Conformal cooling, microstructure and microfluidic tooling

 

(2) Microchannel molding, dense micro-array and replication processes

 

(3) Surface modification and surface treatment techniques

 

(4) Advanced polymers and plastic materials

 

There are exciting developments in automation, simulation software, molding equipment, and 3D printing that have advanced in lock-step with the growth of the microfluidic chip field.

 

Succeeding articles will touch on these breath-taking developments and more examples of Prognostic Devices that are breaking new ground.




SPE Council Meeting
Friday, August 25, 2017
Detroit, MI

The following summary of the SPE Council Meeting is offered to all. This summary may be published in affiliate journals and newsletters. The official meeting minutes are posted to The Chain and contain complete details of attendees, policy and by-law changes, and procedural votes.

Questions or comments? Contact Conor Carlin, VP Marketing & Communications at ccarlin@4spe.org or communicate via Leadership Lane on The Chain.


COUNCIL MEETING SUMMARY


Respectively Submitted,

Michael LoDico
SPE GGS Director / Councilor
mld@plasco-corp.com



 
CHICO STATE UNIVERSITY  SAN JOSE STATE UNIVERSITY
Dept. of Mech. Eng, & Mfg. Dept. of  Biomedical, Chemical & Materials Engineering
Chico, Ca. 95929 San Jose, Ca., 95192
Faculty Advisor: Faculty Advisor:
Nathan Anderson
Ozgur Keles, PhD
530-898-5976 408-924-3927
nlanderson@csuchico.edu ozgur.keles@sjsu.edu
STUDENT CHAPTER: STUDENT CHAPTER:
President: Jacob Thorup President: Crystal Pereira
jthorup@mail.csuchico.edu crystal.pereira510@gmail.com
VP: Sam Prince VP: Syed Rahim
sprince4@mail.csuchico.edu syedrahimog@gmail.com
Secretary: Dominic Lerma Secretary: Ashley Oh
dlerma@mail.csuchico.edu soofern.oh@sjsu.edu
Treasurer: Chad Nevin Treasurer: Matthew Montecillo
cnevin2@mail.csuchico.edu matthew.montecillo@gmail.com

CHICO

[ awaiting text at post time ]

Jacob Thorup
Student Chapter President
Chico State University
Jthorup@mail.csuchico.edu
 

SJSU

Fall Events:

September 5th - Recruited new members at the SJSU Club Fair

September 15th - Recruited new members at the Engineering Club Fair

October 21st - Hosted Materials Engineering open labs and presentation for the Engineering Open House

November 16th - Thanksgiving Social at Pizza My Heart from 6pm to 8pm


Upcoming Spring Events:

December 5th - Final Meeting of the Fall Semester

January 23rd - Lockheed Martin Tour

February (Date Unavailable) - Guest Presentation. We are still looking for an industry professional available to give a technical talk on this day. Please contact Crystal Pereira at crystal.pereira510@gmail.com if interested.


The SPE Student Chapter at SJSU aims to provide students interested in the polymers and plastics engineering with opportunities to further their knowledge to become successful in the industry. The student chapter aims to encourage students to follow their interests in the field of polymers through professional networking events, technical talks, team projects, and industry tours.

 
Crystal Pereira

San Jose State University

Undergraduate in Materials Engineering

Golden Gate Chapter of the Society of Plastic Engineers

Student Chapter President

crystal.pereira510@gmail.com


CAMPUS CONNECTION

As an SPE Student Member, Campus Connection offers you and other student members an exclusive online community to ask questions or provide answers to hot topics of interest for today’s engineering students. This Place is professionally moderated by a group of respected plastics professionals from academia and industry who are ready and willing to give you guidance on a path to career success.

Campus Connection 



MATERIAL DEVELOPMENT FOR 3D PRINTING 

In the past few years, injection molders have gone from using 3D printers almost exclusively to create prototypes to exploring larger scale production opportunities for complex parts. However, material developers haven’t always kept up with industry changes.

