IMPLAN follows the same definition provided by the Bureau of Economic Analysis (BEA). https://www.bea.gov/help/glossary/capital-expenditures
The BEA defines Capital Expenditures as "Expenditures made to acquire, add to, or improve property, plant, and equipment (PP&E). PP&E includes: land, timber, and minerals; structures, machinery, equipment, special tools, and other depreciable property; construction in progress; and tangible and intangible exploration and development costs. Changes in PP&E due to changes in entity-such as mergers, acquisitions, and divestitures-or to changes in accounting methods are excluded. Capital expenditures are measured on a gross basis; sales and other dispositions of fixed assets are not netted against them."
Capital Expenditures are not the same as purchases made by an Industry of non-durable goods and services that are used to produce other goods and services rather than for final consumption. Those are Intermediate Inputs.