Since the rotational molding process uses no pressure it will yield stress free plastic tanks or parts, but only if basic processing rules are followed. We at Assmann Corporation are constantly finding ways to increase efficiency in our process but will not abandon successful methods for any cost-cutting measure that would compromise the quality of the polyethylene storage tanks for which we have become known. Our plant personnel are our `experts` in polyethylene and plastic storage tanks. They have pride in the plant and their workmanship. All of us extend a welcome to visit our plant in Garrett, Indiana.

Company details

300 North Taylor Road , Garrett , IN 46738 USA

Locations Served

Subsidiaries

Our Distributors

Business Type:
Manufacturer
Industry Type:
Waste and Recycling
Market Focus:
Nationally (across the country)

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Our high-density crosslink resin tanks are certified by NSF for chemical storage, while our linear polyethylene tanks are certified to NSF/ANSI Standard 61: Drinking Water System Components – Health Effects. The Certification is for multiple potable water contact materials up to 140°F. Our quality management system is also ISO 9001:2008 Certified, meaning our tanks are designed and manufactured under strict quality control standards.

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Why Assmann Plastic Tanks are Better!

  • Assmann Plastic Tanks are designed and molded with a uniform wall thickness that allows the entire surface to cure evenly.
  • Polyethylene tanks are air-cooled for uniform resin cure and improved shrinkage parameters.
  • Quality and service provided is second to none.

 

The Assmann Difference is the The Way We Process our Plastic Storage Tanks

1. Rotational Molding of Polyethelene Tanks and Plastic Products
Assmann manufactures polyethylene and plastic storage tanks and containers in various shapes and capacitiesOur unique and efficient large ovens, which rotate end-over-end, receive convection heat from an adjacent stationary furnaceThe oven shape and foil design create optimum airflow and uniform heat to set the first stage for the highest quality parts possible.

We never exceed 500° F in the molding processUsing higher temperatures will speed up the cycle time and cut costs but will compromise the results, particularly in XLPE and thicker wall parts.

2. Cooling Without Water Allows Cross-Linking Process to Complete All The Way Through the Polytank Wall
We have separate chambers using only very high volume air movement to assure a gradual cooling of the mold and the part insideThis allows the cross-linking process, still taking place upon exiting the oven chamber, to complete all the way through the tank wallThis is essential to optimize the properties of the cross-linked part(The whole idea is to achieve as close to 100% cross-linking as possible).

Even in 1.45' thick walls, we consistently attain gel test results (indication of % of cross-linking that has taken place) in the high 70's and low 80's(ASTM minimum gel requirement is 60%).

It is also important to mention that tanks molded of linear resins, and processed in this manner, will also reach their optimum cure rateWe introduce no water into our cooling cycleWater spray or mist will speed up the process, but will abruptly stop the cross-linking and set up the stresses that will shorten the service life of the tank.

3. Tooling Of Plastic Storage Tanks - Assmann Does Not 'Shield' Tank Walls.
Equally important in our process is that we do not 'shield' the outside of our tank molds. We exceed ASTM design hoop stress minimums for the lower sidewall and carry this wall thickness as uniformly as possible throughout the entire tank for maximum structural integrity.
Assmann provides polyethylene/plastic above ground tanks for many industries
In a competitive marketplace it has become a common practice to wrap and weld layers of sheet metal (shielding) around the outside of the mold to reduce heat transfer and thereby reduce thickness over as much as 80% of the area of the tank. Upper sidewalls, domes and tank bottoms are often reduced to less than 25% of the thickness of the lower sidewall.

Some of the obvious consequences of this practice:

  • There is greater damage when tank restraint systems are put to the test.
  • Tank domes may collapse, even under snow weight.
  • Stress cracking agents along with UV deterioration will accelerate dome failure.

Also, it is important to note 'shielding' triggers a loss of control in the process resulting in uneven cooking and significant variations in gel percentages over the tank structure. This will also shorten the service life of the part.

Those using this technique sell it as 'state-of-the-art' by marketing with such terms as 'tapered', 'engineered', 'strati-formed walls', and 'strategic material placement'. The intent is only to reduce raw material costs. The savings, however, are rarely passed on to the end user.