Plastics Business reached out to injection molders and material suppliers to discuss material development – specifically resin – for the ever expanding world of 3D printing: Mike Idacavage, vice president of business development for Colorado Photopolymer Solutions; Matt Hlavin, president, Thogus Products and its sister company rp+m; and Bob Holbrook, sales and marketing manager, and Ed Graham, engineering manager, ProtoCam. Each was asked for his individual perspectives and experiences regarding material development for 3D printing.

What concerns do plastics molders have about the resin availability for 3D printers, especially as it concerns more precise applications, such as those for the medical industry?

Idacavage: From a liquid resin material supplier perspective, the concerns that I hear from plastic manufacturers can be bucketed into several categories. The first would deal with achieving physical properties that match or exceed current plastic specifications. The second area of concern involves the safety and handling of the resin materials, especially for medical and electronic applications. Once again, this issue seems to be more of a concern for liquid resin suppliers. Finally, the issue of cost does come up. However, compared to the first two concerns, this tends to be a lower priority as the plastics manufacturers are primarily focused on making unique and custom parts that meet target specifications as the highest priority.

FOR MORE INFO --- CLICK HERE ---



BECOME AN SPE YOUNG PROFESSIONAL
http://youtu.be/hcSEUcudwDw
 

BECOME A SPE STUDENT MEMBER
https://www.youtube.com/watch?v=37PIrf5UCkc
 

SPI'S SUSTAINABILITY
http://youtu.be/tyqw6426cnc
 

SPI'S STUDENT VIDEO 1ST PLACE
WAKE UP IT'S THE PLASTICS AGE
http://youtu.be/JXX7jyAAahc
 

MAN CONVERTS PLASTICS TO OIL
http://youtu.be/qGGabrorRS8
 

Mike Biddle: We can recycle plastic
http://youtu.be/RD07GkmM2fc

STANFORD'S SELF-HEALING PLASTIC SKIN
http://youtu.be/R0YPRomPDOo
 

SPI STUDENT VIDEO
THE TRUE MEANING OF PLASTICS
http://youtu.be/yFcZ4GklhOA
 

WHY PLASTICS?
http://youtu.be/Sxezn9uJLHw
 

SPE is ME ! 
https://youtu.be/FWiFFoqUYnk
 

THE PLASTIVAN PROGRAM
https://youtu.be/J3BGmU_IgG4
 

JON RATZLAFF, SPE PRESIDENT, 2013--2014
http://youtu.be/oGOoW1K5lfE
 

CASSINI PROBE FINDS PROPYLENE ON SATURN'S MOON TITAN
http://youtu.be/IN0SbMeOGIA


SPE and ANTEC Groups Continue To Grow on LinkedIn® and Facebook®

SPE has Largest Group for Plastics Professionals on LinkedIn
Membership in the LinkedIn® group of the Society of Plastics Engineers now exceeds 10,000, making it the largest group for plastics professionals on the LinkedIn social media platform.
The SPE LinkedIn Group has become an industry resource for plastics professionals who are seeking answers to technical questions, networking, and even employment opportunities.
 

If you're a member of LinkedIn or Facebook, join the Society of Plastics Engineers and ANTEC™ Groups and display their logos in your profile.

       


DEFINITION OF RESINS

PLASTICS have developed an amazing presence in our lives. From the most commonplace tasks to our most unusual needs, plastics increasingly have provided the performance in products that consumers want. In fact, if you woke up tomorrow and there were no plastics, you would be in for quite a shock. Life would be much more expensive and much less comfortable. And many of the conveniences you had come to take for granted would be gone. Mostly, though, you would be surprised at the many products that had vanished—things you had never thought of as being plastic. That’s because, in just a few decades, consumers have come to consider the extraordinary properties of plastics as nothing out of the ordinary. Plastics’ popularity and wide usage can be attributed to one basic fact: Because of their range of properties and design technologies, plastics offer consumer benefits unsurpassed by other materials. Let’s take a look at the different types of plastics, usually referred to as “resins,” and see how they are made and used:

