Tri-Blend Polymer Patent Technology
Product Announcement from Associated Polymer Labs, Inc.
US Patent Number: 7,226,956. This Tri-Blend is a unique, cost effective polymer formulation for your foam products. Our blending technology allows the use of different materials to manufacture a variety of unique products.
The blends and alloys in this patent have properties that no other homopolymer can offer.
The following is a detailed description of the Tri-Blend Polymer but not limited to. There are other capabilities of this polymer blend. Contact Associated Polymer Labs, Inc. about any questions or interest about this polymer and it's uses.
- A polymeric composition to be used in producing low density foam in which the polymeric composition comprises high density polyethylene, alkenyl aromatic polymer and a linear low density polyethylene.
- The polymeric resins may be prime virgin resin, offgrade virgin resin, recycled resin from a post industrial source, recycled resin from a post consumer source, or blends thereof.
- Inventive compositions for producing polymeric foam are characterized by Dynamic Mechanical Spectroscopy to have a complex viscosity (*) in the range of 6.0x104 to 2.5x105 poise and a loss tangent (tan 6) in the range of 0.7 to 2.1 at 190° C. and a power-law relation between tan 6 and * where the exponent is within the range between -0.70 and -0.30 for the temperature range of 190° to 230° C.
- The present invention is directed to a polymeric composition to be used in producing foam. Specifically, the polymeric composition is comprised of a high density polyethylene, an alkenyl aromatic polymer and a linear low density
- Low density polymeric foams, which have a density in the range of 10 kg/m3 to 160 kg!m3, have been made for many years. These polymeric foams have generally been made by combining a physical blowing agent with a molten polymeric mixture under pressure and, after thorough mixing, extruding the combination through an appropriate die into a lower pressure atmosphere.
- Polymeric foams designed for protective packaging of:
- office equipment
- other items of value require light weight, resilient materials in order to protect the packaged items from handling without adding significant weight and bulk, and thus cost, to the overall package for transport.
- Polymeric foams designed for applications such as recreational items like:
- bodyboards and floatation devices also require resilient materials so as not to permanently deform under multiple applications of compressive and shear forces during use.
- Floor underlayment also require resilient materials so as not to permanently deform under multiple applications of compressive forces during use. Although there have been recent reports of compositions comprising other polymers for foams made for such applications, resilient, low-density polymeric foams are most commonly made from low density polyethylene (LDPE).
- Polymeric foams composed of LDPE are generally considered to be resilient and non-brittle, which are desirable properties. However, despite widespread usage, these foams have disadvantages related directly to the LDPE component. Because LDPE will reduce important physical properties of blends that comprise the more widely-used polyethylenes, "high density polyethylene" and "linear low density polyethylene", there are limited recovery or reuse options for the LDPIE packaging material afier the packaged item is delivered to the end-user. Consequently, the major fraction of LDPE-only materials used for packaging is destroyed by incineration or is deposited in landfills. Another disadvantage is that LDPE is not a commodity and therefore poses higher material costs than related commodity plastics like high density polyethylene (HDPE) and linear low density polyethylene (LLDPE).
- HDPE has extensive usage in many applications such as bottles for freshly packaged liquids for human consumption like:
- Milk, orange juice, and ciders
- Bottles for household and industrial chemicals, flexible tubing, and toys.
- LLDPE has widespread usage for:
- Packaging films
- Plastic wraps
- Plastic bags.
- The current process requirements for LDPE foams severely restrict the incorporation of recycled polyethylene from post-consumer and post-industrial sources. Incorporation of recycled polyethylene into a polyethylene foam structure would be very desirable as new regulations are introduced to reduce waste and to recover and reuse industrial materials.
Accordingly, a need exists for foams that overcome the
above-noted shortcomings associated with LDPE-only
- Lastly, it is an object of the invention to produce a resilient, non-brittle, low cost foam structure that:
- can be used for sports and leisure equipment such as bodyboards, life vests, seat cushions
- can be used for floor underlayment and which would also be suitable for protective packaging of delicate and fragile high surface quality goods.
The polymeric composition to be used in producing foam of the present invention comprises from about 5 to about 85 weight percent of a HDPE, from about 5 to about 85 weight percent alkenyl aromatic polymer, and from about 5 to about 85 of a LLDPE. Inventive blends for producing foam
comprising the three polymeric types are characterized by a complex viscosity (*) in the range of 6.Ox 10 to 2.5x105 poise and a loss tangent (tan 6) in the range of 0.7 to 2.1 at 190° C., and a power-law relation between tan 6 and where the exponent is within the range between -0.70 and
-0.35 for the temperature range of 190° to 230° C.