UHMW polyethylene has countless applications for the DIY community but as we head into winter there is one simple application that we have to highlight on this blog. That is the UHMW plow blade for snow plows. Let’s not over-complicate things: this is just a UHMW strip with some holes drilled in. But in order to get what you need, you need to know what to ask for! First of all know that the material you likely want is the reprocessed-black UHMW grade. While being less expensive than the natural grade, the cross-linking in its production actually improves wear properties. A nice bonus when you’re also saving some money.

You also need to know what thickness of blade you want. In general, the blades are almost always 1″, 1.5″ or 2″ thick with 1.5″ being the most common. If you don’t know what you need, pick 1.5″. Many plastic companies will pre-drill holes for you if you need them for a fee (usually about $80.00) but we would recommend you do not. Firstly to save money, secondly you need to remember that UHMW is not a dimensionally stable plastic. Changes in temperature may expand the blade from when the holes were drilled meaning by the time you get it – the holes don’t line up! To avoid disappointment we recommend you do the drilling if at all possible.

If you have questions about UHMW snow plow blades please contact us.

SAMSUNG

SAMSUNG

Acrylic sheet (sometimes called “acrylic glass”) is a well known plastic with countless applications for the “DIY” community. Everything from cold frames, to decorations, window replacements or even laser-etched business cards (look them up!). Acrylic offers several advantages other plastics, particularly see-through plastics, do not have. Acrylic’s main competitor in the world of plastics is Polycarbonate. Polycarbonate has higher impact strength than acrylic and should be selected when that is the main concern. Otherwise, acrylic will be slightly (about 15%) less expensive, have superior UV and weathering resistance and be much more scratch resistant: which is a major concern with polycarbonate.

Recently we stumbled across a website called www.instructables.com which has an index for all sorts of really neat acrylic projects to get your creative juices flowing! You can find these projects here: http://www.instructables.com/id/Projects-with-Acrylic/

instructables

Over the years we over at Redwood Plastics (the company that sponsors this blog) get inquiries all the time asking for synthetic ice. Most customers have seen it, but they do not know what it is, how much it costs, or how to install it. This can cause disappointment in people who dream of skating on an all-weather, all-year rink.

The first “fact” to discuss is what is synthetic ice in the first place? It could be one of two types of plastic. Companies that specialized in synthetic ice, of offering pieces that are perhaps 24″ x 48″ or 48″ x 48″ with interlocking segments, that synthetic is usually high-density polyethylene (HDPE) material in 3/8″-1/2″ thick. However, when asking for synthetic ice from a general plastics distributor you will usually be offered Ultra-High Molecular Weight Polyethylene (UHMWPE or shortened, UHMW) this slicker, stronger, and yes – more expensive – polyethylene variant is widely stocked. Almost no plastics distributor will stock purpose-made interlocking sheets of synthetic ice: the market doesn’t warrant the inventory space.

The next question that comes up is cost and here is where a lot of the disappointment occurs. All synthetic ice is “expensive” but UHMWPE, as an engineering-grade industrial plastic, is more so. Prices will vary but a ballpark price for 3/8″ thick material would be $400.00/sheet and $600.00/sheet for 1/2″ thick in a 48″ x 120″ sheet. For a power skater who is also procuring a harness and wants to “skate on the spot” for training, this price can be OK, because only one sheet will be needed. But many potential customers want to build an entire rink out of the material and that becomes cost-prohibitive for many upon quoting.

The next barrier faced in a synthetic ice application is that customers usually do not know how to “make” a rink defer that responsibility to the plastic distributor. Unfortunately, most distributors just sell plastic and do not operate like a hardware store where representatives are well-versed in most potential applications you would use a particular plastic for. They can tell you how slick it is and how it will react to sun exposure all day long – but they won’t be able to tell you how to make a rink. What they can also tell you, which often comes as a surprise, is that the UHMW cannot be “glued” to a floor. You must figure out another way to keep the sheets stationary. Most often this is done by the customer designing a frame which is just big enough to contain their rink: the frame and pressure of the sheets pushing against each other keeps the rink stable.

One of the other common questions we get asked is “how long does the rink last?” Impossible to answer with accuracy since there’s no baseline in how much people use it. But perhaps 2 years is typical before the surface is so worn the sheets need replacement. Half-inch thick plastic will slightly last longer as there’s more area to get chewed up.

Synthetic ice remains an excellent DIY project for the skating enthusiast; however, you need to understand the facts about what it’s going to involved to design and purchase your rink.

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We found an interesting blog that brings up a great point for those of us with a green thumb – in many areas of North America late fall and even winter does not mean the end to the growing season! Lots of cold-hardy vegetables and herbs are available but you do need to make some precautions. Specifically, you need to shelter the plants from heavy frost. What we like about the idea on this blog is that it’s 1.) easy and 2.) fits around your standard rectangular planter bed. You just need some PVC brackets, some 3/4″ OD PVC pipe and a bunch of flexible 1/2″ OD pipe. Over that you can drape some flexible clear plastic. The plastic protects the plants from frost damage and also provides some heat insulation.

You can read the blog in its entirety here.

