Plastic Injection Molding Site Blog

Industry Proven Mould Designs For Sale

Sun, 22 Mar 2026 19:59:09 -0400

Industry Proven Mould Designs For Sale

Ejecting of the lid

Sun, 15 Feb 2026 20:34:27 -0500

Is it better to eject the lids (inside injected) by the stripper ring (plate) that is powered by hydraulic or pneumatic cylinder?

Tooling Dept.

Thu, 29 Aug 2024 02:44:26 -0400

I have a 3 plate mould with 4 cavities and an angular slider in each cavity, at less than 50k shots the slider breaks, What can i do to improve the slider

Hot Runner versus Cold Runner

Wed, 10 Jan 2024 23:18:24 -0500

Hot runner versus cold runner, which is better for your project?

Ultra thin wall injection molding-Light weighting

Mon, 24 Apr 2023 23:11:49 -0400

Want to reduce your plastic part weight. Click here to see an example of how to light weight your part design using ultra thin wall injection molding.

Uneven Wall Thickness in Injection Molding

Sat, 12 Nov 2022 00:11:19 -0500

If you are wrestling with uneven wall thickness in injection molding then we might have the anwers for you

3 Plate Mold Design For Injection Molding

Sat, 5 Nov 2022 03:48:10 -0400

Learn how to design a 3 plate mold and when to use a 2 plate mold design.

MOLD WEIGHT CALCULATOR

Sat, 5 Nov 2022 01:08:01 -0400

MOLD WEIGHT CALCULATOR

Learning Injection molding design

Thu, 3 Nov 2022 06:02:34 -0400

when wearplate is designed, is it necessary that there should be a very small gap between the core and cavity side of the mold right where the wearplate

carlos ramos

Thu, 3 Nov 2022 05:57:49 -0400

do you have an online course?

Isolate plates

Wed, 13 Apr 2022 22:18:04 -0400

Where is better to put isolate during mold design? inside mold (between clamp plate and cavity plates) or outside? (after clamp plate) Can be an important

Clamp plate thickness

Wed, 13 Apr 2022 22:11:01 -0400

How can we calculate the minimum thickness o clamp plate to avoid bad design?

animation

Sat, 5 Feb 2022 18:36:33 -0500

animation

Ketan

Sat, 22 Jan 2022 19:18:36 -0500

How to avoid weld lines.

mold size calculation

Mon, 26 Jul 2021 00:45:52 -0400

From part size & number of sliders,undercut how to calculate tentative mold size?

What’s would be the extra material to keep at the matching area of core and cavity inserts

Fri, 1 Jan 2021 01:36:22 -0500

1What’s would be the extra material to keep at the matching area of core and cavity Inserts 2. How to provide spacer lengths interms of ejection length

Injection Molding Training for Thin Wall Packaging Parts

Mon, 21 Oct 2019 22:05:44 -0400

Start making & processing thin wall molds at a profit with injection molding training.

Support pillars

Wed, 8 Aug 2018 04:15:08 -0400

Is there any specific calculation for using a particular size of support pillars and it's placing?

Gas vent

Sun, 8 Oct 2017 23:41:54 -0400

How to improve gas vent for part having mirror face?

Setting Hold Time and Hold Pressure to Run an Optimized Process

Sun, 6 Nov 2016 21:17:47 -0500

Learn how to make quality parts without spending money

3D Rapid Prototyping in Injection Molding

Sat, 21 May 2016 21:31:45 -0400

Learn how 3D rapid prototyping benefits the injection molding industry

Injection Capacity Calculator For Injection Molding Machines

Mon, 16 Mar 2015 16:06:51 -0400

Different plastics have different melt densities which alters the injection capacity of a screw and barrel assembly. Use this injection capacity calculator to find the capacity of your machine.

Production Calculators For Injection Molding

Wed, 25 Feb 2015 14:39:41 -0500

Need to know how long your next production run will take? Or how much material to order? Production calculators used to find the production rate, time & plastic material requirement.

Stack Molds Improve Productivity And Reduce Your Costs

Tue, 22 Jul 2014 02:34:28 -0400

If you want to nearly double your production per molding machine, then stack molds might be for you.

Mold Polishing Tips For Injection Molds

Fri, 20 Jun 2014 23:54:18 -0400

Learn about the different types of finishes in mold polishing

How To Estimate Weight Of An Injection Mold Tool

Mon, 5 May 2014 03:49:26 -0400

For those of you who do not have scales here is an easy way to find mold weight. Calculation For Metric Units (cm) Measure overall dimensions of the mold. Refer to above image of mold for length, width & height. For example: If Length=80cm Width=90cm Height=45cm and Weight(kgs)= LengthxWidthxHeightxDensityOfSteel where density is 7.9 grams/cm^3 for tool steel (P20,H13) then Weight(kgs)= (80x90x45x7.9)/1000= 2,560 kgs Calculation For Imperial Units (Inches) Measure overall dimensions of the mold. Refer to above image of mold for length, width & height. For example: If Length=25 inch Width=35 inch Height=20 inch and Weight(lbs)= LengthxWidthxHeightxDensityOfSteel where density is 0.28 lbs/inch^3 for tool steel (P20,H13) then Weight(kgs)= (25x35x20x0.28)= 4,900 lbs
All calculations & technical data are for comparison purposes only and are NOT for design or safe working practices. It is derived from sources that we believe to be accurate, but can NOT guarantee its validity. Your specific application should NOT be undertaken without independent evaluation for accuracy.

