Blowing Agents.

PRODUCT LINES REVIEWED

AMERICHEM INC.

Custom-formulated concentrates for most thermoplastics can include a nontoxic blowing agent for food-contact applications and can contain color and other additives. Supercell modified azo compounds reportedly permit improved control of gas generation.

AMPACET CORP.

LDPE-based foaming-agent concentrates specially designed for thin blown, cast, or coextruded films. Grade 10123 is for LDPE, HDPE or PP homopolymers. Universal 10349 concentrate is for engineering resins, polar or nonpolar.

ATOFINA CHEMICALS INC.

Isotron line of HCFCs used as physical blowing agents for PUR, PS, and PE.

BAYER CORP.

Porofor AUG azodicarbonamide chemical blowing agents for rigid and flexible vinyls, crosslinked PE foam, ABS, and PS. (See Insert in Materials Section.)

BERGEN INTERNATIONAL

Foamazol chemical blowing agents for use in most application such as structural foam, wire and cable, profile and sheet, blown and extruded films, blow molded containers, injection molding, and PP ribbon extrusion. Products offered in 100% active free-flowing powders and pelletized masterbatches. Endothermic and exothermic formulations available as well as blends. Masterbatches in a range of base resins for improved compatibility with resins such as PP, PE, copolymers, PS, PPE, ABS and PVC. Processing temperatures from 300-500 F. Custom formulations available. (See ad this page.)

BIDDLE SAWYER CORP.

Distributes azodicarbonamide products from Otsuka Chemical Co. of Japan for producing foams from PVC, PE, PP, EVA and rubber. Newest line is Azofoam Ultra, which have superior dispersibility, very low dusting, and do not cake up. Products available in powder form. In addition to these exothermal products, a separate line of endothermal blowing agents is available.

CHROMA CORP.

Dry powders or compounding of blowing agent masterbatches from 25 lb to truckloads in all resin systems and additives combined with colorants to provide multifunctional concentrates.

CINCINNATI SPECIALTIES GROUP

Chemical blowing agents reportedly produce no corrosive by-products. KemTec 500 is for nylon, polyesters, ABS, and PC.

CLARIANT CORP.

Business Unit Additives Masterbatches offers full range of Hydrocerol endothermic foaming agents, Exocerol exothermic and exothermic/endothermic chemical foaming agents, and Activex sink mark removers and cell stabilizers for wide range of thermoplastics.

CROMPTON CORP. POLYMER ADDITIVES

Chemical blowing agents as nondusting powders in coarse and fine particles. Ammonia-free and nonplating formulations and pre-activated whiter-than-normal foams. Alos metal organic products such as aluminum alkyls, alkyl silanes, methylaluminoxanes, and metallocenes used as co-catalysts for polyolefins.

CROMPTON CORP. UNIROYAL CHEMICAL

Celogen/Expandex family of azodicarbonamide and tetrazole chemical foaming agents includes products to foam plastics at temperatures from 250 F to 698 F:

* Celogen AZ-120, 130, 140, 150, 180, 199 unmodified azodicarbonamides for PVC plastisols, food applications, sink mark elimination in molded PE, PP, HIPS, ABS. TPO/TPE, TPU, TPR. Suitable for some FDA-regulated applications.

* Celogen R-9370, AZ-1901, AZ-1901-C for crosslinked, low-density polyolefin foams.

* Celogen AZRV for extruded rigid PVC pipe, profiles, and sheet.

* Celogen AZNP-130 for molded and extruded HDPE, ABS, HIPS, PPO/PPE, TPO/TPE, TPU, TPR; Santoprene and Sarlink. Suitable for some FDA-regulated applications.

* Celogen AZ-760-A for polyolefin wire and cable compounds (HDPE, PP). Suitable for some FDA-regulated applications.

* Celogen AZ-2990 and 3990 for vinyl plastisols and rotational molding of LDPE, LLDPE, MDPE, HDPE, PP, and PVC plastisols. Suitable for some FDA-regulated. applications. Flow-treated for ease of dispersion.

* Celogen 754-A activated azodicarbonamide for molded and extruded flexible PVC, TPO, TPE, and TPU.

* Celogen 765-A activated azodicarbonamide for PVC sound-deadening materials and low-temperature TP elastomers.

