Plastic Sheet - Polypropylene Sheet

Plastic sheeting (also known as plastic tarpaulin, tarp or polythene sheet) is a sheet of strong, fl exible, water resistant or waterproof material. Although different qualities exist, those suitable for humanitarian relief are made from polyethylene. A standard sheet has a black woven or braided core and is laminated on both sides. All plastic sheeting must reach minimum performance standards .

Polypropylene Sheet


Polypropylene is a crystalline plastic that is known for high strength-to-weight ratio, excellent chemical resistance and high performance in thermoforming and corrosive environments. Polypropylene sheet is often used for orthotic and prosthetic devices, plating and anodizing process equipment, plenums, manifolds, and pump components.

Features of Polypropylene Sheet:

  • Appropriate for applications to 180°F(82°C).
  • Low moisture absorption.
  • Resists most acids, alkalis and solvents.
  • Corrosion resistant.
  • Thermoforming performance.
  • Meets USDA federally inspected meat and poultry packing guidelines.

PTFE Barbell

Clear PTFE flexible straight barbell tongue ring. High quality body jewelry.
PTFE Barbell
PTFE, polytetrafluoroethylene, is flexible, Nickel free wire. It can be sterilized with autoclave. It is hospital grade, non toxic, allergy free material. PTFE is totally flexible, may cut to any desired length with a blade or scissor. It is also self threading with any balls, spikes, or any other parts. Just screw on to the PTFE wire, and make a treading which will hold very firmly.
User Reviews:
I wear these as nipple rings, and they're great. I do have to buy a lot of extra ball ends because they do tend to fall of either in my sleep, in the shower, or changing, but I still prefer them to metal. 
These are great. I got them to use as retainers for genital piercings when I was going into surgery (no metal jewelry allowed). It was easy to cut them to the right size and bend them a bit for a great and comfortable fit. These are comfy enough that I now switch between my usual stainless steel jewelry and the PTFE. Just have to be careful not to over-tighten the balls or I end up breaking off the end of the bar... 
I bought this for my tongue piercing, and at first I was really happy with this, but it started to bend a lot after a while, so I had to switch back to the old ones. I wish this had worked out better so that I could just buy different color attachments for it. 
I use these for nipple piercings to avoid pitting (because the shaft is longer than most of my other barbell piercings so the dents are sort of offset enough to allow recovery ) and they work really well. They're comfortable and the perfect length. I just wish the acryllic ball ends were smaller. 
I absolutely loved this barbell. I have to take my industrial out occationally for my job and this kept my ear from getting irritated. I keep looking to replace it (sadly I lot it), just waiting for the right length. 
Really comfortable!! I loved wearing this bar while sleeping when my ear was still sensitive before the piercing matured. Now i still wear it because its comfortable!! :D Highly recommend for every new (less than a couple years old, but not super fresh) piercings. 

Food Grade Tubing

Vinyl tubing is clear and flexible and provides an economical means of fluid transfer in a variety of applications. PVC tubing exhibits excellent elongation and drape. It is typically used for lower pressure applications and for OEM designs with complex tubing pathways.
Food Grade Tubing
This flexible, smooth, corrosion resistant, non-aging, and non-oxidizing food grade vinyl plastic tubing is produced from raw materials meeting the FDA and U.S. Pharmacopoeia Classes I through VI requirements. Also available is a flexible vinyl tubing produced from raw materials meeting Federal Specification A-A-55697 criteria for laboratory and medical tubing (including oxygen handling). For prolonged exposure this material is available in extruded black because of its resistance to bacteria.
PROPERTIES
Food Grade Tubing
NOTE: The property values presented above are typical values intended for reference and comparison purposes only. They should NOT be used as a basis for design specifications or quality control. Contact us for manufacturers’ complete material property datasheets. All values at 73°F (23°C) unless otherwise noted.
APPLICATIONS:Medical, laboratory;Drainage lines;Chemical processing;Semiconductor processing;Environmental;Industrial.
ADVANTAGES:Natural resistance to combustion;Withstands a variety of conditions;Does not rust or corrode;Economical;Clear;Flexible;FDA Approved.

