When injecting plastic parts and components, it's inevitable to get faults, defects and issues. You must have a robust, stable, controlled process to prevent this as much as possible.

If any injected part has been previously produced satisfactorily and it now goes wrong, something has changed. The main principle is never to change conditions immediately. The cause / reason should be identified and rectified.

Never adjust one condition to compensate for a failure or change in another condition.

For example, if melt temperature has increased, don’t reduce speeds or pressures or mold temperature to compensate. Identify the problem, that is to say reduce melt temperature, check and replacing thermocouples, etc. in order to get melt temperature back to intended.


Ask yourself questions:

Identify causes of defects:


Problem solver:

Now we'll use some method and help you solve the most common problems and issues that might show up when injecting plastic parts. Some are due to the process itself, but some come from mold issues and even from as early as part design and project!

Please find bellow comprehensive links to MoldPlast's technical and very concise troubleshooter for the injection of plastic parts and components:

Plastic is a versatile, moldable material made from synthetic or natural polymers (long chains of molecules) derived mainly from crude oil, gas, or biomass, known for being lightweight, durable, and cheap, used in countless products but posing significant environmental challenges due to slow decomposition and waste accumulation, especially in oceans.

• Key Characteristics & Properties

• Moldable (Plasticity): The word "plastic" comes from Greek/Latin for "fit for molding," allowing shaping via heat and pressure.


• Lightweight & Durable: Strong, long-lasting, and low density, reducing transport costs and making them hard-wearing.


• Versatile: Can be transparent, opaque, flexible, rigid, or insulators (heat/electricity).


• Chemically Resistant: Offers protection against damage from many chemicals.

• Composition & Production

• Polymers: Plastics are large molecules (polymers) formed by linking smaller units (monomers).


• Raw Materials: Primarily from petroleum (via naphtha), but also natural gas, coal, salt, cellulose, and renewable sources.


• Manufacturing: Involves processes like polymerization or polycondensation to link monomers into chains.

• Uses & Environmental Impact

• Widespread Use: From packaging and bottles to space rockets, due to low cost and versatility.


• Environmental Concern: Most plastics don't biodegrade easily (lasting centuries), leading to significant pollution in oceans and landfills, harming wildlife.


• Recycling: A small percentage is recycled, highlighting the need for better waste management and circular economy solutions.

1. Look beyond the data sheet
Instead of regarding data sheets as a definitive source of information, engineers should think of them as resumes. Use the information sheets for screening and comparing materials only - and perhaps inputting the values into simple, back-end calculations. "Data sheet properties can give you a quick feel for the material's ability ... [Read more..]

2. Do some digging
To access multipoint information, engineers just have to search a little deeper - not much deeper in many cases. In fact, some information is readily available on the Web. For example, the CAMPUS database provides standardized materials data from dozens of suppliers and much of that information is multipoint. From this source ... [Read more..]

3. Consult materials suppliers
If researching doesn't yield all the necessary information, then it's time to ask materials suppliers for help. Their expertise is valuable, as they have gathered a wealth of data on impact, creep and acceptable design values - information they provide to customers or ... [Read more..]

4. Pay extra attention to five basic properties
According to materials experts, engineers should heed five basic properties in order to avoid many design errors and even facilitate the more advanced work of later design phases. These properties include ... [Read more..]

5. Perform some testing yourself
Unfortunately, obtaining extra information early in the design cycle won't attend to all of the more complicated concerns that come up later on. Thermal issues, high-rate impact and fatigue, to name just a few, often demand sophisticated computer simulations and thorough testing ... [Read more..]

Hey, if you work in the manufacture of plastic parts and components by injection, we have some tips to help you solve most of the major issues and defects that can occur during production. And, with that, make Quality people happier too.

This has been on the MoldPlast - Plastics section since.. forever, but maybe people need to be reminded it exists.

The entry page is a general troubleshooter that gives general information and some logical principles on how to address the issues, then it leads you to the main problem solver, where you'll find all common problems and very concise, comprehensive solutions to help you solve component defects and improve it's quality.

Solutions to equipment, molds and raw material derivative mis-adjustments and errors.

It is free information and in fact tries to pass by the experience from 40 years work with the plastics industry, adjusting equipment, improving cycles, and all that is related to manufacture.

Hope this may be useful to you too and assist in producing better parts with less effort and rejects! Better parts ~ less waste ~ lower costs

Plastic's raw material producers, some of the largest companies in the world, have known for more than 60 years that recycling is not an economically or technically feasible plastic waste management solution. That has not stopped them from promoting it, according to several reports and insider information.

Plastic, which is made from oil and gas, is notoriously difficult to recycle. Doing so requires meticulous sorting, since most of the thousands of chemically distinct varieties of plastic cannot be recycled together. That renders an already pricey process even more expensive. Another challenge: the material degrades each time it is reused, meaning it can generally only be reused once or twice at most, before losing it's properties.

The industry has known this for decades, but obscured the information in its marketing campaigns. Over the past several decades, industry companies have referred to plastic recycling as "uneconomical" and that it "cannot be considered a permanent solid waste solution".

In the 1950s, plastic producers came up with an idea to ensure a continually growing market for their products: disposability. They knew if they focused on single-use plastics, people would buy and buy and buy! In the 50's, the Society of the Plastics Industry told producers to focus on "low cost, big volume" and "expendability".

Over the following decades, the industry told the public that plastics can easily be tossed into landfills or burned in garbage incinerators.

More recently, one big company confirmed that: "We are committed to the activities [of plastics recycling], but not committed to the results".

(...)

source:
https://www.theguardian.com/.../recycling-plastics-producers-report

MoldPlast webpage has been somewhat reworked, still keeping it as a manufacture free resource and info for the all of the plastics industry, that will try to pass on the experience acquired throughout all those years, in as simple a way as possible.

MoldPlast's main manufacture related themes available to you are:

• Plastic injection industry
  
• Plastic materials history & development
  
• Diverse plastic raw material types
  
• Plastics most common uses
  
• Production troubleshooter
  
• Problem solver & production solutions
  

And if you have any doubts, suggestions or need something else, you know you are always welcome to contact me at Jose Falcao