Mold Flow Analysis Simulation Benefits

Sat, 29 Mar 2014 19:54:20 -0400

Learn how mold flow analysis software can save you time and money in getting quality parts to market on time.

Injection Molding Consulting Will Improve Quality and Productivity.

Tue, 10 Dec 2013 01:32:27 -0500

Specializing in Troubleshooting Thin Wall Molding Problems - Injection Molding Consulting

Life of a wear plate

Wed, 20 Nov 2013 17:31:07 -0500

How long is the maximum life of a wear plate? Answer: The purpose of a wear plate in an injection mould is to act as a sacrificial component in preference

Gate Type & Mold Steels

Wed, 13 Nov 2013 16:23:01 -0500

Question by Mohamed: How to choose the correct gate type and the correct mold steel? Answer: The type of gate depends upon a number of factors including

Nox-Rust Paper

Thu, 17 Oct 2013 02:20:48 -0400

Question: What problems other than a visual indicator could be caused by using nox-rust paper on the back plates of injection molds? My answer: I wouldn't

A Nucleating Agent Can Improve Productivity Immediately

Thu, 30 May 2013 04:23:14 -0400

Learn how a nucleating agent can improve part quality and reduce cycle time with this case study

Plastic Raw Material For Easier Processing

Wed, 29 May 2013 02:57:30 -0400

Learn which plastic raw material will improve cycle time and part quality in injection molding

When To Refurbish An Injection Mold

Wed, 22 May 2013 03:05:07 -0400

The quality of the plastic parts produced from an injection mold are a good indicator of the condition of a mold. If the mold has been in production for a while and the parts have the following quality issues then it probably needs refurbishment. The quality issues are flashing, shorting (short shots), cosmetic defects (such as trapped air), uneven weights between cavities, shifting wall thickness and lower than normal production rates (long cycle times). Although some of these issues can be due to incorrect processing or poor moulding machine condition, if they are occurring at the same time then it is most likely the mould is at fault and needs refurbishment. Inspect the most important surfaces such as the part line shutoff faces and the back plates. Disassemble the mold and look for signs of uneven wear, damage, corrosion (see photo) or unusual hard mark patterns. Some simple checks with measuring equipment will confirm the extent of any wear. The photo below is the surface of a back plate from a single cavity thin wall lid mold (wall thickness 0.55mm). The core was bolted to this plate. The water corrosion is evident especially at the centre, which was 0.1mm deep. This resulted in the wall thickness of the lid to be 0.1mm deeper in one section of the lid. This is too deep for a thin wall part. The back plate had to be surface ground in order to reinstate the flat surface and to maintain even wall thickness (0.55mm) on the lid. Note: when buying used plastic injection molds, they are most likely in need of refurbishment. Click the link below to find out how to source the best quality used molds using this 9-step process.

Common Ejection Methods

Tue, 14 May 2013 00:54:41 -0400

There are 3 main methods of ejecting a plastic part off an injection mould tool. These methods use: 1. Ejector pins 2. Pressurized air 3. Stripper plate When designing an injection mold, the use of ejector pins should always be considered first since they are cheap and easy to use. They are most suited to parts that are strong and rigid and have an irregular shape. Pressurized air is often used together with ejector pins to aid in the ejection process. The purpose of the air is to release the vacuum between the part and the core of the mold tool. Without this air, the ejector pins would probably punch holes in the part or distort the part during ejection. The third method of ejection is done by a stripper plate. This is a very reliable method for parts that are flexible or weak. To learn more about stripper plates click the link below:

Medical Device Injection Molding Challenges

Thu, 25 Apr 2013 02:38:17 -0400

Learn how to be successful at medical device injection molding.