PTFE Forming and Fabrication - Working Speeds

When extreme tolerance must be specified, or when product shapes are very complex, or when just one or two prototypes are required, the machining of TEFLON@ PTFE resins becomes a logical means of fabrication.
All standard operations-turning, facing, boring, drilling, threading, tapping, reaming, grinding, etc.-are applicable to TEFLON PTFE resins.Special machinery is not necessary.
PTFE Forming
When machining parts from TEFLON PTFE resins, either manually or automatically, the basic rule to remember is that these resins possess physical properties unlike those of any other commonly machined material. They are soft, yet springy. They are waxT, yet tough. They have the cutting "feel" of brass, yet the tool-wear effect of stainless steel. Nevertheless, any trained machinist can readily shape TEFLON PTFE to tolerances of +0.001 inch and, with special care,to +0.0005 inch.

CHOOSE CORRECT WORKING SPEEDS

One property of TEFLON PTFE resins strongly influencing machining techniques is their exceptionally low thermal conductivity. They do nor rapidly absorb and dissipate heat generated at a cutting edge. If too much generated heat is retained in the cutting zone, it will tend to dull the tool and overheat the resin. Coolants, then, are desirable during machining operations, particularly above a surface speed of I50 m/min (500 fpm).
Coupled with low conductivity, the high thermal expansion of TEFLON PTFE resins (nearly IQ times that of metals) could pose supplemental problems. Any generation and localization of excess heat will cause expansion of the fluoropolymer material at that point. Depending on the thickness of the section and the operation being performed, Iocalized expansion may result in overcuts or undercuts, and in drilling a tapered hole .
Machining procedures then, especially working speeds, must take conductivity and expansion effects into account.
Surface speeds from 60-150 m/min (200-500 fpm) are most satisfactory for fine-finish turning operations; at these speecls, flood coolants are not needed. Higher speeds can be used with very low feeds or for rougher cuts, but coolants become a necessiry for removal of excess generated heat. A good coolant consists of water plus water-soluble oil in a ratio of 10:1 to 20:I.
Feeds for the 60-150 m/min (200-500 frm) speed range should run berween 0.05-0.25 mm (0.002-0.010 inch) per revolurion. If a finishing cut is the object of a high-speed operation (e.g., an automatic screw-machine running at240 m/min [800 fp-]), then feed musr be dropped to a correspondingly lower value. Recommended depth of cut varies from 0.005-6.3 mm (0.0002- 0.25 inch).
In drilling operations, the forward travel of the tool should be held to 0.13-0.23 mm (0.005-0.009 inch) per revolution. It may prove advantageous to drill with an in-out motion to allow dissipation of heat into the coolant.

Industrial Hoses - stainless steel braided hyperline PTFE Hose

The PTFE lined tube is smooth bore on the inside but convoluted on the outside, to combine the ease of assembly and high flow rates of a smooth bore hose with the flexibility and kink resistance of a convoluted hose in one product.
PTFE lined tube
Material:PTFE
Reinforcement:Single or double PTFE stainless steel braid
Working temp.:From -70°C up to +260°C (working pressure depends on temperature)
Characteristics:The internal layer made of seamless extruded, premium grade PTFE that ensures minimum porosity, maximum flexibility and high resistance to vibration. The braid made of heat treated PTFE stainless steel wire (tensile strength: 1700 MPa). Hyperline hose is a version of Smoothbore hose, however its wall is medium thick and inside diameter suitable for standard hydraulic fittings. Supplied with a single braid as a standard.
For temperatures above +130°C reduce the maximum working pressure given in the
tables by 0.75% for each 1°C of temperature rise above +130°C.
Example: at +170°C temperature, maximum working pressure for hyperline PTFE hose is:
          320 bar - (170°C - 130°C) x 0.75 = 320 bar - 30% = 224 bar.
Safety factor (working pressure/ bursting pressure) is 1:3.