Plastics generally are organic high polymers (i.e., they consist of large chainlike molecules containing carbon) that are formed in a plastic state either during or after their transition from a small-molecule chemical to a solid material. Stated very simply, the large chainlike molecules are formed by hooking together short-chain molecules of chemicals (monomers: mono = one, mer = unit) in a reaction known as polymerization (poly = many). When units of a single monomer are hooked together, the resulting plastic is a homopolymer, such as polyethylene, which is made from the ethylene monomer. When more than one monomer is included in the process, for example, ethylene and propylene, the resulting plastic is a copolymer.
Thermosets and Thermoplastics

The two basic groups of plastic materials are the thermoplastics and the thermosets. Thermoplastic resins consist of long molecules, each of which may have side chains or groups that are not attached to other molecules (i.e., are not crosslinked). Thus, they can be repeatedly melted and solidified by heating and cooling so that any scrap generated in processing can be reused. No chemical change generally takes place during forming. Usually, thermoplastic polymers are supplied in the form of pellets, which often contain additives to enhance processing or to provide necessary characteristics in the finished product (e.g., color, conductivity, etc.). The termperature service range of thermoplastics is limited by their loss of physical strength and eventual melting at elevated temperatures.

Thermoset plastics, on the other hand, react during processing to form crosslinked structures that cannot be remelted and reprocessed. Thermoset scrap must be either discarded or used as a low-cost filler in other products. In some cases, it may be pyrolyzed to recover inorganic fillers such as glass reinforcements, which can be reused. Thermosets may be supplied in liquid form or as a partially polymerized solid molding powder. In their uncured condition, they can be formed to the finished product shape with or without pressure and polymerized by using chemicals or heat.

The distinction between thermoplastics and thermosets is not always clearly drawn. For example, thermoplastic polyethylene can be extruded as a coating for wire and subsequently crosslinked (either chemically or by irradiation) to form a thermoset material that no longer will melt when heated. Some plastic materials even have members in both families; there are, for instance, both thermoset and thermoplastic polyester resins.


As the world's leading membership organization in the plastics industry, SPE is committed to providing a link between those seeking a specific resource and the providers of products and services.

This is a NEW online resource to help you quickly and easily find the expert services you need. The listing comprises members of the Society who offer technical and non-technical services, and is searchable in a variety of ways—by area of specialty, company name, and regions serviced.

For any questions about this service, please contact consultantscircle@4spe.org.

CLICK HERE FOR THE CONSULTANTS CIRCLE


SHORT SHOTS

When we ask customers what their most pressing quality issues are, short shots or non-filled parts are inevitably on the list. So why don’t we start by defining a short shot. A short shot is when a plastic part does not completely fill out. A portion of it is missing. A few issues can cause shorts, and the fix is not always that straightforward. Poor venting, material variations, improper machine settings, blocked gates or other possible mechanical failures can cause them. The fix to these issues are equally numerous – depending on the root cause of the problem.

One of the first steps in troubleshooting a short shot is to turn off second-stage pressure and time, and make what is referred to as a fill-only part. This will give you an idea of the flow pattern of the material inside the cavity and help with the troubleshooting process. Our goal is for this part to appear to be 95 to 98 percent full with no second stage being applied.

If the part is significantly smaller than that, we need to start with a root cause analysis of the problem.

  1. Verify the machine settings are correct by comparing them to the process setup document.
     
  2. Make sure there are not any mechanical problems. Check for any foreign material that possibly could be blocking the gates and impeding flow into the cavity.
     
  3. While the machine is down, it’s a good time to give the mold surface and vents a good wipe down to make sure they haven’t been clogged.

If everything seems to be in good working order, the problem simply could be material variation. The raw material coming into your plant will vary over time and may cause significant changes in your process. If this seems to be the cause of the short shot, then add material to the cavity. Again, the goal is to have this fill-only part 95 to 98 percent full. We recommend adjusting the shot size to achieve this, if necessary.

