How Much Plastic Do You Need?

Calculate Amount of Plastic To Be Processed Per Hour



Calculating the amount of material per hour that you will be processing is a fairly simple calculation, but with DZynSource for Molds it's even easier.

From the main menu, choose the "Production Calculations" command button.

Figure 1. DZynSource Main Screen

This is one of the few calculations that can be chosen from more than one sub-menu. It can also be found under the "Molding Calculations" sub-menu.

 

The blank form for doing this particular production calculation is fairly self explanatory. You first choose the unit of weight for the plastic molded part. In my experience, the part weight is usually measured in grams. The industry that I work in, caps and closures, packaging, medical disposables, and so forth, the parts are fairly small and usually measured in grams. The ounces and pounds are there for the molders, mold makers and other personnel that work with the larger parts.

So, choose the unit of measurement for the part weight, enter the number of cavities in the mold, and enter the cycle time in seconds. If the mold is full hot runner, then there will be no cold runner to allow for and you enter zero for the runner weight.

If the mold has any amount of cold runner, enter it in the text box next to "Enter runner weight in grams". 
The unit of weight for the runner changes with the units chosen for the molded part, so that they are always in the same units.

Press calculate, and that's all there is to it. You can press clear to clear all fields and start again, press "Print" to send a copy of the form to the default printer, or press "Menu" to return to the Main Screen.  The solved example below is for a 12-gram part being produced by a 64-cavity full hot runner mold that runs a 10 second cycle.  As you can see, you'll be processing almost 610 pounds of material per hour.  The equivalent weight in kilograms is also given.

Pneumatic Cylinders Made Simple

Pneumatic cylinder calculations can be done in a matter of minutes, if not seconds, with DZynSource. From the main screen choose the "Fluids" command button.   The Fluids sub-menu appears, and you'll want to select the "Pneumatic Cylinder Calculations" command.

The blank pneumatic cylinder form appears. As with almost all of the calculations within DZynSource, you must choose metric or imperial units to work with as your first step.

You are now offered the option of calculating what size pneumatic cylinder you need to accomplish your task. If you know the force that must be generated, you enter that into the text box provided next to the "Enter the force that the cylinder must generate" text. You are also asked enter the air pressure that will be provided to the cylinder. The sizing of the piston is based on this premise: you want to deliver a force that is double the minimum force required. A smaller cylinder will move slower, due to being under-powered. a larger cylinder will usually move slower too, due to the increased volume of air required.

The calculation provides a size, and you would choose the next larger size of standard cylinder. For example, if you needed to push with a force of 450 pounds, and you have a line pressure of 80 p.s.i., you would need a 3.758 inch diameter piston. You would choose the next larger standard size, or 4 inch diameter piston. See the picture below.

In this case we have calculated an appropriate piston size, which is 4.000 diameter. I next entered all of my know data for the project that I'm working on. The piston I chose has a 1.000 diameter rod, a 12 inch stroke, a compressed air supply at 80 pounds per square inch, and we need to cycle the cylinder 10 times per minute, or every 6 seconds. Press calculate and we see that the forward force will be just over 1000 pounds. The return force is always less that the forward force because we have to subtract the piston diameter from the piston diameter. The air cannot act on the area of the piston rod. We are also given the standard cubic feet per minute of air that will be required to run this cylinder at this cycle. This information is used to determine the extra compressor load, and to size the valves that will control the air flow. That's all there is to it.

Hydraulic Cylinder Calculations The Easy Way

Hydraulic cylinder calculations need to be done quite often, as a matter of course, when designing molds. These calculations are done effortlessly, and in a matter of seconds, with DZynSource for Molds Software. The following steps show the beauty and simplicity of our software for doing this and other common mold engineering tasks:

1. This is the main screenshot from DZynSource for Molds, in this case click on the "Fluids" command button.

The Fluids sub-menu appears, and you choose the "Hydraulic Cylinder Calculations" command button.

The blank Hydraulic Cylinder worksheet appears, ready for you to enter your known data. The second article that I wrote on this blog used the following example:

You have a hydraulic cylinder with a 2.000 diameter piston, a 1.000 diameter rod, a 12-inch stroke, and want to extend the rod in .5 seconds, and the system pressure is 1000 pounds per square inch.  Calculate the forward and return forces generated and the flow rate, in gallons per minute, of hydraulic oil required to accomplish the stroke outwatd in .5 seconds.

We'll enter this data into the Hydraulics worksheet:

First, choose the units that you want to work in, enter the data, Press Enter, and Voila, all of your answers appear.

Customers will very often call to find out how many gallons per minute their hydraulic pump will need to delivery to the mold, particularly with unscrewing molds. You can answer them in the blink of an eye, and not have to take the time to figure it out and call them back. What if scenarios are worked out fast as you can think of them.  DZynSource for Molds really does save time, and enables you to create better designs. 

As always, over designing is expensive, under-designing can be disastrous!