* Celogen 780 activated azodicarbonamide for lower processing temperature polymers.

* Celogen RA semicarbazide for molded and extruded PP, ABS, HIPS, and PPO/PPE.

* Celogen OT (OBSH) hydrazide for LDPE insulated coaxial cables, vinyl plastisols, screen-printing inks, rotational molded FE and EVA, and elastomer-resin blends in pipe insulation and sporting goods; nondiscoloring, odorless, and suitable for some FDA-regulated applications.

* Celogen TSH low-temperature hydrazide generates gas at 250 F.

* Celogen XP-100 proprietary sulfone for use with spray-up applications of thermoset polyester foams; reacts with standard MEKP peroxides in the presence of copper and cobalt promoters.

* Celogen SD dispersions in plasticizer or epoxidized soybean oil with one of two azo particle sizes, with and without activator.

* Expandex tetrazoles for high-melting thermoplastics such as PC, nylon, thermoplastic polyesters (PET, PBT), ABS alloys, PPE/PPO alloys, PPS, and polysulfone; Expandex 5-PT has a foaming range of 464 F and higher.

CYLATEC CORP.

Cylacell is a predictable, environmentally safe, and equipment-friendly inorganic sodium silicate endothermic blowing agent for thermoplastics, rubber, silicone, and thermoset polyester bulk molding compounds. It contains bound water, which causes particles to expand into closed-cell spheres at temperatures above 300 F. Fume- and odor-free, it will not discolor resins or postblow. Molded parts do not exhibit outgassing, and painting can be done immediately.

Compared with some fluorocarbon, hydrocarbon, or other liquid physical foaming agents, Cylacell reportedly can show improved cell structure, lighter foam densities, and sometimes higher flame retardancy and smoke suppression. It can also obviate the need for nucleating agents. Tests have shown that Cylacell can increase useful life of foams by eliminating any potentially reactive blowing-agent byproducts that can degrade elastomers.

DONG JIN CHEMICAL INDUSTRY CO.

See Stanchem.

DOW CHEMICAL CO.

Methylene chloride urethane grade is a modified methylene chloride for flexible PUR slabstock foam. Contains an inhibitor that minimizes foam oxidation and scorching. Can be used as sole auxiliary blowing agent. Reportedly offers high volatility, low flammability, low raw-material and handling costs, and low toxicity and is said to be non-polluting.

For PS foam sheet, Dow Plastics is licensing technology for using 100% [CO.sub.2] to produce foam sheet in thicknesses up to 1/4 in. and densities comparable to those produced with hydrocarbon or HCFC-22 blowing agents (2-10 pcf). It requires retrofitting of existing extrusion lines.

DUPONT CO.

Line of fluorochemical blowing agents includes Formacel Z-2 (HFC-152a), FDA approved for use in PS food service and packaging foams; Formacel S (HCFC-22) used in closed-cell polyurethane and polyisocyanurate foams; and Formacel Z-4 (HFC-134a) for polyurethane systems and appliance foams, and in PS insulating board.

EASTMAN CHEMICAL CO.

Foamable concentrates in a PP base supplied for blending with PP in foam molding or extrusion.

ELF ATOCHEM NORTH AMERICA INC.

See Atofina Chemicals Inc.

ENDEX POLYMER ADDITIVES INC.

Endex endothermic chemical foaming and nucleating agents, and endothermic/exothermic synergistic hybrids for thermoplastic foams generate fine closed-cell structures. Products improve flow, compatibilize mixed/cycled polymers, reduce molding cycle or increase extrusion rates, and are used for sink mark elimination and improved weld-line strength.

Endex ABC 2750, a 50% active pelletized endothermic chemical foaming agent, is compatible with almost all thermoplastic polymers, including commodity polymers, engineering polymers such as ABS, acetal, PC, modified PPO/PPE, and polyolefin elastomers.

Endex ABC 100, a 100% active powder endothermic chemical foaming agent is also an effective nucleating agent in physical foaming processes.

Endex PBS 2610 and Endex PBS 2625 concentrates designed for use in engineering polymers, which are moisture sensitive such as PET and PC. Products may be used in extrusion or injection molded structural foam for weight reduction, and also to remove problem sink marks. The combination of low use levels, typically 0.5-2%, and good physical property retention in the finished part, make these products very cost effective.