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We write a lot on this blog about doing things with plastics purchased from distributors – but what if you could create your own plastic at home? We stumbled on an open-sourced recycled plastic manufacturing system called the “Precious Plastic V1.0” and, at least from the video, it looks to be a really neat system. What is interesting is that it combines an extruder, rotational molder, a shredder, and compression molding system. This would allow you to create a wide variety of plastic products because those are three main processes to manufacture virgin plastics. The only system missing is a cell cast mold for sheet but presumably you could make one yourself by laying out the plastic from the extruder in between some metal sheet than compressing it.

The system allows you to recycle old plastic into items you would use. They look…Creative, but anyone who bothers to set up this system likely doesn’t care about the funky colors and look! The best part of all is that the creator of the system wants it to be “open-source” so the information and plans he has are free for you to use. You can find them on his website here.

Here is a quick video of the system in action:

3 “Insider” Plastic Tips for the DIY Community

Posted: September 30, 2016 in Uncategorized
Tags: , , , ,

When you’re a member of the public who just needs some plastic for a home project, dealing with a plastics distributor can be a little awkward. They’re not like a “store” in the traditional sense, with product neatly displayed with nice little price tags. Product is quoted based on specific needs – and often, you don’t even know what those needs are! Sure, you may have an application in mind, and you might have heard of a plastic that works well in that application. But how do you know for sure? In addition, industrial plastics are a premium material and the cost can be a surprise to some people. Here are three “insider” tips from those of us in the plastic industry which will help you have a more satisfying experience with your DIY application:

1.) Be open-minded – and don’t care about looks

Many people have an idea that, like with products made of consumer or “commodity” plastic, that a wide array of colors, textures, and sizes are available. This is not the case at the level of industrial plastic. Most plastics only come in one color per grade and the color is often just white or black. Colorful plastics like frosted acrylic are hard to come by in small quantities. You need to place the needs of your application beyond color matching or other aesthetics.

Also, be open-minded about material. It’s quite possible a knowledgeable salesperson will recommend a different material. If you’re worried about the increased costs, ask for some clarification on why the suggested plastic might be better and what other options you have available.

2.) Ask about offcuts

For many smaller projects you don’t need a lot of material but plastics will commonly be offered in 4′ x 10′ or 4′ x 8′ sheets. One potential option is to ask your distributor if they have some offcuts they would be willing to sell. Many plastic distributors will have companies under contract to buy their offcuts, but some are usually kept on the shelf and either way the distributor usually makes a bit more by selling offcuts for cash. You may have to take a slightly larger piece, but it could save you money, and it’s worth an ask.

3.) Arrange your own pickup/freight

“Quote and include the freight” is a common request a plastic distributor gets but do you know what you’re actually asking for? True, to get a contract done industrial supply companies will mostly quote the freight. But what they’re doing for the most part is contacting a freight broker and getting them to spit out a quote, which is then marked up to you by 10-15%. The time a salesperson takes away from their primary job needs to be compensated for. Your best option is to just ask for the product weight and dimensions and contact a logistics provider yourself. Or make a UPS, Purolator, or Loomis account for the smaller orders.

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UHMW polyethylene is probably the most popular engineering plastic for use in DIY projects. But how do you work with it? People often get overly concerned with fabrication, especially in regards to the “tolerances” needed for most home projects, but regardless here are some tips to get the most out of your UHMW application.

Sawing:

UHMW can be cut with either a circular or band saw. A band saw is best as it will vent heat away from the plastic and allow for faster cutting speeds. The band saw blades may be 10-30mm wide and about 1-2mm thick with the circular pitch between 3 and 10mm. To prevent the saw blades from becoming jammed, the teeth must be set at approximately 0.5mm. When using circular saws, saw blades with a minimum setting 0.5mm are also preferred. Normal cutting speed for band saws is 1,000-2,000m/min and for circular saws, 3,000-4,000 m/min.

Drilling:

Lower RPM drilling is recommended unless compressed air, water, or cooling oils are used – UHMW melts easily. Twist drills are most commonly used but pointed drills and circular cutters can be used for higher diameter holes.

Welding

Because of its high melt viscosity, friction and butt welding are the only practical methods for joining Redco UHMW by welding.

Machining

Machining is the principal method used to fabricate finished parts from UHMW. UHMW can be sawed, turned, planed, milled drilled, stamped and welded easily on woodworking or metalworking machines. The following general directions should be observed in these operations: To obtain surfaces of high quality, tools should always be sharp. For the most purposes, normal tool steel is satisfactory through many fabricators use special steels.

The optimum cutting speed is between 250 and 1,000 m/min. At lower cutting speeds cooling is not required, but at higher cutting speed range, water cooling or the use of soluble cutting oil is essential. In all cases, care must be taken to avoid heat build-up in the machining operation, so that the work piece does not smear the cutting edges. In milling and turning, the feed should not be too fast and the depth of the cut should be greater than 0.3mm.

Bonding

Questions about solvent bonding are common but unfortunately this is not recommended with UHMW. It resists most solvents and, at best, will create a below-average to poor bond. Mechanical fixation is recommended wherever possible.

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