Next, put back the second stage pressure settings and take a look at the parts. Ideally we would have a target part weight to help us get back on track. If the short is still present or the part is underweight, then we can increase the second-stage pressure to drive more material into the cavity. As we do this, the short will hopefully disappear and the part weight will come up.

The ultimate goal is to follow a systematic troubleshooting procedure that allows everyone to work through the process in the same manner for the same reasons to fix the problem.

Shane Vandekerkhof is an RJG Consultant/Trainer. He is a certified Master MolderSM that is qualified to teach Scientific and DECOUPLED MOLDINGSM methodologies and techniques. He also has extensive field experience networking RJG’s eDART System and implementing cavity pressure sensor technology. For more information, visit www.rjginc.com.


PAINTING STRUCTURAL FOAM

The Foam Surface

The surface of structural foam differs greatly from that produced by conventional injection molding. The internal structure of foam molded products is produced by what are known as "blowing agents. These substances are available in solid, liquid and gas forms and are used to produce gas bubbles in the melted resins. This foaming action produces a rough swirled pattern on the surface of the part. For this reason the finishing techniques involved with foam are somewhat different than those used with conventional molded parts. There are new foam parts finished today are of the rougher surface variety.

Part Preparation

In most cases it is possible to finish a foam molded part with no secondary surface preparation; but, as with all finishing operations, there are times when it is necessary. An uncontaminated surface is key in achieving satisfactory finishing results. Parts should be checked for oils, mold release agents, and mold cleaning agents. If contamination is found the substance should be removed with an appropriate solvent or sanding. Sanding may also be necessary to promote paint adhesion or to remove molding imperfections that would mar the surface of the finished part. Unlike solid molded parts, foam molded parts cannot be finished immediately after molding. The gasses produced by the blowing agents must be allowed to come to equilibrium with surrounding air. This "outgassing" process will take from 24 to 48 hours, the time being dependent on temperature and relative humidity. It is important that sufficient air flow be provided around the parts to allow them to "breathe". If the parts are enclosed or improperly spaced during the set time, outgassing may not proceed to completion. If painting is attempted before this process is competed, blistering of the finish may result

Finishing System

There are many factors governing the choice of a paint system. End-use environment, physical properties of the cured film, applications techniques, and EPA regulations will all have an effect in the selection process. For this reason, careful consideration should be given to which aspects are prevalent in a given application. The poor quality of the foam molded surface makes it difficult to achieve an acceptable surface with one coal of paint. In many cases it is necessary to use two or three coats: primer, color coat, texture. The primer, sometimes called a filler, is used to fill the rough surface of the part. The color coat provides the color and is also used for the final surface texture of the part. In some cases, it may be possible to use a higher solids paint systems to eliminate the need for one of the coats. Even with the use of high solids paints, high gloss finishes are difficult to obtain. Many primer coats and sanding operations are needed to smooth the surface enough to apply a gloss coat. If the surface has any remaining imperfections when the final coat is applied, the gloss of the finish will make them more evident. The difficulty and labor intensity of this process makes gloss finishing foam molded parts relatively expensive.
Higher solids paints and water based systems have gained popularity in recent times due to high costs and governmental regulations concerning organic solvents. The lower solvent content of high solids paints allows a greater amount of film to be deposited per amount of solvent released into the atmosphere. Water borne systems offer the advantages of low solvent content and cost stability. The drawback of water borne systems is the need for a primer to cover the surface before the color and texture coats are applied.

The cure times of some coating systems can be increased by the use of heat. Baking at elevated temperature decreases cure times and speeds the evaporation of solvents. Parts should not be baked above the heat deflection temperature of the material. This can cause distortion and post blow of the part.





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MESSAGE FROM THE MEMBERSHIP COMMITTEE CHAIR

Greetings from your Membership Chair!  I am excited about the coming year with new plans and actions envisioned for increasing our Section membership fold.

 

These plans and actions are embodied in a year-long New Membership Drive, to be kicked-off with a “Membership Recruitment Blitz” in January.

