Posts Tagged ‘plastic’

Plastics are very recyclable in general and it is a travesty that poor recycling behaviors have given the material an undeserved bad reputation. Efforts begin at home and fortunately LDPE and HDPE, two common household plastics, can be melted down using household appliances and then remade into new objects. The video we are sharing below doesn’t actually teach you what to make with the polyethylene recycled plastic; however, it does teach you a simple way to melt the plastic into a brick, which could then me fabricated into a new project or alternatively, melted down into a new mold.

In less than five minutes this video will provide you with the essentials to recycle your own HDPE and LDPE:

One of the most common questions the DIY community has is trying to figure out what type of plastic they have or need. Maybe you have an old part or sample and you forget what it is? Perhaps the two plastics people most want to differentiate between are acetal and UHMW (or other polyethylene). But they both come in white and black and they kind of look similar, so what to do? Well, if you’re familiar with the two plastics UHMW or HDPE will feel different: more waxy and lighter than the acetal which almost feels like more of a metal than anything.

There’s another way to identify polyethylene though as long as you can disfigure the sample. Take a sharp knife, such as a steak knife, and start scraping the plastic, give it some gusto with long strokes. If the plastic shaves off in curls then you have polyethylene. Acetal and other plastics will not do this, an example of polyethylene with this type of shaving is pictured here:

 

Part of the trick of figuring out your plastic application and finding which type of plastic to use. This is because 1.) engineering plastics are not widely known to most people and 2.) several of the plastics may work in an application. The trick is to find out which plastic is ideal in a given application, but how do you do that? Well, first you need to figure out what your priorities are either regarding properties: do you need a plastic with excellent impact-resistance? Or perhaps slickness? How about the ability to hold tight tolerances when machined?

After you pick your top couple priorities the next step is find a plastic that best matches your needs. Redwood Plastics and Rubber offers a handy webpage with some information here. However, we’ll also copy and paste the contents of that page below:

SLICKNESS (Most to Least)

Redco PTFE (Teflon®)

Redco UHMW

Redco Tuffkast

Redco Polyurethane (Redco 750SXL)

Redco Nylon

Redco Polyurethane (Redco 750)

Redco Phenolic

 

 

MAXIMUM TEMPERATURE (500+ F) (260+ C)

Redco PTFE (Teflon®) (500 – 600°F)

Redco Phenolic (400 – 500°F)

Redco Nylon (240 – 275°F)

Redco Tuffkast (220 – 240°F)

Redco Polyurethane (200 – 240°F)

Redco UHMW (160 – 180°F)

 

 

HARDNESS

Redco Phenolic

Redco Nylon

Redco Tuffkast

Redco Polyurethane (Redco 750 & Redco 750SXL)

 

 

GLAZING

Breakage Resistant Windows

(Redco Acrylic/ Redco Polycarbonate)

Security Windows

(Redco Acrylic / Redco Polycarbonate)

 

 

LOAD STRENGTH (P.S.I)

Redco Phenolic (10000)

Redco Nylon (4000)

Redco Tuffkast (3800)

Redco Polyurethane (3000)

Redco UHMW (500 – 800)

 

 

IMPACT STRENGTH

Redco Polyurethane

Redco Tuffkast

Redco Phenolic

Redco UHMW

Redco Nylon

 

 

SHOCK & VIBRATION

Redco SVI PADS

 

 

(KRAFT MILL) PULP SAFE

Redco Synsteel (Redco UHMW)

Redco SPS-2000 (Redco POLYURETHANE)

 

 

LOW WATER ABSORPTION

Redco Acetal

Redco UHMW

 

 

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.