Blow molding inflates a heated parison or preform inside a cooled mold to form hollow plastic parts. Using HDPE, PP, PET, and multilayers with precision tooling, the process produces bottles, tanks, ducts, and packaging with controlled wall thickness and strength.
Blow molding is a forming process used to produce hollow thermoplastic parts by inflating a heated polymer parison or preform inside a mold. In extrusion blow molding, a continuous parison is extruded and captured between mold halves, then inflated with air to conform to the cavity. Injection stretch blow molding uses an injection‑molded preform that is reheated, stretched axially, and blown to achieve high clarity and mechanical strength—common for PET bottles. Typical materials processed include HDPE, LDPE, PP, PET, PVC, and barrier multilayer structures. Tooling consists of precision‑machined aluminum or alloyed tool steel or stainless steel molds with optimized cooling channels, pinch‑off areas, blow needles, and venting to ensure uniform wall thickness and rapid cycle times. Process parameters such as melt temperature, parison control, blow pressure, stretch ratio, and cooling rate influence part strength, transparency, and barrier performance. Blow molding is widely used for bottles, tanks, ducts, containers, fuel reservoirs, and lightweight packaging in automotive, consumer goods, food and beverage, and industrial applications.
BÖHLER M303 is a corrosion-resistant, martensitic chromium steel with very good toughness, corrosion resistance, good wear resistance and improved machinability and polishability. Compared to 1.2316, BÖHLER M303 has better homogeneity and is approved for food and beverage contact.
Read MoreBÖHLER M303 ISOPLAST corresponds to a remelted BÖHLER M303 . The variation in the production route enables greater toughness and polishability thanks to higher purity and improved homogeneity. Also available as product variant BÖHLER M303HH ISOPLAST (high-hard variant).
Read MoreBÖHLER M310 ISOPLAST is a corrosion-resistant, martensitic chromium steel which, through electroslag remelting and optimization of the chemical composition, has a good homogeneity and a balanced hardness-toughness-corrosion resistance ratio.
Read MoreBÖHLER M333 ISOPLAST is a corrosion-resistant, martensitic plastic mold steel with excellent polishability and toughness for products with highest surface requirements. BÖHLER M333 ISOPLAST is also approved for food and beverage contact.
Read MoreBÖHLER W300 ISOBLOC is a 5% chromium steel and corresponds to material number 1.2343 (X37CrMoV5-1). Produced via the electroslag remelting process (ESR), this tool steel has very high hot toughness as well as good hot hardness and very good resistance against heat-checkings. The combination of these properties makes it a top performer in high- and low-pressure die casting as well as in closed-die and open-die forging. In addition, this material has very good polishability and is therefore also often used as a molding material for plastic injection molds.
Read MoreBÖHLER W302 ISOBLOC is a 5% chromium steel and corresponds to material number 1.2344 (X40CrMoV5-1). Produced via the electroslag remelting process (ESR), this tool steel has very high hot toughness as well as very high hot hardness and a very good resistance against heat-checkings. The combination of these properties makes it a top performer in closed- and open-die forging as well as in high- and low-pressure die casting. In addition, this material has very good polishability and is therefore also often used as a molding material for plastic injection molds.
Read MoreBÖHLER W302 ISODISC is a 5% chromium steel and corresponds to material number 1.2344 (X40CrMoV5-1). This common tool steel has good hot toughness as well as a high hot hardness and a high resistance against heat-checkings. The combination of these properties makes it a standard choice in extrusion, forging and low-pressure die casting. This material is also available as W302 ISOBLOC which is a remelted grade with improved cleanliness, homogeneity and toughness.
Read MoreUddeholm Corrax is a precipitation hardening steel with a unique set of properties that makes it perfect for many demanding applications. The superior resistance against corrosion combined with a hardness up to 50 HRC and a simple heat treatment makes Uddeholm Corrax the obvious choice for long run series of aggressive plastics such as PVC. The chemical composition makes Uddeholm Corrax easy to process by Additive Manufacturing. Hence, it is also available as powder for Laser Powder Bed Fusion (LPBF) and Laser Metal Deposition (LMD). Benefits Very good corrosion resistance Flexible hardness of 34-50 HRC achieved by ageing No hard “white layer” after EDM
Read MoreUddeholm Impax Supreme is prehardened mould steel with very good polishing and photo etching properties. It is suitable for a wide range of injection moulds, blow moulds and extrusion dies for plastic. Uddeholm Impax Supreme is supplied at 290-330 HB. In east/south east asian countries served by Assab, Uddeholm Impax Supreme is sold as AS 718 Supreme. Benefits No hardening risks No hardening costs Time saving, e.g. no waiting for heat treatment Lower tool cost (e.g. no distortion to rectify) Modifications easily carried out Can be subsequently nitrided to increase surface wear resistance or locally flame hardened to reduce surface damage. Standard specification W.nr 1.2738 / AISI P20 / AFNOR 35 CND 7
Read MoreUddeholm Mirrax 40 is a prehardened remelted stainless tool steel, supplied at 40 HRC. Uddeholm Mirrax 40 is produced using the electroslag remelting (ESR) process – an additional step in the steelmaking process that ensures very clean steel. Consequently, Uddeholm Mirrax 40 is capable of being polished to a very high surface finish. In addition, the combination of high hardness with high toughness results in a mould with good resistance to indentations and minimize the risk of unexpected failures, leading to a safer mould and a prolonged tool life. Benefits Lower production costs Fast tool making Excellent surface finish possible Less maintenance work Safe production
Read MoreUddeholm Mirrax ESR is a through hardening corrosion resistant steel with very good polishability. Mainly intended for medium to large cross sections. It has a unique combination of toughness, corrosion resistance and through-hardening properties. Benefits Low mold maintenance costs: The surface of cavity impressions retain their original finish over extended running periods Molds stored or operated in humid conditions require less protection Low production costs: Water cooling channels are less affected by corrosion Heat transfer characteristics, and therefore cooling efficiency, are constant throughout the mold life, ensuring consistent cycle times Safe mold use because of good toughness also in big dimensions
Read MoreUddeholm Stavax ESR is a premium stainless mold steel for small and medium inserts and cores. Uddeholm Stavax ESR combines corrosion and wear resistance with excellent polishability, good machinability and stability in hardening. Mold maintenance requirement is reduced by assuring that core and cavity surfaces retain their original finish over extended operating periods. When compared with non stainless mold steel, Uddeholm Stavax ESR offers lower production costs by maintaining rust free cooling channels, assuring consistent cooling and cycle time. This classic stainless tool steel is the right choice when rust in production is unacceptable and where requirements for good hygiene are high, as within the medical industry, optical industry and for other high quality transparent parts. Uddeholm Stavax ESR is a part of the Uddeholm Stainless Concept. Benefits Low mold maintenance because of corrosion resistance: Surfaces retain their original finish Less production during storing and operation in humid condition Lower production costs: Since water-cooling channels are unaffected by corrosion Heat transfer characteristics, therefore cooling efficiency is constant throughout the mold life, ensuring consistent cycle times Long life mold Standard specification W.nr 1.2083 / AISI 420 / AFNOR Z40 CV 14 (RSL)
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