 

My primary goal for this fiscal year is to increase our Section membership roster by at least 15% by October 2018.  In aid of achieving this goal, the Membership Committee would like to enact a set of Action Plans for Fiscal Year 2017-2018:

 

1.     Increase Membership Plan:

 

a.     Start emailing and calling individual Section members of good standing to create personal contact and encourage each of them to help in the membership recruitment drive.

b.     Launch a year-long “New Membership Drive” starting with Recruitment Blitz to jump start our recruitment effort and drum up interest and support, including prizes for a “Recruit Me a New Member” promo, New Members Gala at the end of the recruitment drive, etc.

c.      Set-up a small Section Booth within the SPE pavilion in Bay Area plastics expos or plastics events, such as MD&M West, BIOMEDevice, Design-2-Part, etc.

d.     Design and print a new Section brochure that highlights our long history in the Bay Area, some of our accomplishments, and benefits of joining SPE and the Golden Gate Section, in addition to our existing virtual info sites.

e.      Increase our visibility by partnering with GGPF, ACS and other organizations in the Bay Area.

f.      Do not limit Section membership to residents of the Bay Area, but widen our membership net to out-of-state SPE members who have interest in or ties to the Bay Area.

g.     Reach out to companies in the Bay Area and encourage them to provide free memberships to interested employees, including reminding them of tax benefits, etc.

h.     Increase mailing list by attending networking events and expos, and gathering business cards; enlist the help of Section membership by giving prizes for an “Increase Our Mailing List” promo.

 

2.     Increase Outreach and Participation Plan:

 

a.     Offer membership recognition perks, such as letters of appreciation, length of membership certificates, free dinners at Section events, car stickers “I am a SPE GGS Member”, etc. 

b.     Organize formal groups within the Section for members with common interest, such an ‘All Emeritus Group’ who will provide “old fogies/plastics guru” expertise to young plastics engineers with specific technical problems, or ‘Ladies Golden Gate Group’ who will encourage more female membership in SPE GGS, etc.

c.      Set-up a General Membership Discussion Board in our new website along the lines of Community of Plastics Professionals LinkedIn Group.

d.     Set-up a Process Engineers Blog in our new website catering to technical discussion among Section members specifically devoted to plastics-related challenges, issues and solutions in their respective jobs.

e.      In coordination with the Mentorship Program being organized at each Student Chapter (Chico State, SJSU), organize a mentorship program with Very Senior Section members, who will mentor individual SPE student chapter members in the Bay Area to offer their perspective in their respective plastics careers.

f.      Set-up a new Facebook page in order to enhance this personal connection.

 

All these action plans align with our President’s Goals for SPE GGS 2017-2018, including plans to upgrade our Section website to incorporate features and interactive links suggested in the action plans.

 

So the first order of business is to kick-off a 2-month Recruitment Blitz starting the first of the year.

 

The formal mechanics of this Recruitment Blitz will be published by SPE GGS, under the coordination of the Membership Committee, over the next few weeks. 

 

I have sent out welcome letters to our new members and hope that they in turn will encourage their colleagues and friends to sign-up.

 

I would also like to promote a more personal touch with our membership, and have started personally calling, emailing, and thanking members who have attended recent SPE GGS events, and encourage those who may be interested to join specific “common interest” groups, such as:

 

·      “The Mavens Group”  --  Like-minded very senior members with long experience in plastics who can share their life experience in their respective plastic fields with younger members and give sage advice in pursuing a career path in plastics.

·      “Young Guns Group”  --  Young engineers who share a passion for ground-breaking, paradigm shifting plastics technologies, such as 3D bioprinting, shape-shifting polymers, surface-mobile plastics, injection-compression molding, microfluidic conformal tooling, nano-feature molding, and highly-advanced plastics-related technologies nobody has even heard of.

·      “Ladies Golden Gate Group”  --  Lady members who can conclave on a regular basis and discuss activities of interest focused on increasing young women graduates to pursue plastics engineering career.

·      Other groups of common interest to be formed and organized.

 

All these new initiatives are meant to improve this personal connection between members, as well generate interest in non-members to join our fold.

