Welcome!

This informative blog allows plastics professionals to discuss plastics training and technology. Brought to you by Routsis Training: the plastic industry's premiere training provider.

VISIT OUR STORE
VISIT OUR WEBSITE

Safely Removing Stuck Runners…

Last week, while at a molding facility, I had to instruct a molder on the safe way to remove a stuck runner…

Situation
When touring the plant, I witnessed a machine operator removing opening the door, reaching in with his bare hand, and pull a stuck sprue from the bushing.
Problem
This action by itself seems pretty routine, but the operator forgot a key element… YOU MUST BACK UP THE BARREL AND PURGE BEFORE REACHING INTO THE MOLD AREA DURING PROCESS INTERRUPTIONS. This will help prevent the possibility of pressure build-up and melted material being injected into the mold area while the operator reaches into the mold area.
I know hundreds of people who have either been burned or know someone who has been burned as a result of this oversight. Hot molten plastic will either burn your hand or actually become injected under your skin. In either case, the result is almost always disfigurement, amputation, or death. Never let your employees do this.
Recommendation
Please review your procedures and ensure that your employees are not making this dangerous mistake.
-Andy 

How Often to Train…

Earlier this week, I was asked this common question…

JR
How often should I train my employees?

My Response
I will address this in two ways… Frequency and Time:
Frequency of Training – When possible, try to train your employees at least once a week. This training could be an online course, focused on-the-job instruction, instructional presentation, or skill development exercise. This is crucial to advancing the behaviors and actions you wish to reinforce. Without frequency, people will become complacent.
Length of Training Session – Try to keep the training sessions around an hour or less at a time. Extended training sessions become cumbersome to the trainee, and their ability to retain information is significantly reduced over time. If you have a significant amount of information to present, break it up into manageable pieces.
Additional Thoughts
To ensure long lasing effectiveness of employee training, the key is to have routine and ongoing training sessions to promote a healthy atmosphere of learning.
-Andy 

How Much Re-Training…

Yesterday, I received a question I get asked all the time…

Jason
Should I do any re-training of my employees?
My Response
We recommend regular retraining of your employees for two reasons…
1) Each time someone takes the training, they will pick up, learn, or understand something new.
2) Retraining also ensures they do not lose track of the fundamentals, which can often happen over time.
Basically, your employees should always be learning and reviewing,,, especially in the complex and diverse field of plastics processing.
Additional Thoughts
Any good plastics professional should be should always be learning and honing their skills. What I know, and the approach I take to processing adjusts, and improves as every year passes. Likewise, when I refer back to educational and reference materials I have used in the past, I always find good information that I forgot or have not used in a while.
-Andy

Open-Loop and Closed-Loop Process Sheets…

I was recently at a customer with both open-loop and closed-loop molding machines…

BD
Can a standard, machine-independent, process sheet be used for all our molding machines?
My Response
In this case, the best way to process an open-loop machine is much different than a closed-loop molding machine. An open-loop machine should be full at the end of 1st stage… while a closed-loop process should be short-shot at the end of 1st stage.
As a result, molders who process both types of machines should have one machine independent process sheet specifically for open-loop machines, and one process sheet for closed-loop molding machines.
Additional Thoughts
It is always preferable to process with a closed-loop molding machine… and it is almost always cost beneficial to replace your open-loop molding machines when possible.
-Andy

Volumetric or Gravimetric Feeder?

Normal
0

false
false
false

EN-US
X-NONE
X-NONE

MicrosoftInternetExplorer4


/* Style Definitions */
table.MsoNormalTable
{mso-style-name:”Table Normal”;
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-qformat:yes;
mso-style-parent:””;
mso-padding-alt:0in 5.4pt 0in 5.4pt;
mso-para-margin-top:0in;
mso-para-margin-right:0in;
mso-para-margin-bottom:10.0pt;
mso-para-margin-left:0in;
line-height:115%;
mso-pagination:widow-orphan;
font-size:11.0pt;
font-family:”Calibri”,”sans-serif”;
mso-ascii-font-family:Calibri;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:”Times New Roman”;
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:Calibri;
mso-hansi-theme-font:minor-latin;
mso-bidi-font-family:”Times New Roman”;
mso-bidi-theme-font:minor-bidi;}

I recently received this question…

 

JC

How do I decide whether to choose a volumetric
or gravimetric feeder?

 

Note: A gravimetric feeder measures the flow’s weight and adjusts the feeder output to
maintain the desired set point. On the other hand, a volumetric feeders, by
definition, do not measure the weight of the flow.

 

My Response

Having said
this, volumetric feeders are inexpensive and simple but are open loop devices.
They will not detect or make adjustments for changes in material density. Because
they are open loop devices, volumetric feeders are also unable to measure the
flow for data acquisition. A volumetric feeder may be good for your application
if your material has little variation in density and pellet uniformity.


Most
materials do have variations in density great enough to warrant the use of a
gravimetric feeder.


Most feeder
manufacturers have the resources to determine whether a given material can be
fed volumetrically at a required accuracy or if a gravimetric feeder is
required.


You must
also consider what you will be feeding based on cost and concentration. If you
need to feed a material in at 1% by weight a gravimetric feeder is almost
always a must. Also, for expensive additives, the material saved by having a
gravimetric feeder may pay for itself.

 

-Andy

  • Recent Posts

  • Recent Comments

  • Archives

  • Categories

    • © 2016 All Rights Reserved | Powered by Wordpress | Made with ❤ by Themely