Posts Tagged ‘plastic’

Safely Working With Phenolic

Posted: August 9, 2018 in Uncategorized
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“Phenolic” which really refers to a wide range of plastics called the “industrial laminate” family offers remarkable physical properties such as strength and dimensional tolerances. When you combine that with immunity to rot, rust, mold, termites, etc. it can be an excellent replacement for wood and metal in many applications for the DIY community. However, different than most other plastics working with phenolics can cause a big mess and the product can irritate your lungs and is not a good thing to breathe in. This is especially an issue when phenolics are saw cut! You will need the following items:

  • Dust mask
  • Safety goggles
  • Long sleeved shirt and pants (coveralls are preferred)
  • Gloves

In general, you don’t want the dust to collect but you don’t want to dry sweep it either. Use some sort of wetting agent like water to coagulate it for removal. We found a safety document that is quite helpful and you can view and download it here.

In the plastics world and probably material distribution in general, one of the most deflating statements is when we as plastic solution provider knows the optimal material but the customer doesn’t see the value in the solution. What we mean by that is the solution is judged to be too expensive, even if it’s exactly what the customer needs. This feeds from the “it’s just plastic” myth that engineering and high-performance plastics should be cheaper, or at least equal to, comparative metal, wood, or other traditional materials. Engineering plastics are a premium material – both in price and performance. You truly do ‘get what you pay for’.

Commonly a plastics sales representative is asked immediately after the conversation above, “It’s too expensive, what do you have that’s cheaper and have the same properties?” Realistically it’s virtually never the case that you can get a similar material, but cheaper, and has the same properties. Would we expect that with other material solutions? If you found a high-grade of steel and felt it was too expensive: would you then ask “Ok, what metal is cheaper but has the same properties?” Reading that your immediate thought is probably “there is none!” For example, aluminum is a metal and is less expensive but nobody would argue that aluminum has very different properties than steel.

We have to see value beyond price. When a distributor helps you select the optimal material for a project and expresses that, there needs to be a level of trust involved. Trust that your application will work the best it possibly can, trust that what’s being supplied will last as long as possible, with as little maintenance as possible, giving you as much satisfaction as possible. We encounter a disparity in value vs. cost sometimes with our industrial customers. They would rather spend $50 per part five times per year on cheap replaceable parts, then spend $175.00 once per year and have a long-lasting solution. Note that the customer is losing out both financially and in ways that are difficult to quantify: they spend more time doing maintenance and replacements than if they just used the right solution, the first time.

An example of a product the public has difficulty seeing the value in is wood grain HDPE. This is a new product that is strong and formulated for outdoor use. The approximate cost per sheet is several hundred dollars for a 4′ x 8′ sheet of plastic. Customers balk at the cost, how could it be so much more expensive than wood? Well, it’s an engineered product that needs to be made in a factory and not produced by the thousands or millions of board feet like lumber, but it also has all sorts of additives to make sure it lasts long with very little maintenance. If you could have an outdoor kitchen area with cabinets that would never rot, never rust, never suffer insect attack, isn’t that worth something?

The next time a plastics representative suggests confidently what the optimal material is, perhaps do give it second thought, knowing that “less, but equal” really doesn’t exist and try to see the long-term value of the solution you’re buying!

 

Know Your “Phenolic”

Posted: May 28, 2018 in Uncategorized
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Phenolics, more correctly known as “industrial laminates“, are one of the most misunderstood industrial plastics available. There is so much confusion among the general public that many in the DIY community don’t even know what to ask for. This isn’t a good thing, as these plastics are on the more expensive side and a failure to figure out what’s best for your application could lead to failure or wasted money. The first thing you need to figure out is what your application requires and why a phenolic is necessary. Phenolic plastics are used in two primarily applications: where a super “hard” and mechanically strong plastic is needed and also in electrical applications, such as circuit boards. For applications where mechanical strength is key, then CE grade laminate is the most available and least expensive option. If the application is electrical and/or fire-retardant properties are important then a fiberglass epoxy product called FR-4 is likely the best.

An important note here is that the FR-4 product, which is very popular and widely used, isn’t a phenolic at all! Phenolic is an old plastic resin, one of the first ever used, and it became associated with industrial laminates which are essentially compressed layers of fabric, cloth, paper with a plastic resin binder. Typically the brown colored mechanical grade products like the CE grade laminates are the true phenolic. However, many industrial laminates exist which use different binding agents.

One other area people get tripped up with is the branch of “melamine” laminates. Melamine laminates are commonly used as kitchen cupboards; however, this is different from the engineering grade melamine laminates available from industrial distributors such as Redwood Plastics and Rubber. Watch out for that, as the products are not interchangeable.

At the end of the day, do not feel anxious or embarrassed to simply ask a plastics expert for help. They will work with you to understand the priorities of your application and deliver the best solution. That’s their job!

Why You Should Be Using More Acetal

Posted: April 30, 2018 in Acetal
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Let’s start with a question: Do you know what acetal plastic is? If you don’t, and you’re a member of the DIY community interested in using plastics you’re probably missing out on this readily available plastic with excellent properties. Acetal shot to fame in the 1990s in the paintball gun (called “marker”) aftermarket modification community. Acetal offers a plastic with the closest properties to metal: when you hold an acetal part it *feels* different than most plastics. Admittedly, most plastics feel and look the same…Soft and waxy. However, acetal is heavy and dense, it has a weight to it that makes it feel more like metal and that is where this material really shines: replacing metal.