 

I look forward to a very productive and dynamic year, starting slowly at first and then revving up and snowballing as the fiscal year progresses.

Welcome, New Members!

 

REY PAREL

Membership Committee Chair


MOLD MANUFACTURERS GAIN COMPETITIVENESS

What makes one mold manufacturer more competitive in a downturn over another? Why do some moldmakers weather the storm, and even prosper, while others fail? Harbour Results, Inc., through the Harbour IQ database, has recently completed a number of studies and conducted in-depth analytics which uncovered common trends among what it calls the" Have's" and the "Have Nots". "Have" shops will gain competitiveness and will be able to weather a downturn. "Have Not" shops are more likely to struggle. One "Have" shop has built barriers to competition by selectively focusing on the specific types and sizes of molds it produces - this has allowed the company to invest in the specific machines, people and processes to sustain its competitive advantage, and make a significant margin premium over the average shop. Another mold manufacturing shop, a former "Have" turned "Have Not", has rested on its laurels and failed to continue to invest in its business. The result is that the company has been forced to be less selective about the projects it takes and increasingly compete on price. As a result, the margins have slipped into dangerous levels.
 

For a glimpse at the analysis and to view where shops fall on the spectrum, visit the HRI blog here


Attending SPE Conferences and Webinars is a great way to keep up with current progress in plastics technology and learn about the latest breakthroughs in polymer science. Find practical solutions, share best practices and network with your professional peers throughout the year at SPE's many events.

SPE Members receive discounted rates on all event registrations.


Click here for the SPE Events.

NOVEMBER 2017

 

Nov. 15-16, Santa Clara

IDTechEx Show

http://www.idtechex.com/usa2017/show/en/

           


DECEMBER 2017

Dec. 6-7, San Jose

BIOMEDevice meeting

http://biomedevicesj.mddionline.com/

 

Dec. 17-20, San Diego

ACS POLY Division Workshop:  Polymers and Nanotechnology

http://polyacs.net/Workshops/17Nano/home.html

 


JANUARY 2018

Jan 27-Feb 1, San Francisco

Photonics West 2018

https://spie.org/conferences-and-exhibitions/photonics-west?SSO=1



FEBRUARY 2018

Feb 25-March1, San Jose

Annual SPIE Advanced Lithography meeting

https://spie.org/conferences-and-exhibitions/advanced-lithography

 

Feb. 22, San Jose

NCCAVS 2018 Annual Equipment Exhibition

https://www.avs.org/Chapters/NCCAVS/Symposia-Exhibitions

 

Feb 23 – March 1, San Diego

Adhesion Society Annual Meeting +

6th World Congress on Ahesion and Related Phenomenon

https://www.adhesionsociety.org/TAS/ASAnnualMeeting/Home/ASAnnualMeeting/Home.aspx



FIVE FACTORS IMPORTANT TO INJECTION MOLDING

Injection Molding MachineThere have been a lot of breakthroughs to make the injection molding process more effective and predictable.

When field experts apply their knowledge with the experience of years of producing highest-quality injection molding services and processes, you end up with the highest-quality designs, processes and approaches that continue to move forward the advancements into this internationally critical back-bone industry.

There are several factors that are critical to the injection molding process. These include:

    Plastic Melt Temperatures
    Barrel Temperatures
    Nozzle Temperatures
    Plastic Flow Rates
    Plastic Pressure or Screw Back Pressure
    Plastic Cooling Rates and Times

Plastic Melt Temperatures

These melt temperatures are a combination of multiple factors and settings. The three areas of temperature that need to be considered include barrel, nozzle and mold temperatures.
Barrel temperatures and nozzle temperatures are respectively related to plasticizing and flowability of the plastics being moved through the mold. The actual mold temperature is directly connected to the ability of the plastic to flow through as well as cool down during the injection molding process.
Barrel temperatures need to be considered carefully, and set between melting points and thermo-decomposition temperatures. When set too high, it can cause overflow and flash, where too low temperatures can cause melt lines, slowing of flow, unfilled parts and even ripples in the product going through the injection molding process.