PROPERTIES
Temperature Rating : The temperature rating is from -70° (-94°F) to +260°C (500°F), but the maximum working pressure (MWP) must be reduced by 1% for each 1°C above 130°C (1% for each 1.8°F above 266°F).
The maximum working temperature for the PTFE braided hose is +180°C (+365°F)
Pressure Resistance : The maximum working pressures are as listed, up to 130°C (266°F). The design of conventional auto convoluted PTFE hose liner permits internal “pressing out” of the convolutions inside the braid over time and under temperature and pressure, leading to premature failures. The narrow and highly compressed web sections of Hyperline FX are much more resistant to pressing out, hence a much longer service life under pressure can be achieved.
Tube Only grades can only be used at pressures up to 4 Bar (60 psi) up to 130°C (266°F) and are not fully vacuum resistant.
Full Vacuum Resistance : Stainless Steel braided Hyperline hose is vacuum resistant up to 130°C (266°F).
Reduced Diffusion Rates : The way the Hyperline tube liner is made, by web compression without fracture, surprisingly generates a much improved resistance to gas permeation, compared to any other type of smooth bore or convoluted PTFE hose. Much lower diffusion rates can therefore be achieved.
Excellent Flow Rates : Due to the non turbulent flow through a smooth bore hose, Hyperline flow rates for a given pressure drop and actual bore size are 2 to 3 times higher than for a convoluted PTFE hose. (This applies to the hose itself. If end fittings are applied, however, which introduce a smaller bore at the ends, this multiple is reduced).
Applications:Due to the unique properties of PTFE (wide temperature range, excellent chemical resistance,non-stick surface), widely used to transfer chemicals, foodstuffs, fuels, oils, paints, solvents,adhesives, detergents, inks, steam, etc.

Fluoropolymer Monomer Properties

Fluoropolymer Monomer Synthesis: Tetrafluoroethylene;Hexafluoropropylene;Perfluoroalkyl Vinyl Ethers;Chlorotrifluoroethylene;Vinylidene Fluoride;Vinyl Fluoride.
Properties of Tetrafluoroethylene
Tetrafluoroethylene is a colorless, odorless, tasteless,nontoxic gas which boils at 76.3 C and melts at 142.5 C. The critical temperature and pressure of TFE are 33.3 C and 3.92 MPa. TFE is stored as a liquid; vapor pressure at 20 C is 1 MPa. Its heat of formation is reported to be 151.9 kcal/mole. Polymerization of TFE is highly exothermic and generates 41.12 kcal/mole heatdthe extent of which can be compared with the heats of polymerization of vinyl chloride and styrene, at 23-26 kcal/mole and 16.7 kcal/mole, respectively. 
Safe storage of TFE requires its oxygen content to be less than 20 ppm. Temperature and pressure should be controlled during its storage. Increasing the temperature, particularly at high pressures, can initiate deflagration in the absence of air (TFE degrades into carbon tetrafluoride). In the presence of air or oxygen, TFE forms explosive mixtures in the molar percentage range of 14-43%. Detonation of a mixture of TFE and oxygen can increase the maximum pressure to 100 times the initial pressure.
Properties of Hexafluoropropylene
Hexafluoropropylene is a colorless, odorless, tasteless, and relatively low toxicity gas, which boils at 29.4 C and freezes at 156.2 C. In a 4-hour exposure, a concentration of 3000 ppm corresponded to LC50 in rats. Critical temperature and pressure of HFP are 85 C and 3254 MPa. Unlike TFE, HFP is extremely stable with respect to autopolymerization and may be stored in liquid state without the addition of telogen. HFP is thermally stable up to 400e500 C. At about 600 C under vacuum, it decomposes and produces octafluoro-2-butene (CF3CF¼CFCF3) and octa-fluoroisobutylene.
Properties of Perfluoroalkyl Vinyl Ethers
Perfluoroalkyl vinyl ethers (PAVE) form an important class of monomers in that they are comonomers of choice for the “modification” of the properties of homofluoropolymers in additionto broad use inthe structure of copolymers of TFE. The madvantage of PAVEs as modifiers over HFP is their remarkable thermal stability. A commercially significant example is per-fluoropropyl vinyl ether (PPVE). PPVE is an odorless, colorless liquid at room temperature. It is extremely flammable and burns with a colorless flame. It is less toxic than HFP.
Properties of Chlorotrifluoroethylene
Chlorotrifluoroethylene is a colorless gas at room temperature and pressure. It is fairly toxic with an LC50 (rat) at 4-hour exposure and a concentration of 4000 ppm. It has a critical temperature and pressure of 105.8 C and 4.03 MPa. Oxygen and liquid CTFE react and form peroxides at fairly low temperatures. A number of oxygenated products, such as chlorodifluoroacetylfluoride, are generated by oxidation of CTFE. The same reaction can occur photochemically in the vapor phase. Chlorotrifluoroethylene oxide is a by-product of this reaction. The peroxides act as initiators for the polymerization of CTFE, which can occur violently.
Properties of Vinylidene Fluoride
Vinylidene fluoride, (CH2¼CF2), is [49] flammable and is a gas at room temperature. It is colorless and almost odorless and boils at 84 C. VDF can form explosive mixtures with air. Polymerization of this gas is highly exothermic and takes place above its critical temperature and pressure.
Properties of Vinyl Fluoride
Vinyl fluoride (75-02-5) (fluoroethene) is a colorless gas at ambient conditions. It is flammable in air between the limits of 2.6 and 22% by volume. Minimum ignition temperature for VF and air mixtures is 400 C. Adding a trace amount (<0.2%) of terpenes is effective to prevent spontaneous polymerization of VF. Inhibited VF has been classified as a flammable gas by the U.S. Department of Transportation.

