Waterjet Cut Urethane Parts

Waterjet cutting is widely known for its ability to cut virtually any material to near net shape. These materials vary from rubber to plastics, composites to metals. Versatility is a benefit waterjet cutting brings to many businesses, including New Hampshire based company, Plan Tech. Plan Tech has been manufacturing urethane parts for over 30 years, providing products for diverse groups of industries. Urethane is a high-performance rubber that can be molded easily, shaped accurately, and offers many different finishing options. We’ve invited guest blogger Kevin Healy, Vice President of engineering at Plan Tech, to tell you more about how waterjet cutting has impacted their productivity. With their vast experience and in-house capabilities, they consistently deliver tight tolerance custom urethane parts.

Plan Tech has extensive experience manufacturing custom casting urethane products that are found in the automotive industry, or any other applications requiring a high-performance rubber-like material with superior physical properties. In the past, Plan Tech would cast each and every part by hand. This process totaled a cycle time of 30 minutes, completing 10 parts at a time depending on urethane hardness. Once we were introduced to waterjet cutting technology from Flow, it has made it possible for us to produce thousands of parts from just one sheet. We were able to increase our process time by blasting out about 10 parts in 10 minutes, decreasing our time by 20 minutes.

Flow waterjet cutting urethane parts, decreasing Plan Tech's processing time by 20 minutes.

Our 4’ x 8’ cutting capacity Flow waterjet with a 60,000 psi HyPlex® pump has transformed how we design molds and high volume cut urethane parts. Utilizing FlowNest, Flow’s nesting platform, allows us to make thousands of parts from just one urethane sheet. The software saves us labor and wasted material with an increased level of accuracy versus hand casting parts.

Casting urethane products using traditional open cast method leaves room for error. If open cast parts are not de-molded in a timely manner, the finished size of the custom urethane products are changed. Being able to cast a sheet and let it cure to its final size before cutting on the waterjet takes all the guesswork out, yielding perfects parts every time.

Adding a Flow waterjet to our manufacturing capabilities has increased our production rate and has allowed us to work on other projects while the machine is cutting. Using the waterjet has eliminated issues with tight tolerance parts with our urethane parts. What took hours on a manual machine now takes minutes and delivers better tolerances, increasing our efficiency overall. Being able to produce high volume waterjet cut urethane parts with extreme accuracy, while reducing labor and lead time has greatly improved our profit and increased the quality the parts we deliver to our customers.

With Flow’s Dynamic Waterjet® cutting head we have the capabilities to cut hundreds of metal backed urethane sheets with no trimming necessary. The cutting head virtually eliminates the taper normally associated with waterjet cut urethane parts while improving cutting speeds, part accuracy, and tolerances in cutting flat stock materials. Having this capability contributes to our improved cycle time over traditional casting processes. Casting urethane products with traditional methods leave flashing that needs to be trimmed off each part after the product has cured. While trimming flashing might be a quick process, going through the process with thousands of parts requires a full-time dedicated employee to complete the task.

We recently quoted a new project for a glass manufacturing company that uses thousands of aluminum backed urethane pads to move large pieces of glass. We evaluated our options to help us determine which production process will work best for this project. Below is a chart comparing our two methods.

 

Comparison of waterjet versus molding methods with urethane parts

Our evaluation brought us to the conclusion that we were most competitive presenting the waterjet process when we quoted the customer. Our Flow waterjet gave us a significant advantage to process the order in one day in comparison to three days using other methods, improving our delivered lead time to our customer.

Our expenses to produce these parts on a waterjet in comparison to traditional casting is also considerably lower. The rate to run a waterjet for the duration of a project doesn’t come close to the value of a full-time employee. We were able to see a cost reduction by taking a full-time employee away from trimming flashing, giving us an additional 40 hours a week as a resource to tackle other projects.  As we continue to quote and manufacture more complex urethane parts, it is a key benefit to have the waterjet in our production capabilities.

Plan Tech cutting urethane parts on their waterjet, one of the many services they provide.