Nozzle Temperatures

Nozzle temperatures also need to be lower than barrel temperatures.  The nozzle temperature should be lower than the barrel temperature. If it is too high-- melting plastic will drool in the nozzle and the plastic will decompose if the temperature is too low. Materials may also block the nozzle-- causing bad components. The mold temperature completely impacts the flowability, the cooling speed, and the performance of plastic products created by the mold.

Plastic Flow Rates

The plastic flow rates need to support the ability of the heated plastic to be injected as fast as possible into the cavity until it is 95 to 99 percent full. Here transfers are made into the pack and hold machines that are in position to make these transfers. These flow rates determine viscosity as it enters into the mold cavity. When the hold pressures are too high--you get overflow and flash, but pressure being too low means void problems.
With the plastic pressure settings the packing of parts to finish filling while adding just enough plastic to compensate for any shrinkage is important. The pressure needs to be established to give the part the needed cosmetic look and size. Plasticizing and injection pressures are also very important to consider.

Plastic Pressure

Screw Back pressures are also known as plastic pressures. They are controlled relief valves located in the hydraulic system. With daily use, most products need to be as small as possible so that the pressure can vary from material to material. When considering injection molding pressures the pressure applied to melting plastic by the head of the screw (hence the name "screw-back pressure") this happens when the screw is moving forward, a process controlled by the automated systems of the machine.
When injection pressure is really high, the flow-ability of the plastic is increased which can also increase issues such as overflowing and flash, while pressure too low means the flow of the plastic is decreased and problems like bubbles and void again will arise.

Cooling Rates and Timing

With cooling rates you have the difference between melt and mold temperatures. The mold temperatures are established by using materials that the manufacturers recommend for the ranges as well as the temperatures that your customers recommend for that specific part.
The cooling time can be established by basing your information on the part and mold designs as well as the materials being used. In order to fine-tune your cooling times during your process development, you need to consider customer expectation with part appearance, desired properties and the requested size.

Source: Crescent Industries


EIGHT TIPS FROM D-M-E

Give your tooling an end-of-the-year checkup with these 8 tips from D-M-E

Yearly maintenance procedures will be different for every injection molding location depending on mold cycle volume. Here are some general guidelines that any molder can use for your hot runners, heaters, leader and ejector pins
and more to keep your tooling running efficiently and to prevent unwanted surprises.

1. Check vents for telltale rust or moisture – If you see rust or moisture around a hot runner vent hole, it indicates internal condensation or the possibility that a water line popped off. This moisture causes a short and can be fatal to
heaters. When machines are not running 24/7 and are turned off overnight or on weekends, the chances of such condensation increases.

2. Take the time to remind operators not to ‘clear’ nozzle tips from gates – If an operator happens to notice a tiny piece of steel flush with the gate of the mold, it may turn out to be a point-gate needle assembly. ‘Clearing’ this
perceived obstruction usually destroys the nozzle tip. To prevent nozzle destruction, verify the tip style of the hot runner system before taking action and assure all operators are well trained to identify the different tip styles they
will come in contact with.

3. Lubricate the slide retainers – This is an activity that really should be done once a week if running a 24/7 operation. Year-end is a great opportunity to create a routine maintenance program for lubricating these parts.

4. Cross-check your heater ohm readings – Assuming you checked the ohm readings when your heater was new, this is the time to take a new reading and compare. If the readings are up or down by 10 percent, it is time to start
thinking about replacing the heater to ensure it does not fail at a critical time during your production process. If the initial ohm reading was never taken, get a reading now and use that as a baseline for future checks on that heater.

5. Look for signs of wear between leader pins and bushings – Look for scores or scrapes. This damage is due to a lack of grease. If marks are just beginning, you can extend the life of the leader pins and bushings by keeping them
well greased. If you find significant wear, it is time to install new parts. Otherwise, cavities and cores may not line-up properly, resulting in unequal wall thickness on your part.

