CUSTOM COMPOUNDING

Most often the compounding is done by the formulators who are specialists in compounding methods and equipment. They can marry a set of specifications to a formula and provide the product at lowest cost. These independent compounders can be subdivided into two main groups the proprietary compounder and the custom compounder. Proprietary compounders compound and sell their own special formulations, and custom compounders do compounding for someone else. 

Quality control — Also known as QC, these activities verify product quality before delivery to customers. Compound management for HTS, in a sense, manufactures sample plates for screening and it is necessary to establish rigorous QC to ensure the quality of deliverables before they are delivered. A few examples would be checking for missing wells in assay plates (as shown in Figure 12.8), inspection of plate orientations, and examinations of barcode clarity among other reviews. 

In practical applications, fluoroelastomer parts often involve contact with hazardous fluids at elevated temperatures. Failure of parts such as seals may result in personal injury in some cases. Care should be taken by users of parts to assure that proper fluoroelastomer grade and composition are used. Detailed information from the custom compounder or the supplier of the fluoroelastomer should be obtained to minimize such hazards. 

Kreisher, K. Custom compounders get flexible with reactive extrusion methods. In Modern Plastics, 1990 36-38. 

Combs, hard rubber Culture cups, rubber Custom compounding of rubber materials... 

Custom Compounding of Purchased Plastics Resins Establishments primarily engaged in custom compounding of purchased plastics resins. 

Custom Compounder. Mixes rubber gums with other compounding ingredients to create compounds. The compounds may be proprietary to the compounder or follow a customer s specific formulation. 

Rubber Parts Manufacturer. May mix his own proprietary compound or purchase one from a custom compounder. The manufacturer then fabricates finished rubber products. 

Another approach to patterning is to sensitize the target material to directly be photosensitive and wash off the remaining material. A number of custom compounded and commercially available materials have been applied as pho-topatternable gate dielectrics. A similar strategy has also been demonstrated for a soluble pentacene precursor, which converts to an insoluble and well ordered form after treatment [60], and conductor traces in an integrated circuit device [61]. 

Thermoplastic resins are available to the processing industry as pellets of resin. Converting the raw material into useful products can involve separate segments of the plastics industry. As Figure 2.10 suggests, the resin might be compounded by a custom compounder and formed into the final product by a processor or a fabricator. The compounding can also be carried out by the processor in an in-house facility. 

Though not as popular in the 1980s, the custom compounder segment in the US plastics industry is still viable. But compounding is increasingly undertaken by resin manufacturers or more commonly by plastic processors. This often results in cost savings (and even environmental benefits) as the resin does not have to be transported. Pre-made formulations or compounds are commercially available... 

Blends of PVC and NBR (possibly the oldest of commercial polymer blends) have found some use in areas where the service temperature is at or near ambient and oil resistance is needed, such as in the hose and electrical wire and cable markets. They are normally custom compounded for a specific use. 

The segments of the plastics industry that perform most of the compounding today generally fall into three separate categories resin suppliers, independent compounders, and processor/fabricators. Independent compounders are either proprietary compounders or custom compounders. Proprietary compounders compound and sell their own special formulation. Custom compounders do compounding for someone else. They may supply processors or fabricators with compounds not available off the shelf from resin suppliers or proprietary compounders. Or they may supply compounding for resin suppliers on a toll basis or under a fee arrangement in these cases they are referred to as toll compounders. 

Polylite Profile, Mold-making resin, Reichhold Polylube, PTFE micropowder. Custom Compounding, A Div. of Dyneon LLC Polyman, ABS alloys, Schulman, A., Inc. Polymeric Series Foams, Synthetic rubber substitute, Gaska-Tape Inc. 

Primary polyacetal resin producers, custom compounders, and distributors are shown in Table 5.1. 

TABLE 5.1 Primary Poiyacetai Resin Producers, Custom Compounders, and Distributors... 

Custom compounders Ashley Polymers Polyacetals, other engineering plastics... 

PAEK compounds contain fibres, fillers and other effect additives. A range of compounds is available from PAEK producers and general compounders. There are also speciality products produced by a number of custom compounders - such as RTP and Lehman and Voss. Polymics produces compounds based on PEEK, PEKK and their new high temperature PAEKs. As true thermoplastics, PAEK can be compounded using conventional single-screw and twin-screw equipment. The normal effects of fillers and additives apply in PAEK as they do in other thermoplastics. However, temperature is an important limitation. Many fillers, additives, fibre treatments, etc., are too volatile or thermally unstable to be used at 400 °C. In some cases these problems could be overcome by redesign of the molecules, for example to reduce volatility, but the size of the PAEK market is relatively small and so relatively unattractive to additive developers. 

Continuous compoxmding and mixing [23,24] is accomplished by a variety of machines ranging from single-screw to twin screw extruders with variations in design and additional equipment units to achieve a range of end products. The type of compounder or mixer chosen depends upon the specifications and properties required of the end product, volume requirements, overall economics, and whether the compounding is done in-house or by a custom compounder. 

The treatment of KCS by artificial tears in most cases is unsatisfactory in dogs, since to be effective, artificial tears must be applied very frequently (10-15 times/day) which makes this kind of treatment very inconvenient, if not impossible, for many owners. Until today there are no approved products for the treatment of KCS in dogs and desire for various cocktails of different ingredients (tear stimulants, antibiotics, corticosteroids, acetylcystein) have led veterinarians to custom compounding of ophthalmic products with questionable quality control. 

Once the preliminary decisions have been made on the type of material that will meet the requirement of the application, a resin supplier or a custom compounder can be consulted for specific grade of material. 

Plastic products are manufactured using a variety of processing techniques and materials. It is practically impossible to identify a plastic material or product by a visual inspection or a simple mechanical test. There are many reasons that necessitate the identification of plastics. One of the most common reasons is the need to identify plastic materials used in competitive products. Defective products returned from the field are quite often put through rigorous identification analysis. Sometimes it is necessary to identify a finished product at a later date in order to verify the material used during its manufacture. The custom compounders of reprocessed materials may also need to identify already processed material purchased from different sources. Quite often, processors find substantial quantities of plastic material, hot stamp foils, and decals in the warehouse without any labels to identify the particular type. A little knowledge of the identification process can save time and money. 

Former LNP employees founded Modified Plastics in 1976 as a toll compounder, which has since expanded a full range of custom compounds. In 1990, Modified expanded by adding a color match and master batch business. Color Science. In 2008, a third company was added. Plastics Analytical Laboratory, to provide customers with testing and certifications. The combined companies—they are co-located—have grown steadily over the years, offering a full range of compounded products, and have become the largest West Coast compounder. Modified has further... 

DuPont Engineering Polymers has announced an expansion of production capacity for its speciality products in Shenzhen, China, through a licence with a custom compounder in Shanghai. The products involved are speciality grades of DuPont Zytel HTN high performance polyamide, DuPont Thermx PCT thermoplastic polyester, DuPont Rynite PET thermoplastic polyester, DuPont Crastin PBT thermoplastic polyester, DuPont Hytrel thermoplastic polyester elastomers and DuPont Zenite LCP resin. Increased supply to the market is expected by the fourth quarter of 2004. 

PVC /ABS and PVC/ASA blends are widely available from custom compounders and polymer suppliers, including Novatec, A. Schulman, Solvay, ComAlloy, Shuman, PolyOne, Denka, AlphaGary, Georgia Gulf, and Sparteeh. This is particularly useful if they must contain conductive carbon black, for example, to aid electrodeposition of metallic coatings. An example is Royalite R63 (Sparteeh). 

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