Endex 1040 is a concentrate based on OBSH in PE carrier resin. It is designed for use in the processes using temperatures in the range 150C to 175C (300F to 350F). It produces very fine cell structures, with a combination of carbon dioxide and nitrogen gases.

EPI ENVIRONMENTAL PRODUCTS INC.

Endothermic, exothermic, and endothermic/exothermic chemical blowing agents in powders and resin concentrates. Concentrates come with compatible resin carriers for polyolefins, PS, ABS, PPO, PPE, PET, PVC, nylon, and PC. Concentrate activity levels from 30% to 70%.

EPIcor endothermic chemical blowing and nucleating agents reportedly offer better dispersion and physical properties, faster cycle times and extrusion rates, higher gas volumes, smooth surfaces, and fine cell structure with thick skins.

EPIcell exothermic chemical agents include OBSH concentrates, azodicarbonamide, and non-plateout grades.

POLYcor endothermic/exothermic hybrid chemical blowing agent is compounded in one pellet. Offered in structural-foam molding grades for high-temperature resins such as PPO, PC, and PC/ABS alloys. POLYcor combines surface property benefits of EPIcor and higher gas pressure typical of EPIcell along with fast degassing and part paintability. Various grades provide finer cell structures and smooth surfaces.

EXPANCEL INC.

Expancel expandable thermoplastic microspheres used as blowing agents in systems exposed to 200-400 F. Microspheres are white, spherical polymeric particles. Thermoplastic shell encapsulates a gas and softens when heated, allowing sphere expansion from the increased internal vapor pressure. Expansion factor is 40-60 times the original volume. Other features include defined pore size, closed-cell structure. Suitable as a blowing agent in plastisols, elastomers, thermosets, and thermoplastics.

FERRO CORP., LIQUID COLORANTS & DISPERSIONS DIV.

Spectraflo liquid chemical exothermic and endothermic blowing-agent dispersions produce higher volumes of nitrogen gas per unit of additive than conventional blowing agents while improving structural uniformity and processing control. They are said to improve sink mark removal and reduce weight while preserving structural properties of ABS, LDPE, HDPE, and PP parts injection molded and extruded/coextruded.

Endothermic formulations require no "gas-off" period, allowing painting of parts immediately after molding. Custom formulations available to gas-off at specific temperatures. Liquid vehicle reportedly allows higher loading of active ingredients than is possible with solid carriers. (See ads p. 327, Cover IV.)

FLOW POLYMERS, INC.

Concentrated dispersions of organic blowing agents or sodium bicarbonate.

M.A. HANNA COLOR

Wil-Foam chemical blowing-agent concentrates (solid or liquid) for vinyls, polyolefins, styrenics, acrylics, polyesters, and nylons. Custom-made, multicomponent concentrates feature high concentration and superior dispersion. Also concentrates, which can contain colors and other additives, for wire and cable, fibers, film, sheet, profile extrusions, injection and blow molding, and structural foam.

HARWICK CHEMICAL MANUFACTURING

Azodicarbonamide-based blowing agents in various plasticizers for foam acrylics, EVA, PE, and vinyl.

HITECH POLYMERS, INC.

Pelletized concentrates of blowing agents can be incorporated into a variety of elastomers, engineering thermoplastics, and commodity polymers.

LAROCHE INDUSTRIES INC.

HCFC-141b environmentally improved blowing agent for rigid polyurethane foam. Replaces CFC-11 in foam blowing, and CFC-11 and CDC-113 in approved solvent applications.

LNP ENGINEERING PLASTICS INC.

Foam concentrates include Foam-Kon 20 for resins processed below 450 F, such as ABS, SAN, PP and acetal; and Foam-Kon 28 for resins processed above 450 F, such as nylons, PPS, polysulfone, and polyethersulfone.

OPTIMER, INC.

Micropoppers, hollow polymeric microspheres, have been used as a syntactic foaming agent in PS and PVDC. Spheres will expand to 10 times their original volume inside the resin matrix when heated to 265-300 F and can be made of various resins including PMMA, PVDC, or SAN.

OTSUKA CHEMICAL CO.

See Biddle Sawyer Corp.

PHOENIX COLOR & COMPOUNDING

New line of high-activity endothermic and exothermic chemical blowing agents or hybrids reduce product density and shorten mold cycle times. Endothermic formulations available with loads up to 90%; exothermics with loads to 60%. Because of high activity levels less product is needed for a higher level of gas production.

