Plastic Processing Equipment

As discussed in our previous article on Polymer Testing Equipment, plastic is fast becoming the most popular choice of material in manufacturing industries. As many readers have been asking me to give some details about Plastic Processing Equipment and methods, I took out time to inform our readers about the various methods involved in procuring finished plastic parts.
The family of polymers is extraordinarily large and varied. There are, however, some fairly broad and basic approaches that can be followed when designing or fabricating a product out of polymers or, more commonly, polymers compounded with other ingredients. The type of fabrication process to be adopted depends on the properties and characteristics of the polymer and on the shape and form of the final product.
In the broad classification of plastics there are two generally accepted categories: thermoplastic resins and thermosetting resins.

Thermoplastic resins consist of long polymer molecules, each of which may or may not have side chains or groups. The side chains or groups, if present, are not linked to other polymer molecules (i.e., are not cross-linked). Thermoplastic resins, usually obtained as a granular polymer, can therefore be repeatedly melted or solidified by heating or cooling. Heat softens or melts the material so that it can be formed; subsequent cooling then hardens or solidifies the material in the given shape. No chemical change usually takes place during this shaping process.
In thermosetting resins the reactive groups of the molecules from cross-links between the molecules during the fabrication process. The cross-linked or “cured” material cannot be softened by heating.
Thermoset materials are usually supplied as a partially polymerized molding compound or as a liquid monomer–polymer mixture. In this uncured condition they can be shaped with or without pressure and polymerized to the cured state with chemicals or heat.
With the progress of technology the demarcation between thermoplastic and thermoset processing has become less distinct. For thermosets processes have been developed which make use of the economic processing characteristics or thermoplastics. For example, cross-linked polyethylene wire coating is made by extruding the thermoplastic polyethylene, which is then cross-linked (either chemically or by irradiation) to form what is actually a thermoset material that cannot be melted again by heating.
More recently, modified machinery and molding compositions have become available to provide the economics of thermoplastic processing to thermosetting materials. Injection molding of phenolics and other thermosetting materials are such examples. Nevertheless, it is still a widespread practice in industry to distinguish between thermoplastic and thermosetting resins.
Compression and transfer molding are the most common methods of processing thermosetting plastics. For thermoplastics, the more important processing techniques are extrusion, injection, blow molding, and calendaring; other processes are thermoforming, slush molding, and spinning.
Tooling for plastics processing defines the shape of the part. It falls into two major categories, molds and dies. A mold is used to form a complete three-dimensional plastic part. The plastics processes that use molds are compression molding, injection molding, blow molding, thermoforming, and reaction injection molding (RIM). A die, on the other hand, is used to form two of the three dimensions of a plastic part. The third dimension, usually thickness or length, is controlled by other process variables.
The plastics processes that use dies are extrusion and thermoforming. Many plastics processes do not differentiate between the terms mold and die. Molds, however, are the most predominant form of plastics tooling.
Types of Molds for Plastic Processing Equipment
2PlateInjectionMold3PlateInejctionMoldDesign



The basic types of mold, regardless of whether they are compression, injection, transfer, or even blow molds, are usually classified by the type and number of cavities they have. For example, Figure below illustrates three mold types: (a) single-cavity, (b) dedicated multiple-cavity, and (c) family multiple cavity.
Single-cavity mold represents one of the simplest mold concepts. This design lends itself to low-volume production and to large plastic part designs. The multiple-cavity molds may be of two types. A dedicated multiple-cavity mold has cavities that produce the same part. This type of mold is very popular because it is easy to balance the plastic flow and establish a controlled process. In a family multiple-cavity mold , each cavity may produce a different part. Historically, family mold designs were avoided because of difficulty in filling uniformly; however, recent advances in mold making and gating technology make family molds appealing. This is the case especially when a processor has a multiple-part assembly and would like to keep inventories balanced.
Not: You might want to check out for a complete article on Injection Molding Troubleshooting and get some important Plastic Injection Mold Design and Process Tips to guard against the problems that might appear when Molding Plastic Components .
Types of Dies for Plastic Processing Equipment
Within the plastics industry, the term die is most often applied to the processes of extrusion (see EXTRUSION). Extrusion dies may be categorized by the type of product being produced (e.g., film, sheet, profile, or coextrusion), but they all have some common features as described below.
1. Steel. The extrusion process being continuous, both erosion and corrosion are significant factors.
Hence the dies must be made of a high-quality tool steel, hardened so that the areas that contact the plastic material do not erode. Additionally, many dies have a dense, hard chrome plating in the area where plastic melt contacts the die.
2. Heaters. Extrusion dies are to be heated in order to maintain a melt flow condition for the plastic material. Most of the heaters are cartridge-type elements that slip fit into the die at particular locations. In addition to the heaters, the dies have to accommodate temperature sensors, such as thermocouples.
3. Melt Pressure. Many sophisticated dies are equipped with sensors that monitor melt pressure. This allows the processor to better monitor ad control the process.
4. Parting Line. Large extrusion dies must be able to separate at the melt flow line for easier fabrication and maintenance. Smaller extrusion dies may not have a parting area, because they can be constructed in one piece.
5. Die Swell Compensation. The polymer melt swells when it exits the die, as explained previously.
This die swell is a function of the type of plastic material, the melt temperature, the melt pressure, and the die configuration. The die must be compensated for die swell so that the extruded part has the corrected shape and dimensions. Molds and dies for different fabrication processes will be
described later in more detail when the processes are discussed in coming posts on our site.
This concludes our informative post on Plastic Processing Equipment and you should have a clear idea about it by now. If you have any doubts then read the post again. In case of more queries, contact me and I will answer you as ASAP. Also, feel free to add comments below to get answers quickly and help others. For more informative posts on Plastic Injection Mold Design, be sure to bookmark this page and check back regularly.