Our Position
Since the rotational molding process uses no pressure it will yield a stress free tank or part, but only if basic processing rules are followed.

We at Assmann Corporation are constantly finding ways to increase efficiency in our process but will not abandon successful methods for any cost-cutting measure that would compromise the quality of the product for which we have become known.

Our plant personnel are our 'experts'. They have pride in the plant and their workmanship. All of us extend a welcome to visit our plant in Garrett, Indiana.

The Assmann Position on Rotational Molding Process of Plastic Chemical Storage Tanks.
Since the rotational molding process uses no pressure it will yield stress free plastic tanks or parts, but only if basic processing rules are followed.

We at Assmann Corporation are constantly finding ways to increase efficiency in our process but will not abandon successful methods for any cost-cutting measure that would compromise the quality of the polyethylene storage tanks for which we have become known.

Our plant personnel are our 'experts' in polyethylene and plastic storage tanks. They have pride in the plant and their workmanship. All of us extend a welcome to visit our plant in Garrett, Indiana.

Assmann Southwest


Assmann Corporation of America in Garrett, Indiana has opened Assmann Southwest, a full manufacturing facility in Marshall, Texas with state-of-the-art rotational molding manufacturing and equipment. Assmann has capabilities to do all necessary plastic tank and secondary processing such as fittings, vents, fill lines, heat tracing and insulation. Expansion of centralized shipping and distribution creates faster turnaround time and shipping to the Southern and Western states.

ISO 9001:2008 Certification

Assmann Corporation of America has been ISO Certified since 1994. An ISO certificate is not a once-and-for-all award, but must be renewed at regular intervals recommended by the certification body, usually around three years. Two types of auditing are required to become registered to the standard. Auditing by an external certification body and audits by internal staff trained for this process. By regular auditing, we are required to constantly improve our systems.

ISO audits engineering and manufacturing processes for effectiveness and continuous improvement. This monitoring helps Assmann Corporation set achievable goals, track our goals and best of all complete them. Assmann Corporation employee's commitment to the ISO program is second to none; our entire staff monitors each individual stage of our manufacturing process for errors and possibilities for improvement.

ISO forces Assmann Corporation to place the concept of process management front and center. 'Process management' is the monitoring and optimizing of a company's tasks and activities, instead of just inspecting the final product. By regulating and monitoring our process, we continue to improve our products. This constant review makes us proactive rather than reactive to process design flaws and virtually eliminates poor quality products from ever being supplied.

What does this mean to you? Assmann tanks are designed and manufactured under strict quality control standards. Each tank we manufacture has its own quality control and routing card that links the product back to date of manufacture, raw material lot numbers, and processing times. This complete traceability is critical especially when governing laws are being created daily regarding bulk chemical storage.

NSF Certification
  • Assmann Corporation's Crosslink Tanks are approved for chemical storage by NSF!
  • Schulink XL-350 Crosslink Resin
  • Assmann is the FIRST Crosslink Tank approved by NSF for chemical storage!
NSF is an independent testing company that requires Assmann Corporation of America to comply with strict standards. These standards require extensive product testing and material analysis. NSF undertakes a complete evaluation of our product development before we can meet their certification.

NSF / ANSI 61 program is responsible for the certification of drinking water treatment chemicals and drinking water system components to ensure that these products do not contribute contaminants to drinking water that could cause adverse health effects.

Assmann Corporation's crosslink polyethylene tanks have been certified by NSF International to ANSI 61 standards for chemical storage. Assmann's unique crosslink resin is certified for many chemical applications. Sodium Hypochlorite, Sulfuric Acid, and Sodium Hydroxide are within the list of chemicals our tanks can be used to store. For a complete list of certified chemicals, visit www.nsf.org.

In addition to our crosslink tanks for chemical storage, Assmann Corporation's linear polyethylene tanks have been certified by NSF International to ANSI 61 standards for potable water. With both crosslink and linear polyethylene certifications Assmann Corporation can be your first source for both potable water & chemical storage for water treatment.

Our certification includes tank models ranging in size from 20 through 12,000 gallons.