In paintball markers acetal was a no-brainer. Like metals, and better than all other plastics, acetal is beautiful to machine and excels in replacing metals for small, precision parts. As a plastic, it does not suffer the same corrosion issues metals do and yet is still lighter. This allowed the markers to shoot better and faster. Outside of paintball, acetal works great as a bushing replacing nylon. It handles the same PSI in application (4000) but does not suffer the moisture absorption issues nylon does. As such, acetal is often used as a direct replacement for cast nylon in “wet” applications.

Acetal comes in two forms, the homopolymer (white) and copolymer (black). There used to be quality issues with the white but those have been remedied. Though the materials have some small differences, they probably would not affect any DIY application, so pick whichever is more available from your local distributor. Besides being available in rod acetal is also available in plate with 24″ x 48″ plate being the most common. For more information on Redco acetal please click here.

 

Building backyard playgrounds and “forts” for kids is a common job for the hobbyist. Usually lumber is employed in this application; however, sometimes you want to go the extra mile. You may be surprised to learn that the same colorful playground plastic used in public and commercial playgrounds is available to the public. The product is called “Densetec Play” and is plastic sheeting for this express purpose. Densetec play is available in all the bright colors you’d expect but has additional hidden advantages as well. Designed for outdoor use, Densetec Play is fully UV-stable and will not be affected by rot, rust, or mold which will attack traditional materials used in this application.

Densetec Play is easily fabricated using household power tools. It can be cut, drilled, sawed or routered with easy into endless complex shapes. The special “orange peel” surface texture helps the product be resistant to liquids, dirt, and grime allowing for easy cleanup. Densetec Play is available in 1/4″, 3/8″ and 1/2″ thicknesses. The average cost per 4′ x 8′ sheet would be $200-$350 USD depending on quantity. For more information on Densetec Play, contact the distributor Redwood Plastics and Rubber.

Many members of the “DIY” community are attracted to the concept of plastic lumber. Usually made from recycled materials it carries both benefits to the environment by using less new material. In addition, plastic lumber can be manufactured in grades that are much stronger than regular wood. Most grades of plastic lumber are UV stable and involve much less maintenance than wood. They will not require repainting, will hold their color, will not rot or splinter, and will not come under insect attack.

However, with everything there is a “catch”. In the case of plastic lumber it’s the price and delivery. The problem comes down to two factors 1.) customers assume that plastic lumber is widely stocked in the available colors, sizes, and profiles they see on the internet. 2.) Customers assume that plastic lumber is, well, “it’s just plastic”. What people do not often understand is that many plastics, including plastic lumber, are not considered the “commodity” grade of plastics that the public usually encounters in everyday life. Commodity plastics make up consumer items, what’s in your car, your toys, your kitchen. Plastics are actually available in not one but three higher quality grades above “commodity” (yes, the actual grade of plastics used in consumer items is called ‘commodity’). The other three grades are, from lower to top, engineering, high-performance, and imidized.

The DIY crowd will usually only encounter high-performance plastics in PTFE, which is used in items like telescope mounts. They will never encounter the ultra-expensive and hard to obtain imidized plastics. What you need to understand is plastic lumber falls into the engineering grade of plastic and the most commonly quoted grade, fiberglass reinforced, is at the upper end of engineering grade plastic cost.

What are we getting at here?

You need to understand that the cost of plastic lumber vs. equivalent wood will be approximately 8-10x the cost of wood! We’re just stating the facts here, folks. Plastic lumber is not “just plastic” in the way a milk jug is. These plastics are considered a premium, specialty building material, which is why you see them in so many cool applications! It needs to be a great application to be worth the cost! The reason we provided a range on cost is that the color of the lumber actually plays significantly into the cost. Black is the least expensive, followed by wood tones, and finally really off-wood colors such as yellow or white. the difference is about 30% across the spread.

So when do you go for plastic lumber?

First of all, you need to be realistic about the cost. In addition to the lumber’s cost it likely will need to be shipped in from the manufacturing plant and this can easily cost several hundred dollars. You need to be realistic that the lumber will not get to you within a day or two (getting it on site in a month is typical). Finally you need to be realistic about your project. Hey, we love plastic here, but it has it’s time and place. If you want a premium, low-maintenance building material for your project, great, splurge and make your dream project come true! The issue is you need to have the facts on hand and analyze whether or not plastic lumber actually fits your needs.

 

 

Quadrant Engineering Plastics is a major manufacturer of industrial plastics. While they do not sell directly to end-users, and instead sell through distribution, they still invest in many resources for end-users to help them reach their goal with their applications. One of the best is the “Machinists Toolkit” which is available by clicking here. This gives a variety of tips from what coolant to use, to tool tips and even troubleshooting specific issues that come up. It also gives feed rates and end milling/slotting guides for various plastics.

One handy section the toolkit has is a rating of the machinability of various plastics on a rating system. Acetal is usually the best where tight, critical tolerances are involved. But like with all plastics, there are situations where acetal is not ideal. In those cases when reviewing the various options you need to know what the “next best option” is. More useful still, is on the left side of the toolkit page is a link to the chemical resistance chart. This will allow you to look up alphabetically various plastics and their resistance to various chemicals. Please do not think that just because plastics in general are resistant to many chemicals, that a given plastic will be resistant to chemical exposure in your application! And do not assume that just because a chemical is “household” that it will not attack your plastic – it might, so do not assume!

Finally, Quadrant has also released a short video giving some machining tips. While the video says it is geared for a few high performance materials, much of the advice given is relevant to any home machinist working with plastics. That video can be seen here: