This challenging LDPE part measures 14 × 16 × 0.175 in. thick and weighs around 0.65 lb. You might call it a Duffer’s Delight: It’s a mat designed to protect golf greens and other grass surfaces from damaging “divots.” Just hitting the market last month, it’s called “Terfy” and comes from inventor Philip Vala and his firm, Innovation Equity Group Ltd. in Oakville, Ont. ( It was custom molded by Omachron Technologies in Pontypool, Ont. ( Omachron developed a tabletop injection machine that uses intrusion molding to mold parts weighing up to 140 lb with a screw no larger than 1.25 in., as well as low-cost aluminum molds (see March ’19 Close-Up). This system can mold large parts—comparable to the capabilities of a 500-ton injection press at low pressures (up to 900 psi) and low temperatures, with resulting low internal stresses, according to the company. The Terfy part was molded in 20 min for development purposes, but Omachron is confident that it can be done in 6 min for commercial production.

The inventor first tried producing the product from HDPE sheet via water-jet or die cutting, neither of which proved cost-effective. Injection molding was the only way to go, but found it lacking in “design flexibility for an early-stage product where design could still undergo changes,” Vala says. “Upfront mold costs were extremely high and the moldmaking process was slow, so small production runs were prohibitively expensive.” Then the inventor came across Omachron. During an initial phone call, “We covered a wide range of manufacturing processes and possible alternative materials. We discussed design, shipping and packaging considerations and possible go-to-market strategies. Six weeks after the first call, and at a fraction of the previous price, we had a finished prototype to show to prospective clients and a viable, flexible manufacturing process than can scale with expected demand.” Omachron says this and many other parts can be molded on its machine from 100% post-consumer recycle, which will be the next major thrust in marketing its machines and custom-molding services.

First find out if they are the result of trapped gas or a vacuum void. Then follow these steps to get rid of them.

Modifications to the common core pin can be a simple solution, but don’t expect all resins to behave the same. Gas assist is also worth a try.

Plastic Injection Molding, Plastic Injection Mold Machinery - JUST,