Waterjet cut urethane parts are just one of the many cast urethane services that Plan Tech provides. We manufacture a wide variety of custom cast urethane parts such as urethane molded bearings, urethane sprockets, and rollers for industrial applications across the United States.  Almost every vehicle build uses urethane suspension bushing much like the ones Plan Tech reproduces for antique vehicles.

Hope you found this interesting! If you’d like to learn more about urethane cast parts, you can visit our website at PlanTech.com.

Manufacturing Trends Waterjet Technology Overview

Tough Applications Where Waterjet Shines

It is true that waterjets are used for common materials such as steel, aluminum, gasket, and foam. But many people feel the tougher applications are where waterjet really shines. In this post I’ll highlight some that I believe best illustrate waterjet and abrasive waterjet capability.

  1. Stone
  2. Composites
  3. Exotic metal: Titanium and Inconel
  4. Thick insulation
  5. Cement board

The first three are abrasive waterjet related, and the last two use pure waterjet.

Waterjet Jobs

Impact of Grit Size on Abrasive Waterjet Cutting

Garnet abrasive is used on 95% of all waterjet machines. The size of the garnet abrasive typically used today for waterjet cutting ranges from 50 mesh to 220 mesh, with the most common being 80 mesh. Mesh values do not represent particles of an exact dimension, but represent a distribution of particle sizes. An 80 mesh abrasive will have some particles larger and smaller than exactly 80 mesh. Mesh sizes are usually determined by allowing abrasive to fall through a series of screens – each screen smaller in mesh size from top to bottom. A known quantity of abrasive is placed on the top and vibrated for a fixed period of time, and then the amount of abrasive on each screen is weighed to obtain the distribution.

How Waterjets Work Waterjet 101 Waterjet Technology Overview
A child working in the FlowCut program

Anyone Can Program a Waterjet

A waterjet is a beam type cutter, somewhat like a plasma, oxy acetylene, CO2 laser, or fiber laser. Programming a waterjet, and operating one for that matter, is actually simple. In fact, a waterjet is usually considered to be easier to program and operate than most other machine tools. I say this because a waterjet typically does not require a change in parameters when going from one material to another.  The tool is non-contact, pierces material easily to start a cut, and cuts without heat so materials don’t change or warp from the cutting process. If you are newer to this blog, a previous article  on what makes up a waterjet might be a good precursor to reading this post.

Programming Waterjet 101

Fixture Well, And Often

Everyone who cuts parts out of raw stock or a work-piece knows you can’t cut a good part if it isn’t sufficiently held in place. So, what do we have to consider when we’re talking about waterjet cutting? The good news is a waterjet cuts with low force. Where a milling machine might force a rigid cutting tool into a material at 10, 100, 300 pounds of force (4.5, 45, 136 kg), the waterjet head doesn’t touch the part — just the supersonic stream that exits the head touches the part.The machine can’t tell if the jet is cutting material or just shooting into nothingness. The part, however, does feel low forces during cutting.

Cutting-pizza

Although the picture is of pure waterjet cutting pizza, I’m going to focus on abrasive waterjet cutting applications in this post. Fixturing requirements are different in pure waterjet cutting, partially because the material is often very light and the jet forces are an order of magnitude (10x) lower compared to abrasive waterjet.

Waterjet 101 Waterjet Jobs

So, What Is Stream Lag & Taper?

A waterjet stream acts like a beam when cutting, much like plasma cutting and laser cutting. These types of non-rigid cutting tools have to address the beam flexing and changing within the target material to minimize part cutting errors.

What is taper?

Taper in waterjet cutting is when the entrance width of cut is different than the exit width of cut.

Taper_v2

What is stream lag?
Stream lag causes corner damage when the exit point lags behind the entrance point, shown in the bottom of the part below.

Plasma cut parts often exhibit an upside-down V-shaped taper where the width of cut is wider at the bottom. Laser and waterjet exhibit a normal V-shaped taper (more narrow width of cut at the bottom). Plasma, laser and waterjet can all yield stream lag errors when cutting a part.

How Waterjets Work Waterjet 101 Waterjet Technology Overview