6. Check for water flow – Hookup a hose to the out port and run water through the water line into a bucket. Unclear or colored water may be a sign of rust and poor water flow signifies blockage. Drill out the water lines if these
problems are found (or clean with whatever method you typically use). Future problems due to rust and blockage can be prevented by improvements in the plant's water treatment system.

7. Clean the ejector pins – Over the course of one year, ejector pins will become dirty with gas buildup and film.  A good cleaning with mold cleaner every six to 12 months is recommended. Once clean, put a light coating of grease on
the pins to prevent galling or breakage.

8. Look for nicks in the radius area of your sprue bushings – Nicks are caused by leftover loose, hardened pieces of plastic left in the machine nozzle that cause damage due to clamping force from the injection carriage unit during
injection forward. Problems may also occur from a misalignment issue. Look for both possibilities when nicks are found. Replace sprue bushings if damage is bad to prevent a flower pot leak (an old molders term: leakage of plastic
between the bushing and the machine nozzle tip).

Following these tips will help you to recognize and prevent potential problems, keeping your molds running at optimal levels.


VENT MAINTENANCE 

As overlooked as vents can be in the design phase of molds, the ongoing condition of vents also typically is ignored – just as much as the lowly water line when molds get into the production environment. And, just like the poor water line, vent integrity usually only comes under a spotlight after it begins to cause part or processing issues.

In a perfect world, perfectly placed vents would never get hobbed (typed) in or washed out and the depth always would remain at the original specification. But, in the real world, mold vents take a pounding from being slammed shut, hobbed in from excess tonnage due to incorrect set-up parameters or run in presses too large for the job. Or, they become washed out from abrasive resin off-gassing, overzealous use of Scotch-Brite™ or the application of other cleaning methods using hand stones, sandpaper and glass bead blasting. Tenths of a thousandth of an inch can affect the performance of mold vents.

Another consideration is the finish in the vent. Many processors feel vents need to be polished to an SPI A3 finish to allow the compressed air to escape more easily and to make the vent “self-cleaning” by allowing the vent residue to exit into the vent dumps instead of sticking in the vent itself. While I can’t attest to ever measuring any decrease in the cavity pressure during filling of cavities with polished vs. unpolished vents, I can attest to the residue not loading up as quickly in polished vents, and this allows molds to run longer in between PMs. Polishing vents as an afterthought – especially small ones – is a task best left to skilled technicians as it is easy to roll critical edges and take the vents too deep.

Keeping vents fresh and breathing easily relies on an ability to adequately measure the depths at specific periodic frequencies. While not something that needs to be performed after every 30-, 60- or 90-day run, vent integrity should be validated before burning and inconsistent backpressure issues are allowed to surface.

Monitoring of vent depths should be performed using a tenth indicator and base on a surface plate, and the results mapped by cavity and vent location. Parting line vents being crushed in specific locations can point to unequal pressure being applied by out of square or hobbed press platens and other tooling stack issues that can affect mold face shut-offs.

Vent residue buildup between cores, sleeves and other dynamic tooling, as well as internal lubrication levels, is one of the prime considerations when determining PM schedules for molds and should always be noted before mold tooling is cleaned. Vent dumps that fill up will force the gas/residue into areas where it shouldn’t go, such as between a core and sleeve or other moving and close-fitting tooling. This becomes a big problem simply because typical residue is gummy and has been the root cause of many molds galling up.

As usual, all the mechanical and physics wizardry in the world won’t work for long without a solid maintenance plan that keeps tabs on the critical elements of molds being run.

Steve Johnson is the operations manager for ToolingDocs, a provider of maintenance training products and services. His more than 35 years in the tooling industry includes eight years as senior tooling engineer for Abbott Laboratories and 24 years as a toolmaker at Calmar Inc., repairing and rebuilding high cavitation, close-tolerance, multi-cavity molds. Johnson also has designed and developed MoldTrax, a leading documentation software system for tracking mold performance and maintenance, and he authors articles for several plastics industry magazines. For more information, call 419.281.0790 or email Steve.Johnson@ToolingDocs.com.




 
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