Products can be designed for compatibility with most resins and are available in 100% active dry form or in pelletized Color Gems in activity levels from 5% or 90%. Also available in low-temperature (280-320 F) and high-temperature (360-400 F) formulas.

PMC SPECIALTIES GROUP

See Cincinnati Specialities Group.

POLYVEL INC.

Custom-formulated blowing-agent concentrates for thermoplastics:

* BA20T for EVA and LDPE foamed at 290 to 340 F.

* BA210 for LDPE, HDPE, and PS foamed at 350 to 400 F.

* BA20 for PP, PB, PS, PPE alloys, and ABS foamed at 380 to 440 F.

* BA205PT for nylon, polyester, PC, and PPE alloys foamed at 440-540 F.

* BA2575 for high-temperature polymers foamed at 700 F.

REEDY INTERNATIONAL CORP.

Safoam endothermic chemical nucleating and blowing agents for thermoplastics produced from natural materials and reportedly environmentally safe and nontoxic. Available as free-flowing powders or concentrates. Fast outgassing concentrates in various activity levels contain special carrier resins that improve melt flow, tensile strength, and impact properties in extrusion and injection molding. Help to decrease weight and improve process cycle time. A microcellular structure is created that reduces internal stress, eliminates sink marks, improves surface finish, and cools faster.

Compatible thermoplastics include ABS, PS, EVA, HDPE, LDPE, and PPO/PPE alloys. Also grades for flexible and rigid PVC and moisture-sensitive resins such as nylon, PET, PC, and PC/ABS blends. Cost savings have been reported in the manufacture of PVC and ABS foam pipe, using Safoam concentrates.

In partnership with Genpak Corp., licenses a foam sheet extrusion process that reportedly meets current and future global emission requirements without major equipment changes or compromises in product quality, density, or production rates. Technology is specially designed to replace CFCs and HCFCs in production of PS foam food packaging.

REGENCY SALES INC.

Endothermic chemical blowing agent does not leave residual mold deposits. Special formulations available.

RTP CO.

Concentrates for various resins include FCX 27301 for PP, PE, acetal, and nylons 11 and 12; FCX 27310 for nylon 6, 66 and 612, PBT, and PET; FCX 27312 for PC and its alloys; and FCX 27314 for PS, ABS, and SAN.

A. SCHULMAN INC.

Polybatch additive concentrates include different carriers and other additives as required.

SPARTECH COLOR

Supplies foaming concentrates.

STANCHEM, UNIT OF HCI, INC.

Distributes azo-based chemical blowing agents from Dong Jin Chemical Industry Co in Korea:

* Unicell D azodicarbonamide in particle sizes from 2 to 25 microns.

* Unicell DX multiple grades of modified azo for moderate and low foaming temperatures.

* Unicell D300 SD modified azo for self-dispersing applications.

* Unicell NP modified azos for nucleating, nonplating applications in injection molding and extrusion.

* Unicell FF modified azos for injection molding inhibit undesirable byproducts and die build-up.

* Unicell OH oxybis-benzene sulfonyl hydrazide for LLDPE, PVC, and plastisols.

* Unicell TSH toluene sulfonyl hydrazide for polyester, PVC, and rubber.

* Unicell AD modified azo mixture for EVA and other elastomers.

* Unicell TS toluene sulfonyl semi-carbazide for high foaming temperatures.

TEKNOR COLOR CO.

SUB. OF TEKNOR APEX CO.

Chemical blowing-agent dispersions in concentrates, liquids, or dry-powders. Up to 12.5% azo and hydrazide active ingredients in a universal carrier permit letdowns from 100:1 to 40:1. Suitable for injection molding and extrusion of all polyolefins and styrenics.

THERMOFIL, INC.

Thermofoam foam concentrates for most thermoplastics include Thermofoam I for styrenics and polyolefins; Thermofoam II for nylons, TP polyesters, and other resins with processing temperatures of 405-600 F; more highly concentrated Thermofoam III for nylon and TP polyester structural foams; and nonreleasing ammonia Thermofoam VI for PPE alloys.

UNIROYAL CHEMICAL

See Crompton Corp.

WITCO CORP.

See Crompton Corp.