Skiving Tubing / Pipe

Edge treatment of coil strip before it enters a tube and pipe mill, called skiving, is a rapidly advancing technology. Improving the coil edge before it is welded helps increase the quality of the seam join and helps prevent rejected tube or pipe.
Skiving Tubing
Edge treatment of coil strip before it enters a tube and pipe mill, called skiving, is a rapidly advancing technology. Improving the coil edge before it is welded helps increase the quality of the seam join and helps prevent rejected tube or pipe.

TRADITIONAL SKIVING EQUIPMENT

Edge skiving to obtain smooth abutting edges for seam welding has been a viable process for many years. Most traditional skivers use triangular high-speed steel cutting knives held in bolted, clamped holders.
The toolholders are rigidly mounted on movable screwjack slides and are manually engaged with the strip to attain the desired depth of cut. Each tool is manually set, with the individual screwjack settings determining the depth of cut with each tool and, therefore, the tool load sharing.
Traditional skiving units are most successful at speeds above effective planing speeds, or about 40 feet per minute (FPM). Below this speed, the metal tends to tear instead of being smoothly cut, resulting in jagged edges that can be worse than the "as slit" edge.
Cambered material can jam between the rigid tools used with this equipment, causing tool blunting and changed depth of cut.
When tools wear and become blunt, they have a tendency to chatter, which can cause a rough finish and poor welds. In addition, blunt tools cannot easily be changed on-stream. They must be retracted by hand and another tool station advanced to replace the cutting action of the defective tool.
The load sharing and depth of cut of each tool depends on the individual tool settings. Uneven tool wear upsets the selected load sharing.Traditional skiving equipment has been generally satisfactory, but modern mills are now demanding higher quality, a wider operating range, and less operator dependency.
For instance, since most tungsten inert gas (TIG) welding mills using stainless steel, high-alloy steels, titanium, or aluminum must run slower than 40 FPM, these materials must be used "as slit."
Untreated or imperfectly treated edges cause pinholes in completed welds. The product is often 100 percent inspected for defective welds using ultrasound, and defective lengths are scrapped. As much as 2 percent can be routinely rejected in some mills.
Conventional edging equipment performs well with high-speed mills when properly set up with sharp tools and when the material is of uniform width and free of camber.

DEVELOPMENTS IN SKIVING

Recent research and development has resulted in a range of new skiving equipment being developed.
A four-station edger suited to skiving at down to near-zero strip speed is available to the market. This patented edger uses electrically vibrated tools that impart relative movement between the tools and strip at all times. The vibration amplitude is fully adjustable, and so is the cutting pressure and depth of cut on each module.
These machines have a skiving speed range of 0 to 600 FPM. Each mini tool carriage is oscillated in the direction of material travel. The frequency can be varied. The higher the frequency, the less the depth of cut and the better the finish. Because vibratory action is in the direction of material travel, vibration perpendicular to direction of travel (or chatter) is suppressed.

REMAINING CHALLENGES

The skiving process is still in need of improvement. Higher-frequency oscillation of vibratory tools is being developed to give better finishes at low cutting speeds. Also, new methods of reducing the effects of tool wear are being developed.
Edge sensing rolls fitted with sonic detectors are being designed to enable edge quality monitoring on-stream. These can be used to initiate automatic tool changing. The process is slowly evolving into self-checking smart technology.