polymer processing

We live in the world of polymers. Hair, protein, sugars, cellulose, sand, stone, glass, plastic bowls, buckets, plastic bags - you will find polymer structures everywhere. Polymers resemble a thread. If we could look into the world of molecules, we would see long chains made up of thousands of interconnected and repeating elements, or monomers. Our hair is made of natural polymers, but it can also be made synthetically. This way we get all the plastics and some fabrics. Who has not heard of celluloid, silicones, bakelite, nylon or PVC, i.e. polyvinyl chloride, from which gramophone records and many others are made. - The first polymers were discovered by accident in cotton plantations in the 19th century. Someone poured nitric acid on the cotton and it formed nitrocellulose. It has been noticed that when the material is heated it starts to melt and that it can be formed into various shapes. So, operative entrepreneurs began to produce billiard balls from it. However, the great career o

Request Your Free White Paper Now Learn how to save time, reduce costs and improve the quality of injection-molded parts with mold-filling simulation. With more of today's products containing plastic components, there is a need to shorten injection-molded part and tooling development cycles while simultaneously improving the quality of injection-molded parts. Learn how plastics simulation software helps part designers, mold makers and injection-molding manufacturing professionals optimize parts for manufacturability, refine tooling to improve quality and  shorten cycle times to reduce manufacturing costs.

In weekend, silly, inadequately age. Once again the same, but so different embodiment. Commercially it is called Clever Putty  chemical is a mixture of polydimethylsiloxane (ang. Polydimethylsiloxane, PDMS) (a polymer built of alternating silicon and oxygen atoms in the main chain and the methyl groups (-CH3)), and of bromine, mechanically / non-Newtonian rheological material and more specifically dilatant (compacted shear). And really who it draws attention? Important that thrown bounces (elastic body), extends stretched slowly, breaking the tension quickly (liquid dilatantny), left "flows" (viscous liquid). A mechanism? They arise after the molecular structure of matter. Not discussed and the relevant properties are known as thickening shear, that is, increase in viscosity with increasing shear rate. You can buy it in the form of ready-made Clever Putty toys, or obtain directly from the manufacturer mix Dow Corning 3179 Dilatant Compound (additional ingredients are fi

The eleventh step in validating a injection mold with the overall process shown in injection mold validation flow chart is Mold Metal Adjustments - Centering Process . The steps before: 1. Mold certification  2. Dry cycle mold 3. Process stability test 4. Gage repeatability & reproducibility (R&R) test  5. Mold viscosity test 6. Balance of fill analysis 7. Gate Freeze Test 8. Commissioning (multi-cavity analysis) 9. Design of Experiments (DOE or DOX) 10. Qualification (Process Capability Study)  Purpose: After achieving a capability ratio (Cr) of < 0.75 for key part dimensions, the mold metal is re-cut to center the average to match target. Changing the metal in the mold based on the optimal process, even if it means remaking mold components due to non-metal safe conditions, is preferred vs. changing the process to get the dimensional variation centered. Otherwise the process may not be capable of achieving part specified tolerances. The centering proces