Grinding of Tool Steel and Cracking

Tue, 23 Apr 2013 07:33:10 -0400

When grinding tool steel a lot of heat is generated. Too much heat will cause cracks. Although cracks are usually not visible to the naked eye, a good indication is the presence of burn marks on the surface of the steel. These cracks can get bigger and lead to failure of the steel during the injection molding process. Usually the first indication of a crack is a water leak in the injection mold. To avoid grinding cracks do the following: • Use the correct grade of grinding wheel for the tool steel • Dress the wheel properly so that the wheel actually cuts and doesn’t just generate heat • Use correct grinding parameters such as wheel speed and depth of cut • Use plenty of cooling fluid • When grinding hardened steel only grind steel that has been tempered • Always let the wheel “spark out” before finishing the grinding process. This will help to minimize the stresses induced by grinding For more information on this go to http://www.uddeholm.com/files/TB_grinding-english.pdf

Corrosion Resistant Processes In Injection Molding Improves Productivity

Wed, 17 Apr 2013 04:55:06 -0400

Learn how platings, coatings and heat treatments can provide a corrosion resistant injection mold

Make Your Own Hot Runners

Thu, 4 Apr 2013 03:18:33 -0400

Some injection mold makers are capable of making their own hot runners. The advantage is that one company can take full responsibility of the entire mold and it reduces the hot runner price. To make a hot runner requires standard tool making equipment such as a radial drill, cnc machining center, a surface grinder, a cylindrical grinder and a cnc lathe. All heater elements can be bought and a person qualified in electrical wiring can connect them to the temperature controller. The materials required to make a hot tip hot runner are P20 for the manifold and H13 for the nozzles and insulators. The nozzle tips are usually made from a copper alloy but can also be made from H13 and thru hardened for long life.

Single Cavity Injection Molds

Sat, 30 Mar 2013 01:35:04 -0400

Single cavity molds are the most commonly built molds in the injection molding industry. They are used in all markets whether its packaging, medical, automotive, industrial or electronic. Compared to multi-cavity molds, the advantages of single cavity molds are they are cheap to make, easy to make, easy to use, easy to maintain and give production flexibility which means they can fit into different sized molding machines within limits. However, compared to multi-cavity molds they have 2 limitations: annual production quantity is limited and they can give part quality issues such as flashing if the mold design does not take into account the weakness in a molding machines fixed side platen due to the location ring hole.

The Benefits Of Moldmax In Injection Molding

Wed, 20 Mar 2013 04:48:34 -0400

Learn when and why to use Moldmax copper alloys in injection moulds.

Injection Molding Screws Are Critical To Part Quality

Tue, 19 Mar 2013 05:48:46 -0400

The right injection molding screws will reduce your reject rate and increase production output.

4 Injection Molding Mistakes To Avoid

Wed, 13 Mar 2013 16:08:36 -0400

Injection molding is a complicated process. Managing a molding business is even more complicated. Learn what injection molding mistakes to avoid

Plastic Dryers, Moisture Measurement And Part Quality

Sat, 9 Mar 2013 18:05:47 -0500

Learn how plastic dryers and moisture influence part quality.

Training In Injection Molding

Thu, 28 Feb 2013 17:08:59 -0500

One of the biggest issues in the injection molding industry is lack of training on the factory floor. The plastic injection molding process is complicated and to be able to produce good quality parts consistently and efficiently requires a systematic approach using the right tools and techniques. Setting up jobs in a rushed and chaotic way will result in an inefficient process meaning on-going quality issues and slow cycle times. The worst part about this approach is that if it goes on for too long it becomes habitual so it is very difficult to change. It becomes part of the company culture. However, the fact is, with a commitment by management to improve company culture and train people in the correct ways of molding will not only improve an injection molding companies bottom line, but will also result in a happier and more motivated work force.

Stripper Plate In Injection Molding

Tue, 19 Feb 2013 02:28:14 -0500

Learn when to use a stripper plate in an injection mold and how to move it.

Molding Machine Clamp Tonnage Calculator For Polypropylene

Thu, 17 Jan 2013 03:58:21 -0500

Clamp tonnage calculator for round and square parts.

Troubleshooting Short Shots And Cost Savings

Sat, 5 Jan 2013 04:57:37 -0500

Troubleshooting short shots to improve quality, save costs and increase productivity.

Using Higher Water Temperature To Save Energy Costs In The Injection Molding Process

Thu, 13 Dec 2012 03:11:32 -0500

In injection molding, the set temperature on the chiller system directly influences how much energy is used to maintain water temperature. In countries with moderate to high temperature climates, the lower the set temperature the more energy consumed and the higher the power costs. But what about part quality and cycle time I hear you ask. Well, a case study which was done on a single cavity mould producing a 2 litre container made from polypropylene co polymer weighing 49 grams confirmed that cycle time could remain the same at 6.5 seconds throughout 3 different temperature increases (10, 20, 25 degrees Celsius). What’s more, the only difference in part quality was a higher shrinkage rate (with higher water temperature), which posed no problem to the lid fit. In fact, the set water temperature on the lid mould was also increased (from 14 to 25 ) to get more shrinkage to match the tub fitting. Although in this case study the energy consumption was not measured, the time the chiller spent maintaining temperature was recorded: At 10 degrees it was on all of the time. At 20 degrees it was on for 30 seconds every 3 minutes and for 25 degrees it was on for 16 seconds every 3 minutes. In conclusion, it can be seen that power consumption almost halved when the water temperature setting was increased by 5 degrees while maintaining quality and productivity. You should try the same test with your chillers and you will reduce your energy consumption costs especially over extended periods of time.