38 comments:

Injection Molding said...

Superb posting

I like Types of Molds for Plastic Processing Equipment

Hope to see more posting related to Injection Molding

aliah said...

plastic processing equipment is easily available..and i think plastics processing equipment, having the highest quality materials is vital for your ongoing success and profitability business..
plastic fabricators

chinaplastic molding said...

Sino BMC mould Co. Ltd, a professional China BMC injection moldings supplier, mainly devoted in BMC Injection Molding, BMC moulds, SMC injection molding and SMC/BMC molding services.

Dakumar said...

This is very good information you are giving about Plastic Processing Equipment People must be visit your site. Thanks for sharing. DAKUMAR is a leading Injection Molding Machine Suppliers in china provided best quality Injection Molding Equipments.

Tasnim said...

I have enjoyed reading your articles. It is well written. It looks like you spend a large amount of
time and effort in writing the blog. I am appreciating your effort. You can visit my site.
blow molding machine

jack thomas said...

FET has such a track record. As an established reputable provider, FET designs, Polymer extrusion equipmentdevelops and manufactures extrusion equipment for a wide range of high value textile material applications worldwide.

Nilpesh Patel said...

The blog was absolutely fantastic! There is Lot of great information which can be helpful in some or other way. Keep updating the blog, looking forward for more contents.

Cutting And Sealing Machine Manufacture by nijranggroup.com

kasty jonsen said...

China plastic injection molding http://www.billion-electronics.com & Blow molding Factory. Customized plastic parts supplier - Plastic products made from custom plastics molds.

lusida rubber said...

A direct contact between structural silicone and gaskets are essential for full compatibility. Non-structural and incidental contact applications like weather seal or cap bead requires a compatibility degree. EPDM got sustained appearance and long term performance.
EPDM
Thanks

Austin Clarke said...

Hello, Fantastic blog Action Mold also provides ultra-high performance resins, with or without the addition of modifiers. Looking forward for more contents. Thanks for posting this blog

Seetha G said...

Your post it is really good. Useful content. Nice to read. i have blog for Plastic parts manufacturer in India
see my products also

Plastic parts manufacturer in India

Sheamus Warior said...

Your articles make whole sense of every topic.plastic compounding

Alsia timon said...

Your website is terribly informative and your articles are wonderful.best sitation service

Roney Wilson said...

It’s my fortune to go to at this blog and realize out my required stuff that is also in the quality.password managers

Jullia Grace said...

It’s my fortune to go to at this blog and realize out my required stuff that is also in the quality.payday loans with a savings account

Eva Karea said...

It’s my fortune to go to at this blog and realize out my required stuff that is also in the quality.healthy lifestyle

Alsia timon said...

It’s my fortune to go to at this blog and realize out my required stuff that is also in the quality.auto insurance quotes

Feonacy Tyson said...

It’s my fortune to go to at this blog and realize out my required stuff that is also in the quality.5 star escorts services

Alsia timon said...

It’s my fortune to go to at this blog and realize out my required stuff that is also in the quality.samanthareed.org/garcinia-cambogia-free-trial/

Mr.Froodo said...

I certainly appreciate your stuff provided in the blogs.full coverage insurance on car

Mickey James said...

Your articles and blogs are inspirational.payday loan

Dr.Jones Methews said...

Your blogs stuff is purely enough for me personally. payday lenders in new york city

Dr.Jones Methews said...

This post is really valuable that designed for the new visitors. Pleasing work, keep on writing. credit repair companies

Hawai Mindas said...

This post is really valuable that designed for the new visitors. Pleasing work, keep on writing.clash of clans triche astuce

Micle Bango said...

It’s my fortune to go to at this blog and realize out my required stuff that is also in the quality.auto insurance

Sheamus said...

It’s amazing in support of me to truly have a web site that is valuable meant for my knowledge.therons

Jennifer Lawrance said...

A particular tips that solves your application problems which help to getting finished plastic parts through plastic processing equipment. thermoplastic compounding solutions

wi caksono said...

very good information about injection mold process , thank's

smith mak said...

This is quite fascinating blog; the stuff has really allured me. Thanks a lot
personal loans

Justin Bieber said...

Quickly this site will indisputably be famous among all blogging people, because of its fastidious articles or reviews.american cash loans

Melvin Gregor said...

Hmm this is one of my favorite blogs; it’s quite simple writing that can help me a lot. vehicle insurance

Chris Pratt said...

Superb way of explaining, and great blog to get wonderful information.whole life insurance

Julia Robert said...

Outstanding blog, in my opinion site owners should acquire a great deal out of this blog its very user welcoming. convertible term life insurance policy

Robbert Lewis said...

This article has some vast and valuable information about this subject.Businessman

Rngpolymers.com said...

Rubber molded articles - R and G polymers is one of the leading company for the production of molded articles and more particularly to an improved method for molding such articles as are made of rubber containing quality materials.

Charles Murse said...

GŠ³eat article!Plastic molding is practiced by many industries and used for various different products. There are many plastic molding techniques used in industry. Each type of method is suitable for a specific type of product or part.Plastic Injection Mold

Cutie Chen said...


Your post is really good. Useful content. Very helpful.
plastic injection molding 

Mitsu Chem Plast Ltd said...

Cool post.
I like the way you written on Plastic Processing Equipment.
We are in business of manufacture Blow Molding, Injection Molding & Custom Molding including Industrial Containers, Automotive Plastic Components and Healthcare / Infrastructure Furniture parts & Medical device parts.


plastic products manufacturers
injection molded products

Post a Comment